what-core 1.7.4

//! HTML parser for custom tags
//!
//! Parses HTML documents and resolves custom tags like <jumbo>, <loop>, etc.
//! Also handles `<what>` page directives for auth, routing, etc.
//! Also handles `.what` config files for directory-level configuration.

use regex::Regex;
use serde_json::{Value, json};
use std::collections::HashMap;
use std::sync::LazyLock;

/// Regex to match #variable# syntax, including arithmetic expressions like #var + 1#
static VAR_REGEX: LazyLock<Regex> =
    LazyLock::new(|| Regex::new(r"#([a-zA-Z_][a-zA-Z0-9_. +\-*/]*(?:\|[^#]*)?)#").unwrap());

/// Regex to match tag attributes
static ATTR_REGEX: LazyLock<Regex> =
    LazyLock::new(|| Regex::new(r#"([a-zA-Z_][a-zA-Z0-9_-]*)\s*=\s*"([^"]*)""#).unwrap());

/// Regex to match boolean attributes (standalone words after key="value" pairs are removed)
static BOOL_ATTR_REGEX: LazyLock<Regex> =
    LazyLock::new(|| Regex::new(r#"([a-zA-Z_][a-zA-Z0-9_-]*)"#).unwrap());

/// Regex to match <what> directive tags (self-closing or with content)
/// Does NOT match <what-*> component tags (which have hyphen immediately after "what")
static WHAT_DIRECTIVE_REGEX: LazyLock<Regex> = LazyLock::new(|| {
    // Match <what with optional whitespace+attrs, then /> or >...</what>
    // The pattern requires either:
    //   - <what/> (immediate self-close)
    //   - <what> (immediate close, may have content)
    //   - <what attrs...> (space before attrs)
    // This naturally excludes <what-nav> because hyphen is not whitespace, /, or >
    Regex::new(r"(?s)<what((?:\s[^>]*)?)(?:/>|>(.*?)</what>)").unwrap()
});

// ============================================================================
// Wired Variable Scoping
// ============================================================================

/// Scope for a wired variable — determines which WebSocket clients receive updates
#[derive(Clone, Debug, Default)]
pub enum WiredScope {
    /// All clients receive (backwards compatible default)
    #[default]
    Public,
    /// Only clients with a matching JWT role
    Roles(Vec<String>),
    /// Only the specific user who triggered the mutation (user_id filled at mutation time)
    User(String),
}

impl std::fmt::Display for WiredScope {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            WiredScope::Public => write!(f, "public"),
            WiredScope::Roles(r) => write!(f, "roles: {}", r.join(", ")),
            WiredScope::User(_) => write!(f, "per-user"),
        }
    }
}

impl WiredScope {
    /// Check if a client with the given roles/user_id is allowed to receive this update
    pub fn allows(&self, client_roles: &[String], client_user_id: Option<&str>) -> bool {
        match self {
            WiredScope::Public => true,
            WiredScope::Roles(required) => client_roles.iter().any(|r| required.contains(r)),
            WiredScope::User(uid) => client_user_id == Some(uid.as_str()),
        }
    }
}

/// A parsed variable declaration with its scope. Used for both `data.wired`
/// (real-time push, scope filters delivery) and `data.application` (shared
/// state, scope gates who may write via `w-set`).
#[derive(Clone, Debug)]
pub struct WiredVarDecl {
    pub name: String,
    pub scope: WiredScope,
}

/// Alias clarifying intent when a scoped decl governs write access rather than
/// WebSocket delivery (e.g. `data.application = ["revenue [admin]"]`).
pub type ScopedVarDecl = WiredVarDecl;

/// Parse a wired variable value that may contain bracket scope syntax.
/// Examples:
///   "counter"           → WiredVarDecl { name: "counter", scope: Public }
///   "revenue [admin]"   → WiredVarDecl { name: "revenue", scope: Roles(["admin"]) }
///   "x [admin, editor]" → WiredVarDecl { name: "x", scope: Roles(["admin", "editor"]) }
///   "notifs [user]"     → WiredVarDecl { name: "notifs", scope: User("") }
fn parse_wired_decl(s: &str) -> WiredVarDecl {
    let s = s.trim();
    if let Some(bracket_start) = s.find('[') {
        if let Some(bracket_end) = s.find(']') {
            let name = s[..bracket_start].trim().to_string();
            let roles_str = &s[bracket_start + 1..bracket_end];
            let roles: Vec<String> = roles_str
                .split(',')
                .map(|r| r.trim().to_string())
                .filter(|r| !r.is_empty())
                .collect();
            // Special case: [user] means per-user scoping
            if roles.len() == 1 && roles[0] == "user" {
                return WiredVarDecl {
                    name,
                    scope: WiredScope::User(String::new()),
                };
            }
            return WiredVarDecl {
                name,
                scope: WiredScope::Roles(roles),
            };
        }
    }
    WiredVarDecl {
        name: s.to_string(),
        scope: WiredScope::Public,
    }
}

// ============================================================================
// .what File Parser
// ============================================================================

/// Configuration from a .what file
///
/// .what files use a simple key-value format:
/// ```text
/// // Comments start with // or #
/// title = "My Application"
/// port = 8080
/// debug = true
/// nav_items = ["Home", "About", "Contact"]
/// auth = "admin"
/// layout = "sections/main.html"
/// ```
#[derive(Debug, Clone, Default)]
pub(crate) struct WhatConfig {
    /// Parsed configuration values
    pub values: HashMap<String, Value>,
    /// Page directives extracted from the config (auth, protected, etc.)
    pub directives: PageDirectives,
    /// Layout template path (stored separately for easy access)
    pub layout: Option<String>,
    /// Application-level data keys to expose (shared across all sessions).
    /// Bracket scope syntax (`"revenue [admin]"`) gates `w-set` writes.
    pub data_application: Vec<ScopedVarDecl>,
    /// Session-level data keys to expose (per-user)
    pub data_session: Vec<String>,
    /// Wired data keys to expose (shared + real-time push via WebSocket, with optional scope)
    pub data_wired: Vec<WiredVarDecl>,
}

#[allow(dead_code)]
impl WhatConfig {
    /// Get a string value
    pub fn get_string(&self, key: &str) -> Option<&str> {
        self.values.get(key).and_then(|v| v.as_str())
    }

    /// Get a number value
    pub fn get_number(&self, key: &str) -> Option<f64> {
        self.values.get(key).and_then(|v| v.as_f64())
    }

    /// Get a boolean value
    pub fn get_bool(&self, key: &str) -> Option<bool> {
        self.values.get(key).and_then(|v| v.as_bool())
    }

    /// Get an array value
    pub fn get_array(&self, key: &str) -> Option<&Vec<Value>> {
        self.values.get(key).and_then(|v| v.as_array())
    }

    /// Merge another config into this one (other takes precedence)
    pub fn merge(&mut self, other: &WhatConfig) {
        for (key, value) in &other.values {
            self.values.insert(key.clone(), value.clone());
        }
        // For directives, other takes precedence if it sets auth
        if other.directives.requires_auth() {
            self.directives.auth = other.directives.auth.clone();
        }
        if other.directives.protected {
            self.directives.protected = true;
        }
        if !other.directives.roles.is_empty() {
            self.directives.roles = other.directives.roles.clone();
        }
        if other.directives.exclude {
            self.directives.exclude = true;
        }
        if other.directives.title.is_some() {
            self.directives.title = other.directives.title.clone();
        }
        if other.directives.redirect.is_some() {
            self.directives.redirect = other.directives.redirect.clone();
        }
        if other.directives.cache_ttl.is_some() {
            self.directives.cache_ttl = other.directives.cache_ttl;
        }
        // Headers: merge (child overrides parent for same header name)
        for (k, v) in &other.directives.headers {
            self.directives.headers.insert(k.clone(), v.clone());
        }
        // Layout: child overrides parent (including "none" to disable)
        if other.layout.is_some() {
            self.layout = other.layout.clone();
        }
        if other.directives.layout.is_some() {
            self.directives.layout = other.directives.layout.clone();
        }
        // Data: child overrides parent (or could extend - using override for now)
        if !other.data_application.is_empty() {
            self.data_application = other.data_application.clone();
        }
        if !other.data_session.is_empty() {
            self.data_session = other.data_session.clone();
        }
        if !other.data_wired.is_empty() {
            self.data_wired = other.data_wired.clone();
        }
    }

    /// Convert to context for template rendering
    pub fn to_context(&self) -> HashMap<String, Value> {
        self.values.clone()
    }
}

/// Parse a .what file content
///
/// Supports:
/// - Strings: `key = "value"` or `key = 'value'`
/// - Numbers: `key = 123` or `key = 45.67`
/// - Booleans: `key = true` or `key = false`
/// - Arrays: `key = ["a", "b", "c"]` or `key = [1, 2, 3]`
/// - Comments: `// comment` or `# comment`
///
/// Special keys are converted to directives:
/// - `auth` → AuthLevel
/// - `protected` → protected directive
/// - `roles` → roles directive
/// - `exclude` → exclude directive
/// - `title` → title directive
/// - `redirect` → redirect directive
/// - `cache` / `cache_ttl` → cache TTL directive
/// - `layout` → layout template path
pub(crate) fn parse_what_file(content: &str) -> WhatConfig {
    let mut config = WhatConfig::default();

    for line in content.lines() {
        let line = line.trim();

        // Skip empty lines and comments
        if line.is_empty() || line.starts_with("//") || line.starts_with('#') {
            continue;
        }

        // Parse key = value
        if let Some(idx) = line.find('=') {
            let key = line[..idx].trim().to_lowercase();
            let value_str = line[idx + 1..].trim();

            // Parse the value
            let value = parse_what_value(value_str);

            // Check if this is a directive key that shouldn't be exposed as a template variable
            let is_security_directive = matches!(
                key.as_str(),
                "auth"
                    | "protected"
                    | "roles"
                    | "exclude"
                    | "redirect"
                    | "cache"
                    | "cache_ttl"
                    | "layout"
                    | "data.application"
                    | "data.session"
            );

            // Handle special directive keys
            match key.as_str() {
                "auth" => {
                    if let Some(s) = value.as_str() {
                        config.directives.auth = parse_auth_level(s);
                    }
                }
                "protected" => {
                    if let Some(b) = value.as_bool() {
                        config.directives.protected = b;
                    } else if let Some(s) = value.as_str() {
                        config.directives.protected = s != "false";
                    }
                }
                "roles" => {
                    if let Some(arr) = value.as_array() {
                        config.directives.roles = arr
                            .iter()
                            .filter_map(|v| v.as_str().map(String::from))
                            .collect();
                        if !config.directives.roles.is_empty() {
                            config.directives.protected = true;
                        }
                    } else if let Some(s) = value.as_str() {
                        config.directives.roles = s
                            .split(',')
                            .map(|s| s.trim().to_string())
                            .filter(|s| !s.is_empty())
                            .collect();
                        if !config.directives.roles.is_empty() {
                            config.directives.protected = true;
                        }
                    }
                }
                "exclude" => {
                    if let Some(b) = value.as_bool() {
                        config.directives.exclude = b;
                    }
                }
                "title" => {
                    if let Some(s) = value.as_str() {
                        config.directives.title = Some(s.to_string());
                    }
                }
                "redirect" => {
                    if let Some(s) = value.as_str() {
                        config.directives.redirect = Some(s.to_string());
                    }
                }
                "layout" => {
                    if let Some(s) = value.as_str() {
                        config.layout = Some(s.to_string());
                        config.directives.layout = Some(s.to_string());
                    }
                }
                "cache" | "cache_ttl" => {
                    if let Some(n) = value.as_u64() {
                        config.directives.cache_ttl = Some(n);
                    }
                }
                "data.application" => {
                    config.data_application = parse_wired_array(&value);
                }
                "data.session" => {
                    config.data_session = parse_string_array(&value);
                }
                "data.wired" => {
                    config.data_wired = parse_wired_array(&value);
                }
                _ => {
                    // Handle header.* keys: header.X-Custom = "value"
                    if let Some(header_name) = key.strip_prefix("header.") {
                        if let Some(s) = value.as_str() {
                            config
                                .directives
                                .headers
                                .insert(header_name.to_string(), s.to_string());
                        }
                    }
                }
            }

            // Store non-security values for template access
            let is_header = key.starts_with("header.");
            if !is_security_directive && !is_header {
                // Parity with <what> blocks: recommend quoting string values
                // (data.* keys carry config syntax, not template strings)
                if !key.starts_with("data.")
                    && value.is_string()
                    && !value_str.starts_with('"')
                    && !value_str.starts_with('\'')
                    && is_unquoted_string(value_str)
                {
                    tracing::warn!(
                        "Unquoted string in .what file: {} should be quoted, e.g. {} = \"{}\"",
                        key,
                        key,
                        value_str
                    );
                }
                config.values.insert(key, value);
            }
        }
    }

    config
}

/// Parse a Value into a Vec<String>
fn parse_string_array(value: &Value) -> Vec<String> {
    if let Some(arr) = value.as_array() {
        arr.iter()
            .filter_map(|v| v.as_str().map(String::from))
            .collect()
    } else if let Some(s) = value.as_str() {
        // Single string becomes a one-element array
        vec![s.to_string()]
    } else {
        Vec::new()
    }
}

/// Parse a Value into a Vec<WiredVarDecl> with optional bracket scope syntax
fn parse_wired_array(value: &Value) -> Vec<WiredVarDecl> {
    if let Some(arr) = value.as_array() {
        arr.iter()
            .filter_map(|v| v.as_str().map(parse_wired_decl))
            .collect()
    } else if let Some(s) = value.as_str() {
        vec![parse_wired_decl(s)]
    } else {
        Vec::new()
    }
}

/// Split a string on commas that are not inside quotes or nested brackets.
/// Used for `.what` array literals so a scoped element like
/// `"revenue [admin, editor]"` is not split at the inner comma.
fn split_top_level_commas(s: &str) -> Vec<String> {
    let mut parts = Vec::new();
    let mut current = String::new();
    let mut depth = 0i32;
    let mut quote: Option<char> = None;
    for c in s.chars() {
        match quote {
            Some(q) => {
                if c == q {
                    quote = None;
                }
                current.push(c);
            }
            None => match c {
                '"' | '\'' => {
                    quote = Some(c);
                    current.push(c);
                }
                '[' | '{' => {
                    depth += 1;
                    current.push(c);
                }
                ']' | '}' => {
                    depth -= 1;
                    current.push(c);
                }
                ',' if depth == 0 => {
                    parts.push(current.trim().to_string());
                    current.clear();
                }
                _ => current.push(c),
            },
        }
    }
    if !current.trim().is_empty() {
        parts.push(current.trim().to_string());
    }
    parts
}

/// Parse a value from .what file format
fn parse_what_value(s: &str) -> Value {
    let s = s.trim();

    // Boolean
    if s == "true" {
        return json!(true);
    }
    if s == "false" {
        return json!(false);
    }

    // String (double or single quotes)
    if (s.starts_with('"') && s.ends_with('"')) || (s.starts_with('\'') && s.ends_with('\'')) {
        return json!(s[1..s.len() - 1].to_string());
    }

    // Array
    if s.starts_with('[') && s.ends_with(']') {
        let inner = s[1..s.len() - 1].trim();
        if inner.is_empty() {
            return json!([]);
        }

        // Split on top-level commas only — commas inside quotes or nested
        // brackets (e.g. a scope like "revenue [admin, editor]") stay together.
        let items: Vec<Value> = split_top_level_commas(inner)
            .into_iter()
            .map(|item| parse_what_value(item.trim()))
            .collect();
        return json!(items);
    }

    // Number (integer or float)
    if let Ok(n) = s.parse::<i64>() {
        return json!(n);
    }
    if let Ok(n) = s.parse::<f64>() {
        return json!(n);
    }

    // Default to string without quotes
    json!(s.to_string())
}

/// Parse attributes from a tag string
pub(crate) fn parse_attributes(attr_str: &str) -> HashMap<String, String> {
    let mut attrs = HashMap::new();
    for cap in ATTR_REGEX.captures_iter(attr_str) {
        let key = cap[1].to_string();
        let value = cap[2].to_string();
        attrs.insert(key, value);
    }
    attrs
}

// ============================================================================
// Filter System
// ============================================================================

/// A parsed filter with name and arguments
#[derive(Debug, Clone, PartialEq)]
struct Filter {
    name: String,
    args: Vec<String>,
}

/// Result of applying filters — tracks whether output is html_safe
struct FilterResult {
    value: String,
    html_safe: bool,
}

/// Parse the filter chain from a variable expression.
/// Input: "var.path|filter1:arg|filter2:arg1,arg2"
/// Returns: (var_path, Vec<Filter>)
fn parse_filter_chain(expr: &str) -> (&str, Vec<Filter>) {
    let Some(first_pipe) = expr.find('|') else {
        return (expr, Vec::new());
    };

    let var_path = &expr[..first_pipe];
    let filter_str = &expr[first_pipe + 1..];
    let mut filters = Vec::new();

    // Split by | to get individual filters, but respect quoted strings
    for segment in split_filters(filter_str) {
        let segment = segment.trim();
        if segment.is_empty() {
            continue;
        }

        if let Some(colon_pos) = segment.find(':') {
            let name = segment[..colon_pos].trim().to_string();
            let args_str = &segment[colon_pos + 1..];
            let args = parse_filter_args(args_str);
            filters.push(Filter { name, args });
        } else {
            filters.push(Filter {
                name: segment.to_string(),
                args: Vec::new(),
            });
        }
    }

    (var_path, filters)
}

/// Split filter chain by `|`, respecting quoted strings
fn split_filters(s: &str) -> Vec<&str> {
    let mut parts = Vec::new();
    let mut start = 0;
    let mut in_quote = false;
    let mut quote_char = '"';

    for (i, c) in s.char_indices() {
        match c {
            '"' | '\'' if !in_quote => {
                in_quote = true;
                quote_char = c;
            }
            c if c == quote_char && in_quote => {
                in_quote = false;
            }
            '|' if !in_quote => {
                parts.push(&s[start..i]);
                start = i + 1;
            }
            _ => {}
        }
    }
    parts.push(&s[start..]);
    parts
}

/// Parse filter arguments from a string like `"value"` or `50` or `"old","new"`
fn parse_filter_args(s: &str) -> Vec<String> {
    let mut args = Vec::new();
    let mut current = String::new();
    let mut in_quote = false;
    let mut quote_char = '"';

    for c in s.chars() {
        match c {
            '"' | '\'' if !in_quote => {
                in_quote = true;
                quote_char = c;
                // Don't include the quote in the arg value
            }
            c if c == quote_char && in_quote => {
                in_quote = false;
                // Don't include the closing quote
            }
            ',' if !in_quote => {
                args.push(current.trim().to_string());
                current = String::new();
            }
            _ => {
                current.push(c);
            }
        }
    }
    let trimmed = current.trim().to_string();
    if !trimmed.is_empty() {
        args.push(trimmed);
    }
    args
}

