selfware 0.6.1

//! Project Intelligence Layer
//!
//! Background indexer providing code intelligence:
//! - File watching for real-time updates
//! - Symbol index for functions, structs, enums
//! - Dependency graph from Cargo.toml
//! - Git state monitoring
//! - Pattern detection for code structure

use crate::bm25::BM25Index;
use anyhow::Result;
use chrono::{DateTime, Utc};
use once_cell::sync::Lazy;
use regex::Regex;
use serde::{Deserialize, Serialize};
use std::collections::HashMap;
use std::path::{Path, PathBuf};
use std::sync::{Arc, RwLock};

// Pre-compiled regexes for Rust symbol indexing (compiled once, reused across calls)
static FN_REGEX: Lazy<Regex> = Lazy::new(|| {
    Regex::new(r"^\s*(pub(\(.*?\))?\s+)?(async\s+)?fn\s+(\w+)")
        .unwrap_or_else(|e| panic!("Invalid regex pattern: {e}"))
});
static STRUCT_REGEX: Lazy<Regex> = Lazy::new(|| {
    Regex::new(r"^\s*(pub(\(.*?\))?\s+)?struct\s+(\w+)")
        .unwrap_or_else(|e| panic!("Invalid regex pattern: {e}"))
});
static ENUM_REGEX: Lazy<Regex> = Lazy::new(|| {
    Regex::new(r"^\s*(pub(\(.*?\))?\s+)?enum\s+(\w+)")
        .unwrap_or_else(|e| panic!("Invalid regex pattern: {e}"))
});
static TRAIT_REGEX: Lazy<Regex> = Lazy::new(|| {
    Regex::new(r"^\s*(pub(\(.*?\))?\s+)?trait\s+(\w+)")
        .unwrap_or_else(|e| panic!("Invalid regex pattern: {e}"))
});
static IMPL_REGEX: Lazy<Regex> = Lazy::new(|| {
    Regex::new(r"^\s*impl(<.*?>)?\s+(\w+)").unwrap_or_else(|e| panic!("Invalid regex pattern: {e}"))
});
static CONST_REGEX: Lazy<Regex> = Lazy::new(|| {
    Regex::new(r"^\s*(pub(\(.*?\))?\s+)?const\s+(\w+)")
        .unwrap_or_else(|e| panic!("Invalid regex pattern: {e}"))
});
static TYPE_REGEX: Lazy<Regex> = Lazy::new(|| {
    Regex::new(r"^\s*(pub(\(.*?\))?\s+)?type\s+(\w+)")
        .unwrap_or_else(|e| panic!("Invalid regex pattern: {e}"))
});
static MACRO_REGEX: Lazy<Regex> = Lazy::new(|| {
    Regex::new(r"^\s*(pub(\(.*?\))?\s+)?macro_rules!\s+(\w+)")
        .unwrap_or_else(|e| panic!("Invalid regex pattern: {e}"))
});
static MOD_REGEX: Lazy<Regex> = Lazy::new(|| {
    Regex::new(r"^\s*(pub(\(.*?\))?\s+)?mod\s+(\w+)")
        .unwrap_or_else(|e| panic!("Invalid regex pattern: {e}"))
});

// std::sync::RwLock is intentional here. All ProjectIntelligence methods are synchronous,
// so std::sync::RwLock avoids requiring .await at every lock acquisition. Migrating to
// tokio::sync::RwLock would require making refresh(), search(), index_files(), and all
// accessor call-sites async (~50+ changes) with no functional benefit.

