agent_core/core/

config.rs

use std::collections::BTreeMap;
use std::path::PathBuf;
use std::sync::OnceLock;
use crate::core::shell_config::ShellConfig;

static PROFILE_NAME: OnceLock<Option<String>> = OnceLock::new();
static PROVIDER_KEYS: OnceLock<BTreeMap<String, String>> = OnceLock::new();
static IDENTITY: OnceLock<String> = OnceLock::new();

const DEFAULT_IDENTITY: &str = "You are an AI assistant running in SynapsCLI, an open-source agent runtime.";

/// Returns the configured identity string for the system prompt preamble.
/// Falls back to `DEFAULT_IDENTITY` (the SynapsCLI identity above) if not set
/// in config. Initialized by `load_config()` — safe to call anytime after boot.
pub fn get_identity() -> String {
    IDENTITY.get().cloned().unwrap_or_else(|| DEFAULT_IDENTITY.to_string())
}

/// Provider API keys parsed from `provider.<name> = ...` lines in config.
/// Empty if `load_config()` hasn't been called. The registry falls back to
/// env vars, so e.g. `GROQ_API_KEY` works even with an empty map.
pub fn get_provider_keys() -> BTreeMap<String, String> {
    PROVIDER_KEYS.get().cloned().unwrap_or_default()
}

/// Returns the active profile name, if any.
/// Reads from `SYNAPS_PROFILE` environment variable if not already set programmatically.
pub fn get_profile() -> Option<String> {
    PROFILE_NAME.get_or_init(|| std::env::var("SYNAPS_PROFILE").ok()).clone()
}

/// Sets the active profile name. Must be called before any `get_profile()` call
/// (i.e., before config resolution begins). Uses OnceLock — first write wins,
/// subsequent calls are no-ops. No env var mutation (unsafe under tokio).
pub fn set_profile(name: Option<String>) {
    let _ = PROFILE_NAME.set(name);
}

pub fn base_dir() -> PathBuf {
    if let Ok(path) = std::env::var("SYNAPS_BASE_DIR") {
        return PathBuf::from(path);
    }
    let home = std::env::var("HOME")
        .or_else(|_| std::env::var("USERPROFILE"))
        .unwrap_or_else(|_| ".".to_string());
    PathBuf::from(home).join(".synaps-cli")
}

/// Overrides the Synaps base directory. Intended for tests and embedded harnesses.
#[doc(hidden)]
pub fn set_base_dir_for_tests(path: PathBuf) {
    std::env::set_var("SYNAPS_BASE_DIR", path);
}

/// Resolves a path for reading. Checks the profile folder first, then falls back to the default folder.
pub fn resolve_read_path(filename: &str) -> PathBuf {
    let base = base_dir();
    
    if let Some(profile) = get_profile() {
        let profile_path = base.join(&profile).join(filename);
        if profile_path.exists() {
            return profile_path;
        }
    }
    
    base.join(filename)
}

/// Resolves a path for reading with an extended arbitrary path tree.
pub fn resolve_read_path_extended(path: &str) -> PathBuf {
    let base = base_dir();
    
    if let Some(profile) = get_profile() {
        let profile_path = base.join(&profile).join(path);
        if profile_path.exists() {
            return profile_path;
        }
    }
    
    base.join(path)
}

/// Resolves a path for writing. Unconditionally writes to the profile folder if a profile is active.
pub fn resolve_write_path(filename: &str) -> PathBuf {
    let mut base = base_dir();
    
    if let Some(profile) = get_profile() {
        base.push(profile);
    }
    
    let _ = std::fs::create_dir_all(&base);
    base.join(filename)
}

/// Gets the absolute directory for the current profile (or root if default).
pub fn get_active_config_dir() -> PathBuf {
    let mut base = base_dir();
    if let Some(profile) = get_profile() {
        base.push(profile);
    }
    base
}

/// Server security configuration parsed from `server.*` keys.
#[derive(Debug, Clone, Default)]
pub struct ServerConfig {
    /// Comma-separated list of allowed Origin headers. Empty = allow all (localhost-only protection).
    pub allowed_origins: Vec<String>,
    /// Pre-shared authentication token. If set, clients must provide it on WebSocket upgrade
    /// via `?token=X` query param or `Authorization: Bearer X` header. If None, auto-generated on boot.
    pub token: Option<String>,
    /// When true, `HookResult::Confirm` is auto-approved without prompting (useful for headless/agent mode).
    pub auto_approve_confirms: bool,
    /// Maximum inbound message size in bytes. Defaults to context_window * 4 (rough token→byte estimate).
    /// None means no artificial cap.
    pub max_message_size: Option<usize>,
}

/// Bridge daemon configuration parsed from `bridge.*` keys.
///
/// Controls best-effort mirroring of watcher heartbeats over the bridge
/// daemon's UDS `ControlSocket` (`heartbeat_emit` op). All keys are optional
/// and the feature is OFF by default.
#[derive(Debug, Clone)]
pub struct BridgeConfig {
    /// Path to the bridge daemon's UDS control socket.
    /// When `None`, defaults to `base_dir().join("bridge/control.sock")`.
    pub uds_path: Option<PathBuf>,
    /// When true, every watcher heartbeat tick mirrors a `heartbeat_emit`
    /// JSON-RPC call over the UDS socket. Errors are logged at debug only.
    pub heartbeat_mirror: bool,
    /// Per-call timeout in milliseconds (covers connect + write + read).
    pub heartbeat_timeout_ms: u64,
}

impl Default for BridgeConfig {
    fn default() -> Self {
        Self {
            uds_path: None,
            heartbeat_mirror: false,
            heartbeat_timeout_ms: 250,
        }
    }
}

impl BridgeConfig {
    /// Resolve the UDS path, falling back to the default under `base_dir()`.
    pub fn resolved_uds_path(&self) -> PathBuf {
        self.uds_path
            .clone()
            .unwrap_or_else(|| base_dir().join("bridge/control.sock"))
    }
}