/// Apply a single filter to a value. Returns the filtered value and whether it's html_safe.
fn apply_filter(value: &str, filter: &Filter) -> FilterResult {
    match filter.name.as_str() {
        "raw" => FilterResult {
            value: value.to_string(),
            html_safe: true,
        },
        "uppercase" => FilterResult {
            value: value.to_uppercase(),
            html_safe: false,
        },
        "lowercase" => FilterResult {
            value: value.to_lowercase(),
            html_safe: false,
        },
        "capitalize" => FilterResult {
            value: capitalize_first(value),
            html_safe: false,
        },
        "title" => FilterResult {
            value: title_case(value),
            html_safe: false,
        },
        "truncate" => {
            let max_len: usize = filter
                .args
                .first()
                .and_then(|a| a.parse().ok())
                .unwrap_or(50);
            let suffix = filter.args.get(1).map(|s| s.as_str()).unwrap_or("...");
            FilterResult {
                value: truncate_str(value, max_len, suffix),
                html_safe: false,
            }
        }
        "count" => {
            // Arrays/objects reach filters as their serialized JSON — count
            // items, not bytes of the serialization. Plain strings count
            // characters (not bytes), so "José" is 4, not 5.
            let n = match serde_json::from_str::<Value>(value) {
                Ok(Value::Array(items)) => items.len(),
                Ok(Value::Object(map)) => map.len(),
                Ok(Value::String(s)) => s.chars().count(),
                _ => value.chars().count(),
            };
            FilterResult {
                value: n.to_string(),
                html_safe: false,
            }
        }
        "number" => {
            // Format number with thousands separator
            FilterResult {
                value: format_number(value),
                html_safe: false,
            }
        }
        "currency" => {
            let code = filter.args.first().map(|s| s.as_str()).unwrap_or("USD");
            FilterResult {
                value: format_currency(value, code),
                html_safe: false,
            }
        }
        "date" => {
            let fmt = filter.args.first().map(|s| s.as_str()).unwrap_or("medium");
            FilterResult {
                value: format_date(value, fmt),
                html_safe: false,
            }
        }
        "json" => FilterResult {
            value: serde_json::to_string(&serde_json::Value::String(value.to_string()))
                .unwrap_or_else(|_| format!("\"{}\"", value)),
            html_safe: false,
        },
        "markdown" => FilterResult {
            value: simple_markdown(value),
            html_safe: true,
        },
        "pluralize" => {
            let singular = filter.args.first().map(|s| s.as_str()).unwrap_or("s");
            let plural = filter.args.get(1).map(|s| s.as_str()).unwrap_or(singular);
            // If value is a number, use it to determine singular/plural
            let n: f64 = value.parse().unwrap_or(0.0);
            FilterResult {
                value: if n == 1.0 {
                    // With 2 args: first is singular suffix, second is plural suffix
                    // With 1 arg: it's the plural suffix, singular is empty
                    if filter.args.len() >= 2 {
                        singular.to_string()
                    } else {
                        String::new()
                    }
                } else {
                    plural.to_string()
                },
                html_safe: false,
            }
        }
        "default" => {
            let default_val = filter.args.first().map(|s| s.as_str()).unwrap_or("");
            FilterResult {
                value: if value.is_empty() {
                    default_val.to_string()
                } else {
                    value.to_string()
                },
                html_safe: false,
            }
        }
        "replace" => {
            let old = filter.args.first().map(|s| s.as_str()).unwrap_or("");
            let new = filter.args.get(1).map(|s| s.as_str()).unwrap_or("");
            FilterResult {
                value: value.replace(old, new),
                html_safe: false,
            }
        }
        "slice" => {
            let start: usize = filter
                .args
                .first()
                .and_then(|a| a.parse().ok())
                .unwrap_or(0);
            let end: usize = filter
                .args
                .get(1)
                .and_then(|a| a.parse().ok())
                .unwrap_or(value.len());
            let chars: Vec<char> = value.chars().collect();
            let start = start.min(chars.len());
            let end = end.min(chars.len());
            FilterResult {
                value: chars[start..end].iter().collect(),
                html_safe: false,
            }
        }
        "round" => {
            let decimals: u32 = filter
                .args
                .first()
                .and_then(|a| a.parse().ok())
                .unwrap_or(0);
            let n: f64 = value.parse().unwrap_or(0.0);
            let factor = 10f64.powi(decimals as i32);
            let rounded = (n * factor).round() / factor;
            FilterResult {
                value: if decimals == 0 {
                    format!("{}", rounded as i64)
                } else {
                    format!("{:.prec$}", rounded, prec = decimals as usize)
                },
                html_safe: false,
            }
        }
        "ceil" => {
            let n: f64 = value.parse().unwrap_or(0.0);
            let ceiled = n.ceil();
            FilterResult {
                value: if ceiled.abs() < i64::MAX as f64 {
                    format!("{}", ceiled as i64)
                } else {
                    format!("{}", ceiled)
                },
                html_safe: false,
            }
        }
        "floor" => {
            let n: f64 = value.parse().unwrap_or(0.0);
            let floored = n.floor();
            FilterResult {
                value: if floored.abs() < i64::MAX as f64 {
                    format!("{}", floored as i64)
                } else {
                    format!("{}", floored)
                },
                html_safe: false,
            }
        }
        // Unknown filter — pass through unchanged, but say so: a typo'd
        // filter (#price|currancy#) otherwise fails with no symptom at all
        unknown => {
            warn_unknown_filter_once(unknown);
            FilterResult {
                value: value.to_string(),
                html_safe: false,
            }
        }
    }
}

/// Filter names already reported as unknown (warn once per name per process).
static WARNED_UNKNOWN_FILTERS: LazyLock<std::sync::Mutex<std::collections::HashSet<String>>> =
    LazyLock::new(|| std::sync::Mutex::new(std::collections::HashSet::new()));

fn warn_unknown_filter_once(name: &str) {
    let mut warned = WARNED_UNKNOWN_FILTERS
        .lock()
        .unwrap_or_else(|e| e.into_inner());
    if warned.insert(name.to_string()) {
        tracing::warn!(
            "Unknown filter '|{}' — the value passes through unchanged. Check the spelling against the filter reference.",
            name
        );
    }
}

/// Apply a chain of filters, returning final value and html_safe flag
fn apply_filters(value: &str, filters: &[Filter]) -> FilterResult {
    let mut current = FilterResult {
        value: value.to_string(),
        html_safe: false,
    };
    for filter in filters {
        current = apply_filter(&current.value, filter);
    }
    current
}

// -- Arithmetic evaluation --

/// Check if a string contains arithmetic operators (space-separated)
fn contains_arithmetic(s: &str) -> bool {
    s.contains(" + ") || s.contains(" - ") || s.contains(" * ") || s.contains(" / ")
}

/// Resolve variable-like tokens in an arithmetic expression, then evaluate.
/// E.g. "session.age + 1" with context where session.age=25 → "25 + 1" → Some(26.0)
fn resolve_and_evaluate_arithmetic(expr: &str, context: &HashMap<String, Value>) -> Option<String> {
    static INLINE_VAR: LazyLock<Regex> =
        LazyLock::new(|| Regex::new(r"[a-zA-Z_][a-zA-Z0-9_.]*").unwrap());
    // Resolve all variable-like tokens
    let resolved = INLINE_VAR
        .replace_all(expr, |caps: &regex::Captures| {
            let token = &caps[0];
            let val = resolve_variable(token, context);
            // If unresolved (still #token#), return the token as-is (will fail arithmetic)
            if val.starts_with('#') && val.ends_with('#') {
                token.to_string()
            } else {
                val
            }
        })
        .to_string();
    evaluate_arithmetic(&resolved).map(format_f64_clean)
}

/// Evaluate a simple arithmetic expression: "10 + 1", "25.5 * 0.21", etc.
/// Supports +, -, *, / with standard precedence (* / before + -).
/// Returns None if the expression is not valid arithmetic or contains division by zero.
pub(crate) fn evaluate_arithmetic(expr: &str) -> Option<f64> {
    let expr = expr.trim();
    if expr.is_empty() {
        return None;
    }

    let tokens = tokenize_arithmetic(expr)?;
    if tokens.len() < 3 {
        return None; // Need at least: number op number
    }

    evaluate_with_precedence(&tokens)
}

/// Format f64 cleanly — no trailing .0 for whole numbers
pub(crate) fn format_f64_clean(n: f64) -> String {
    if n == n.trunc() && n.abs() < i64::MAX as f64 {
        format!("{}", n as i64)
    } else {
        format!("{}", n)
    }
}

#[derive(Debug, Clone)]
enum ArithToken {
    Num(f64),
    Op(char), // +, -, *, /
}

/// Tokenize an arithmetic expression into numbers and operators.
/// Handles negative numbers (leading - or - after operator).
fn tokenize_arithmetic(expr: &str) -> Option<Vec<ArithToken>> {
    let mut tokens = Vec::new();
    let mut chars = expr.chars().peekable();

    while let Some(&c) = chars.peek() {
        if c.is_whitespace() {
            chars.next();
            continue;
        }

        // Number (possibly negative at start or after operator)
        if c.is_ascii_digit()
            || c == '.'
            || (c == '-' && (tokens.is_empty() || matches!(tokens.last(), Some(ArithToken::Op(_)))))
        {
            let mut num_str = String::new();
            if c == '-' {
                num_str.push('-');
                chars.next();
            }
            while let Some(&nc) = chars.peek() {
                if nc.is_ascii_digit() || nc == '.' {
                    num_str.push(nc);
                    chars.next();
                } else {
                    break;
                }
            }
            let n: f64 = num_str.parse().ok()?;
            tokens.push(ArithToken::Num(n));
        } else if "+-*/".contains(c) {
            tokens.push(ArithToken::Op(c));
            chars.next();
        } else {
            // Non-arithmetic character — not a valid expression
            return None;
        }
    }

    // Validate: must alternate Num Op Num Op Num ...
    for (i, token) in tokens.iter().enumerate() {
        match (i % 2, token) {
            (0, ArithToken::Num(_)) => {}
            (1, ArithToken::Op(_)) => {}
            _ => return None,
        }
    }
    // Must end with a number
    if tokens.len() % 2 == 0 {
        return None;
    }

    Some(tokens)
}

/// Evaluate tokens with standard precedence: * / first, then + -
fn evaluate_with_precedence(tokens: &[ArithToken]) -> Option<f64> {
    // Extract numbers and operators into separate vecs
    let mut nums: Vec<f64> = Vec::new();
    let mut ops: Vec<char> = Vec::new();
    for token in tokens {
        match token {
            ArithToken::Num(n) => nums.push(*n),
            ArithToken::Op(op) => ops.push(*op),
        }
    }

    // First pass: evaluate * and /
    let mut i = 0;
    while i < ops.len() {
        if ops[i] == '*' || ops[i] == '/' {
            let result = if ops[i] == '*' {
                nums[i] * nums[i + 1]
            } else {
                if nums[i + 1] == 0.0 {
                    return None; // Division by zero
                }
                nums[i] / nums[i + 1]
            };
            nums[i] = result;
            nums.remove(i + 1);
            ops.remove(i);
        } else {
            i += 1;
        }
    }

    // Second pass: evaluate + and -
    let mut result = nums[0];
    for (i, op) in ops.iter().enumerate() {
        match op {
            '+' => result += nums[i + 1],
            '-' => result -= nums[i + 1],
            _ => return None,
        }
    }

    Some(result)
}

// -- Filter helper functions --

fn capitalize_first(s: &str) -> String {
    let mut chars = s.chars();
    match chars.next() {
        None => String::new(),
        Some(c) => c.to_uppercase().to_string() + &chars.as_str().to_lowercase(),
    }
}

fn title_case(s: &str) -> String {
    s.split_whitespace()
        .map(|word| capitalize_first(word))
        .collect::<Vec<_>>()
        .join(" ")
}

fn truncate_str(s: &str, max_len: usize, suffix: &str) -> String {
    let chars: Vec<char> = s.chars().collect();
    if chars.len() <= max_len {
        return s.to_string();
    }
    let truncated: String = chars[..max_len].iter().collect();
    format!("{}{}", truncated, suffix)
}

fn format_number(s: &str) -> String {
    // Parse as f64, format with thousands separator
    if let Ok(n) = s.parse::<f64>() {
        if n == n.floor() && n.abs() < i64::MAX as f64 {
            // Integer formatting with commas
            let n = n as i64;
            let is_negative = n < 0;
            let s = n.unsigned_abs().to_string();
            let chars: Vec<char> = s.chars().collect();
            let mut result = String::new();
            for (i, c) in chars.iter().enumerate() {
                if i > 0 && (chars.len() - i) % 3 == 0 {
                    result.push(',');
                }
                result.push(*c);
            }
            if is_negative {
                format!("-{}", result)
            } else {
                result
            }
        } else {
            // Float — keep as-is but with commas in integer part
            format!("{}", n)
        }
    } else {
        s.to_string()
    }
}

fn format_currency(s: &str, code: &str) -> String {
    let n: f64 = s.parse().unwrap_or(0.0);
    let symbol = match code.to_uppercase().as_str() {
        "USD" => "$",
        "EUR" => "\u{20ac}",
        "GBP" => "\u{00a3}",
        "JPY" => "\u{00a5}",
        "CAD" => "CA$",
        "AUD" => "A$",
        _ => "$",
    };
    // Format with 2 decimal places and thousands separator
    let abs_n = n.abs();
    let integer_part = abs_n.floor() as i64;
    let decimal_part = ((abs_n - abs_n.floor()) * 100.0).round() as i64;

    let int_str = format_number(&integer_part.to_string());
    let sign = if n < 0.0 { "-" } else { "" };
    format!("{}{}{}.{:02}", sign, symbol, int_str, decimal_part)
}

fn format_date(s: &str, mask: &str) -> String {
    use chrono::{NaiveDate, NaiveDateTime};

    // Parse input into NaiveDateTime
    let dt = if let Ok(date) = NaiveDate::parse_from_str(s, "%Y-%m-%d") {
        date.and_hms_opt(0, 0, 0).unwrap()
    } else if let Ok(dt) = NaiveDateTime::parse_from_str(s, "%Y-%m-%dT%H:%M:%S") {
        dt
    } else if let Ok(dt) = NaiveDateTime::parse_from_str(s, "%Y-%m-%d %H:%M:%S") {
        dt
    } else if let Ok(dt) = chrono::DateTime::parse_from_rfc3339(s) {
        dt.naive_local()
    } else {
        return s.to_string();
    };

    apply_date_mask(&dt, mask)
}

fn apply_date_mask(dt: &chrono::NaiveDateTime, mask: &str) -> String {
    use chrono::{Datelike, Timelike};

    // Resolve presets
    let mask = match mask {
        "short" => "m/d/yy",
        "medium" => "mmm d, yyyy",
        "long" => "mmmm d, yyyy",
        "full" => "dddd, mmmm d, yyyy",
        "time" => "h:nn tt",
        "iso" => "yyyy-mm-dd",
        other => other,
    };

    static MONTHS: &[&str] = &[
        "",
        "January",
        "February",
        "March",
        "April",
        "May",
        "June",
        "July",
        "August",
        "September",
        "October",
        "November",
        "December",
    ];
    static MONTHS_SHORT: &[&str] = &[
        "", "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec",
    ];
    static DAYS: &[&str] = &[
        "Monday",
        "Tuesday",
        "Wednesday",
        "Thursday",
        "Friday",
        "Saturday",
        "Sunday",
    ];
    static DAYS_SHORT: &[&str] = &["Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"];

    let day = dt.day();
    let month = dt.month() as usize;
    let year = dt.year();
    let hour24 = dt.hour();
    let hour12 = if hour24 == 0 {
        12
    } else if hour24 > 12 {
        hour24 - 12
    } else {
        hour24
    };
    let minute = dt.minute();
    let second = dt.second();
    let weekday_idx = dt.weekday().num_days_from_monday() as usize;
    let ampm = if hour24 < 12 { "AM" } else { "PM" };

    let mut result = String::new();
    let chars: Vec<char> = mask.chars().collect();
    let mut i = 0;

    while i < chars.len() {
        // Try longest tokens first
        let remaining = &mask[i..];

        if remaining.starts_with("dddd") {
            result.push_str(DAYS[weekday_idx]);
            i += 4;
        } else if remaining.starts_with("ddd") {
            result.push_str(DAYS_SHORT[weekday_idx]);
            i += 3;
        } else if remaining.starts_with("dd") {
            result.push_str(&format!("{:02}", day));
            i += 2;
        } else if remaining.starts_with('d') && !remaining.starts_with("dd") {
            result.push_str(&day.to_string());
            i += 1;
        } else if remaining.starts_with("mmmm") {
            result.push_str(MONTHS[month]);
            i += 4;
        } else if remaining.starts_with("mmm") {
            result.push_str(MONTHS_SHORT[month]);
            i += 3;
        } else if remaining.starts_with("mm") {
            result.push_str(&format!("{:02}", month));
            i += 2;
        } else if remaining.starts_with('m') && !remaining.starts_with("mm") {
            result.push_str(&month.to_string());
            i += 1;
        } else if remaining.starts_with("yyyy") {
            result.push_str(&format!("{:04}", year));
            i += 4;
        } else if remaining.starts_with("yy") {
            result.push_str(&format!("{:02}", year % 100));
            i += 2;
        } else if remaining.starts_with("HH") {
            result.push_str(&format!("{:02}", hour24));
            i += 2;
        } else if remaining.starts_with('H') && !remaining.starts_with("HH") {
            result.push_str(&hour24.to_string());
            i += 1;
        } else if remaining.starts_with("hh") {
            result.push_str(&format!("{:02}", hour12));
            i += 2;
        } else if remaining.starts_with('h') && !remaining.starts_with("hh") {
            result.push_str(&hour12.to_string());
            i += 1;
        } else if remaining.starts_with("nn") {
            result.push_str(&format!("{:02}", minute));
            i += 2;
        } else if remaining.starts_with('n') && !remaining.starts_with("nn") {
            result.push_str(&minute.to_string());
            i += 1;
        } else if remaining.starts_with("ss") {
            result.push_str(&format!("{:02}", second));
            i += 2;
        } else if remaining.starts_with('s') && !remaining.starts_with("ss") {
            result.push_str(&second.to_string());
            i += 1;
        } else if remaining.starts_with("tt") {
            result.push_str(ampm);
            i += 2;
        } else if remaining.starts_with('t') && !remaining.starts_with("tt") {
            result.push(ampm.chars().next().unwrap());
            i += 1;
        } else {
            // Literal character
            result.push(chars[i]);
            i += 1;
        }
    }

    result
}

fn simple_markdown(s: &str) -> String {
    // Escape HTML entities BEFORE markdown processing to prevent XSS.
    // Markdown output (tags like <strong>, <em>, <a>) is added after escaping.
    let escaped = html_escape(s);

    let mut result = String::new();
    let mut in_paragraph = false;

    for line in escaped.lines() {
        let trimmed = line.trim();
        if trimmed.is_empty() {
            if in_paragraph {
                result.push_str("</p>");
                in_paragraph = false;
            }
            continue;
        }

        // Process inline formatting
        let processed = process_markdown_inline(trimmed);

        if !in_paragraph {
            result.push_str("<p>");
            in_paragraph = true;
        } else {
            result.push(' ');
        }
        result.push_str(&processed);
    }

    if in_paragraph {
        result.push_str("</p>");
    }

    result
}

// Hoisted: process_markdown_inline runs once per non-blank line of a
// |markdown block — compiling these per call multiplied per render.
static MD_BOLD_RE: LazyLock<Regex> = LazyLock::new(|| Regex::new(r"\*\*(.+?)\*\*").unwrap());
static MD_ITALIC_RE: LazyLock<Regex> = LazyLock::new(|| Regex::new(r"\*(.+?)\*").unwrap());
static MD_LINK_RE: LazyLock<Regex> =
    LazyLock::new(|| Regex::new(r"\[([^\]]+)\]\(([^)]+)\)").unwrap());

fn process_markdown_inline(s: &str) -> String {
    let mut result = s.to_string();

    // Bold: **text** → <strong>text</strong>
    result = MD_BOLD_RE
        .replace_all(&result, "<strong>$1</strong>")
        .to_string();

    // Italic: *text* → <em>text</em>
    result = MD_ITALIC_RE.replace_all(&result, "<em>$1</em>").to_string();

    // Links: [text](url) → <a href="url">text</a>
    // Only emit an href for a safe URL scheme; otherwise render the text alone.
    result = MD_LINK_RE
        .replace_all(&result, |caps: &regex::Captures| {
            let text = &caps[1];
            let url = caps[2].trim();
            if markdown_url_is_safe(url) {
                format!(r#"<a href="{}">{}</a>"#, url, text)
            } else {
                text.to_string()
            }
        })
        .to_string();

    result
}

/// Whether a markdown link URL is safe to emit as an `href`. Uses a scheme
/// allowlist (http/https/mailto/tel + relative), and first strips characters
/// browsers ignore when evaluating a scheme — so `java\tscript:` / `java\nscript:`
/// cannot smuggle a `javascript:` URL past a naive `starts_with` check.
fn markdown_url_is_safe(url: &str) -> bool {
    let stripped: String = url
        .chars()
        .filter(|c| !c.is_control() && !c.is_whitespace())
        .collect();
    let lower = stripped.to_lowercase();
    match lower.find(':') {
        None => true, // no scheme — relative URL / fragment / query
        Some(colon) => {
            let before = &lower[..colon];
            // A '/', '#' or '?' before the colon means it's a path, not a scheme
            // (e.g. "/a:b" or "foo?x=1:2").
            if before.contains('/') || before.contains('#') || before.contains('?') {
                return true;
            }
            let is_scheme = !before.is_empty()
                && before.chars().next().unwrap().is_ascii_alphabetic()
                && before
                    .chars()
                    .all(|c| c.is_ascii_alphanumeric() || c == '+' || c == '-' || c == '.');
            if is_scheme {
                matches!(before, "http" | "https" | "mailto" | "tel")
            } else {
                true
            }
        }
    }
}