/// Main intelligence hub coordinating all analysis
#[derive(Debug)]
pub struct ProjectIntelligence {
    /// Root directory being indexed
    root: PathBuf,
    /// Symbol index
    symbols: Arc<RwLock<SymbolIndex>>,
    /// Dependency graph
    dependencies: Arc<RwLock<DependencyGraph>>,
    /// Git state
    git_state: Arc<RwLock<GitState>>,
    /// File index
    files: Arc<RwLock<FileIndex>>,
    /// Pattern detector
    patterns: Arc<RwLock<PatternDetector>>,
    /// Last update time
    last_update: DateTime<Utc>,
}

/// Symbol types that can be indexed
#[derive(Debug, Clone, PartialEq, Eq, Hash, Serialize, Deserialize)]
pub enum SymbolKind {
    Function,
    Struct,
    Enum,
    Trait,
    Impl,
    Const,
    Static,
    Type,
    Macro,
    Module,
}

impl SymbolKind {
    /// Icon for display
    pub fn icon(&self) -> &'static str {
        match self {
            SymbolKind::Function => "ƒ",
            SymbolKind::Struct => "◇",
            SymbolKind::Enum => "◆",
            SymbolKind::Trait => "▸",
            SymbolKind::Impl => "▹",
            SymbolKind::Const => "C",
            SymbolKind::Static => "S",
            SymbolKind::Type => "T",
            SymbolKind::Macro => "M",
            SymbolKind::Module => "◫",
        }
    }

    /// Color for display (ANSI code)
    pub fn color(&self) -> &'static str {
        match self {
            SymbolKind::Function => "\x1b[33m",                   // Yellow
            SymbolKind::Struct => "\x1b[36m",                     // Cyan
            SymbolKind::Enum => "\x1b[35m",                       // Magenta
            SymbolKind::Trait => "\x1b[34m",                      // Blue
            SymbolKind::Impl => "\x1b[32m",                       // Green
            SymbolKind::Const | SymbolKind::Static => "\x1b[31m", // Red
            SymbolKind::Type => "\x1b[94m",                       // Light blue
            SymbolKind::Macro => "\x1b[95m",                      // Light magenta
            SymbolKind::Module => "\x1b[37m",                     // White
        }
    }
}

/// A symbol found in the codebase
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct Symbol {
    /// Symbol name
    pub name: String,
    /// Symbol kind
    pub kind: SymbolKind,
    /// File containing this symbol
    pub file: PathBuf,
    /// Line number (1-indexed)
    pub line: usize,
    /// Column (1-indexed)
    pub column: usize,
    /// Full signature/declaration
    pub signature: String,
    /// Documentation comment if any
    pub doc: Option<String>,
    /// Visibility (pub, pub(crate), etc.)
    pub visibility: Visibility,
    /// Parent symbol (for nested items)
    pub parent: Option<String>,
}

impl Symbol {
    /// Create a new symbol
    pub fn new(name: String, kind: SymbolKind, file: PathBuf, line: usize) -> Self {
        Self {
            name,
            kind,
            file,
            line,
            column: 1,
            signature: String::new(),
            doc: None,
            visibility: Visibility::Private,
            parent: None,
        }
    }

    /// Set signature
    pub fn with_signature(mut self, signature: String) -> Self {
        self.signature = signature;
        self
    }

    /// Set documentation
    pub fn with_doc(mut self, doc: String) -> Self {
        self.doc = Some(doc);
        self
    }

    /// Set visibility
    pub fn with_visibility(mut self, visibility: Visibility) -> Self {
        self.visibility = visibility;
        self
    }

    /// Set parent
    pub fn with_parent(mut self, parent: String) -> Self {
        self.parent = Some(parent);
        self
    }

    /// Set column
    pub fn with_column(mut self, column: usize) -> Self {
        self.column = column;
        self
    }

    /// Format for display
    pub fn display(&self) -> String {
        format!(
            "{} {} {}:{}",
            self.kind.icon(),
            self.name,
            self.file.display(),
            self.line
        )
    }
}