/// Prompt-cache TTL strategy for Anthropic requests.
///
/// Controls the `cache_control` value emitted at every cache marker site:
/// - `FiveMinutes` (default): bare `{"type": "ephemeral"}` — byte-identical
///   to historical payloads; the default path can never invalidate existing
///   cached prefixes.
/// - `OneHour`: `{"type": "ephemeral", "ttl": "1h"}` on all markers.
/// - `Hybrid`: 1h on the stable prefix (tools + system, written rarely),
///   bare 5m on the message-tail marker (written every turn).
#[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
pub enum CacheTtl {
    #[default]
    FiveMinutes,
    OneHour,
    Hybrid,
}

impl CacheTtl {
    /// Parse a config value (case-insensitive). Returns `None` for unknown
    /// values so the caller can warn and fall back to the default.
    pub fn parse(val: &str) -> Option<CacheTtl> {
        match val.to_ascii_lowercase().as_str() {
            "5m" | "5min" | "default" => Some(CacheTtl::FiveMinutes),
            "1h" | "60m" | "1hr" => Some(CacheTtl::OneHour),
            "hybrid" => Some(CacheTtl::Hybrid),
            _ => None,
        }
    }
}

/// Parsed configuration from the config file.
#[derive(Debug, Clone)]
pub struct SynapsConfig {
    pub model: Option<String>,
    pub thinking_budget: Option<u32>,
    pub context_window: Option<u64>,   // override auto-detected context window (tokens)
    pub compaction_model: Option<String>, // model used for /compact (default: claude-sonnet-4-6)
    pub max_tool_output: usize,        // default 30000
    pub bash_timeout: u64,             // default 30
    pub bash_max_timeout: u64,         // default 300
    pub subagent_timeout: u64,         // default 300
    pub api_retries: u32,              // default 3
    pub telemetry: String,             // off | basic | full (default off)
    pub cache_diagnostics: bool,       // opt into cache-diagnosis beta (default false)
    /// Prompt-cache TTL strategy: "5m" (default) | "1h" | "hybrid".
    pub cache_ttl: CacheTtl,
    /// Max TUI redraw rate in frames/sec — caps streaming redraws (e.g. 60,
    /// 144, 240). User input always redraws immediately regardless. Default
    /// 60. Range 1–1000. The frame budget is `1000 / max_fps` ms.
    pub max_fps: u32,
    pub theme: Option<String>,
    pub agent_name: Option<String>,
    pub identity: Option<String>,
    pub disabled_plugins: Vec<String>,
    pub favorite_models: Vec<String>,
    pub disabled_skills: Vec<String>,
    /// Built-in tools to disable by runtime name (e.g. "bash", "ls"). Removed
    /// from the registry at boot so they're never offered to the model.
    pub disabled_tools: Vec<String>,
    pub shell: ShellConfig,
    pub server: ServerConfig,
    pub bridge: BridgeConfig,
    pub provider_keys: BTreeMap<String, String>,
    pub keybinds: std::collections::HashMap<String, String>,
    /// Non-fatal problems found while parsing the config file (unknown keys,
    /// unparseable values). Surfaced once at startup — never block boot.
    pub warnings: Vec<String>,
}

impl Default for SynapsConfig {
    fn default() -> Self {
        Self {
            model: None,
            thinking_budget: None,
            context_window: None,
            compaction_model: None,
            max_tool_output: 30000,
            bash_timeout: 30,
            bash_max_timeout: 300,
            subagent_timeout: 300,
            api_retries: 3,
            telemetry: "off".to_string(),
            cache_diagnostics: false,
            cache_ttl: CacheTtl::default(),
            max_fps: 60,
            theme: None,
            agent_name: None,
            identity: None,
            disabled_plugins: Vec::new(),
            favorite_models: Vec::new(),
            disabled_skills: Vec::new(),
            disabled_tools: Vec::new(),
            shell: ShellConfig::default(),
            server: ServerConfig::default(),
            bridge: BridgeConfig::default(),
            provider_keys: BTreeMap::new(),
            keybinds: std::collections::HashMap::new(),
            warnings: Vec::new(),
        }
    }
}

/// Known top-level config keys — used for unknown-key warnings + did-you-mean.
const KNOWN_CONFIG_KEYS: &[&str] = &[
    "model", "thinking", "compaction_model", "context_window", "max_tool_output",
    "bash_timeout", "bash_max_timeout", "subagent_timeout", "api_retries",
    "telemetry", "cache_diagnostics", "cache_ttl", "max_fps", "theme", "agent_name", "identity",
    "disabled_plugins", "favorite_models", "disabled_skills", "disabled_tools",
];

/// Simple Levenshtein distance for did-you-mean suggestions.
fn levenshtein(a: &str, b: &str) -> usize {
    let a: Vec<char> = a.chars().collect();
    let b: Vec<char> = b.chars().collect();
    let mut prev: Vec<usize> = (0..=b.len()).collect();
    let mut cur = vec![0; b.len() + 1];
    for (i, ca) in a.iter().enumerate() {
        cur[0] = i + 1;
        for (j, cb) in b.iter().enumerate() {
            let cost = if ca == cb { 0 } else { 1 };
            cur[j + 1] = (prev[j + 1] + 1).min(cur[j] + 1).min(prev[j] + cost);
        }
        std::mem::swap(&mut prev, &mut cur);
    }
    prev[b.len()]
}