/// Replace #variable# syntax with values from context.
/// All output is HTML-escaped by default. Use `|raw` filter to bypass escaping.
/// Supports filter chaining: `#var|filter1:arg|filter2#`
pub(crate) fn replace_variables(
    template: &str,
    context: &HashMap<String, serde_json::Value>,
) -> String {
    VAR_REGEX
        .replace_all(template, |caps: &regex::Captures| {
            let expr = &caps[1];
            let (var_path, filters) = parse_filter_chain(expr);

            // Check if var_path contains arithmetic operators
            let raw_value = if contains_arithmetic(var_path) {
                resolve_and_evaluate_arithmetic(var_path, context)
                    .unwrap_or_else(|| resolve_variable(var_path, context))
            } else {
                resolve_variable(var_path, context)
            };

            // If variable was unresolved and there's no default filter, keep as #var#
            let is_unresolved = raw_value.starts_with('#') && raw_value.ends_with('#');

            // A strict not-found passthrough returns exactly `#<var_path>#` — the
            // author's own token, which must be preserved verbatim. A resolved
            // value that merely *looks* like a token (e.g. a DB field equal to
            // "#env.SECRET#") does NOT match this, so it is treated as data and
            // gets its `#` neutralized below.
            let is_preserved_token = raw_value == format!("#{var_path}#");

            // Apply filters
            let filtered = if filters.is_empty() {
                FilterResult {
                    value: raw_value,
                    html_safe: false,
                }
            } else {
                // If unresolved and first filter is "default", use empty string to trigger default
                let input = if is_unresolved && filters.iter().any(|f| f.name == "default") {
                    String::new()
                } else {
                    raw_value
                };
                apply_filters(&input, &filters)
            };

            // Auto-escape unless html_safe. Resolved (data) values additionally
            // have their `#` neutralized so they cannot be re-resolved on a later
            // render pass; the preserved `#unknown#` token is emitted as-is.
            if filtered.html_safe {
                filtered.value
            } else if is_preserved_token {
                html_escape(&filtered.value)
            } else {
                escape_and_neutralize_hashes(&filtered.value)
            }
        })
        .to_string()
}

/// Result of reactive variable replacement
#[derive(Debug, Clone, Default)]
pub struct ReactiveReplaceResult {
    /// The rendered HTML content
    pub html: String,
    /// Session keys that were used (for OOB updates)
    pub session_keys: std::collections::HashSet<String>,
}

/// Replace #variable# syntax with values from context, wrapping session variables
/// with reactive `<span w-bind>` elements when they appear in text content.
/// Variables inside attributes are replaced without wrapping.
/// All output is HTML-escaped by default. Supports filter chaining: `#var|filter1:arg|filter2#`
pub(crate) fn replace_variables_reactive(
    template: &str,
    context: &HashMap<String, serde_json::Value>,
) -> ReactiveReplaceResult {
    let mut session_keys = std::collections::HashSet::new();

    // We need to track position to determine if we're in an attribute context
    let mut result = String::with_capacity(template.len());
    let mut last_end = 0;

    for caps in VAR_REGEX.captures_iter(template) {
        let m = caps.get(0).unwrap();
        let expr = &caps[1];
        let start = m.start();

        // Add the text before this match
        result.push_str(&template[last_end..start]);

        // Parse filter chain
        let (var_path, filters) = parse_filter_chain(expr);

        // Check if this is a session or wired variable
        let is_session_var = var_path.starts_with("session.");
        let is_wired_var = var_path.starts_with("wired.");

        // Resolve the variable value (with arithmetic support)
        let raw_value = if contains_arithmetic(var_path) {
            resolve_and_evaluate_arithmetic(var_path, context)
                .unwrap_or_else(|| resolve_variable(var_path, context))
        } else {
            resolve_variable(var_path, context)
        };
        let is_unresolved = raw_value.starts_with('#') && raw_value.ends_with('#');
        // Exact strict not-found passthrough (`#<var_path>#`) — preserve verbatim;
        // a resolved value that merely looks like a token is data and gets its
        // `#` neutralized on the escaped emit paths below (second-order injection).
        let is_preserved_token = raw_value == format!("#{var_path}#");

        // Apply filters
        let filtered = if filters.is_empty() {
            FilterResult {
                value: raw_value,
                html_safe: false,
            }
        } else {
            let input = if is_unresolved && filters.iter().any(|f| f.name == "default") {
                String::new()
            } else {
                raw_value
            };
            apply_filters(&input, &filters)
        };

        if is_session_var || is_wired_var {
            let (bind_prefix, bind_key) = if is_session_var {
                let key = &var_path[8..]; // Skip "session."
                session_keys.insert(key.to_string());
                ("session", key)
            } else {
                let key = &var_path[6..]; // Skip "wired."
                ("wired", key)
            };

            // If the value is unresolved (still looks like #var#), use empty string
            // to prevent double-wrapping when layouts re-process the output
            let display_value = if filtered.value.starts_with('#') && filtered.value.ends_with('#')
            {
                String::new()
            } else {
                filtered.value
            };

            // Check if we're inside an attribute by looking at the text before this match
            let text_before = &template[..start];
            let in_attribute = is_in_attribute_context(text_before);

            if in_attribute {
                // Inside attribute - replace with escaped value (no wrapping)
                if filtered.html_safe {
                    result.push_str(&display_value);
                } else {
                    result.push_str(&escape_and_neutralize_hashes(&display_value));
                }
            } else {
                // In text content - wrap with reactive span
                // The span content is always escaped (XSS protection in reactive updates)
                result.push_str(&format!(
                    r#"<span w-bind="{}.{}">{}</span>"#,
                    bind_prefix,
                    bind_key,
                    escape_and_neutralize_hashes(&display_value)
                ));
            }
        } else {
            // Non-reactive variable
            if filtered.html_safe {
                result.push_str(&filtered.value);
            } else if is_preserved_token {
                result.push_str(&html_escape(&filtered.value));
            } else {
                result.push_str(&escape_and_neutralize_hashes(&filtered.value));
            }
        }

        last_end = m.end();
    }

    // Add any remaining text after the last match
    result.push_str(&template[last_end..]);

    ReactiveReplaceResult {
        html: result,
        session_keys,
    }
}

/// Check if a position in the template is inside an HTML attribute
/// by analyzing the text before that position
fn is_in_attribute_context(text_before: &str) -> bool {
    // Look for the last opening tag or attribute quote
    // We're in an attribute if we find an unclosed attribute pattern
    let mut in_attr_value = false;
    let mut quote_char: Option<char> = None;

    for c in text_before.chars().rev() {
        match c {
            '"' | '\'' if quote_char == Some(c) => {
                // End of attribute value (going backwards, this is actually the start)
                quote_char = None;
                in_attr_value = false;
            }
            '"' | '\'' if quote_char.is_none() => {
                // Start of attribute value (going backwards, this is actually the end)
                quote_char = Some(c);
                in_attr_value = true;
            }
            '>' if quote_char.is_none() => {
                // We hit a '>' before finding an unclosed attribute, so we're in text content
                return false;
            }
            '<' if quote_char.is_none() => {
                // We hit a '<' - we were inside a tag
                // If we have an unclosed quote, we're in an attribute
                return in_attr_value;
            }
            _ => {}
        }
    }

    // If we reach here with an open quote, we're in an attribute
    in_attr_value
}

/// Escape HTML special characters
fn html_escape(s: &str) -> String {
    s.replace('&', "&amp;")
        .replace('<', "&lt;")
        .replace('>', "&gt;")
        .replace('"', "&quot;")
        .replace('\'', "&#39;")
}

/// HTML-escape a resolved variable value AND neutralize any `#` it contains so a
/// data-provided value shaped like a template token (e.g. `#env.SECRET#`) cannot
/// be re-interpreted on a later render pass. The engine renders in multiple
/// passes (loops/components/includes resolve their bodies, then a final pass
/// re-scans the whole page); without this, an attacker-controlled field rendered
/// inside a loop could smuggle a live `#env.*#` / `#x|raw#` token into the final
/// pass — leaking secrets or bypassing escaping (second-order template injection).
///
/// `#` is neutralized to the `&num;` HTML entity (renders identically as `#`).
/// A private-use sentinel protects data `#` from html_escape's own `&#39;` output,
/// which itself contains a `#` we must not touch.
fn escape_and_neutralize_hashes(s: &str) -> String {
    const SENTINEL: &str = "\u{E000}"; // Unicode private use — never appears in real content
    let protected = s.replace('#', SENTINEL);
    html_escape(&protected).replace(SENTINEL, "&num;")
}

/// Reverse of html_escape, for comparison operands: values resolve through
/// replace_variables (which escapes for output), so comparing them against
/// an author-written literal like `"Ben & Jerry"` must undo the escaping.
/// `&amp;` is unescaped LAST — the mirror of html_escape escaping `&` first —
/// so `&amp;lt;` round-trips to `&lt;` and never collapses to `<`.
pub(crate) fn html_unescape(s: &str) -> String {
    if !s.contains('&') {
        return s.to_string();
    }
    s.replace("&lt;", "<")
        .replace("&gt;", ">")
        .replace("&quot;", "\"")
        .replace("&#39;", "'")
        .replace("&amp;", "&")
}

/// Resolve computed variables from page directives and inject them into the context.
/// Computed variables use string interpolation: `compute.name = "Hello #user.name#!"`
/// They become available as `#name#` (without the `compute.` prefix) in templates.
/// Resolved in order, so later computed vars can reference earlier ones.
pub(crate) fn resolve_computed_variables(
    computed: &[(String, String)],
    context: &mut HashMap<String, serde_json::Value>,
) {
    for (name, template) in computed {
        // Interpolate #var# references in the template using current context
        let resolved = VAR_REGEX
            .replace_all(template, |caps: &regex::Captures| {
                let var_path = &caps[1];
                resolve_variable(var_path, context)
            })
            .to_string();

        // Insert as a string value (without the compute. prefix)
        context.insert(name.clone(), serde_json::Value::String(resolved));
    }
}

/// Resolve a variable path like "user.email" from context.
/// Also supports "env.VAR_NAME" to read environment variables.
/// Returns the resolved string value, or "#var_path#" if not found.
fn resolve_variable(path: &str, context: &HashMap<String, serde_json::Value>) -> String {
    let parts: Vec<&str> = path.split('.').collect();

    if parts.is_empty() {
        return String::new();
    }

    // Check for environment variable: #env.VAR_NAME#
    if parts[0] == "env" && parts.len() >= 2 {
        let env_var_name = parts[1..].join("_"); // env.DATABASE_URL -> DATABASE_URL
        return std::env::var(&env_var_name).unwrap_or_default();
    }

    let root = context.get(parts[0]);
    let mut current: Option<&serde_json::Value> = root;

    for part in parts.iter().skip(1) {
        current = current.and_then(|v| {
            if let serde_json::Value::Object(obj) = v {
                obj.get(*part)
            } else {
                None
            }
        });
    }

    match current {
        Some(serde_json::Value::String(s)) => s.clone(),
        Some(serde_json::Value::Number(n)) => n.to_string(),
        Some(serde_json::Value::Bool(b)) => b.to_string(),
        Some(serde_json::Value::Null) => String::new(),
        Some(v) => v.to_string(),
        None if root.is_some() && parts.len() > 1 => String::new(), // Parent exists, child missing → empty
        None => format!("#{}#", path), // Root not in context → keep literal for strict mode
    }
}

/// Check if a tag name is a standard HTML tag
#[allow(dead_code)]
pub(crate) fn is_standard_html_tag(name: &str) -> bool {
    matches!(
        name,
        "html"
            | "head"
            | "body"
            | "title"
            | "meta"
            | "link"
            | "script"
            | "style"
            | "div"
            | "span"
            | "p"
            | "a"
            | "img"
            | "br"
            | "hr"
            | "h1"
            | "h2"
            | "h3"
            | "h4"
            | "h5"
            | "h6"
            | "ul"
            | "ol"
            | "li"
            | "dl"
            | "dt"
            | "dd"
            | "table"
            | "thead"
            | "tbody"
            | "tfoot"
            | "tr"
            | "th"
            | "td"
            | "form"
            | "input"
            | "textarea"
            | "select"
            | "option"
            | "button"
            | "label"
            | "header"
            | "footer"
            | "main"
            | "nav"
            | "section"
            | "article"
            | "aside"
            | "figure"
            | "figcaption"
            | "video"
            | "audio"
            | "source"
            | "canvas"
            | "iframe"
            | "embed"
            | "object"
            | "param"
            | "strong"
            | "em"
            | "b"
            | "i"
            | "u"
            | "s"
            | "mark"
            | "small"
            | "sub"
            | "sup"
            | "blockquote"
            | "pre"
            | "code"
            | "kbd"
            | "samp"
            | "var"
            | "time"
            | "address"
            | "abbr"
            | "cite"
            | "q"
            | "ins"
            | "del"
            | "dfn"
            | "ruby"
            | "rt"
            | "rp"
            | "bdi"
            | "bdo"
            | "wbr"
            | "details"
            | "summary"
            | "dialog"
            | "slot"
            | "template"
            | "noscript"
    )
}

/// Authentication level for a page
#[derive(Debug, Clone, PartialEq)]
pub(crate) enum AuthLevel {
    /// Public page - no authentication required (auth: all)
    All,
    /// Any authenticated user (auth: user)
    User,
    /// Specific roles required (auth: admin, editor)
    Roles(Vec<String>),
}

impl std::fmt::Display for AuthLevel {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            AuthLevel::All => write!(f, "all"),
            AuthLevel::User => write!(f, "user"),
            AuthLevel::Roles(v) => write!(f, "roles: {}", v.join(", ")),
        }
    }
}

impl Default for AuthLevel {
    fn default() -> Self {
        AuthLevel::All
    }
}

/// Page directives extracted from <what> tags
///
/// Example usage in HTML:
/// ```html
/// <what auth="all" />              <!-- Public page -->
/// <what auth="user" />             <!-- Any authenticated user -->
/// <what auth="admin, editor" />    <!-- Specific roles -->
/// <what layout="sections/main.html" /> <!-- Use a layout -->
/// ```
///
/// Or with content:
/// ```html
/// <what>
///   auth: all           # Public page (no auth)
///   auth: user          # Any authenticated user
///   auth: admin, editor # Specific roles
///   layout: sections/main.html
///   title: Dashboard
/// </what>
/// ```
///
/// Legacy syntax still supported:
/// ```html
/// <what protected roles="admin,editor" />
/// ```
/// Session mutation operation
#[derive(Debug, Clone)]
pub(crate) enum SessionMutation {
    /// Increment a session variable by a value: session.counter += 1
    Increment { key: String, value: i64 },
    /// Set a session variable: session.name = "value"
    Set { key: String, value: Value },
    /// Push a value to the end of an array: session.list.push(value)
    Push { key: String, value: Value },
    /// Push a value to the end of an array with a max size, dropping oldest: session.list.pushmax(10, value)
    PushMax {
        key: String,
        max: usize,
        value: Value,
    },
    /// Push a value to the beginning of an array: session.list.unshift(value)
    Unshift { key: String, value: Value },
    /// Clear an array: session.list.clear()
    Clear { key: String },
}

#[derive(Debug, Clone, Default)]
pub(crate) struct PageDirectives {
    /// Authentication level for this page
    pub auth: AuthLevel,
    /// Page is protected (requires authentication) - LEGACY, use `auth` instead
    pub protected: bool,
    /// Required roles (any of these roles grants access) - LEGACY, use `auth` instead
    pub roles: Vec<String>,
    /// Page should be excluded from routing
    pub exclude: bool,
    /// Custom page title
    pub title: Option<String>,
    /// Redirect to another page
    pub redirect: Option<String>,
    /// Cache TTL in seconds (overrides global)
    pub cache_ttl: Option<u64>,
    /// Layout template path (e.g., "sections/layout.html")
    /// Use "none" to explicitly disable layout inheritance
    pub layout: Option<String>,
    /// Session mutations to apply before rendering
    pub session_mutations: Vec<SessionMutation>,
    /// Computed variables: compute.name = "interpolated #var# string"
    pub computed: Vec<(String, String)>,
    /// Custom response headers (from `header.Name = "value"` in application.what)
    pub headers: HashMap<String, String>,
    /// Any additional custom directives
    pub custom: HashMap<String, String>,
    /// Inline variables from `<what>` blocks (typed: strings, numbers, arrays, objects)
    pub vars: HashMap<String, Value>,
}

impl PageDirectives {
    /// Check if page requires authentication
    /// Returns true if auth level is User or Roles, or if legacy `protected` is set
    pub fn requires_auth(&self) -> bool {
        match &self.auth {
            AuthLevel::All => self.protected, // Fall back to legacy
            AuthLevel::User => true,
            AuthLevel::Roles(_) => true,
        }
    }

    /// Check if user has access based on auth level
    /// - All: always returns true
    /// - User: returns true if authenticated
    /// - Roles: returns true if user has any required role
    pub fn check_access(&self, authenticated: bool, user_roles: &[String]) -> bool {
        match &self.auth {
            AuthLevel::All => {
                // Legacy fallback
                if self.protected {
                    if !authenticated {
                        return false;
                    }
                    self.has_role(user_roles)
                } else {
                    true
                }
            }
            AuthLevel::User => authenticated,
            AuthLevel::Roles(required) => {
                authenticated && required.iter().any(|r| user_roles.contains(r))
            }
        }
    }

    /// Check if user has any of the required roles (legacy method)
    pub fn has_role(&self, user_roles: &[String]) -> bool {
        if self.roles.is_empty() {
            return true; // No role requirement
        }
        self.roles.iter().any(|r| user_roles.contains(r))
    }
}

/// Parse <what> directives from page content
/// Returns the directives and the content with <what> tags removed
pub(crate) fn parse_page_directives(content: &str) -> (PageDirectives, String) {
    let mut directives = PageDirectives::default();

    let cleaned = WHAT_DIRECTIVE_REGEX
        .replace_all(content, |caps: &regex::Captures| {
            let attrs_str = caps.get(1).map(|m| m.as_str()).unwrap_or("");
            let inner_content = caps.get(2).map(|m| m.as_str());

            // Parse attributes from the tag
            parse_directive_attributes(attrs_str, &mut directives);

            // Parse inner content if present (YAML-like syntax)
            if let Some(inner) = inner_content {
                parse_directive_content(inner, &mut directives);
            }

            "" // Remove the <what> tag from output
        })
        .to_string();

    (directives, cleaned)
}

/// Parse auth value into AuthLevel
pub(crate) fn parse_auth_level(value: &str) -> AuthLevel {
    let value = value.trim().to_lowercase();
    match value.as_str() {
        "all" | "public" | "none" => AuthLevel::All,
        "user" | "authenticated" => AuthLevel::User,
        _ => {
            // Parse as comma-separated roles
            let roles: Vec<String> = value
                .split(',')
                .map(|s| s.trim().to_string())
                .filter(|s| !s.is_empty())
                .collect();
            if roles.is_empty() {
                AuthLevel::All
            } else {
                AuthLevel::Roles(roles)
            }
        }
    }
}