/// Visibility of a symbol
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, Default)]
pub enum Visibility {
    #[default]
    Private,
    Pub,
    PubCrate,
    PubSuper,
    PubIn(String),
}

impl Visibility {
    /// Parse visibility from source
    pub fn parse(s: &str) -> Self {
        if s.starts_with("pub(crate)") {
            Visibility::PubCrate
        } else if s.starts_with("pub(super)") {
            Visibility::PubSuper
        } else if s.starts_with("pub(in") {
            // Extract path
            if let Some(start) = s.find("pub(in ") {
                if let Some(end) = s[start..].find(')') {
                    let path = s[start + 7..start + end].to_string();
                    return Visibility::PubIn(path);
                }
            }
            Visibility::Pub
        } else if s.starts_with("pub") {
            Visibility::Pub
        } else {
            Visibility::Private
        }
    }

    /// Is this public?
    pub fn is_public(&self) -> bool {
        matches!(self, Visibility::Pub)
    }
}

/// Symbol index for the project
#[derive(Debug, Default)]
pub struct SymbolIndex {
    /// All symbols by name
    by_name: HashMap<String, Vec<Symbol>>,
    /// Symbols by file
    by_file: HashMap<PathBuf, Vec<Symbol>>,
    /// Symbols by kind
    by_kind: HashMap<SymbolKind, Vec<Symbol>>,
    /// Total count
    count: usize,
    /// BM25 index for ranked search
    bm25: BM25Index,
}

impl SymbolIndex {
    /// Create new empty index
    pub fn new() -> Self {
        Self::default()
    }

    /// Add a symbol to the index
    pub fn add(&mut self, symbol: Symbol) {
        // Build searchable text for BM25: name + signature + doc
        let searchable = format!(
            "{} {} {}",
            symbol.name,
            symbol.signature,
            symbol.doc.as_deref().unwrap_or("")
        );
        let doc_id = Self::make_doc_id(&symbol.file, symbol.line, &symbol.name);
        self.bm25.add(&doc_id, searchable);

        self.by_name
            .entry(symbol.name.clone())
            .or_default()
            .push(symbol.clone());
        self.by_file
            .entry(symbol.file.clone())
            .or_default()
            .push(symbol.clone());
        self.by_kind
            .entry(symbol.kind.clone())
            .or_default()
            .push(symbol);
        self.count += 1;
    }

    /// Search symbols using BM25 ranking
    ///
    /// Returns symbols ranked by relevance to the query.
    /// Uses BM25 for ranking with CamelCase and snake_case tokenization.
    pub fn search(&mut self, query: &str) -> Vec<&Symbol> {
        // Use BM25 for ranked search
        let bm25_results = self.bm25.search(query, 100);

        // Map BM25 results back to symbols
        let mut results = Vec::new();
        for result in bm25_results {
            // Parse doc_id using null-byte separator (handles paths with colons)
            if let Some((file_str, line, name)) = Self::parse_doc_id(&result.id) {
                if let Some(symbols) = self.by_name.get(name) {
                    // Find the specific symbol by file and line
                    for symbol in symbols {
                        if symbol.file.to_string_lossy() == file_str && symbol.line == line {
                            results.push(symbol);
                            break;
                        }
                    }
                }
            }
        }
        results
    }

    /// Get symbols by exact name
    pub fn get(&self, name: &str) -> Option<&Vec<Symbol>> {
        self.by_name.get(name)
    }

    /// Get symbols in a file
    pub fn in_file(&self, file: &Path) -> Option<&Vec<Symbol>> {
        self.by_file.get(file)
    }

    /// Get symbols of a specific kind
    pub fn of_kind(&self, kind: &SymbolKind) -> Option<&Vec<Symbol>> {
        self.by_kind.get(kind)
    }

    /// Get all functions
    pub fn functions(&self) -> Vec<&Symbol> {
        self.by_kind
            .get(&SymbolKind::Function)
            .map(|v| v.iter().collect())
            .unwrap_or_default()
    }

    /// Get all structs
    pub fn structs(&self) -> Vec<&Symbol> {
        self.by_kind
            .get(&SymbolKind::Struct)
            .map(|v| v.iter().collect())
            .unwrap_or_default()
    }