/// Closest known key within edit distance 2, for typo suggestions.
fn did_you_mean(key: &str) -> Option<&'static str> {
    KNOWN_CONFIG_KEYS
        .iter()
        .map(|k| (*k, levenshtein(key, k)))
        .filter(|(_, d)| *d <= 2)
        .min_by_key(|(_, d)| *d)
        .map(|(k, _)| k)
}


fn parse_thinking_budget(val: &str) -> Option<u32> {
    match val {
        "low" => Some(2048),
        "medium" => Some(4096),
        "high" => Some(16384),
        "xhigh" => Some(32768),
        "adaptive" => Some(0), // sentinel: model decides depth
        _ => val.parse::<u32>().ok(),
    }
}

fn parse_comma_list(val: &str) -> Vec<String> {
    val.split(',')
        .map(|s| s.trim().to_string())
        .filter(|s| !s.is_empty())
        .collect()
}

fn write_comma_list(key: &str, values: &[String]) -> std::io::Result<()> {
    write_config_value(key, &values.join(", "))
}

/// Parse shell.* configuration keys and update the ShellConfig.
fn parse_shell_config_key(shell_config: &mut ShellConfig, key: &str, val: &str) {
    match key {
        "shell.max_sessions" => {
            if let Ok(sessions) = val.parse::<usize>() {
                shell_config.max_sessions = sessions;
            } else {
                eprintln!("Warning: invalid value for shell.max_sessions: '{}', using default", val);
            }
        }
        "shell.idle_timeout" => {
            if let Ok(timeout) = val.parse::<u64>() {
                shell_config.idle_timeout = std::time::Duration::from_secs(timeout);
            } else {
                eprintln!("Warning: invalid value for shell.idle_timeout: '{}', using default", val);
            }
        }
        "shell.readiness_timeout_ms" => {
            if let Ok(timeout) = val.parse::<u64>() {
                shell_config.readiness_timeout_ms = timeout;
            } else {
                eprintln!("Warning: invalid value for shell.readiness_timeout_ms: '{}', using default", val);
            }
        }
        "shell.max_readiness_timeout_ms" => {
            if let Ok(timeout) = val.parse::<u64>() {
                shell_config.max_readiness_timeout_ms = timeout;
            } else {
                eprintln!("Warning: invalid value for shell.max_readiness_timeout_ms: '{}', using default", val);
            }
        }
        "shell.default_rows" => {
            if let Ok(rows) = val.parse::<u16>() {
                shell_config.default_rows = rows;
            } else {
                eprintln!("Warning: invalid value for shell.default_rows: '{}', using default", val);
            }
        }
        "shell.default_cols" => {
            if let Ok(cols) = val.parse::<u16>() {
                shell_config.default_cols = cols;
            } else {
                eprintln!("Warning: invalid value for shell.default_cols: '{}', using default", val);
            }
        }
        "shell.readiness_strategy" => {
            let val_lower = val.to_lowercase();
            match val_lower.as_str() {
                "timeout" | "prompt" | "hybrid" => {
                    shell_config.readiness_strategy = val.to_string();
                }
                _ => {
                    eprintln!("Warning: invalid value for shell.readiness_strategy: '{}', using default", val);
                }
            }
        }
        "shell.max_output" => {
            if let Ok(max_output) = val.parse::<usize>() {
                shell_config.max_output = max_output;
            } else {
                eprintln!("Warning: invalid value for shell.max_output: '{}', using default", val);
            }
        }
        _ => {
            // Unknown shell.* keys are preserved (not rejected)
        }
    }
}

/// Parse server.* configuration keys and update the ServerConfig.
#[allow(clippy::collapsible_match)]
fn parse_server_config_key(server_config: &mut ServerConfig, key: &str, val: &str) {
    match key {
        "server.allowed_origins" => {
            server_config.allowed_origins = parse_comma_list(val);
        }
        "server.token" => {
            if !val.is_empty() {
                server_config.token = Some(val.to_string());
            }
        }
        "server.auto_approve_confirms" => {
            server_config.auto_approve_confirms = matches!(val, "true" | "1" | "yes");
        }
        "server.max_message_size" => {
            if let Ok(size) = val.parse::<usize>() {
                server_config.max_message_size = Some(size);
            } else {
                eprintln!("Warning: invalid value for server.max_message_size: '{}', ignored", val);
            }
        }
        _ => {
            // Unknown server.* keys preserved (not rejected)
        }
    }
}

/// Parse bridge.* configuration keys and update the BridgeConfig.
fn parse_bridge_config_key(bridge_config: &mut BridgeConfig, key: &str, val: &str) {
    match key {
        "bridge.uds_path" => {
            if val.is_empty() {
                bridge_config.uds_path = None;
            } else {
                bridge_config.uds_path = Some(PathBuf::from(val));
            }
        }
        "bridge.heartbeat_mirror" => {
            bridge_config.heartbeat_mirror = matches!(val, "true" | "1" | "yes");
        }
        "bridge.heartbeat_timeout_ms" => {
            if let Ok(ms) = val.parse::<u64>() {
                bridge_config.heartbeat_timeout_ms = ms;
            } else {
                eprintln!("Warning: invalid value for bridge.heartbeat_timeout_ms: '{}', using default", val);
            }
        }
        _ => {
            // Unknown bridge.* keys preserved (not rejected)
        }
    }
}

/// Parse the config file at ~/.synaps-cli/config (or profile variant).
/// Returns default config if file doesn't exist or can't be read.
pub fn load_config() -> SynapsConfig {
    let path = resolve_read_path("config");
    let mut config = SynapsConfig::default();
    
    let Ok(content) = std::fs::read_to_string(&path) else {
        return config;
    };
    