/// Parse attributes from <what> tag
fn parse_directive_attributes(attrs_str: &str, directives: &mut PageDirectives) {
    // Parse key="value" attributes
    let attrs = parse_attributes(attrs_str);

    for (key, value) in &attrs {
        match key.as_str() {
            "auth" => {
                directives.auth = parse_auth_level(value);
            }
            // Legacy support
            "protected" => directives.protected = value != "false",
            "roles" => {
                directives.roles = value
                    .split(',')
                    .map(|s| s.trim().to_string())
                    .filter(|s| !s.is_empty())
                    .collect();
                // If roles are specified, page is implicitly protected
                if !directives.roles.is_empty() {
                    directives.protected = true;
                }
            }
            "exclude" => directives.exclude = value != "false",
            "title" => directives.title = Some(value.clone()),
            "redirect" => directives.redirect = Some(value.clone()),
            "layout" => directives.layout = Some(value.clone()),
            "cache" | "cache-ttl" => {
                directives.cache_ttl = value.parse().ok();
            }
            _ => {
                // Handle header.* keys
                if let Some(header_name) = key.strip_prefix("header.") {
                    directives
                        .headers
                        .insert(header_name.to_string(), value.clone());
                } else {
                    warn_access_directive_near_miss(key);
                    directives.custom.insert(key.clone(), value.clone());
                }
            }
        }
    }

    // Parse boolean attributes (no value)
    // Find words that aren't part of key="value" pairs
    let without_attrs = ATTR_REGEX.replace_all(attrs_str, "");
    for cap in BOOL_ATTR_REGEX.captures_iter(&without_attrs) {
        let key = &cap[1];
        match key {
            "protected" => directives.protected = true,
            "exclude" => directives.exclude = true,
            _ => {}
        }
    }
}

/// Reserved directive keys — these are NOT inline variables
fn is_reserved_directive(key: &str) -> bool {
    matches!(
        key,
        "auth"
            | "protected"
            | "roles"
            | "exclude"
            | "title"
            | "redirect"
            | "layout"
            | "cache"
            | "cache-ttl"
            | "method"
            | "paginate"
    ) || key.starts_with("fetch.")
        || key.starts_with("session.")
        || key.starts_with("compute.")
        || key.starts_with("set.")
        || key.starts_with("data.")
        || key.starts_with("header.")
        || key.starts_with("mutation.")
}

/// True when `a` and `b` are within one edit of each other: a single
/// substitution, insertion, deletion, or adjacent transposition.
fn within_one_edit(a: &str, b: &str) -> bool {
    if a == b {
        return true;
    }
    let a: Vec<char> = a.chars().collect();
    let b: Vec<char> = b.chars().collect();
    if a.len().abs_diff(b.len()) > 1 {
        return false;
    }
    if a.len() == b.len() {
        let diffs: Vec<usize> = (0..a.len()).filter(|&i| a[i] != b[i]).collect();
        match diffs.len() {
            1 => true,
            2 => {
                diffs[1] == diffs[0] + 1
                    && a[diffs[0]] == b[diffs[1]]
                    && a[diffs[1]] == b[diffs[0]]
            }
            _ => false,
        }
    } else {
        let (short, long) = if a.len() < b.len() { (&a, &b) } else { (&b, &a) };
        let mut i = 0;
        let mut j = 0;
        let mut skipped = false;
        while i < short.len() && j < long.len() {
            if short[i] == long[j] {
                i += 1;
                j += 1;
            } else if skipped {
                return false;
            } else {
                skipped = true;
                j += 1;
            }
        }
        true
    }
}

/// Detect a likely misspelling of an access-control directive key.
///
/// An unknown `<what>` key falls through to "inline variable", and
/// `AuthLevel` defaults to `All` — so `auht: user` would silently leave the
/// page PUBLIC. Only the access-control keys get fuzzy matching: a typo'd
/// `title` or `layout` breaks visibly, but a typo'd `auth` fails open with
/// no symptom. Requires a matching first letter so common real variable
/// names near these words (e.g. `oauth`) don't trip it.
fn access_directive_near_miss(key: &str) -> Option<&'static str> {
    const ACCESS_KEYS: [&str; 3] = ["auth", "protected", "roles"];
    let lower = key.to_lowercase();
    // Compare the ORIGINAL key for the exact-match exclusion: `Auth` is a
    // case typo worth flagging, only a byte-exact `auth` parses as the
    // real directive.
    ACCESS_KEYS.into_iter().find(|reserved| {
        key != *reserved
            && lower.chars().next() == reserved.chars().next()
            && within_one_edit(&lower, reserved)
    })
}

/// Keys already reported as access-directive near-misses (warn once per key
/// per process — directives re-parse on every request).
static WARNED_NEAR_MISSES: LazyLock<std::sync::Mutex<std::collections::HashSet<String>>> =
    LazyLock::new(|| std::sync::Mutex::new(std::collections::HashSet::new()));

/// Warn loudly (all modes, not just dev) when a `<what>` key looks like a
/// misspelled access-control directive. The page renders unchanged — this
/// must never fail closed on a false positive — but silence here means a
/// world-readable page the author believes is protected.
fn warn_access_directive_near_miss(key: &str) {
    if let Some(reserved) = access_directive_near_miss(key) {
        let mut warned = WARNED_NEAR_MISSES.lock().unwrap();
        if warned.insert(key.to_string()) {
            tracing::error!(
                "<what> key '{}' looks like a misspelling of the '{}' access-control directive. \
                 It was treated as an inline variable, so NO access restriction was applied to this page. \
                 If you meant '{}', fix the spelling; if it is a real variable, rename it.",
                key,
                reserved,
                reserved
            );
        }
    }
}

/// Parse inner content of <what> tag (YAML-like syntax)
fn parse_directive_content(content: &str, directives: &mut PageDirectives) {
    let mut current_section: Option<String> = None;

    // Multi-line JSON accumulation state
    let mut json_key: Option<String> = None;
    let mut json_buf = String::new();
    let mut json_depth: usize = 0;
    let mut json_bracket: char = ' '; // '[' or '{'

    let lines: Vec<&str> = content.lines().collect();
    let mut i = 0;

    while i < lines.len() {
        let raw_line = lines[i];
        let trimmed = raw_line.trim();
        i += 1;

        // If we're accumulating a multi-line JSON value, keep appending
        if json_key.is_some() {
            json_buf.push('\n');
            json_buf.push_str(trimmed);
            let close_char = if json_bracket == '[' { ']' } else { '}' };
            json_depth += trimmed.matches(json_bracket).count();
            json_depth -= trimmed.matches(close_char).count();
            if json_depth == 0 {
                // Done accumulating — parse the JSON
                let key = json_key.take().unwrap();
                let relaxed = relax_json(&json_buf);
                match serde_json::from_str::<Value>(&relaxed) {
                    Ok(val) => {
                        directives.vars.insert(key, val);
                    }
                    Err(e) => {
                        tracing::warn!("Invalid JSON for inline var: {}", e);
                    }
                }
                json_buf.clear();
            }
            continue;
        }

        if trimmed.is_empty() {
            continue;
        }

        // Section header: [name] sets prefix, [] resets to root
        if trimmed.starts_with('[') && trimmed.ends_with(']') {
            let inner = trimmed[1..trimmed.len() - 1].trim();
            if inner.is_empty() {
                current_section = None;
            } else {
                current_section = Some(inner.to_lowercase().to_string());
            }
            continue;
        }

        // Apply section prefix to raw line (syntactic sugar for flat dotted keys)
        let line_owned;
        let line: &str = if let Some(ref section) = current_section {
            line_owned = format!("{}.{}", section, trimmed);
            line_owned.trim()
        } else {
            trimmed
        };

        // Check for session mutation: session.key += value or session.key = value
        if line.starts_with("session.") {
            if let Some(mutation) = parse_session_mutation(line) {
                directives.session_mutations.push(mutation);
            }
            continue;
        }

        // Check for computed variable: compute.name = "interpolated #var# string"
        if line.starts_with("compute.") {
            if let Some(eq_pos) = line.find('=') {
                let name = line[8..eq_pos].trim().to_string(); // Skip "compute."
                let value = line[eq_pos + 1..].trim();
                // Remove surrounding quotes if present (one symmetric pair only)
                let value = strip_symmetric_quotes(value).0.to_string();
                directives.computed.push((name, value));
            }
            continue;
        }

        // Check for boolean directive (just a word)
        if !line.contains(':') && !line.contains('=') {
            match line.to_lowercase().as_str() {
                "protected" => directives.protected = true,
                "exclude" => directives.exclude = true,
                _ => {}
            }
            continue;
        }

        // Parse key: value or key = value
        // Prefer '=' when it appears before ':' (handles URLs like https://...)
        let colon_idx = line.find(':');
        let equals_idx = line.find('=');
        let (key, value) = match (colon_idx, equals_idx) {
            (Some(c), Some(e)) => {
                if e < c {
                    (&line[..e], line[e + 1..].trim())
                } else {
                    (&line[..c], line[c + 1..].trim())
                }
            }
            (Some(c), None) => (&line[..c], line[c + 1..].trim()),
            (None, Some(e)) => (&line[..e], line[e + 1..].trim()),
            _ => continue,
        };

        let key = key.trim().to_lowercase();
        let (value, value_was_quoted) = strip_symmetric_quotes(value);
        if !value_was_quoted
            && value.len() >= 2
            && (value.starts_with('"')
                || value.starts_with('\'')
                || value.ends_with('"')
                || value.ends_with('\''))
        {
            tracing::warn!(
                "Mismatched quotes in <what> block value for '{}': {} — use one matching pair, e.g. \"value\"",
                key,
                value
            );
        }

        match key.as_str() {
            "auth" => {
                directives.auth = parse_auth_level(value);
            }
            // Legacy support
            "protected" => directives.protected = value != "false",
            "roles" => {
                directives.roles = value
                    .split(',')
                    .map(|s| s.trim().to_string())
                    .filter(|s| !s.is_empty())
                    .collect();
                if !directives.roles.is_empty() {
                    directives.protected = true;
                }
            }
            "exclude" => directives.exclude = value != "false",
            "title" => {
                if !value_was_quoted && is_unquoted_string(value) {
                    tracing::warn!(
                        "Unquoted string in <what> block: title should be quoted, e.g. title: \"{}\"",
                        value
                    );
                }
                directives.title = Some(value.to_string());
            }
            "redirect" => {
                if !value_was_quoted && is_unquoted_string(value) {
                    tracing::warn!(
                        "Unquoted string in <what> block: redirect should be quoted, e.g. redirect: \"{}\"",
                        value
                    );
                }
                directives.redirect = Some(value.to_string());
            }
            "layout" => {
                if !value_was_quoted && is_unquoted_string(value) {
                    tracing::warn!(
                        "Unquoted string in <what> block: layout should be quoted, e.g. layout: \"{}\"",
                        value
                    );
                }
                directives.layout = Some(value.to_string());
            }
            "cache" | "cache-ttl" => {
                directives.cache_ttl = value.parse().ok();
            }
            _ => {
                // Handle header.* keys
                if let Some(header_name) = key.strip_prefix("header.") {
                    directives
                        .headers
                        .insert(header_name.to_string(), value.to_string());
                } else if is_reserved_directive(&key) {
                    // Reserved prefixed directives (fetch.*, set.*, data.*, etc.)
                    if !value_was_quoted && !value.is_empty() && is_unquoted_string(value) {
                        tracing::warn!(
                            "Unquoted string in <what> block: {} should be quoted, e.g. {} = \"{}\"",
                            key,
                            key,
                            value
                        );
                    }
                    directives.custom.insert(key, value.to_string());
                } else {
                    // Non-reserved key — treat as inline variable
                    warn_access_directive_near_miss(&key);
                    // Check if value starts a multi-line JSON block
                    let value_untrimmed = {
                        let eq_pos = line.find('=').or_else(|| line.find(':')).unwrap();
                        line[eq_pos + 1..].trim()
                    };
                    if (value_untrimmed.starts_with('[') || value_untrimmed.starts_with('{'))
                        && !value_untrimmed.ends_with(']')
                        && !value_untrimmed.ends_with('}')
                    {
                        // Start multi-line JSON accumulation
                        json_bracket = value_untrimmed.chars().next().unwrap();
                        json_buf = value_untrimmed.to_string();
                        json_depth = value_untrimmed.matches(json_bracket).count();
                        let close_char = if json_bracket == '[' { ']' } else { '}' };
                        json_depth -= value_untrimmed.matches(close_char).count();
                        if json_depth == 0 {
                            // Single-line JSON that's complete
                            let relaxed = relax_json(value_untrimmed);
                            match serde_json::from_str::<Value>(&relaxed) {
                                Ok(val) => {
                                    directives.vars.insert(key, val);
                                }
                                Err(e) => {
                                    tracing::warn!("Invalid JSON for inline var '{}': {}", key, e);
                                }
                            }
                            json_buf.clear();
                        } else {
                            json_key = Some(key);
                        }
                    } else if value_untrimmed.starts_with('[') || value_untrimmed.starts_with('{') {
                        // Single-line JSON (complete on one line)
                        let relaxed = relax_json(value_untrimmed);
                        match serde_json::from_str::<Value>(&relaxed) {
                            Ok(val) => {
                                directives.vars.insert(key, val);
                            }
                            Err(e) => {
                                tracing::warn!("Invalid JSON for inline var '{}': {}", key, e);
                            }
                        }
                    } else {
                        // Scalar inline variable — quoting forces string type
                        // (`zip = "01234"` stays "01234"; unquoted values are
                        // type-inferred as before).
                        let parsed = if value_was_quoted {
                            Value::String(value.to_string())
                        } else {
                            parse_inline_value(value)
                        };
                        // Warn if string value is unquoted (numbers/bools are fine)
                        if !value_was_quoted && is_unquoted_string(value) {
                            tracing::warn!(
                                "Unquoted string in <what> block: {} should be quoted, e.g. {} = \"{}\"",
                                key,
                                key,
                                value
                            );
                        }
                        directives.vars.insert(key, parsed);
                    }
                }
            }
        }
    }
}

/// Strip exactly one symmetric pair of matching quotes.
/// Returns (stripped_value, was_quoted). Mismatched, unterminated, or nested
/// quotes are left intact so author mistakes stay visible instead of being
/// silently swallowed (the old `trim_matches` stripped repeated AND mismatched
/// quote characters).
pub(crate) fn strip_symmetric_quotes(s: &str) -> (&str, bool) {
    let bytes = s.as_bytes();
    if bytes.len() >= 2 {
        let first = bytes[0];
        if (first == b'"' || first == b'\'') && bytes[bytes.len() - 1] == first {
            return (&s[1..s.len() - 1], true);
        }
    }
    (s, false)
}

/// Check if a value is a string that should have been quoted.
/// Returns false for numbers, booleans, and known keywords.
fn is_unquoted_string(value: &str) -> bool {
    if value.is_empty() {
        return false;
    }
    if value.parse::<f64>().is_ok() {
        return false;
    }
    match value.to_lowercase().as_str() {
        "true" | "false" | "none" | "all" | "user" => false,
        _ => true,
    }
}

/// Relax JSON: quote unquoted object keys so serde_json can parse it.
/// Turns `{ name: "Widget" }` into `{ "name": "Widget" }`.
fn relax_json(s: &str) -> String {
    static UNQUOTED_KEY: LazyLock<Regex> =
        LazyLock::new(|| Regex::new(r#"(?m)([{\[,])\s*([a-zA-Z_][a-zA-Z0-9_]*)\s*:"#).unwrap());
    UNQUOTED_KEY.replace_all(s, r#"$1 "$2":"#).into_owned()
}

/// Parse a scalar inline value to a typed JSON Value
fn parse_inline_value(s: &str) -> Value {
    // Try integer
    if let Ok(n) = s.parse::<i64>() {
        return json!(n);
    }
    // Try float
    if let Ok(n) = s.parse::<f64>() {
        return json!(n);
    }
    // Booleans
    if s == "true" {
        return json!(true);
    }
    if s == "false" {
        return json!(false);
    }
    // String (already had quotes stripped)
    json!(s)
}

/// Parse session mutation from line like "session.counter += 1" or "session.name = value"
fn parse_session_mutation(line: &str) -> Option<SessionMutation> {
    // Remove "session." prefix
    let rest = line.strip_prefix("session.")?;

    // Check for array operations: key.pushmax(N, value), key.push(value), key.unshift(value), key.clear()
    // pushmax must be checked before push since ".push(" is a prefix of ".pushmax("
    if let Some(idx) = rest.find(".pushmax(") {
        let key = rest[..idx].trim().to_string();
        let value_start = idx + 9; // len of ".pushmax("
        let value_end = rest.rfind(')')?;
        let inner = rest[value_start..value_end].trim();
        // Parse "N, value" — first arg is max size, second is the value
        if let Some(comma) = inner.find(',') {
            let max_str = inner[..comma].trim();
            let (value_str, was_quoted) = strip_symmetric_quotes(inner[comma + 1..].trim());
            if let Ok(max) = max_str.parse::<usize>() {
                let value = parse_mutation_value(value_str, was_quoted);
                return Some(SessionMutation::PushMax { key, max, value });
            }
        }
    }

    if let Some(idx) = rest.find(".push(") {
        let key = rest[..idx].trim().to_string();
        let value_start = idx + 6; // len of ".push("
        let value_end = rest.rfind(')')?;
        let (value_str, was_quoted) = strip_symmetric_quotes(rest[value_start..value_end].trim());
        let value = parse_mutation_value(value_str, was_quoted);
        return Some(SessionMutation::Push { key, value });
    }

    if let Some(idx) = rest.find(".unshift(") {
        let key = rest[..idx].trim().to_string();
        let value_start = idx + 9; // len of ".unshift("
        let value_end = rest.rfind(')')?;
        let (value_str, was_quoted) = strip_symmetric_quotes(rest[value_start..value_end].trim());
        let value = parse_mutation_value(value_str, was_quoted);
        return Some(SessionMutation::Unshift { key, value });
    }

    if let Some(idx) = rest.find(".clear()") {
        let key = rest[..idx].trim().to_string();
        return Some(SessionMutation::Clear { key });
    }

    // Check for increment: key += value
    if let Some(idx) = rest.find("+=") {
        let key = rest[..idx].trim().to_string();
        let value_str = rest[idx + 2..].trim();
        let value: i64 = value_str.parse().ok()?;
        return Some(SessionMutation::Increment { key, value });
    }

    // Check for decrement: key -= value (convert to negative increment)
    if let Some(idx) = rest.find("-=") {
        let key = rest[..idx].trim().to_string();
        let value_str = rest[idx + 2..].trim();
        let value: i64 = value_str.parse().ok()?;
        return Some(SessionMutation::Increment { key, value: -value });
    }

    // Check for assignment: key = value
    if let Some(idx) = rest.find('=') {
        let key = rest[..idx].trim().to_string();
        let (value_str, was_quoted) = strip_symmetric_quotes(rest[idx + 1..].trim());
        let value = parse_mutation_value(value_str, was_quoted);
        return Some(SessionMutation::Set { key, value });
    }

    None
}

/// Parse a mutation value — quoting forces string type, unquoted values are
/// type-inferred (`session.zip = "01234"` stays "01234"; `session.count = 42`
/// is a number).
fn parse_mutation_value(value_str: &str, was_quoted: bool) -> Value {
    if was_quoted {
        json!(value_str)
    } else {
        parse_value_str(value_str)
    }
}

/// Parse a value string into a JSON Value
fn parse_value_str(value_str: &str) -> Value {
    // Check for empty array
    if value_str == "[]" {
        return json!([]);
    }
    // Try to parse as number first, then boolean, then string
    if let Ok(n) = value_str.parse::<i64>() {
        json!(n)
    } else if let Ok(f) = value_str.parse::<f64>() {
        json!(f)
    } else if value_str == "true" {
        json!(true)
    } else if value_str == "false" {
        json!(false)
    } else {
        json!(value_str)
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_parse_attributes() {
        let attrs = parse_attributes(r#"title="Hello" size="large""#);
        assert_eq!(attrs.get("title"), Some(&"Hello".to_string()));
        assert_eq!(attrs.get("size"), Some(&"large".to_string()));
    }

    #[test]
    fn test_replace_variables() {
        let mut context = HashMap::new();
        context.insert("name".to_string(), serde_json::json!("World"));

        let result = replace_variables("Hello #name#!", &context);
        assert_eq!(result, "Hello World!");
    }