    /// Total symbol count
    pub fn len(&self) -> usize {
        self.count
    }

    /// Is empty
    pub fn is_empty(&self) -> bool {
        self.count == 0
    }

    /// Clear the index
    pub fn clear(&mut self) {
        self.by_name.clear();
        self.by_file.clear();
        self.by_kind.clear();
        self.bm25.clear();
        self.count = 0;
    }

    /// Remove symbols from a file
    pub fn remove_file(&mut self, file: &Path) {
        if let Some(symbols) = self.by_file.remove(file) {
            let removed_count = symbols.len();
            for symbol in &symbols {
                // Remove from BM25 index
                let doc_id = Self::make_doc_id(&symbol.file, symbol.line, &symbol.name);
                self.bm25.remove_all(&doc_id);

                if let Some(by_name) = self.by_name.get_mut(&symbol.name) {
                    by_name.retain(|s| s.file != file);
                }
                if let Some(by_kind) = self.by_kind.get_mut(&symbol.kind) {
                    by_kind.retain(|s| s.file != file);
                }
            }
            self.count = self.count.saturating_sub(removed_count);
        }
    }

    /// Create a stable document ID for BM25 (uses \x00 as separator to avoid path issues)
    fn make_doc_id(file: &Path, line: usize, name: &str) -> String {
        format!("{}\x00{}\x00{}", file.display(), line, name)
    }

    /// Parse a document ID back into components
    fn parse_doc_id(doc_id: &str) -> Option<(&str, usize, &str)> {
        let parts: Vec<&str> = doc_id.splitn(3, '\x00').collect();
        if parts.len() == 3 {
            let line = parts[1].parse().ok()?;
            Some((parts[0], line, parts[2]))
        } else {
            None
        }
    }
}

/// Dependency information
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct Dependency {
    /// Crate name
    pub name: String,
    /// Version requirement
    pub version: String,
    /// Features enabled
    pub features: Vec<String>,
    /// Is optional
    pub optional: bool,
    /// Is dev dependency
    pub dev: bool,
    /// Is build dependency
    pub build: bool,
}

impl Dependency {
    /// Create a new dependency
    pub fn new(name: String, version: String) -> Self {
        Self {
            name,
            version,
            features: Vec::new(),
            optional: false,
            dev: false,
            build: false,
        }
    }

    /// Add features
    pub fn with_features(mut self, features: Vec<String>) -> Self {
        self.features = features;
        self
    }

    /// Mark as optional
    pub fn optional(mut self) -> Self {
        self.optional = true;
        self
    }

    /// Mark as dev dependency
    pub fn dev(mut self) -> Self {
        self.dev = true;
        self
    }

    /// Mark as build dependency
    pub fn build(mut self) -> Self {
        self.build = true;
        self
    }
}

/// Dependency graph from Cargo.toml
#[derive(Debug, Default)]
pub struct DependencyGraph {
    /// Direct dependencies
    pub dependencies: Vec<Dependency>,
    /// Dev dependencies
    pub dev_dependencies: Vec<Dependency>,
    /// Build dependencies
    pub build_dependencies: Vec<Dependency>,
    /// Package name
    pub package_name: Option<String>,
    /// Package version
    pub package_version: Option<String>,
    /// Features defined
    pub features: HashMap<String, Vec<String>>,
}

impl DependencyGraph {
    /// Create new empty graph
    pub fn new() -> Self {
        Self::default()
    }

    /// Parse from Cargo.toml content
    pub fn parse(content: &str) -> Result<Self> {
        let value: toml::Value = toml::from_str(content)?;
        let mut graph = Self::new();

        // Parse package info
        if let Some(package) = value.get("package") {
            if let Some(name) = package.get("name").and_then(|v| v.as_str()) {
                graph.package_name = Some(name.to_string());
            }
            if let Some(version) = package.get("version").and_then(|v| v.as_str()) {
                graph.package_version = Some(version.to_string());
            }
        }