    for line in content.lines() {
        let line = line.trim();
        if line.is_empty() || line.starts_with('#') { continue; }
        let Some((key, val)) = line.split_once('=') else { continue };
        let key = key.trim();
        let val = val.trim();
        match key {
            "model" => config.model = Some(val.to_string()),
            "thinking" => {
                config.thinking_budget = parse_thinking_budget(val);
                if config.thinking_budget.is_none() {
                    config.warnings.push(format!("thinking = {val} — expected low|medium|high|xhigh|adaptive or a token count; thinking disabled"));
                }
            }
            "compaction_model" => config.compaction_model = Some(val.to_string()),
            "context_window" => {
                let parsed = match val {
                    "200k" | "200K" => Some(200_000),
                    "1m" | "1M" => Some(1_000_000),
                    _ => val.parse::<u64>().ok(),
                };
                if parsed.is_none() {
                    config.warnings.push(format!("context_window = {val} — expected 200k, 1m, or a token count; ignored"));
                }
                config.context_window = parsed;
            }
            "max_tool_output" => {
                match val.parse::<usize>() {
                    Ok(size) => config.max_tool_output = size,
                    Err(_) => config.warnings.push(format!("max_tool_output = {val} — not a number; using {}", config.max_tool_output)),
                }
            }
            "bash_timeout" => {
                match val.parse::<u64>() {
                    Ok(t) if t >= 1 => config.bash_timeout = t,
                    Ok(_) => config.warnings.push(format!("bash_timeout = {val} — below minimum (1s); using {}", config.bash_timeout)),
                    Err(_) => config.warnings.push(format!("bash_timeout = {val} — not a number; using {}", config.bash_timeout)),
                }
            }
            "bash_max_timeout" => {
                if let Ok(timeout) = val.parse::<u64>() {
                    config.bash_max_timeout = timeout;
                }
            }
            "subagent_timeout" => {
                if let Ok(timeout) = val.parse::<u64>() {
                    config.subagent_timeout = timeout;
                }
            }
            "api_retries" => {
                if let Ok(retries) = val.parse::<u32>() {
                    config.api_retries = retries;
                }
            }
            "telemetry" => config.telemetry = val.to_string(),
            "cache_diagnostics" => {
                config.cache_diagnostics = matches!(val, "true" | "1" | "on" | "yes");
            }
            "cache_ttl" => {
                match CacheTtl::parse(val) {
                    Some(ttl) => config.cache_ttl = ttl,
                    None => config.warnings.push(format!(
                        "cache_ttl = {val} — expected 5m, 1h, or hybrid; using 5m"
                    )),
                }
            }
            "max_fps" => {
                match val.parse::<u32>() {
                    Ok(fps) if (1..=1000).contains(&fps) => config.max_fps = fps,
                    Ok(_) => config.warnings.push(format!(
                        "max_fps = {val} — expected 1–1000; using {}", config.max_fps
                    )),
                    Err(_) => config.warnings.push(format!(
                        "max_fps = {val} — not a number; using {}", config.max_fps
                    )),
                }
            }
            "theme" => config.theme = Some(val.to_string()),
            "agent_name" => config.agent_name = Some(val.to_string()),
            "identity" => config.identity = Some(val.to_string()),
            "disabled_plugins" => {
                config.disabled_plugins = parse_comma_list(val);
            }
            "favorite_models" => {
                config.favorite_models = parse_comma_list(val);
            }
            "disabled_skills" => {
                config.disabled_skills = parse_comma_list(val);
            }
            "disabled_tools" => {
                config.disabled_tools = parse_comma_list(val);
            }
            _ => {
                // Handle namespaced keys
                if key.starts_with("shell.") {
                    parse_shell_config_key(&mut config.shell, key, val);
                } else if key.starts_with("server.") {
                    parse_server_config_key(&mut config.server, key, val);
                } else if key.starts_with("bridge.") {
                    parse_bridge_config_key(&mut config.bridge, key, val);
                } else if let Some(provider_key) = key.strip_prefix("provider.") {
                    config.provider_keys.insert(provider_key.to_string(), val.to_string());
                } else if let Some(keybind_key) = key.strip_prefix("keybind.") {
                    config.keybinds.insert(keybind_key.to_string(), val.to_string());
                } else if key.contains('.') {
                    // Dotted keys are namespaced (plugin/extension config, e.g.
                    // `knowledge.jawz_notes`). Plugins define their own keys —
                    // not ours to police. Silently preserved.
                } else {
                    // Unknown top-level key — warn with a did-you-mean if close.
                    match did_you_mean(key) {
                        Some(suggestion) => config.warnings.push(format!("unknown key '{key}' (did you mean '{suggestion}'?)")),
                        None => config.warnings.push(format!("unknown key '{key}' — ignored")),
                    }
                }
            }
        }
    }

    // Derive max_message_size from context_window if not explicitly set.
    // Rough estimate: 1 token ≈ 4 bytes. Context window in tokens → bytes.
    if config.server.max_message_size.is_none() {
        if let Some(ctx_tokens) = config.context_window {
            config.server.max_message_size = Some((ctx_tokens as usize) * 4);
        }
    }

    // Publish provider keys to the process-wide cache for the API router.
    // First writer wins (OnceLock) — subsequent load_config calls are no-ops.
    let _ = PROVIDER_KEYS.set(config.provider_keys.clone());

    // Publish identity to the process-wide cache for API system prompt preamble.
    let identity_val = config.identity.clone().unwrap_or_else(|| DEFAULT_IDENTITY.to_string());
    let _ = IDENTITY.set(identity_val);

    config
}

/// Read a single config value by exact key from the active config file.
pub fn read_config_value(key: &str) -> Option<String> {
    let path = resolve_read_path("config");
    let content = std::fs::read_to_string(&path).ok()?;
    for line in content.lines() {
        let line = line.trim();
        if line.is_empty() || line.starts_with('#') { continue; }
        let Some((k, v)) = line.split_once('=') else { continue };
        if k.trim() == key.trim() {
            return Some(v.trim().to_string());
        }
    }
    None
}