    #[test]
    fn test_nested_variables() {
        let mut context = HashMap::new();
        context.insert(
            "user".to_string(),
            serde_json::json!({
                "name": "Alice",
                "email": "alice@example.com"
            }),
        );

        let result = replace_variables("#user.name# (#user.email#)", &context);
        assert_eq!(result, "Alice (alice@example.com)");
    }

    #[test]
    fn test_resolved_value_hashes_are_neutralized() {
        // A data value that looks like a template token must NOT survive as a
        // live token — otherwise a later render pass re-resolves it (second-order
        // template injection). See escape_and_neutralize_hashes.
        let mut context = HashMap::new();
        context.insert(
            "bio".to_string(),
            serde_json::json!("#env.SECRET# and #other|raw#"),
        );
        let result = replace_variables("<p>#bio#</p>", &context);
        // The '#' characters are emitted as &num; entities (render as '#' in the
        // browser) so VAR_REGEX cannot match them on a subsequent pass.
        assert_eq!(result, "<p>&num;env.SECRET&num; and &num;other|raw&num;</p>");
        assert!(!result.contains("#env.SECRET#"));
    }

    #[test]
    fn test_unresolved_token_preserved_verbatim() {
        // Strict not-found passthrough keeps the author's literal #unknown# token.
        let context = HashMap::new();
        let result = replace_variables("<p>#unknown_var#</p>", &context);
        assert_eq!(result, "<p>#unknown_var#</p>");
    }

    #[test]
    fn test_reactive_resolved_value_hashes_neutralized() {
        // The reactive render path (used for live pages) must also neutralize '#'
        // in resolved data so a session/data value like "#env.SECRET#" cannot be
        // re-resolved on a later pass. Covers the non-reactive var branch...
        let mut context = HashMap::new();
        context.insert("bio".to_string(), serde_json::json!("#env.SECRET#"));
        let out = replace_variables_reactive("<p>#bio#</p>", &context).html;
        assert!(!out.contains("#env.SECRET#"), "reactive path leaked a live token: {out}");
        assert!(out.contains("&num;env.SECRET&num;"));

        // ...and the reactive <span w-bind> text branch for a session value.
        let mut ctx2 = HashMap::new();
        ctx2.insert(
            "session".to_string(),
            serde_json::json!({ "note": "x #env.SECRET# y" }),
        );
        let out2 = replace_variables_reactive("<p>#session.note#</p>", &ctx2).html;
        assert!(!out2.contains("#env.SECRET#"), "reactive span leaked a live token: {out2}");

        // Strict not-found token still preserved verbatim on the reactive path.
        let empty = HashMap::new();
        let out3 = replace_variables_reactive("<p>#nope#</p>", &empty).html;
        assert_eq!(out3, "<p>#nope#</p>");
    }

    #[test]
    fn test_env_variables() {
        // Set a test environment variable
        unsafe {
            std::env::set_var("WHAT_TEST_VAR", "test_value");
        }

        let context = HashMap::new();
        let result = replace_variables("Value: #env.WHAT_TEST_VAR#", &context);
        assert_eq!(result, "Value: test_value");

        // Clean up
        unsafe {
            std::env::remove_var("WHAT_TEST_VAR");
        }
    }

    #[test]
    fn test_env_variable_not_found() {
        let context = HashMap::new();
        let result = replace_variables("#env.NONEXISTENT_VAR_12345#", &context);
        assert_eq!(result, ""); // Returns empty string for missing env vars
    }

    #[test]
    fn test_page_directives_self_closing() {
        let content = r#"<what protected roles="admin,editor" />
<!DOCTYPE html>
<html>
<body>Hello</body>
</html>"#;

        let (directives, cleaned) = parse_page_directives(content);

        assert!(directives.protected);
        assert_eq!(directives.roles, vec!["admin", "editor"]);
        assert!(cleaned.contains("<!DOCTYPE html>"));
        assert!(!cleaned.contains("<what"));
    }

    #[test]
    fn test_page_directives_boolean() {
        let content = r#"<what protected exclude />
<html></html>"#;

        let (directives, cleaned) = parse_page_directives(content);

        assert!(directives.protected);
        assert!(directives.exclude);
        assert!(!cleaned.contains("<what"));
    }

    #[test]
    fn test_page_directives_content_syntax() {
        let content = r#"<what>
protected
roles: admin, manager
title: Admin Dashboard
</what>
<!DOCTYPE html>
<html></html>"#;

        let (directives, cleaned) = parse_page_directives(content);

        assert!(directives.protected);
        assert_eq!(directives.roles, vec!["admin", "manager"]);
        assert_eq!(directives.title, Some("Admin Dashboard".to_string()));
        assert!(cleaned.contains("<!DOCTYPE html>"));
    }

    #[test]
    fn test_page_directives_roles_imply_protected() {
        let content = r#"<what roles="admin" />
<html></html>"#;

        let (directives, _) = parse_page_directives(content);

        assert!(directives.protected); // Implied by roles
        assert_eq!(directives.roles, vec!["admin"]);
    }

    #[test]
    fn test_no_directives() {
        let content = r#"<!DOCTYPE html>
<html><body>Hello</body></html>"#;

        let (directives, cleaned) = parse_page_directives(content);

        assert!(!directives.protected);
        assert!(directives.roles.is_empty());
        assert_eq!(content, cleaned);
    }

    #[test]
    fn test_page_tag_preserved() {
        // Ensure parse_page_directives doesn't touch <page> tags
        let content = r#"<page title="Test">
  <what-nav active="home"/>
  <main>Content</main>
</page>"#;

        let (_, cleaned) = parse_page_directives(content);
        println!("Cleaned content: '{}'", cleaned);

        assert!(cleaned.contains("<page"), "Should preserve <page> tag");
        assert!(cleaned.contains("</page>"), "Should preserve </page> tag");
        assert!(
            cleaned.contains("<what-nav"),
            "Should preserve <what-nav> tag"
        );
        assert_eq!(content, cleaned, "Content should be unchanged");
    }

    #[test]
    fn test_auth_all() {
        let content = r#"<what auth="all" />
<html></html>"#;

        let (directives, _) = parse_page_directives(content);

        assert_eq!(directives.auth, AuthLevel::All);
        assert!(!directives.requires_auth());
    }

    #[test]
    fn test_auth_user() {
        let content = r#"<what auth="user" />
<html></html>"#;

        let (directives, _) = parse_page_directives(content);

        assert_eq!(directives.auth, AuthLevel::User);
        assert!(directives.requires_auth());
        assert!(directives.check_access(true, &[]));
        assert!(!directives.check_access(false, &[]));
    }

    #[test]
    fn test_auth_roles() {
        let content = r#"<what auth="admin, editor" />
<html></html>"#;

        let (directives, _) = parse_page_directives(content);

        assert_eq!(
            directives.auth,
            AuthLevel::Roles(vec!["admin".to_string(), "editor".to_string()])
        );
        assert!(directives.requires_auth());

        // Has admin role
        assert!(directives.check_access(true, &["admin".to_string()]));
        // Has editor role
        assert!(directives.check_access(true, &["editor".to_string()]));
        // Has neither role
        assert!(!directives.check_access(true, &["viewer".to_string()]));
        // Not authenticated
        assert!(!directives.check_access(false, &["admin".to_string()]));
    }

    #[test]
    fn test_auth_content_syntax() {
        let content = r#"<what>
auth: admin, manager
title: Dashboard
</what>
<html></html>"#;

        let (directives, _) = parse_page_directives(content);

        assert_eq!(
            directives.auth,
            AuthLevel::Roles(vec!["admin".to_string(), "manager".to_string()])
        );
        assert_eq!(directives.title, Some("Dashboard".to_string()));
    }

    #[test]
    fn test_auth_public_aliases() {
        // Test "public" alias
        let (d1, _) = parse_page_directives(r#"<what auth="public" /><html></html>"#);
        assert_eq!(d1.auth, AuthLevel::All);

        // Test "none" alias
        let (d2, _) = parse_page_directives(r#"<what auth="none" /><html></html>"#);
        assert_eq!(d2.auth, AuthLevel::All);

        // Test "authenticated" alias
        let (d3, _) = parse_page_directives(r#"<what auth="authenticated" /><html></html>"#);
        assert_eq!(d3.auth, AuthLevel::User);
    }

    // =========================================================================
    // Fetch Directive Parsing Tests
    // =========================================================================

    #[test]
    fn test_fetch_directive_url_with_equals() {
        let content = r#"<what>
title: Remote Data
fetch.dog_facts = "https://dogapi.dog/api/v2/facts?limit=3"
</what>
<html></html>"#;

        let (directives, _) = parse_page_directives(content);

        assert_eq!(directives.title, Some("Remote Data".to_string()));
        assert_eq!(
            directives.custom.get("fetch.dog_facts"),
            Some(&"https://dogapi.dog/api/v2/facts?limit=3".to_string()),
            "fetch URL should be parsed correctly with = delimiter"
        );
    }

    #[test]
    fn test_fetch_directive_url_with_multiple_equals() {
        // URLs with query params containing = signs
        let content = r#"<what>
fetch.dog_breeds = "https://dogapi.dog/api/v2/breeds?page[number]=1&page[size]=6"
</what>
<html></html>"#;

        let (directives, _) = parse_page_directives(content);

        assert_eq!(
            directives.custom.get("fetch.dog_breeds"),
            Some(&"https://dogapi.dog/api/v2/breeds?page[number]=1&page[size]=6".to_string()),
            "URL with multiple = in query params should be preserved"
        );
    }

    #[test]
    fn test_fetch_directive_full_remote_data_page() {
        // Exact <what> block from remote-data.html
        let content = r#"<what>
title: Remote Data
page: remote-data
fetch.dog_facts = "https://dogapi.dog/api/v2/facts?limit=3"
fetch.dog_breeds = "https://dogapi.dog/api/v2/breeds?page[number]=1&page[size]=6"
fetch.dog_images = "https://dog.ceo/api/breeds/image/random/4"
</what>
<html></html>"#;

        let (directives, cleaned) = parse_page_directives(content);

        assert_eq!(directives.title, Some("Remote Data".to_string()));
        assert_eq!(directives.vars.get("page"), Some(&json!("remote-data")));
        assert_eq!(
            directives.custom.get("fetch.dog_facts"),
            Some(&"https://dogapi.dog/api/v2/facts?limit=3".to_string())
        );
        assert_eq!(
            directives.custom.get("fetch.dog_breeds"),
            Some(&"https://dogapi.dog/api/v2/breeds?page[number]=1&page[size]=6".to_string())
        );
        assert_eq!(
            directives.custom.get("fetch.dog_images"),
            Some(&"https://dog.ceo/api/breeds/image/random/4".to_string())
        );
        assert!(!cleaned.contains("<what>"));
    }

    // =========================================================================
    // Section Header Tests
    // =========================================================================

    #[test]
    fn test_section_header_fetch() {
        let content = r##"<what>
title: Dashboard
[fetch.weather]
url = "https://api.weather.com/current"
method = "GET"
headers = "Authorization: Bearer abc123"
path = "data.current"
limit = 5
</what>
<html></html>"##;

        let (directives, _) = parse_page_directives(content);
        assert_eq!(directives.title, Some("Dashboard".to_string()));
        assert_eq!(
            directives.custom.get("fetch.weather.url"),
            Some(&"https://api.weather.com/current".to_string())
        );
        assert_eq!(
            directives.custom.get("fetch.weather.method"),
            Some(&"GET".to_string())
        );
        assert_eq!(
            directives.custom.get("fetch.weather.headers"),
            Some(&"Authorization: Bearer abc123".to_string())
        );
        assert_eq!(
            directives.custom.get("fetch.weather.path"),
            Some(&"data.current".to_string())
        );
        assert_eq!(
            directives.custom.get("fetch.weather.limit"),
            Some(&"5".to_string())
        );
    }

    #[test]
    fn test_section_header_og() {
        let content = r##"<what>
[og]
title: My Dashboard
description: Real-time weather data
image: /images/dashboard-og.png
</what>
<html></html>"##;

        let (directives, _) = parse_page_directives(content);
        assert_eq!(
            directives.vars.get("og.title"),
            Some(&json!("My Dashboard"))
        );
        assert_eq!(
            directives.vars.get("og.description"),
            Some(&json!("Real-time weather data"))
        );
        assert_eq!(
            directives.vars.get("og.image"),
            Some(&json!("/images/dashboard-og.png"))
        );
    }

    #[test]
    fn test_section_header_session() {
        let content = r##"<what>
[session]
visit_count += 1
theme = "dark"
</what>
<html></html>"##;

        let (directives, _) = parse_page_directives(content);
        assert_eq!(directives.session_mutations.len(), 2);
    }

    #[test]
    fn test_section_header_compute() {
        let content = r##"<what>
[compute]
greeting = "Hello, #user.full_name#!"
</what>
<html></html>"##;

        let (directives, _) = parse_page_directives(content);
        assert_eq!(directives.computed.len(), 1);
        assert_eq!(directives.computed[0].0, "greeting");
        assert_eq!(directives.computed[0].1, "Hello, #user.full_name#!");
    }

    #[test]
    fn test_section_header_reset() {
        let content = r##"<what>
[fetch.weather]
url = "https://api.weather.com/current"

[]
session.visit_count += 1
compute.greeting = "Hello!"
</what>
<html></html>"##;

        let (directives, _) = parse_page_directives(content);
        assert_eq!(
            directives.custom.get("fetch.weather.url"),
            Some(&"https://api.weather.com/current".to_string())
        );
        assert_eq!(directives.session_mutations.len(), 1);
        assert_eq!(directives.computed.len(), 1);
    }

    #[test]
    fn test_section_header_mixed() {
        // Flat syntax and section syntax in the same block
        let content = r##"<what>
title: Dashboard
auth: user
fetch.legacy = "https://old-api.com/data"

[fetch.weather]
url = "https://api.weather.com/current"
method = "POST"

[]
session.count += 1
</what>
<html></html>"##;

        let (directives, _) = parse_page_directives(content);
        assert_eq!(directives.title, Some("Dashboard".to_string()));
        assert_eq!(
            directives.custom.get("fetch.legacy"),
            Some(&"https://old-api.com/data".to_string())
        );
        assert_eq!(
            directives.custom.get("fetch.weather.url"),
            Some(&"https://api.weather.com/current".to_string())
        );
        assert_eq!(
            directives.custom.get("fetch.weather.method"),
            Some(&"POST".to_string())
        );
        assert_eq!(directives.session_mutations.len(), 1);
    }

    #[test]
    fn test_section_header_multiple_fetch() {
        let content = r##"<what>
[fetch.weather]
url = "https://api.weather.com/current"
path = "data.current"

[fetch.news]
url = "https://api.news.com/latest"
path = "articles"
limit = 10
</what>
<html></html>"##;

        let (directives, _) = parse_page_directives(content);
        assert_eq!(
            directives.custom.get("fetch.weather.url"),
            Some(&"https://api.weather.com/current".to_string())
        );
        assert_eq!(
            directives.custom.get("fetch.weather.path"),
            Some(&"data.current".to_string())
        );
        assert_eq!(
            directives.custom.get("fetch.news.url"),
            Some(&"https://api.news.com/latest".to_string())
        );
        assert_eq!(
            directives.custom.get("fetch.news.path"),
            Some(&"articles".to_string())
        );
        assert_eq!(
            directives.custom.get("fetch.news.limit"),
            Some(&"10".to_string())
        );
    }

    #[test]
    fn test_section_header_backward_compat() {
        // Old flat syntax must still work identically
        let content = r##"<what>
title: Remote Data
fetch.dogs = "https://dogapi.dog/api/v2/facts?limit=3"
fetch.dogs.path = "data"
session.count += 1
compute.greeting = "Hello!"
og.title: My Page
</what>
<html></html>"##;

        let (directives, _) = parse_page_directives(content);
        assert_eq!(directives.title, Some("Remote Data".to_string()));
        assert_eq!(
            directives.custom.get("fetch.dogs"),
            Some(&"https://dogapi.dog/api/v2/facts?limit=3".to_string())
        );
        assert_eq!(
            directives.custom.get("fetch.dogs.path"),
            Some(&"data".to_string())
        );
        assert_eq!(directives.session_mutations.len(), 1);
        assert_eq!(directives.computed.len(), 1);
        assert_eq!(directives.vars.get("og.title"), Some(&json!("My Page")));
    }

    // =========================================================================
    // Inline Variable Tests
    // =========================================================================

    #[test]
    fn inline_var_string() {
        let content = r#"<what>
title = "My Page"
subtitle = "Welcome"
</what>
<html></html>"#;
        let (directives, _) = parse_page_directives(content);
        // title is a reserved directive
        assert_eq!(directives.title, Some("My Page".to_string()));
        // subtitle is an inline variable
        assert_eq!(directives.vars.get("subtitle"), Some(&json!("Welcome")));
    }

    #[test]
    fn inline_var_number() {
        let content = r#"<what>
count = 42
price = 9.99
</what>
<html></html>"#;
        let (directives, _) = parse_page_directives(content);
        assert_eq!(directives.vars.get("count"), Some(&json!(42)));
        assert_eq!(directives.vars.get("price"), Some(&json!(9.99)));
    }

    #[test]
    fn inline_var_boolean() {
        let content = r#"<what>
show_banner = true
debug = false
</what>
<html></html>"#;
        let (directives, _) = parse_page_directives(content);
        assert_eq!(directives.vars.get("show_banner"), Some(&json!(true)));
        assert_eq!(directives.vars.get("debug"), Some(&json!(false)));
    }

    #[test]
    fn inline_var_single_line_array() {
        let content = r#"<what>
colors = ["red", "green", "blue"]
</what>
<html></html>"#;
        let (directives, _) = parse_page_directives(content);
        assert_eq!(
            directives.vars.get("colors"),
            Some(&json!(["red", "green", "blue"]))
        );
    }

    #[test]
    fn inline_var_multi_line_array() {
        let content = r##"<what>
products = [
  { "name": "Widget", "price": 9.99 },
  { "name": "Gadget", "price": 24.99 }
]
</what>
<html></html>"##;
        let (directives, _) = parse_page_directives(content);
        let products = directives.vars.get("products").unwrap();
        assert!(products.is_array());
        assert_eq!(products.as_array().unwrap().len(), 2);
        assert_eq!(products[0]["name"], json!("Widget"));
        assert_eq!(products[1]["price"], json!(24.99));
    }

    #[test]
    fn inline_var_multi_line_object() {
        let content = r##"<what>
config = {
  "theme": "dark",
  "sidebar": true
}
</what>
<html></html>"##;
        let (directives, _) = parse_page_directives(content);
        let config = directives.vars.get("config").unwrap();
        assert!(config.is_object());
        assert_eq!(config["theme"], json!("dark"));
        assert_eq!(config["sidebar"], json!(true));
    }

    #[test]
    fn inline_var_relaxed_json_unquoted_keys() {
        let content = r##"<what>
products = [
  { name: "Widget", price: 9.99 },
  { name: "Gadget", price: 24.99 }
]
</what>
<html></html>"##;
        let (directives, _) = parse_page_directives(content);
        let products = directives.vars.get("products").unwrap();
        assert!(products.is_array());
        assert_eq!(products[0]["name"], json!("Widget"));
        assert_eq!(products[1]["price"], json!(24.99));
    }

    #[test]
    fn inline_var_relaxed_json_single_line() {
        let content = r##"<what>
item = { name: "Widget", price: 9.99 }
</what>
<html></html>"##;
        let (directives, _) = parse_page_directives(content);
        let item = directives.vars.get("item").unwrap();
        assert_eq!(item["name"], json!("Widget"));
        assert_eq!(item["price"], json!(9.99));
    }

    #[test]
    fn inline_var_does_not_affect_reserved() {
        let content = r#"<what>
auth = user
layout = main.html
fetch.api = "https://example.com"
my_var = "hello"
</what>
<html></html>"#;
        let (directives, _) = parse_page_directives(content);
        // Reserved directives work normally
        assert!(directives.requires_auth());
        assert_eq!(directives.layout, Some("main.html".to_string()));
        assert_eq!(
            directives.custom.get("fetch.api"),
            Some(&"https://example.com".to_string())
        );
        // Non-reserved goes to vars
        assert_eq!(directives.vars.get("my_var"), Some(&json!("hello")));
        // Reserved keys NOT in vars
        assert!(directives.vars.get("auth").is_none());
        assert!(directives.vars.get("layout").is_none());
    }