        // Parse dependencies
        if let Some(deps) = value.get("dependencies") {
            graph.dependencies = Self::parse_deps(deps)?;
        }

        // Parse dev-dependencies
        if let Some(deps) = value.get("dev-dependencies") {
            graph.dev_dependencies = Self::parse_deps(deps)?;
            for dep in &mut graph.dev_dependencies {
                dep.dev = true;
            }
        }

        // Parse build-dependencies
        if let Some(deps) = value.get("build-dependencies") {
            graph.build_dependencies = Self::parse_deps(deps)?;
            for dep in &mut graph.build_dependencies {
                dep.build = true;
            }
        }

        // Parse features
        if let Some(features) = value.get("features").and_then(|v| v.as_table()) {
            for (name, value) in features {
                if let Some(arr) = value.as_array() {
                    let deps: Vec<String> = arr
                        .iter()
                        .filter_map(|v| v.as_str().map(String::from))
                        .collect();
                    graph.features.insert(name.clone(), deps);
                }
            }
        }

        Ok(graph)
    }

    /// Parse dependencies section
    fn parse_deps(deps: &toml::Value) -> Result<Vec<Dependency>> {
        let mut result = Vec::new();

        if let Some(table) = deps.as_table() {
            for (name, value) in table {
                let dep = match value {
                    toml::Value::String(version) => Dependency::new(name.clone(), version.clone()),
                    toml::Value::Table(t) => {
                        let version = t
                            .get("version")
                            .and_then(|v| v.as_str())
                            .unwrap_or("*")
                            .to_string();
                        let mut dep = Dependency::new(name.clone(), version);

                        if let Some(features) = t.get("features").and_then(|v| v.as_array()) {
                            dep.features = features
                                .iter()
                                .filter_map(|v| v.as_str().map(String::from))
                                .collect();
                        }

                        if let Some(optional) = t.get("optional").and_then(|v| v.as_bool()) {
                            dep.optional = optional;
                        }

                        dep
                    }
                    _ => continue,
                };
                result.push(dep);
            }
        }

        Ok(result)
    }

    /// Get all dependencies (direct + dev + build)
    pub fn all(&self) -> Vec<&Dependency> {
        self.dependencies
            .iter()
            .chain(self.dev_dependencies.iter())
            .chain(self.build_dependencies.iter())
            .collect()
    }

    /// Find dependency by name
    pub fn find(&self, name: &str) -> Option<&Dependency> {
        self.all().into_iter().find(|d| d.name == name)
    }

    /// Count all dependencies
    pub fn count(&self) -> usize {
        self.dependencies.len() + self.dev_dependencies.len() + self.build_dependencies.len()
    }
}

/// Git state for the project
#[derive(Debug, Default)]
pub struct GitState {
    /// Current branch
    pub branch: Option<String>,
    /// Current commit hash
    pub commit: Option<String>,
    /// Is the repo dirty (uncommitted changes)
    pub dirty: bool,
    /// Untracked files
    pub untracked: Vec<PathBuf>,
    /// Modified files
    pub modified: Vec<PathBuf>,
    /// Staged files
    pub staged: Vec<PathBuf>,
    /// Remote tracking branch
    pub remote: Option<String>,
    /// Commits ahead of remote
    pub ahead: usize,
    /// Commits behind remote
    pub behind: usize,
}

impl GitState {
    /// Create new state
    pub fn new() -> Self {
        Self::default()
    }

    /// Update from git repository
    pub fn update(&mut self, repo_path: &Path) -> Result<()> {
        let repo = git2::Repository::open(repo_path)?;

        // Get current branch
        if let Ok(head) = repo.head() {
            if head.is_branch() {
                self.branch = head.shorthand().ok().map(String::from);
            }
            if let Some(oid) = head.target() {
                self.commit = Some(oid.to_string());
            }
        }