/// Write a single `key = value` pair to `~/.synaps-cli/config` (or profile config).
/// Replaces the first existing line that matches the key, or appends if absent.
/// Preserves comments and unknown keys. Writes atomically via temp file + rename.
pub fn write_config_value(key: &str, value: &str) -> std::io::Result<()> {
    let path = resolve_write_path("config");
    let existing = std::fs::read_to_string(&path).unwrap_or_default();

    let key_trimmed = key.trim();
    let replacement = format!("{} = {}", key_trimmed, value);

    let mut found = false;
    let mut new_lines: Vec<String> = existing.lines().map(|line| {
        if found { return line.to_string(); }
        let t = line.trim_start();
        if t.starts_with('#') || t.is_empty() { return line.to_string(); }
        if let Some((k, _)) = t.split_once('=') {
            if k.trim() == key_trimmed {
                found = true;
                return replacement.clone();
            }
        }
        line.to_string()
    }).collect();

    if !found {
        new_lines.push(replacement);
    }

    let mut out = new_lines.join("\n");
    if !out.ends_with('\n') { out.push('\n'); }

    let tmp = path.with_extension("tmp");
    std::fs::write(&tmp, out)?;
    // Config may contain API keys — restrict to owner-only
    #[cfg(unix)]
    {
        use std::os::unix::fs::PermissionsExt;
        std::fs::set_permissions(&tmp, std::fs::Permissions::from_mode(0o600))?;
    }
    std::fs::rename(&tmp, &path)?;
    Ok(())
}

/// Add a favorite model id (`provider/model`) to config, preserving sort/dedup.
pub fn add_favorite_model(id: &str) -> std::io::Result<()> {
    let trimmed = id.trim();
    if trimmed.is_empty() {
        return Ok(());
    }
    let mut values = load_config().favorite_models;
    if !values.iter().any(|v| v == trimmed) {
        values.push(trimmed.to_string());
        values.sort();
    }
    write_comma_list("favorite_models", &values)
}

/// Remove a favorite model id (`provider/model`) from config.
pub fn remove_favorite_model(id: &str) -> std::io::Result<()> {
    let mut values = load_config().favorite_models;
    values.retain(|v| v != id.trim());
    write_comma_list("favorite_models", &values)
}

/// Return whether a model id is marked as favorite.
pub fn is_favorite_model(id: &str) -> bool {
    load_config().favorite_models.iter().any(|v| v == id.trim())
}

/// Resolve the system prompt from CLI flag, config file, or default.
/// Priority: explicit value > ~/.synaps-cli/system.md > built-in default.
pub fn resolve_system_prompt(explicit: Option<&str>) -> String {
    const DEFAULT_PROMPT: &str = "You are a helpful AI agent running in a terminal. \
        You have access to bash, read, and write tools. \
        Be concise and direct. Use tools when the user asks you to interact with the filesystem or run commands.";

    if let Some(val) = explicit {
        let path = std::path::Path::new(val);
        if path.exists() && path.is_file() {
            return std::fs::read_to_string(path).unwrap_or_else(|_| val.to_string());
        }
        return val.to_string();
    }

    let system_path = resolve_read_path("system.md");
    if system_path.exists() {
        return std::fs::read_to_string(&system_path).unwrap_or_default();
    }

    DEFAULT_PROMPT.to_string()
}

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

    #[test]
    fn test_levenshtein_basics() {
        assert_eq!(levenshtein("model", "model"), 0);
        assert_eq!(levenshtein("modle", "model"), 2);
        assert_eq!(levenshtein("them", "theme"), 1);
    }

    #[test]
    fn test_did_you_mean_close_typos() {
        assert_eq!(did_you_mean("modle"), Some("model"));
        assert_eq!(did_you_mean("them"), Some("theme"));
        assert_eq!(did_you_mean("thinkng"), Some("thinking"));
        assert_eq!(did_you_mean("completely_unrelated_key"), None);
    }

    #[test]
    #[serial]
    fn test_config_warnings_unknown_key_and_bad_values() {
        let home = std::env::temp_dir().join(format!("synaps-warn-test-{}", std::process::id()));
        let dir = home.join(".synaps-cli");
        std::fs::create_dir_all(&dir).unwrap();
        std::fs::write(dir.join("config"), "modle = claude-opus-4-6\nthinking = hgih\nbash_timeout = 0\nknowledge.jawz_notes = ~/Jawz/notes\ncustom.plugin.key = 42\n").unwrap();

        with_home(&home, || {
            let config = load_config();
            // Dotted (namespaced) keys must NOT warn — plugins own those.
            assert_eq!(config.warnings.len(), 3, "warnings: {:?}", config.warnings);
            assert!(!config.warnings.iter().any(|w| w.contains("knowledge")), "{:?}", config.warnings);
            assert!(config.warnings.iter().any(|w| w.contains("did you mean 'model'")), "{:?}", config.warnings);
            assert!(config.warnings.iter().any(|w| w.contains("thinking")), "{:?}", config.warnings);
            assert!(config.warnings.iter().any(|w| w.contains("below minimum")), "{:?}", config.warnings);
            // Bad values fall back to defaults
            assert_eq!(config.bash_timeout, 30);
            assert_eq!(config.thinking_budget, None);
        });
        let _ = std::fs::remove_dir_all(&home);
    }

    // ── cache_ttl parse table (spec §3.1) ──

    #[test]
    fn test_cache_ttl_parse_table() {
        // 5m aliases
        assert_eq!(CacheTtl::parse("5m"), Some(CacheTtl::FiveMinutes));
        assert_eq!(CacheTtl::parse("5min"), Some(CacheTtl::FiveMinutes));
        assert_eq!(CacheTtl::parse("default"), Some(CacheTtl::FiveMinutes));
        // 1h aliases
        assert_eq!(CacheTtl::parse("1h"), Some(CacheTtl::OneHour));
        assert_eq!(CacheTtl::parse("60m"), Some(CacheTtl::OneHour));
        assert_eq!(CacheTtl::parse("1hr"), Some(CacheTtl::OneHour));
        // hybrid
        assert_eq!(CacheTtl::parse("hybrid"), Some(CacheTtl::Hybrid));
        // case-insensitive
        assert_eq!(CacheTtl::parse("1H"), Some(CacheTtl::OneHour));
        assert_eq!(CacheTtl::parse("HYBRID"), Some(CacheTtl::Hybrid));
        assert_eq!(CacheTtl::parse("Default"), Some(CacheTtl::FiveMinutes));
        // garbage → None (caller warns + defaults)
        assert_eq!(CacheTtl::parse("2h"), None);
        assert_eq!(CacheTtl::parse(""), None);
        assert_eq!(CacheTtl::parse("forever"), None);
    }