    #[test]
    fn inline_var_mixed_with_directives() {
        let content = r##"<what>
title = "Dashboard"
items_per_page = 25
nav_items = ["Home", "About", "Contact"]
fetch.data = "https://api.example.com/data"
compute.greeting = "Hello #user.name#!"
</what>
<html></html>"##;
        let (directives, _) = parse_page_directives(content);
        assert_eq!(directives.title, Some("Dashboard".to_string()));
        assert_eq!(directives.vars.get("items_per_page"), Some(&json!(25)));
        assert_eq!(
            directives.vars.get("nav_items"),
            Some(&json!(["Home", "About", "Contact"]))
        );
        assert_eq!(
            directives.custom.get("fetch.data"),
            Some(&"https://api.example.com/data".to_string())
        );
        assert_eq!(directives.computed.len(), 1);
    }

    // =========================================================================
    // Named Mutation Block Tests
    // =========================================================================

    #[test]
    fn mutation_stored_as_custom_string() {
        let content = r#"<what>
mutation.reset = "session.score = 0; session.lives = 3"
</what>
<html></html>"#;
        let (directives, _) = parse_page_directives(content);
        assert_eq!(
            directives.custom.get("mutation.reset"),
            Some(&"session.score = 0; session.lives = 3".to_string())
        );
        // Should NOT be in vars (not JSON-parsed)
        assert!(directives.vars.get("mutation.reset").is_none());
    }

    #[test]
    fn mutation_not_parsed_as_inline_var() {
        let content = r#"<what>
mutation.toggle = "session.dark_mode = 1"
my_var = 42
</what>
<html></html>"#;
        let (directives, _) = parse_page_directives(content);
        // mutation goes to custom, my_var goes to vars
        assert!(directives.custom.contains_key("mutation.toggle"));
        assert_eq!(directives.vars.get("my_var"), Some(&json!(42)));
    }

    // =========================================================================
    // .what File Parser Tests
    // =========================================================================

    #[test]
    fn test_what_file_strings() {
        let content = r#"
title = "My Application"
description = 'Single quotes work too'
bare_string = unquoted
"#;
        let config = parse_what_file(content);

        assert_eq!(config.get_string("title"), Some("My Application"));
        assert_eq!(
            config.get_string("description"),
            Some("Single quotes work too")
        );
        assert_eq!(config.get_string("bare_string"), Some("unquoted"));
    }

    #[test]
    fn test_what_file_numbers() {
        let content = r#"
port = 8080
version = 1.5
negative = -42
"#;
        let config = parse_what_file(content);

        assert_eq!(config.get_number("port"), Some(8080.0));
        assert_eq!(config.get_number("version"), Some(1.5));
        assert_eq!(config.get_number("negative"), Some(-42.0));
    }

    #[test]
    fn test_what_file_booleans() {
        let content = r#"
debug = true
production = false
"#;
        let config = parse_what_file(content);

        assert_eq!(config.get_bool("debug"), Some(true));
        assert_eq!(config.get_bool("production"), Some(false));
    }

    #[test]
    fn test_what_file_arrays() {
        let content = r#"
nav_items = ["Home", "About", "Contact"]
numbers = [1, 2, 3]
mixed = ["a", 1, true]
empty = []
"#;
        let config = parse_what_file(content);

        let nav = config.get_array("nav_items").unwrap();
        assert_eq!(nav.len(), 3);
        assert_eq!(nav[0].as_str(), Some("Home"));

        let nums = config.get_array("numbers").unwrap();
        assert_eq!(nums.len(), 3);
        assert_eq!(nums[0].as_i64(), Some(1));

        let empty = config.get_array("empty").unwrap();
        assert!(empty.is_empty());
    }

    #[test]
    fn test_what_file_comments() {
        let content = r#"
// This is a comment
title = "Hello"
# This is also a comment
name = "World"
"#;
        let config = parse_what_file(content);

        assert_eq!(config.get_string("title"), Some("Hello"));
        assert_eq!(config.get_string("name"), Some("World"));
        // Comments should not appear as values
        assert!(config.values.len() == 2);
    }

    #[test]
    fn test_what_file_auth_directive() {
        let content = r#"
auth = "admin"
title = "Dashboard"
"#;
        let config = parse_what_file(content);

        assert_eq!(
            config.directives.auth,
            AuthLevel::Roles(vec!["admin".to_string()])
        );
        assert_eq!(config.directives.title, Some("Dashboard".to_string()));
    }

    #[test]
    fn test_what_file_auth_all() {
        let content = r#"
auth = "all"
"#;
        let config = parse_what_file(content);

        assert_eq!(config.directives.auth, AuthLevel::All);
        assert!(!config.directives.requires_auth());
    }

    #[test]
    fn test_what_file_roles_array() {
        let content = r#"
roles = ["admin", "editor"]
"#;
        let config = parse_what_file(content);

        assert_eq!(config.directives.roles, vec!["admin", "editor"]);
        assert!(config.directives.protected);
    }

    #[test]
    fn test_what_config_merge() {
        let content1 = r#"
title = "Parent"
theme = "light"
auth = "all"
"#;
        let content2 = r#"
title = "Child"
nav = ["Home"]
auth = "admin"
"#;
        let mut config1 = parse_what_file(content1);
        let config2 = parse_what_file(content2);

        config1.merge(&config2);

        // Child overrides parent
        assert_eq!(config1.get_string("title"), Some("Child"));
        // Parent value preserved
        assert_eq!(config1.get_string("theme"), Some("light"));
        // Child adds new value
        assert!(config1.get_array("nav").is_some());
        // Auth from child takes precedence
        assert_eq!(
            config1.directives.auth,
            AuthLevel::Roles(vec!["admin".to_string()])
        );
    }

    // =========================================================================
    // Edge Case Tests
    // =========================================================================

    #[test]
    fn test_auth_level_edge_cases() {
        // Empty string should be All
        assert_eq!(parse_auth_level(""), AuthLevel::All);

        // Whitespace-only should be All
        assert_eq!(parse_auth_level("   "), AuthLevel::All);

        // Case insensitivity
        assert_eq!(parse_auth_level("ALL"), AuthLevel::All);
        assert_eq!(parse_auth_level("User"), AuthLevel::User);
        assert_eq!(
            parse_auth_level("ADMIN"),
            AuthLevel::Roles(vec!["admin".to_string()])
        );

        // Whitespace in roles
        assert_eq!(
            parse_auth_level("  admin  ,  editor  "),
            AuthLevel::Roles(vec!["admin".to_string(), "editor".to_string()])
        );

        // Single role
        assert_eq!(
            parse_auth_level("superuser"),
            AuthLevel::Roles(vec!["superuser".to_string()])
        );
    }

    #[test]
    fn test_page_directives_cache_ttl() {
        // Self-closing with cache attribute
        let content = r#"<what cache="3600" />
<html></html>"#;
        let (directives, _) = parse_page_directives(content);
        assert_eq!(directives.cache_ttl, Some(3600));

        // Content syntax with cache-ttl
        let content = r#"<what>
cache-ttl: 1800
</what>
<html></html>"#;
        let (directives, _) = parse_page_directives(content);
        assert_eq!(directives.cache_ttl, Some(1800));
    }

    #[test]
    fn test_page_directives_custom() {
        let content = r#"<what custom_field="my_value" another="test" />
<html></html>"#;
        let (directives, _) = parse_page_directives(content);

        assert_eq!(
            directives.custom.get("custom_field"),
            Some(&"my_value".to_string())
        );
        assert_eq!(directives.custom.get("another"), Some(&"test".to_string()));
    }

    #[test]
    fn test_page_directives_redirect() {
        let content = r#"<what redirect="/new-page" />
<html></html>"#;
        let (directives, _) = parse_page_directives(content);
        assert_eq!(directives.redirect, Some("/new-page".to_string()));
    }

    #[test]
    fn test_what_file_empty() {
        let content = "";
        let config = parse_what_file(content);
        assert!(config.values.is_empty());
        assert_eq!(config.directives.auth, AuthLevel::All);
    }

    #[test]
    fn test_what_file_only_comments() {
        let content = r#"
// This is a comment
# Another comment
// More comments
"#;
        let config = parse_what_file(content);
        assert!(config.values.is_empty());
    }

    #[test]
    fn test_what_file_data_application() {
        let content = r#"
data.application = ["posts", "products"]
"#;
        let config = parse_what_file(content);
        let names: Vec<&str> = config.data_application.iter().map(|d| d.name.as_str()).collect();
        assert_eq!(names, vec!["posts", "products"]);
        // Should not be exposed as template variable
        assert!(!config.values.contains_key("data.application"));
    }

    #[test]
    fn test_what_file_data_application_scoped() {
        let content = r#"
data.application = ["visits", "revenue [admin, editor]"]
"#;
        let config = parse_what_file(content);
        assert_eq!(config.data_application[0].name, "visits");
        assert!(matches!(config.data_application[0].scope, WiredScope::Public));
        assert_eq!(config.data_application[1].name, "revenue");
        match &config.data_application[1].scope {
            WiredScope::Roles(r) => assert_eq!(r, &vec!["admin".to_string(), "editor".to_string()]),
            other => panic!("expected Roles, got {other:?}"),
        }
    }

    #[test]
    fn test_what_file_data_session() {
        let content = r#"
data.session = ["cart", "wishlist"]
"#;
        let config = parse_what_file(content);
        assert_eq!(config.data_session, vec!["cart", "wishlist"]);
        // Should not be exposed as template variable
        assert!(!config.values.contains_key("data.session"));
    }

    #[test]
    fn test_what_file_data_single_value() {
        // Single string instead of array should still work
        let content = r#"
data.application = "posts"
data.session = "cart"
"#;
        let config = parse_what_file(content);
        assert_eq!(config.data_application.len(), 1);
        assert_eq!(config.data_application[0].name, "posts");
        assert_eq!(config.data_session, vec!["cart"]);
    }

    #[test]
    fn test_what_value_edge_cases() {
        // Empty array
        assert_eq!(parse_what_value("[]"), serde_json::json!([]));

        // Negative float
        assert_eq!(parse_what_value("-3.14"), serde_json::json!(-3.14));

        // Zero
        assert_eq!(parse_what_value("0"), serde_json::json!(0));

        // Very large number
        assert_eq!(
            parse_what_value("9999999999"),
            serde_json::json!(9999999999_i64)
        );
    }

    #[test]
    fn test_page_directives_mixed_syntax() {
        // Mix of boolean and key-value
        let content = r#"<what protected title="Dashboard" exclude />
<html></html>"#;
        let (directives, _) = parse_page_directives(content);

        assert!(directives.protected);
        assert!(directives.exclude);
        assert_eq!(directives.title, Some("Dashboard".to_string()));
    }

    #[test]
    fn test_is_standard_html_tag() {
        // Standard tags
        assert!(is_standard_html_tag("div"));
        assert!(is_standard_html_tag("span"));
        assert!(is_standard_html_tag("html"));
        assert!(is_standard_html_tag("body"));
        assert!(is_standard_html_tag("form"));
        assert!(is_standard_html_tag("input"));
        assert!(is_standard_html_tag("template"));
        assert!(is_standard_html_tag("slot"));

        // Custom tags
        assert!(!is_standard_html_tag("jumbo"));
        assert!(!is_standard_html_tag("card"));
        assert!(!is_standard_html_tag("my-component"));
        assert!(!is_standard_html_tag("loop"));
    }

    #[test]
    fn test_page_directives_requires_auth() {
        // auth: all should not require auth
        let mut d = PageDirectives::default();
        d.auth = AuthLevel::All;
        assert!(!d.requires_auth());

        // auth: user should require auth
        d.auth = AuthLevel::User;
        assert!(d.requires_auth());

        // auth: roles should require auth
        d.auth = AuthLevel::Roles(vec!["admin".to_string()]);
        assert!(d.requires_auth());

        // Legacy: protected = true should require auth even with auth: all
        d.auth = AuthLevel::All;
        d.protected = true;
        assert!(d.requires_auth());
    }

    #[test]
    fn test_page_directives_check_access_legacy() {
        // Test legacy protected + roles behavior
        let mut d = PageDirectives::default();
        d.protected = true;
        d.roles = vec!["admin".to_string(), "editor".to_string()];

        // Not authenticated - denied
        assert!(!d.check_access(false, &[]));

        // Authenticated without roles - denied
        assert!(!d.check_access(true, &[]));

        // Authenticated with wrong role - denied
        assert!(!d.check_access(true, &["viewer".to_string()]));

        // Authenticated with correct role - allowed
        assert!(d.check_access(true, &["admin".to_string()]));
        assert!(d.check_access(true, &["editor".to_string()]));
    }

    // =========================================================================
    // Layout System Tests
    // =========================================================================

    #[test]
    fn test_layout_in_what_file() {
        let content = r#"
layout = "sections/main.html"
title = "Test Page"
"#;
        let config = parse_what_file(content);

        assert_eq!(config.layout, Some("sections/main.html".to_string()));
        assert_eq!(
            config.directives.layout,
            Some("sections/main.html".to_string())
        );
        // Layout should not be exposed as a template variable
        assert!(config.get_string("layout").is_none());
    }

    #[test]
    fn test_layout_in_page_directive_attribute() {
        let content = r#"<what layout="sections/page.html" />
<h1>Hello</h1>"#;
        let (directives, cleaned) = parse_page_directives(content);

        assert_eq!(directives.layout, Some("sections/page.html".to_string()));
        assert!(cleaned.contains("<h1>Hello</h1>"));
        assert!(!cleaned.contains("<what"));
    }

    #[test]
    fn test_layout_in_page_directive_content() {
        let content = r#"<what>
layout: sections/admin.html
title: Dashboard
</what>
<h1>Admin Dashboard</h1>"#;
        let (directives, cleaned) = parse_page_directives(content);

        assert_eq!(directives.layout, Some("sections/admin.html".to_string()));
        assert_eq!(directives.title, Some("Dashboard".to_string()));
        assert!(cleaned.contains("<h1>Admin Dashboard</h1>"));
    }

    #[test]
    fn test_layout_none_disables() {
        // Page can use layout: none to disable inherited layout
        let content = r#"<what layout="none" />
<h1>No Layout</h1>"#;
        let (directives, _) = parse_page_directives(content);

        assert_eq!(directives.layout, Some("none".to_string()));
    }

    #[test]
    fn test_what_config_layout_merge() {
        let parent_content = r#"
layout = "sections/base.html"
title = "Parent"
"#;
        let child_content = r#"
layout = "sections/admin.html"
"#;
        let mut parent = parse_what_file(parent_content);
        let child = parse_what_file(child_content);

        parent.merge(&child);

        // Child layout overrides parent
        assert_eq!(parent.layout, Some("sections/admin.html".to_string()));
    }

    #[test]
    fn test_what_config_layout_inherit() {
        let parent_content = r#"
layout = "sections/base.html"
title = "Parent"
"#;
        let child_content = r#"
title = "Child"
"#;
        let mut parent = parse_what_file(parent_content);
        let child = parse_what_file(child_content);

        parent.merge(&child);

        // Parent layout is preserved when child doesn't set one
        assert_eq!(parent.layout, Some("sections/base.html".to_string()));
        assert_eq!(parent.get_string("title"), Some("Child"));
    }

    #[test]
    fn test_what_config_layout_none_override() {
        let parent_content = r#"
layout = "sections/base.html"
"#;
        let child_content = r#"
layout = "none"
"#;
        let mut parent = parse_what_file(parent_content);
        let child = parse_what_file(child_content);

        parent.merge(&child);

        // Child's "none" overrides parent layout
        assert_eq!(parent.layout, Some("none".to_string()));
    }

    // =========================================================================
    // Reactive Variable Replacement Tests
    // =========================================================================

    #[test]
    fn test_reactive_session_var_in_text() {
        let mut context = HashMap::new();
        context.insert(
            "session".to_string(),
            serde_json::json!({
                "count": 8
            }),
        );

        let template = "<p>Counter: #session.count#</p>";
        let result = replace_variables_reactive(template, &context);

        assert!(
            result
                .html
                .contains(r#"<span w-bind="session.count">8</span>"#)
        );
        assert!(result.session_keys.contains("count"));
    }

    #[test]
    fn test_reactive_session_var_in_attribute() {
        let mut context = HashMap::new();
        context.insert(
            "session".to_string(),
            serde_json::json!({
                "count": 8
            }),
        );

        // Session variable in attribute should NOT be wrapped
        let template = r##"<div title="#session.count#">Content</div>"##;
        let result = replace_variables_reactive(template, &context);

        // Should replace value but not wrap
        assert!(result.html.contains(r##"title="8""##));
        // Should NOT contain span with w-bind
        assert!(!result.html.contains("w-bind"));
        // But should still track the key
        assert!(result.session_keys.contains("count"));
    }

    #[test]
    fn test_reactive_non_session_var() {
        let mut context = HashMap::new();
        context.insert("name".to_string(), serde_json::json!("Alice"));

        let template = "<p>Hello #name#!</p>";
        let result = replace_variables_reactive(template, &context);

        // Non-session variables should be replaced without wrapping
        assert!(result.html.contains("Hello Alice!"));
        assert!(!result.html.contains("w-bind"));
        assert!(result.session_keys.is_empty());
    }

    #[test]
    fn test_reactive_multiple_session_vars() {
        let mut context = HashMap::new();
        context.insert(
            "session".to_string(),
            serde_json::json!({
                "count": 5,
                "name": "Test"
            }),
        );

        let template = "<p>Count: #session.count#, Name: #session.name#</p>";
        let result = replace_variables_reactive(template, &context);

        assert!(
            result
                .html
                .contains(r#"<span w-bind="session.count">5</span>"#)
        );
        assert!(
            result
                .html
                .contains(r#"<span w-bind="session.name">Test</span>"#)
        );
        assert!(result.session_keys.contains("count"));
        assert!(result.session_keys.contains("name"));
    }

    #[test]
    fn test_is_in_attribute_context() {
        // Text content cases (should return false)
        assert!(!is_in_attribute_context("<p>"));
        assert!(!is_in_attribute_context("<p>Hello "));
        assert!(!is_in_attribute_context("<div><span>"));

        // Attribute cases (should return true)
        assert!(is_in_attribute_context(r#"<div title=""#));
        assert!(is_in_attribute_context(r#"<div class="foo "#));
        assert!(is_in_attribute_context(r#"<input value=""#));

        // After closing attribute (should return false)
        assert!(!is_in_attribute_context(r#"<div title="test">"#));
        assert!(!is_in_attribute_context(r#"<div class="foo">Hello"#));
    }

    #[test]
    fn test_html_escape() {
        assert_eq!(html_escape("<"), "&lt;");
        assert_eq!(html_escape(">"), "&gt;");
        assert_eq!(html_escape("&"), "&amp;");
        assert_eq!(html_escape("\""), "&quot;");
        assert_eq!(html_escape("'"), "&#39;");
        assert_eq!(
            html_escape("<script>alert('xss')</script>"),
            "&lt;script&gt;alert(&#39;xss&#39;)&lt;/script&gt;"
        );
    }

    #[test]
    fn test_parse_session_mutation_push() {
        let m = parse_session_mutation("session.items.push(\"hello\")").unwrap();
        match m {
            SessionMutation::Push { key, value } => {
                assert_eq!(key, "items");
                assert_eq!(value, serde_json::json!("hello"));
            }
            _ => panic!("Expected Push"),
        }
    }

    #[test]
    fn test_parse_session_mutation_pushmax() {
        let m = parse_session_mutation("session.history.pushmax(5, \"page1\")").unwrap();
        match m {
            SessionMutation::PushMax { key, max, value } => {
                assert_eq!(key, "history");
                assert_eq!(max, 5);
                assert_eq!(value, serde_json::json!("page1"));
            }
            _ => panic!("Expected PushMax"),
        }
    }