        // Get status
        let statuses = repo.statuses(None)?;
        self.untracked.clear();
        self.modified.clear();
        self.staged.clear();

        for entry in statuses.iter() {
            if let Ok(path) = entry.path() {
                let path = PathBuf::from(path);
                let status = entry.status();

                if status.is_wt_new() {
                    self.untracked.push(path.clone());
                }
                if status.is_wt_modified() || status.is_wt_deleted() {
                    self.modified.push(path.clone());
                }
                if status.is_index_new() || status.is_index_modified() || status.is_index_deleted()
                {
                    self.staged.push(path);
                }
            }
        }

        self.dirty =
            !self.untracked.is_empty() || !self.modified.is_empty() || !self.staged.is_empty();

        Ok(())
    }

    /// Get status summary
    pub fn summary(&self) -> String {
        let mut parts = Vec::new();

        if let Some(ref branch) = self.branch {
            parts.push(format!("on {}", branch));
        }

        if self.dirty {
            let changes = self.modified.len() + self.staged.len();
            parts.push(format!("{} changes", changes));
        }

        if !self.untracked.is_empty() {
            parts.push(format!("{} untracked", self.untracked.len()));
        }

        if self.ahead > 0 {
            parts.push(format!("↑{}", self.ahead));
        }

        if self.behind > 0 {
            parts.push(format!("↓{}", self.behind));
        }

        parts.join(", ")
    }
}

/// File index entry
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct FileEntry {
    /// File path
    pub path: PathBuf,
    /// File size in bytes
    pub size: u64,
    /// Last modified time
    pub modified: DateTime<Utc>,
    /// File type/extension
    pub extension: Option<String>,
    /// Language detected
    pub language: Option<String>,
    /// Line count
    pub lines: Option<usize>,
}

impl FileEntry {
    /// Create from path
    pub fn from_path(path: PathBuf) -> Result<Self> {
        let metadata = std::fs::metadata(&path)?;
        let modified = metadata.modified()?.into();
        let extension = path.extension().map(|e| e.to_string_lossy().to_string());
        let language = extension.as_ref().and_then(|e| detect_language(e));

        Ok(Self {
            path,
            size: metadata.len(),
            modified,
            extension,
            language,
            lines: None,
        })
    }

    /// Count lines in file
    pub fn count_lines(&mut self) -> Result<usize> {
        let content = std::fs::read_to_string(&self.path)?;
        let count = content.lines().count();
        self.lines = Some(count);
        Ok(count)
    }
}

/// Detect language from extension
pub fn detect_language(ext: &str) -> Option<String> {
    let lang = match ext.to_lowercase().as_str() {
        "rs" => "Rust",
        "py" => "Python",
        "js" => "JavaScript",
        "ts" => "TypeScript",
        "tsx" | "jsx" => "React",
        "go" => "Go",
        "java" => "Java",
        "c" | "h" => "C",
        "cpp" | "hpp" | "cc" | "cxx" => "C++",
        "rb" => "Ruby",
        "php" => "PHP",
        "swift" => "Swift",
        "kt" | "kts" => "Kotlin",
        "scala" => "Scala",
        "hs" => "Haskell",
        "ml" | "mli" => "OCaml",
        "ex" | "exs" => "Elixir",
        "erl" | "hrl" => "Erlang",
        "clj" | "cljs" => "Clojure",
        "lua" => "Lua",
        "r" => "R",
        "sql" => "SQL",
        "sh" | "bash" | "zsh" => "Shell",
        "md" | "markdown" => "Markdown",
        "json" => "JSON",
        "yaml" | "yml" => "YAML",
        "toml" => "TOML",
        "xml" => "XML",
        "html" | "htm" => "HTML",
        "css" => "CSS",
        "scss" | "sass" => "SASS",
        "vue" => "Vue",
        "svelte" => "Svelte",
        _ => return None,
    };
    Some(lang.to_string())
}