    #[test]
    fn test_cache_ttl_default_is_five_minutes() {
        assert_eq!(CacheTtl::default(), CacheTtl::FiveMinutes);
        assert_eq!(SynapsConfig::default().cache_ttl, CacheTtl::FiveMinutes);
    }

    #[test]
    fn test_max_fps_default_is_60() {
        assert_eq!(SynapsConfig::default().max_fps, 60);
    }

    #[test]
    #[serial]
    fn test_max_fps_config_parse_and_validation() {
        let home = std::env::temp_dir().join(format!("synaps-maxfps-test-{}", std::process::id()));
        let dir = home.join(".synaps-cli");
        std::fs::create_dir_all(&dir).unwrap();

        // Valid high-refresh value parses, no warning.
        std::fs::write(dir.join("config"), "max_fps = 144\n").unwrap();
        with_home(&home, || {
            let config = load_config();
            assert_eq!(config.max_fps, 144);
            assert!(config.warnings.is_empty(), "warnings: {:?}", config.warnings);
        });

        // Out-of-range (0) → default 60 + boot warning (never blocks boot).
        std::fs::write(dir.join("config"), "max_fps = 0\n").unwrap();
        with_home(&home, || {
            let config = load_config();
            assert_eq!(config.max_fps, 60);
            assert!(
                config.warnings.iter().any(|w| w.contains("max_fps")),
                "warnings: {:?}", config.warnings
            );
        });

        // Non-numeric → default 60 + warning.
        std::fs::write(dir.join("config"), "max_fps = fast\n").unwrap();
        with_home(&home, || {
            let config = load_config();
            assert_eq!(config.max_fps, 60);
            assert!(
                config.warnings.iter().any(|w| w.contains("max_fps")),
                "warnings: {:?}", config.warnings
            );
        });

        let _ = std::fs::remove_dir_all(&home);
    }

    #[test]
    #[serial]
    fn test_cache_ttl_config_parse_and_garbage_warning() {
        let home = std::env::temp_dir().join(format!("synaps-cachettl-test-{}", std::process::id()));
        let dir = home.join(".synaps-cli");
        std::fs::create_dir_all(&dir).unwrap();

        // Valid value parses, no warning.
        std::fs::write(dir.join("config"), "cache_ttl = hybrid\n").unwrap();
        with_home(&home, || {
            let config = load_config();
            assert_eq!(config.cache_ttl, CacheTtl::Hybrid);
            assert!(config.warnings.is_empty(), "warnings: {:?}", config.warnings);
        });

        // Garbage value → 5m default + boot warning (never blocks boot).
        std::fs::write(dir.join("config"), "cache_ttl = 2h\n").unwrap();
        with_home(&home, || {
            let config = load_config();
            assert_eq!(config.cache_ttl, CacheTtl::FiveMinutes);
            assert!(
                config.warnings.iter().any(|w| w.contains("cache_ttl")),
                "warnings: {:?}", config.warnings
            );
        });

        let _ = std::fs::remove_dir_all(&home);
    }

    #[test]
    fn test_parse_thinking_budget() {
        assert_eq!(parse_thinking_budget("low"), Some(2048));
        assert_eq!(parse_thinking_budget("medium"), Some(4096));
        assert_eq!(parse_thinking_budget("high"), Some(16384));
        assert_eq!(parse_thinking_budget("xhigh"), Some(32768));
        assert_eq!(parse_thinking_budget("8192"), Some(8192));
        assert_eq!(parse_thinking_budget("invalid"), None);
    }

    #[test]
    fn test_base_dir() {
        let path = base_dir();
        assert!(path.to_string_lossy().ends_with(".synaps-cli"));
    }

    #[test]
    fn test_resolve_system_prompt_explicit() {
        let result = resolve_system_prompt(Some("test prompt"));
        assert_eq!(result, "test prompt");
    }

    #[test]
    fn test_resolve_system_prompt_none() {
        let result = resolve_system_prompt(None);
        assert!(result.contains("helpful AI agent"));
    }

    // Note: test_load_config_nonexistent_file removed — HOME env var mutation
    // is not thread-safe and races with shell config tests. Coverage provided
    // by shell::config::tests::test_shell_config_from_file.

    #[test]
    fn test_synaps_config_default() {
        let config = SynapsConfig::default();
        assert_eq!(config.model, None);
        assert_eq!(config.thinking_budget, None);
        assert_eq!(config.max_tool_output, 30000);
        assert_eq!(config.bash_timeout, 30);
        assert_eq!(config.bash_max_timeout, 300);
        assert_eq!(config.subagent_timeout, 300);
        assert_eq!(config.api_retries, 3);
        assert_eq!(config.theme, None);
        assert!(config.disabled_plugins.is_empty());
        assert!(config.favorite_models.is_empty());
        assert!(config.disabled_skills.is_empty());
        assert_eq!(config.shell.max_sessions, 5);
        assert_eq!(config.shell.idle_timeout.as_secs(), 600);
        // Server config defaults
        assert!(config.server.allowed_origins.is_empty());
        assert_eq!(config.server.token, None);
        assert!(!config.server.auto_approve_confirms);
        assert_eq!(config.server.max_message_size, None);
        // Bridge config defaults
        assert!(config.bridge.uds_path.is_none());
        assert!(!config.bridge.heartbeat_mirror);
        assert_eq!(config.bridge.heartbeat_timeout_ms, 250);
    }