    #[test]
    fn test_parse_session_mutation_pushmax_numeric() {
        let m = parse_session_mutation("session.ids.pushmax(10, 42)").unwrap();
        match m {
            SessionMutation::PushMax { key, max, value } => {
                assert_eq!(key, "ids");
                assert_eq!(max, 10);
                assert_eq!(value, serde_json::json!(42));
            }
            _ => panic!("Expected PushMax"),
        }
    }

    // =========================================================================
    // Auto-Escaping Tests
    // =========================================================================

    #[test]
    fn test_auto_escape_html_in_variables() {
        let mut context = HashMap::new();
        context.insert(
            "name".to_string(),
            serde_json::json!("<script>alert('xss')</script>"),
        );

        let result = replace_variables("Hello #name#!", &context);
        assert_eq!(
            result,
            "Hello &lt;script&gt;alert(&#39;xss&#39;)&lt;/script&gt;!"
        );
        assert!(!result.contains("<script>"));
    }

    #[test]
    fn test_auto_escape_ampersand() {
        let mut context = HashMap::new();
        context.insert("text".to_string(), serde_json::json!("Tom & Jerry"));

        let result = replace_variables("#text#", &context);
        assert_eq!(result, "Tom &amp; Jerry");
    }

    #[test]
    fn test_auto_escape_quotes() {
        let mut context = HashMap::new();
        context.insert("text".to_string(), serde_json::json!(r#"He said "hello""#));

        let result = replace_variables("#text#", &context);
        assert_eq!(result, "He said &quot;hello&quot;");
    }

    #[test]
    fn test_raw_filter_bypasses_escaping() {
        let mut context = HashMap::new();
        context.insert("html".to_string(), serde_json::json!("<b>bold</b>"));

        let result = replace_variables("#html|raw#", &context);
        assert_eq!(result, "<b>bold</b>");
    }

    #[test]
    fn test_raw_filter_with_default_value() {
        let mut context = HashMap::new();
        context.insert("html".to_string(), serde_json::json!("<em>yes</em>"));

        // |raw at end of filter chain
        let result = replace_variables("#html|raw#", &context);
        assert_eq!(result, "<em>yes</em>");
    }

    #[test]
    fn test_auto_escape_preserves_safe_text() {
        let mut context = HashMap::new();
        context.insert("name".to_string(), serde_json::json!("Alice"));

        let result = replace_variables("Hello #name#!", &context);
        assert_eq!(result, "Hello Alice!");
    }

    #[test]
    fn test_auto_escape_nested_variables() {
        let mut context = HashMap::new();
        context.insert(
            "user".to_string(),
            serde_json::json!({
                "name": "<b>Admin</b>",
                "bio": "Loves coding & testing"
            }),
        );

        let result = replace_variables("#user.name# - #user.bio#", &context);
        assert_eq!(
            result,
            "&lt;b&gt;Admin&lt;/b&gt; - Loves coding &amp; testing"
        );
    }

    #[test]
    fn test_auto_escape_with_default_filter() {
        let context = HashMap::new();

        // New syntax: |default:"value"
        let result = replace_variables(r##"#missing|default:"<fallback>"#"##, &context);
        assert_eq!(result, "&lt;fallback&gt;");
    }

    #[test]
    fn test_reactive_auto_escape_non_session_var() {
        let mut context = HashMap::new();
        context.insert(
            "name".to_string(),
            serde_json::json!("<script>xss</script>"),
        );

        let result = replace_variables_reactive("<p>#name#</p>", &context);
        assert!(result.html.contains("&lt;script&gt;xss&lt;/script&gt;"));
        assert!(!result.html.contains("<script>xss</script>"));
    }

    #[test]
    fn test_reactive_auto_escape_session_var_in_attribute() {
        let mut context = HashMap::new();
        context.insert(
            "session".to_string(),
            serde_json::json!({
                "name": "Tom & Jerry"
            }),
        );

        let template = r##"<div title="#session.name#">Content</div>"##;
        let result = replace_variables_reactive(template, &context);

        // Attribute should be escaped
        assert!(result.html.contains("Tom &amp; Jerry"));
        assert!(!result.html.contains("w-bind"));
    }

    #[test]
    fn test_reactive_raw_filter_non_session_var() {
        let mut context = HashMap::new();
        context.insert("html".to_string(), serde_json::json!("<b>bold</b>"));

        let result = replace_variables_reactive("<p>#html|raw#</p>", &context);
        assert!(result.html.contains("<b>bold</b>"));
    }

    #[test]
    fn test_reactive_session_var_always_escaped_in_span() {
        let mut context = HashMap::new();
        context.insert(
            "session".to_string(),
            serde_json::json!({
                "name": "<script>xss</script>"
            }),
        );

        let result = replace_variables_reactive("<p>#session.name#</p>", &context);
        // Session vars in text are always escaped inside the reactive span
        assert!(result.html.contains("&lt;script&gt;xss&lt;/script&gt;"));
        assert!(result.html.contains("w-bind"));
    }

    #[test]
    fn test_reactive_session_raw_in_attribute() {
        let mut context = HashMap::new();
        context.insert(
            "session".to_string(),
            serde_json::json!({
                "url": "/path?a=1&b=2"
            }),
        );

        // |raw in attribute context should skip escaping
        let template = r##"<a href="#session.url|raw#">Link</a>"##;
        let result = replace_variables_reactive(template, &context);
        assert!(result.html.contains(r#"href="/path?a=1&b=2""#));
    }

    #[test]
    fn test_auto_escape_number_values() {
        let mut context = HashMap::new();
        context.insert("count".to_string(), serde_json::json!(42));

        let result = replace_variables("Count: #count#", &context);
        assert_eq!(result, "Count: 42");
    }

    #[test]
    fn test_auto_escape_boolean_values() {
        let mut context = HashMap::new();
        context.insert("flag".to_string(), serde_json::json!(true));

        let result = replace_variables("Flag: #flag#", &context);
        assert_eq!(result, "Flag: true");
    }

    #[test]
    fn test_auto_escape_unresolved_variable() {
        let context = HashMap::new();
        // Unresolved variables stay as #var# — this should NOT be escaped
        // because the hash signs are part of the template syntax, not user data
        let result = replace_variables("#unknown#", &context);
        // The unresolved var format "#unknown#" gets escaped as-is
        assert_eq!(result, "#unknown#");
    }

    #[test]
    fn test_nested_var_on_empty_parent_resolves_empty() {
        let mut context = HashMap::new();
        // Parent object exists but child key is missing → empty, not literal
        context.insert("old".into(), serde_json::json!({}));
        let result = replace_variables("#old.title#", &context);
        assert_eq!(
            result, "",
            "Missing child on existing parent should be empty"
        );
    }

    #[test]
    fn test_nested_var_on_missing_root_stays_literal() {
        let context = HashMap::new();
        // Root key not in context at all → preserve literal for strict mode
        let result = replace_variables("#old.title#", &context);
        assert_eq!(result, "#old.title#", "Missing root should keep literal");
    }

    #[test]
    fn test_nested_var_on_populated_parent_resolves() {
        let mut context = HashMap::new();
        context.insert("user".into(), serde_json::json!({"name": "Alice"}));
        // Existing child → resolves normally
        assert_eq!(replace_variables("#user.name#", &context), "Alice");
        // Missing child on populated parent → empty
        assert_eq!(replace_variables("#user.role#", &context), "");
    }

    // =========================================================================
    // Filter System Tests
    // =========================================================================

    #[test]
    fn test_filter_parse_chain() {
        let (path, filters) = parse_filter_chain("name|uppercase");
        assert_eq!(path, "name");
        assert_eq!(filters.len(), 1);
        assert_eq!(filters[0].name, "uppercase");
        assert!(filters[0].args.is_empty());
    }

    #[test]
    fn test_filter_parse_with_arg() {
        let (path, filters) = parse_filter_chain("title|truncate:50");
        assert_eq!(path, "title");
        assert_eq!(filters.len(), 1);
        assert_eq!(filters[0].name, "truncate");
        assert_eq!(filters[0].args, vec!["50"]);
    }

    #[test]
    fn test_filter_parse_chained() {
        let (path, filters) = parse_filter_chain("title|truncate:50|uppercase");
        assert_eq!(path, "title");
        assert_eq!(filters.len(), 2);
        assert_eq!(filters[0].name, "truncate");
        assert_eq!(filters[1].name, "uppercase");
    }

    #[test]
    fn test_filter_parse_quoted_args() {
        let (path, filters) = parse_filter_chain(r#"name|default:"Anonymous""#);
        assert_eq!(path, "name");
        assert_eq!(filters.len(), 1);
        assert_eq!(filters[0].name, "default");
        assert_eq!(filters[0].args, vec!["Anonymous"]);
    }

    #[test]
    fn test_filter_parse_multiple_args() {
        let (path, filters) = parse_filter_chain(r#"text|replace:"old","new""#);
        assert_eq!(path, "text");
        assert_eq!(filters.len(), 1);
        assert_eq!(filters[0].name, "replace");
        assert_eq!(filters[0].args, vec!["old", "new"]);
    }

    #[test]
    fn test_filter_uppercase() {
        let mut ctx = HashMap::new();
        ctx.insert("name".to_string(), serde_json::json!("hello"));
        let result = replace_variables("#name|uppercase#", &ctx);
        assert_eq!(result, "HELLO");
    }

    #[test]
    fn test_filter_lowercase() {
        let mut ctx = HashMap::new();
        ctx.insert("name".to_string(), serde_json::json!("HELLO"));
        let result = replace_variables("#name|lowercase#", &ctx);
        assert_eq!(result, "hello");
    }

    #[test]
    fn test_filter_capitalize() {
        let mut ctx = HashMap::new();
        ctx.insert("name".to_string(), serde_json::json!("hello world"));
        let result = replace_variables("#name|capitalize#", &ctx);
        assert_eq!(result, "Hello world");
    }

    #[test]
    fn test_filter_title() {
        let mut ctx = HashMap::new();
        ctx.insert("name".to_string(), serde_json::json!("hello world today"));
        let result = replace_variables("#name|title#", &ctx);
        assert_eq!(result, "Hello World Today");
    }

    #[test]
    fn test_filter_truncate() {
        let mut ctx = HashMap::new();
        ctx.insert(
            "text".to_string(),
            serde_json::json!("This is a long text that should be truncated"),
        );
        let result = replace_variables("#text|truncate:10#", &ctx);
        assert_eq!(result, "This is a ...");
    }

    #[test]
    fn test_filter_truncate_short_text() {
        let mut ctx = HashMap::new();
        ctx.insert("text".to_string(), serde_json::json!("Short"));
        let result = replace_variables("#text|truncate:10#", &ctx);
        assert_eq!(result, "Short");
    }

    #[test]
    fn test_filter_count() {
        let mut ctx = HashMap::new();
        ctx.insert("text".to_string(), serde_json::json!("hello"));
        let result = replace_variables("#text|count#", &ctx);
        assert_eq!(result, "5");
    }

    #[test]
    fn test_filter_number() {
        let mut ctx = HashMap::new();
        ctx.insert("n".to_string(), serde_json::json!(1234567));
        let result = replace_variables("#n|number#", &ctx);
        assert_eq!(result, "1,234,567");
    }

    #[test]
    fn test_filter_currency_usd() {
        let mut ctx = HashMap::new();
        ctx.insert("price".to_string(), serde_json::json!(1299.99));
        let result = replace_variables(r##"#price|currency:"USD"#"##, &ctx);
        assert_eq!(result, "$1,299.99");
    }

    #[test]
    fn test_filter_currency_eur() {
        let mut ctx = HashMap::new();
        ctx.insert("price".to_string(), serde_json::json!(49.5));
        let result = replace_variables(r##"#price|currency:"EUR"#"##, &ctx);
        assert_eq!(result, "\u{20ac}49.50");
    }

    #[test]
    fn test_filter_date() {
        let mut ctx = HashMap::new();
        ctx.insert("d".to_string(), serde_json::json!("2025-03-15"));
        let result = replace_variables("#d|date#", &ctx);
        assert_eq!(result, "Mar 15, 2025"); // default = "medium" preset
    }

    #[test]
    fn test_filter_date_custom_format() {
        let mut ctx = HashMap::new();
        ctx.insert("d".to_string(), serde_json::json!("2025-03-15"));
        let result = replace_variables(r##"#d|date:"dd/mm/yyyy"#"##, &ctx);
        assert_eq!(result, "15/03/2025");
    }

    #[test]
    fn test_date_mask_short() {
        let mut ctx = HashMap::new();
        ctx.insert("d".to_string(), serde_json::json!("2025-03-05"));
        let result = replace_variables(r##"#d|date:"short"#"##, &ctx);
        assert_eq!(result, "3/5/25");
    }

    #[test]
    fn test_date_mask_full() {
        let mut ctx = HashMap::new();
        ctx.insert("d".to_string(), serde_json::json!("2025-03-15"));
        let result = replace_variables(r##"#d|date:"full"#"##, &ctx);
        assert_eq!(result, "Saturday, March 15, 2025");
    }

    #[test]
    fn test_date_mask_long() {
        let mut ctx = HashMap::new();
        ctx.insert("d".to_string(), serde_json::json!("2025-03-15"));
        let result = replace_variables(r##"#d|date:"long"#"##, &ctx);
        assert_eq!(result, "March 15, 2025");
    }

    #[test]
    fn test_date_mask_iso() {
        let mut ctx = HashMap::new();
        ctx.insert("d".to_string(), serde_json::json!("2025-03-05"));
        let result = replace_variables(r##"#d|date:"iso"#"##, &ctx);
        assert_eq!(result, "2025-03-05");
    }

    #[test]
    fn test_date_mask_time() {
        let mut ctx = HashMap::new();
        ctx.insert("d".to_string(), serde_json::json!("2025-03-15T14:05:09"));
        let result = replace_variables(r##"#d|date:"time"#"##, &ctx);
        assert_eq!(result, "2:05 PM");
    }

    #[test]
    fn test_date_mask_combined() {
        let mut ctx = HashMap::new();
        ctx.insert("d".to_string(), serde_json::json!("2025-03-15T14:30:00"));
        let result = replace_variables(r##"#d|date:"mmm d, yyyy h:nn tt"#"##, &ctx);
        assert_eq!(result, "Mar 15, 2025 2:30 PM");
    }

    #[test]
    fn test_date_mask_24hour() {
        let mut ctx = HashMap::new();
        ctx.insert("d".to_string(), serde_json::json!("2025-03-15T09:05:00"));
        let result = replace_variables(r##"#d|date:"HH:nn"#"##, &ctx);
        assert_eq!(result, "09:05");
    }

    #[test]
    fn test_date_mask_weekday() {
        let mut ctx = HashMap::new();
        ctx.insert("d".to_string(), serde_json::json!("2025-03-15"));
        let result = replace_variables(r##"#d|date:"ddd"#"##, &ctx);
        assert_eq!(result, "Sat");
    }

    #[test]
    fn test_date_mask_literals() {
        let mut ctx = HashMap::new();
        ctx.insert("d".to_string(), serde_json::json!("2025-03-15"));
        let result = replace_variables(r##"#d|date:"yyyy-mm-dd"#"##, &ctx);
        assert_eq!(result, "2025-03-15");
    }

    #[test]
    fn test_date_mask_midnight_12hr() {
        let mut ctx = HashMap::new();
        ctx.insert("d".to_string(), serde_json::json!("2025-03-15T00:00:00"));
        let result = replace_variables(r##"#d|date:"h:nn tt"#"##, &ctx);
        assert_eq!(result, "12:00 AM");
    }

    #[test]
    fn test_date_rfc3339_input() {
        let mut ctx = HashMap::new();
        ctx.insert("d".to_string(), serde_json::json!("2025-03-15T14:30:00Z"));
        let result = replace_variables(r##"#d|date:"mmm d"#"##, &ctx);
        assert_eq!(result, "Mar 15");
    }

    #[test]
    fn test_filter_json() {
        let mut ctx = HashMap::new();
        ctx.insert("name".to_string(), serde_json::json!("hello"));
        let result = replace_variables("#name|json#", &ctx);
        assert_eq!(result, "&quot;hello&quot;"); // Escaped because auto-escape
    }

    #[test]
    fn test_filter_json_raw() {
        let mut ctx = HashMap::new();
        ctx.insert("name".to_string(), serde_json::json!("hello"));
        let result = replace_variables("#name|json|raw#", &ctx);
        assert_eq!(result, "\"hello\""); // Not escaped because |raw
    }

    #[test]
    fn test_filter_markdown() {
        let mut ctx = HashMap::new();
        ctx.insert(
            "text".to_string(),
            serde_json::json!("This is **bold** and *italic*"),
        );
        let result = replace_variables("#text|markdown#", &ctx);
        assert!(result.contains("<strong>bold</strong>"));
        assert!(result.contains("<em>italic</em>"));
        // markdown is html_safe, so not escaped
        assert!(result.contains("<p>"));
    }

    #[test]
    fn test_markdown_url_scheme_allowlist() {
        // Safe schemes and relative URLs get an href
        assert!(markdown_url_is_safe("https://example.com"));
        assert!(markdown_url_is_safe("http://example.com"));
        assert!(markdown_url_is_safe("mailto:a@b.com"));
        assert!(markdown_url_is_safe("/relative/path"));
        assert!(markdown_url_is_safe("#anchor"));
        assert!(markdown_url_is_safe("page?x=1:2"));
        // Dangerous schemes are blocked — including control-char smuggling that
        // browsers would strip before evaluating the scheme.
        assert!(!markdown_url_is_safe("javascript:alert(1)"));
        assert!(!markdown_url_is_safe("JavaScript:alert(1)"));
        assert!(!markdown_url_is_safe("java\tscript:alert(1)"));
        assert!(!markdown_url_is_safe("java\nscript:alert(1)"));
        assert!(!markdown_url_is_safe("data:text/html,<script>"));
        assert!(!markdown_url_is_safe("vbscript:msgbox(1)"));

        // End-to-end through the filter: no href, no javascript
        let mut ctx = HashMap::new();
        ctx.insert(
            "t".to_string(),
            serde_json::json!("[x](java\tscript:alert(1))"),
        );
        let out = replace_variables("#t|markdown#", &ctx);
        assert!(!out.contains("href"), "dangerous URL emitted an href: {out}");
    }

    #[test]
    fn test_filter_pluralize() {
        let mut ctx = HashMap::new();
        ctx.insert("count".to_string(), serde_json::json!(1));
        let result = replace_variables(r##"#count# item#count|pluralize:"","s"#"##, &ctx);
        assert_eq!(result, "1 item");

        ctx.insert("count".to_string(), serde_json::json!(5));
        let result = replace_variables(r##"#count# item#count|pluralize:"","s"#"##, &ctx);
        assert_eq!(result, "5 items");
    }

    #[test]
    fn test_filter_default() {
        let ctx = HashMap::new();
        let result = replace_variables(r##"#missing|default:"N/A"#"##, &ctx);
        assert_eq!(result, "N/A");
    }

    #[test]
    fn test_filter_default_not_needed() {
        let mut ctx = HashMap::new();
        ctx.insert("name".to_string(), serde_json::json!("Alice"));
        let result = replace_variables(r##"#name|default:"N/A"#"##, &ctx);
        assert_eq!(result, "Alice");
    }

    #[test]
    fn test_filter_replace() {
        let mut ctx = HashMap::new();
        ctx.insert("text".to_string(), serde_json::json!("Hello World"));
        let result = replace_variables(r##"#text|replace:"World","Rust"#"##, &ctx);
        assert_eq!(result, "Hello Rust");
    }

    #[test]
    fn test_filter_slice() {
        let mut ctx = HashMap::new();
        ctx.insert("text".to_string(), serde_json::json!("Hello World"));
        let result = replace_variables("#text|slice:0,5#", &ctx);
        assert_eq!(result, "Hello");
    }

    #[test]
    fn test_filter_chaining() {
        let mut ctx = HashMap::new();
        ctx.insert("name".to_string(), serde_json::json!("hello world"));
        let result = replace_variables("#name|uppercase|truncate:5#", &ctx);
        assert_eq!(result, "HELLO...");
    }