    #[test]
    #[serial]
    fn test_load_config_bridge_keys() {
        let home = make_test_home("bridge-keys");
        let cfg = home.join(".synaps-cli/config");
        std::fs::write(&cfg, "\
bridge.uds_path = /tmp/some/control.sock\n\
bridge.heartbeat_mirror = true\n\
bridge.heartbeat_timeout_ms = 750\n\
").unwrap();

        with_home(&home, || {
            let config = load_config();
            assert_eq!(
                config.bridge.uds_path,
                Some(std::path::PathBuf::from("/tmp/some/control.sock")),
            );
            assert!(config.bridge.heartbeat_mirror);
            assert_eq!(config.bridge.heartbeat_timeout_ms, 750);
            assert_eq!(
                config.bridge.resolved_uds_path(),
                std::path::PathBuf::from("/tmp/some/control.sock"),
            );
        });

        let _ = std::fs::remove_dir_all(&home);
    }

    #[test]
    fn test_bridge_config_defaults() {
        let cfg = BridgeConfig::default();
        assert!(cfg.uds_path.is_none());
        assert!(!cfg.heartbeat_mirror);
        assert_eq!(cfg.heartbeat_timeout_ms, 250);
        // resolved path falls under base_dir()/bridge/control.sock
        let resolved = cfg.resolved_uds_path();
        assert!(resolved.ends_with("bridge/control.sock"));
    }

    #[test]
    #[serial]
    fn test_bridge_heartbeat_mirror_defaults_off_when_unset() {
        let home = make_test_home("bridge-default-off");
        let cfg = home.join(".synaps-cli/config");
        std::fs::write(&cfg, "model = claude-sonnet-4-6\n").unwrap();

        with_home(&home, || {
            let config = load_config();
            assert!(!config.bridge.heartbeat_mirror);
            assert!(config.bridge.uds_path.is_none());
            assert_eq!(config.bridge.heartbeat_timeout_ms, 250);
        });

        let _ = std::fs::remove_dir_all(&home);
    }

    #[test]
    #[serial]
    fn test_load_config_server_keys() {
        let home = make_test_home("server-keys");
        let cfg = home.join(".synaps-cli/config");
        std::fs::write(&cfg, "\
server.allowed_origins = http://localhost:3000, http://localhost:5193\n\
server.token = my-secret-token\n\
server.auto_approve_confirms = true\n\
server.max_message_size = 65536\n\
context_window = 200k\n\
").unwrap();

        with_home(&home, || {
            let config = load_config();
            assert_eq!(config.server.allowed_origins, vec![
                "http://localhost:3000".to_string(),
                "http://localhost:5193".to_string(),
            ]);
            assert_eq!(config.server.token, Some("my-secret-token".to_string()));
            assert!(config.server.auto_approve_confirms);
            // Explicit max_message_size takes precedence over context_window derivation
            assert_eq!(config.server.max_message_size, Some(65536));
        });

        let _ = std::fs::remove_dir_all(&home);
    }

    #[test]
    #[serial]
    fn test_server_max_message_size_derived_from_context_window() {
        let home = make_test_home("server-derive");
        let cfg = home.join(".synaps-cli/config");
        std::fs::write(&cfg, "context_window = 200k\n").unwrap();

        with_home(&home, || {
            let config = load_config();
            // 200_000 tokens * 4 bytes/token = 800_000 bytes
            assert_eq!(config.server.max_message_size, Some(800_000));
        });

        let _ = std::fs::remove_dir_all(&home);
    }

    fn make_test_home(subdir: &str) -> std::path::PathBuf {
        let dir = std::path::PathBuf::from(format!("/tmp/synaps-write-test-{}", subdir));
        let _ = std::fs::remove_dir_all(&dir);
        std::fs::create_dir_all(dir.join(".synaps-cli")).unwrap();
        dir
    }

    fn with_home<F: FnOnce()>(home: &std::path::Path, f: F) {
        let original = std::env::var("HOME").ok();
        std::env::set_var("HOME", home);
        f();
        if let Some(h) = original {
            std::env::set_var("HOME", h);
        } else {
            std::env::remove_var("HOME");
        }
    }

    #[test]
    #[serial]
    fn write_config_value_replaces_existing_key() {
        let home = make_test_home("replace");
        let cfg = home.join(".synaps-cli/config");
        std::fs::write(&cfg, "model = claude-opus-4-6\nthinking = low\n").unwrap();

        with_home(&home, || {
            write_config_value("model", "claude-sonnet-4-6").unwrap();
        });

        let contents = std::fs::read_to_string(&cfg).unwrap();
        assert!(contents.contains("model = claude-sonnet-4-6"));
        assert!(contents.contains("thinking = low"));
        let _ = std::fs::remove_dir_all(&home);
    }

    #[test]
    #[serial]
    fn write_config_value_appends_when_missing() {
        let home = make_test_home("append");
        let cfg = home.join(".synaps-cli/config");
        std::fs::write(&cfg, "model = claude-opus-4-6\n").unwrap();

        with_home(&home, || {
            write_config_value("theme", "dracula").unwrap();
        });

        let contents = std::fs::read_to_string(&cfg).unwrap();
        assert!(contents.contains("model = claude-opus-4-6"));
        assert!(contents.contains("theme = dracula"));
        let _ = std::fs::remove_dir_all(&home);
    }

    #[test]
    #[serial]
    fn write_config_value_preserves_comments() {
        let home = make_test_home("comments");
        let cfg = home.join(".synaps-cli/config");
        std::fs::write(&cfg, "# user comment\nmodel = claude-opus-4-6\n# another\n").unwrap();

        with_home(&home, || {
            write_config_value("model", "claude-sonnet-4-6").unwrap();
        });

        let contents = std::fs::read_to_string(&cfg).unwrap();
        assert!(contents.contains("# user comment"));
        assert!(contents.contains("# another"));
        assert!(contents.contains("model = claude-sonnet-4-6"));
        let _ = std::fs::remove_dir_all(&home);
    }

    #[test]
    #[serial]
    fn write_config_value_preserves_unknown_keys() {
        let home = make_test_home("unknown");
        let cfg = home.join(".synaps-cli/config");
        std::fs::write(&cfg, "custom_thing = 42\nmodel = claude-opus-4-6\n").unwrap();

        with_home(&home, || {
            write_config_value("model", "claude-sonnet-4-6").unwrap();
        });

        let contents = std::fs::read_to_string(&cfg).unwrap();
        assert!(contents.contains("custom_thing = 42"));
        let _ = std::fs::remove_dir_all(&home);
    }

    #[test]
    #[serial]
    fn write_config_value_creates_file_if_absent() {
        let home = make_test_home("create");
        let cfg = home.join(".synaps-cli/config");
        assert!(!cfg.exists());

        with_home(&home, || {
            write_config_value("model", "claude-sonnet-4-6").unwrap();
        });

        let contents = std::fs::read_to_string(&cfg).unwrap();
        assert!(contents.contains("model = claude-sonnet-4-6"));
        let _ = std::fs::remove_dir_all(&home);
    }

    #[test]
    #[serial]
    fn load_config_parses_theme_key() {
        let dir = std::path::PathBuf::from("/tmp/synaps-config-test-theme/.synaps-cli");
        let _ = std::fs::create_dir_all(&dir);
        std::fs::write(dir.join("config"), "theme = dracula\n").unwrap();

        let original_home = std::env::var("HOME").ok();
        std::env::set_var("HOME", "/tmp/synaps-config-test-theme");

        let config = load_config();

        if let Some(home) = original_home {
            std::env::set_var("HOME", home);
        } else {
            std::env::remove_var("HOME");
        }
        let _ = std::fs::remove_dir_all("/tmp/synaps-config-test-theme");

        assert_eq!(config.theme.as_deref(), Some("dracula"));
    }

    #[test]
    #[serial]
    fn test_load_config_disable_lists() {
        let test_dir = std::path::PathBuf::from("/tmp/synaps-config-test-disable-lists/.synaps-cli");
        let _ = std::fs::create_dir_all(&test_dir);
        let config_path = test_dir.join("config");

        let config_content = r#"
# Test config with disable lists
favorite_models = claude/claude-opus-4-7, groq/llama-3.3-70b-versatile

disabled_plugins = foo, bar
disabled_skills = baz, plug:qual
"#;
        std::fs::write(&config_path, config_content).unwrap();

        let original_home = std::env::var("HOME").ok();
        std::env::set_var("HOME", "/tmp/synaps-config-test-disable-lists");

        let config = load_config();

        if let Some(home) = original_home {
            std::env::set_var("HOME", home);
        } else {
            std::env::remove_var("HOME");
        }

        let _ = std::fs::remove_dir_all("/tmp/synaps-config-test-disable-lists");

        assert_eq!(config.disabled_plugins, vec!["foo".to_string(), "bar".to_string()]);
        assert_eq!(config.favorite_models, vec![
            "claude/claude-opus-4-7".to_string(),
            "groq/llama-3.3-70b-versatile".to_string(),
        ]);
        assert_eq!(config.disabled_skills, vec!["baz".to_string(), "plug:qual".to_string()]);
    }

    #[test]
    #[serial]
    fn favorite_model_helpers_round_trip_through_config_file() {
        let home = make_test_home("favorite-models");
        let cfg = home.join(".synaps-cli/config");
        std::fs::write(&cfg, "model = claude-opus-4-7\n").unwrap();

        with_home(&home, || {
            add_favorite_model("groq/llama-3.3-70b-versatile").unwrap();
            add_favorite_model("claude/claude-opus-4-7").unwrap();
            add_favorite_model("groq/llama-3.3-70b-versatile").unwrap();
            assert!(is_favorite_model("groq/llama-3.3-70b-versatile"));
            remove_favorite_model("groq/llama-3.3-70b-versatile").unwrap();
            assert!(!is_favorite_model("groq/llama-3.3-70b-versatile"));
            assert!(is_favorite_model("claude/claude-opus-4-7"));
        });

        let contents = std::fs::read_to_string(&cfg).unwrap();
        assert!(contents.contains("model = claude-opus-4-7"));
        assert!(contents.contains("favorite_models = claude/claude-opus-4-7"));
        let _ = std::fs::remove_dir_all(&home);
    }

    #[test]
    #[serial]
    fn test_load_config_new_keys() {
        // Create a temporary config directory with the new keys
        let test_dir = std::path::PathBuf::from("/tmp/synaps-config-test-new-keys/.synaps-cli");
        let _ = std::fs::create_dir_all(&test_dir);
        let config_path = test_dir.join("config");
        
        let config_content = r#"
# Test config with new keys
model = claude-haiku
thinking = medium
max_tool_output = 50000
bash_timeout = 45
bash_max_timeout = 600
subagent_timeout = 120
api_retries = 5
"#;
        std::fs::write(&config_path, config_content).unwrap();
        
        // Temporarily override the config path for this test
        let original_home = std::env::var("HOME").ok();
        std::env::set_var("HOME", "/tmp/synaps-config-test-new-keys");
        
        let config = load_config();
        
        // Restore original HOME
        if let Some(home) = original_home {
            std::env::set_var("HOME", home);
        } else {
            std::env::remove_var("HOME");
        }
        
        // Cleanup
        let _ = std::fs::remove_dir_all("/tmp/synaps-config-test-new-keys");
        
        assert_eq!(config.model, Some("claude-haiku".to_string()));
        assert_eq!(config.thinking_budget, Some(4096)); // medium = 4096
        assert_eq!(config.max_tool_output, 50000);
        assert_eq!(config.bash_timeout, 45);
        assert_eq!(config.bash_max_timeout, 600);
        assert_eq!(config.subagent_timeout, 120);
        assert_eq!(config.api_retries, 5);
    }
}