    #[test]
    fn test_filter_chaining_with_escaping() {
        let mut ctx = HashMap::new();
        ctx.insert("text".to_string(), serde_json::json!("<b>hello</b>"));
        // Without |raw, output is escaped after filters
        let result = replace_variables("#text|uppercase#", &ctx);
        assert_eq!(result, "&lt;B&gt;HELLO&lt;/B&gt;");
    }

    #[test]
    fn test_filter_raw_bypasses_escaping() {
        let mut ctx = HashMap::new();
        ctx.insert("html".to_string(), serde_json::json!("<b>bold</b>"));
        let result = replace_variables("#html|raw#", &ctx);
        assert_eq!(result, "<b>bold</b>");
    }

    #[test]
    fn test_filter_in_reactive_mode() {
        let mut ctx = HashMap::new();
        ctx.insert("name".to_string(), serde_json::json!("hello"));
        let result = replace_variables_reactive("<p>#name|uppercase#</p>", &ctx);
        assert!(result.html.contains("HELLO"));
    }

    #[test]
    fn test_filter_default_with_session_var() {
        let ctx = HashMap::new();
        let result = replace_variables_reactive(r##"<p>#session.count|default:"0"#</p>"##, &ctx);
        // Session var not found, default filter triggers, wrapped in span
        assert!(result.html.contains("w-bind"));
        assert!(result.html.contains(">0<"));
    }

    #[test]
    fn test_filter_unknown_passes_through() {
        let mut ctx = HashMap::new();
        ctx.insert("name".to_string(), serde_json::json!("hello"));
        // Unknown filter should pass value through unchanged
        let result = replace_variables("#name|bogusfilter#", &ctx);
        assert_eq!(result, "hello");
    }

    #[test]
    fn test_filter_round() {
        let mut ctx = HashMap::new();
        ctx.insert("price".to_string(), json!("3.14159"));
        assert_eq!(replace_variables("#price|round:2#", &ctx), "3.14");
    }

    #[test]
    fn test_filter_round_no_args() {
        let mut ctx = HashMap::new();
        ctx.insert("val".to_string(), json!("3.7"));
        assert_eq!(replace_variables("#val|round#", &ctx), "4");
    }

    #[test]
    fn test_filter_ceil() {
        let mut ctx = HashMap::new();
        ctx.insert("val".to_string(), json!("3.2"));
        assert_eq!(replace_variables("#val|ceil#", &ctx), "4");
    }

    #[test]
    fn test_filter_floor() {
        let mut ctx = HashMap::new();
        ctx.insert("val".to_string(), json!("3.9"));
        assert_eq!(replace_variables("#val|floor#", &ctx), "3");
    }

    #[test]
    fn test_filter_ceil_negative() {
        let mut ctx = HashMap::new();
        ctx.insert("val".to_string(), json!("-2.3"));
        assert_eq!(replace_variables("#val|ceil#", &ctx), "-2");
    }

    #[test]
    fn test_filter_floor_negative() {
        let mut ctx = HashMap::new();
        ctx.insert("val".to_string(), json!("-2.3"));
        assert_eq!(replace_variables("#val|floor#", &ctx), "-3");
    }

    // =========================================================================
    // Arithmetic Tests
    // =========================================================================

    #[test]
    fn test_arithmetic_basic_addition() {
        assert_eq!(evaluate_arithmetic("10 + 1"), Some(11.0));
    }

    #[test]
    fn test_arithmetic_subtraction() {
        assert_eq!(evaluate_arithmetic("10 - 3"), Some(7.0));
    }

    #[test]
    fn test_arithmetic_multiply() {
        assert_eq!(evaluate_arithmetic("5 * 3"), Some(15.0));
    }

    #[test]
    fn test_arithmetic_divide() {
        assert_eq!(evaluate_arithmetic("10 / 4"), Some(2.5));
    }

    #[test]
    fn test_arithmetic_precedence() {
        // 2 + 3 * 4 = 14 (not 20)
        assert_eq!(evaluate_arithmetic("2 + 3 * 4"), Some(14.0));
    }

    #[test]
    fn test_arithmetic_division_by_zero() {
        assert_eq!(evaluate_arithmetic("10 / 0"), None);
    }

    #[test]
    fn test_arithmetic_negative_result() {
        assert_eq!(evaluate_arithmetic("3 - 10"), Some(-7.0));
    }

    #[test]
    fn test_arithmetic_not_arithmetic() {
        assert_eq!(evaluate_arithmetic("hello"), None);
        assert_eq!(evaluate_arithmetic("42"), None);
    }

    #[test]
    fn test_arithmetic_in_template() {
        let mut ctx = HashMap::new();
        ctx.insert("session".to_string(), json!({"age": 25}));
        let result = replace_variables("#session.age + 1#", &ctx);
        assert_eq!(result, "26");
    }

    #[test]
    fn test_arithmetic_multiply_in_template() {
        let mut ctx = HashMap::new();
        ctx.insert("price".to_string(), json!(100));
        let result = replace_variables("#price * 0.21#", &ctx);
        assert_eq!(result, "21");
    }

    #[test]
    fn test_arithmetic_with_filter() {
        let mut ctx = HashMap::new();
        ctx.insert("price".to_string(), json!(99.99));
        let result = replace_variables("#price * 0.21|round:2#", &ctx);
        assert_eq!(result, "21.00");
    }

    #[test]
    fn test_no_filters_still_escapes() {
        let mut ctx = HashMap::new();
        ctx.insert(
            "xss".to_string(),
            serde_json::json!("<script>alert(1)</script>"),
        );
        let result = replace_variables("#xss#", &ctx);
        assert!(!result.contains("<script>"));
        assert!(result.contains("&lt;script&gt;"));
    }

    // =========================================================================
    // Computed Variables Tests
    // =========================================================================

    #[test]
    fn test_computed_variable_parsing() {
        let content = r##"<what>
title: My Page
compute.greeting = "Hello #user.name#!"
compute.full_url = "/posts/#post.id#"
</what>
<html></html>"##;

        let (directives, _) = parse_page_directives(content);
        assert_eq!(directives.computed.len(), 2);
        assert_eq!(directives.computed[0].0, "greeting");
        assert_eq!(directives.computed[0].1, "Hello #user.name#!");
        assert_eq!(directives.computed[1].0, "full_url");
        assert_eq!(directives.computed[1].1, "/posts/#post.id#");
    }

    #[test]
    fn test_computed_variable_resolution() {
        let mut context = HashMap::new();
        context.insert(
            "user".to_string(),
            serde_json::json!({
                "name": "Alice"
            }),
        );

        let computed = vec![("greeting".to_string(), "Hello #user.name#!".to_string())];

        resolve_computed_variables(&computed, &mut context);

        assert_eq!(
            context.get("greeting"),
            Some(&serde_json::json!("Hello Alice!"))
        );
    }

    #[test]
    fn test_computed_variable_chained() {
        let mut context = HashMap::new();
        context.insert("first".to_string(), serde_json::json!("John"));
        context.insert("last".to_string(), serde_json::json!("Doe"));

        let computed = vec![
            ("full_name".to_string(), "#first# #last#".to_string()),
            ("greeting".to_string(), "Hello #full_name#!".to_string()),
        ];

        resolve_computed_variables(&computed, &mut context);

        assert_eq!(
            context.get("full_name"),
            Some(&serde_json::json!("John Doe"))
        );
        assert_eq!(
            context.get("greeting"),
            Some(&serde_json::json!("Hello John Doe!"))
        );
    }

    #[test]
    fn test_computed_variable_with_nested_path() {
        let mut context = HashMap::new();
        context.insert(
            "post".to_string(),
            serde_json::json!({
                "id": 42,
                "title": "My Post"
            }),
        );

        let computed = vec![(
            "edit_url".to_string(),
            "/admin/posts/#post.id#/edit".to_string(),
        )];

        resolve_computed_variables(&computed, &mut context);

        assert_eq!(
            context.get("edit_url"),
            Some(&serde_json::json!("/admin/posts/42/edit"))
        );
    }

    #[test]
    fn test_computed_variable_unresolved_reference() {
        let mut context = HashMap::new();

        let computed = vec![("url".to_string(), "/page/#missing_var#".to_string())];

        resolve_computed_variables(&computed, &mut context);

        // Unresolved vars stay as-is
        assert_eq!(
            context.get("url"),
            Some(&serde_json::json!("/page/#missing_var#"))
        );
    }

    #[test]
    fn test_computed_variable_no_prefix_in_template() {
        // Computed vars are available as #name# not #compute.name#
        let mut context = HashMap::new();
        context.insert("x".to_string(), serde_json::json!("world"));

        let computed = vec![("greeting".to_string(), "hello #x#".to_string())];

        resolve_computed_variables(&computed, &mut context);

        // Use in template
        let result = replace_variables("Say: #greeting#", &context);
        assert_eq!(result, "Say: hello world");
    }

    #[test]
    fn test_computed_variable_empty() {
        let mut context = HashMap::new();
        let computed: Vec<(String, String)> = Vec::new();

        resolve_computed_variables(&computed, &mut context);
        // No crash, context unchanged
        assert!(context.is_empty());
    }

    // ---- Wired Scope Parsing Tests ----

    #[test]
    fn parse_wired_no_brackets() {
        let decl = parse_wired_decl("counter");
        assert_eq!(decl.name, "counter");
        assert!(matches!(decl.scope, WiredScope::Public));
    }

    #[test]
    fn parse_wired_single_role() {
        let decl = parse_wired_decl("revenue [admin]");
        assert_eq!(decl.name, "revenue");
        match decl.scope {
            WiredScope::Roles(roles) => assert_eq!(roles, vec!["admin"]),
            _ => panic!("Expected Roles scope"),
        }
    }

    #[test]
    fn parse_wired_multi_role() {
        let decl = parse_wired_decl("x [admin, editor]");
        assert_eq!(decl.name, "x");
        match decl.scope {
            WiredScope::Roles(roles) => assert_eq!(roles, vec!["admin", "editor"]),
            _ => panic!("Expected Roles scope"),
        }
    }

    #[test]
    fn parse_wired_user_scope() {
        let decl = parse_wired_decl("notifs [user]");
        assert_eq!(decl.name, "notifs");
        assert!(matches!(decl.scope, WiredScope::User(_)));
    }

    #[test]
    fn wired_backwards_compat() {
        // data.wired = ["counter", "visitors"] without brackets → all Public
        let content = r#"data.wired = ["counter", "visitors"]"#;
        let config = parse_what_file(content);
        assert_eq!(config.data_wired.len(), 2);
        assert_eq!(config.data_wired[0].name, "counter");
        assert!(matches!(config.data_wired[0].scope, WiredScope::Public));
        assert_eq!(config.data_wired[1].name, "visitors");
        assert!(matches!(config.data_wired[1].scope, WiredScope::Public));
    }

    #[test]
    fn wired_scope_allows_public() {
        let scope = WiredScope::Public;
        assert!(scope.allows(&[], None));
        assert!(scope.allows(&["admin".into()], Some("user1")));
    }

    #[test]
    fn wired_scope_allows_role_match() {
        let scope = WiredScope::Roles(vec!["admin".into(), "editor".into()]);
        assert!(scope.allows(&["admin".into()], None));
        assert!(scope.allows(&["editor".into()], None));
        assert!(!scope.allows(&["viewer".into()], None));
        assert!(!scope.allows(&[], None));
    }

    #[test]
    fn wired_scope_allows_user_match() {
        let scope = WiredScope::User("user42".into());
        assert!(scope.allows(&[], Some("user42")));
        assert!(!scope.allows(&[], Some("user99")));
        assert!(!scope.allows(&[], None));
    }

    #[test]
    fn test_is_unquoted_string() {
        // Numbers are not unquoted strings
        assert!(!is_unquoted_string("42"));
        assert!(!is_unquoted_string("3.14"));
        assert!(!is_unquoted_string("-1"));
        // Booleans and keywords are not unquoted strings
        assert!(!is_unquoted_string("true"));
        assert!(!is_unquoted_string("false"));
        assert!(!is_unquoted_string("none"));
        assert!(!is_unquoted_string("all"));
        assert!(!is_unquoted_string("user"));
        assert!(!is_unquoted_string("None"));
        assert!(!is_unquoted_string(""));
        // Actual strings should be flagged
        assert!(is_unquoted_string("Hello World"));
        assert!(is_unquoted_string("local:items"));
        assert!(is_unquoted_string("main"));
        assert!(is_unquoted_string("/login"));
    }

    #[test]
    fn test_quoted_strings_no_warning() {
        // Quoted values should parse without warnings
        let content = r#"title: "My Page"
layout: "main"
fetch.items = "local:items"
greeting = "Hello World""#;
        let mut directives = PageDirectives::default();
        parse_directive_content(content, &mut directives);
        assert_eq!(directives.title.as_deref(), Some("My Page"));
        assert_eq!(directives.layout.as_deref(), Some("main"));
        assert_eq!(
            directives.custom.get("fetch.items").map(|s| s.as_str()),
            Some("local:items")
        );
        assert_eq!(
            directives.vars.get("greeting"),
            Some(&serde_json::json!("Hello World"))
        );
    }

    #[test]
    fn test_unquoted_numbers_and_bools_ok() {
        // Numbers and booleans should not trigger warnings
        let content = "count = 42\nprice = 9.99\nactive = true";
        let mut directives = PageDirectives::default();
        parse_directive_content(content, &mut directives);
        assert_eq!(directives.vars.get("count"), Some(&serde_json::json!(42)));
        assert_eq!(directives.vars.get("price"), Some(&serde_json::json!(9.99)));
        assert_eq!(
            directives.vars.get("active"),
            Some(&serde_json::json!(true))
        );
    }

    #[test]
    fn test_html_unescape_round_trip() {
        assert_eq!(html_unescape(&html_escape("Ben & Jerry")), "Ben & Jerry");
        assert_eq!(html_unescape(&html_escape("O'Brien")), "O'Brien");
        assert_eq!(html_unescape(&html_escape("a < b > c")), "a < b > c");
        // Author-written entity text survives the round trip un-collapsed
        assert_eq!(html_unescape(&html_escape("&lt;")), "&lt;");
        assert_eq!(html_unescape("plain"), "plain");
    }

    #[test]
    fn test_count_filter_counts_items_not_bytes() {
        let mut ctx = HashMap::new();
        ctx.insert(
            "items".to_string(),
            serde_json::json!([{"name": "a"}, {"name": "b"}, {"name": "c"}]),
        );
        ctx.insert("name".to_string(), serde_json::json!("José"));
        assert_eq!(replace_variables("#items|count#", &ctx), "3");
        assert_eq!(replace_variables("#name|count#", &ctx), "4");
    }

    #[test]
    fn test_within_one_edit() {
        assert!(within_one_edit("auth", "auth"));
        assert!(within_one_edit("auht", "auth")); // adjacent transposition
        assert!(within_one_edit("atuh", "auth")); // adjacent transposition
        assert!(within_one_edit("aut", "auth")); // deletion
        assert!(within_one_edit("auths", "auth")); // insertion
        assert!(within_one_edit("autj", "auth")); // substitution
        assert!(within_one_edit("oauth", "auth")); // deletion (filtered by first-letter guard)
        assert!(!within_one_edit("author", "auth"));
        assert!(!within_one_edit("au", "auth"));
        assert!(!within_one_edit("layout", "auth"));
    }

    #[test]
    fn test_access_directive_near_miss() {
        assert_eq!(access_directive_near_miss("auht"), Some("auth"));
        assert_eq!(access_directive_near_miss("atuh"), Some("auth"));
        assert_eq!(access_directive_near_miss("aut"), Some("auth"));
        assert_eq!(access_directive_near_miss("Auth"), Some("auth")); // case typo
        assert_eq!(access_directive_near_miss("role"), Some("roles"));
        assert_eq!(access_directive_near_miss("protectd"), Some("protected"));
        // Exact key is not a near-miss (it parses as the real directive)
        assert_eq!(access_directive_near_miss("auth"), None);
        // Different first letter: legitimate variable names near these words
        assert_eq!(access_directive_near_miss("oauth"), None);
        // Unrelated keys
        assert_eq!(access_directive_near_miss("title"), None);
        assert_eq!(access_directive_near_miss("items"), None);
    }

    #[test]
    fn test_auth_typo_key_stays_inline_var_and_page_stays_public() {
        // Documents the fail-open the near-miss warning exists for: `auht:`
        // is NOT `auth`, so the page keeps AuthLevel::All (public) and the
        // key becomes an inline variable.
        let content = r#"auht: "user""#;
        let mut directives = PageDirectives::default();
        parse_directive_content(content, &mut directives);
        assert!(matches!(directives.auth, AuthLevel::All));
        assert_eq!(directives.vars.get("auht"), Some(&serde_json::json!("user")));
    }

    #[test]
    fn test_strip_symmetric_quotes() {
        assert_eq!(strip_symmetric_quotes(r#""hello""#), ("hello", true));
        assert_eq!(strip_symmetric_quotes("'hello'"), ("hello", true));
        assert_eq!(strip_symmetric_quotes("hello"), ("hello", false));
        // Mismatched quotes are left intact
        assert_eq!(strip_symmetric_quotes(r#""hello'"#), (r#""hello'"#, false));
        // Only ONE pair is stripped (the old trim_matches stripped repeats)
        assert_eq!(strip_symmetric_quotes("''x''"), ("'x'", true));
        // Empty quoted string
        assert_eq!(strip_symmetric_quotes(r#""""#), ("", true));
        // Bare quote char is not a pair
        assert_eq!(strip_symmetric_quotes(r#"""#), (r#"""#, false));
    }

    #[test]
    fn test_quoting_forces_string_type_inline_vars() {
        // v1.0 rule: quoted values are strings, unquoted values are type-inferred.
        let content = "zip = \"01234\"\nversion = \"1.0\"\nflag = \"true\"\ncount = 42";
        let mut directives = PageDirectives::default();
        parse_directive_content(content, &mut directives);
        assert_eq!(
            directives.vars.get("zip"),
            Some(&serde_json::json!("01234")),
            "quoted leading-zero value must stay a string"
        );
        assert_eq!(
            directives.vars.get("version"),
            Some(&serde_json::json!("1.0")),
            "quoted numeric-looking value must stay a string"
        );
        assert_eq!(
            directives.vars.get("flag"),
            Some(&serde_json::json!("true")),
            "quoted boolean-looking value must stay a string"
        );
        assert_eq!(directives.vars.get("count"), Some(&serde_json::json!(42)));
    }

    #[test]
    fn test_quoting_forces_string_type_session_mutations() {
        let set = parse_session_mutation(r#"session.zip = "01234""#).unwrap();
        match set {
            SessionMutation::Set { key, value } => {
                assert_eq!(key, "zip");
                assert_eq!(value, serde_json::json!("01234"));
            }
            other => panic!("expected Set, got {:?}", other),
        }
        let set = parse_session_mutation("session.count = 42").unwrap();
        match set {
            SessionMutation::Set { value, .. } => {
                assert_eq!(value, serde_json::json!(42));
            }
            other => panic!("expected Set, got {:?}", other),
        }
        let push = parse_session_mutation(r#"session.items.push("42")"#).unwrap();
        match push {
            SessionMutation::Push { value, .. } => {
                assert_eq!(value, serde_json::json!("42"));
            }
            other => panic!("expected Push, got {:?}", other),
        }
    }

    #[test]
    fn test_mismatched_quotes_left_intact() {
        // A mismatched pair must not be silently swallowed.
        let content = "label = \"oops'";
        let mut directives = PageDirectives::default();
        parse_directive_content(content, &mut directives);
        assert_eq!(
            directives.vars.get("label"),
            Some(&serde_json::json!("\"oops'"))
        );
    }

    #[test]
    fn test_what_file_quoted_number_stays_string() {
        // application.what files already kept quoted numbers as strings — lock it.
        let config = parse_what_file("zip = \"01234\"\ncount = 7");
        assert_eq!(config.values.get("zip"), Some(&serde_json::json!("01234")));
        assert_eq!(config.values.get("count"), Some(&serde_json::json!(7)));
    }
}