/// File index for the project
#[derive(Debug, Default)]
pub struct FileIndex {
    /// All files
    files: HashMap<PathBuf, FileEntry>,
    /// Files by extension
    by_extension: HashMap<String, Vec<PathBuf>>,
    /// Files by language
    by_language: HashMap<String, Vec<PathBuf>>,
}

impl FileIndex {
    /// Create new index
    pub fn new() -> Self {
        Self::default()
    }

    /// Add a file to the index
    pub fn add(&mut self, entry: FileEntry) {
        let path = entry.path.clone();

        if let Some(ext) = &entry.extension {
            self.by_extension
                .entry(ext.clone())
                .or_default()
                .push(path.clone());
        }

        if let Some(lang) = &entry.language {
            self.by_language
                .entry(lang.clone())
                .or_default()
                .push(path.clone());
        }

        self.files.insert(path, entry);
    }

    /// Get file by path
    pub fn get(&self, path: &Path) -> Option<&FileEntry> {
        self.files.get(path)
    }

    /// Get files by extension
    pub fn by_extension(&self, ext: &str) -> Vec<&FileEntry> {
        self.by_extension
            .get(ext)
            .map(|paths| paths.iter().filter_map(|p| self.files.get(p)).collect())
            .unwrap_or_default()
    }

    /// Get files by language
    pub fn by_language(&self, lang: &str) -> Vec<&FileEntry> {
        self.by_language
            .get(lang)
            .map(|paths| paths.iter().filter_map(|p| self.files.get(p)).collect())
            .unwrap_or_default()
    }

    /// Remove file from index
    pub fn remove(&mut self, path: &Path) {
        if let Some(entry) = self.files.remove(path) {
            if let Some(ext) = &entry.extension {
                if let Some(paths) = self.by_extension.get_mut(ext) {
                    paths.retain(|p| p != path);
                }
            }
            if let Some(lang) = &entry.language {
                if let Some(paths) = self.by_language.get_mut(lang) {
                    paths.retain(|p| p != path);
                }
            }
        }
    }

    /// Total file count
    pub fn len(&self) -> usize {
        self.files.len()
    }

    /// Is empty
    pub fn is_empty(&self) -> bool {
        self.files.is_empty()
    }

    /// Clear index
    pub fn clear(&mut self) {
        self.files.clear();
        self.by_extension.clear();
        self.by_language.clear();
    }

    /// Get language statistics
    pub fn language_stats(&self) -> HashMap<String, usize> {
        self.by_language
            .iter()
            .map(|(lang, paths)| (lang.clone(), paths.len()))
            .collect()
    }
}

/// Code pattern detection
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct CodePattern {
    /// Pattern name
    pub name: String,
    /// Description
    pub description: String,
    /// Category
    pub category: PatternCategory,
    /// Locations where this pattern was found
    pub locations: Vec<PatternLocation>,
}

impl CodePattern {
    /// Create new pattern
    pub fn new(name: String, description: String, category: PatternCategory) -> Self {
        Self {
            name,
            description,
            category,
            locations: Vec::new(),
        }
    }

    /// Add a location
    pub fn add_location(&mut self, file: PathBuf, line: usize, snippet: String) {
        self.locations.push(PatternLocation {
            file,
            line,
            snippet,
        });
    }
}

/// Pattern category
#[derive(Debug, Clone, PartialEq, Eq, Hash, Serialize, Deserialize)]
pub enum PatternCategory {
    Design,      // Design patterns (singleton, factory, etc.)
    AntiPattern, // Bad practices
    Convention,  // Coding conventions
    Security,    // Security-related patterns
    Performance, // Performance patterns
    Testing,     // Testing patterns
}

impl PatternCategory {
    /// Icon for category
    pub fn icon(&self) -> &'static str {
        match self {
            PatternCategory::Design => "🏗️",
            PatternCategory::AntiPattern => "⚠️",
            PatternCategory::Convention => "📏",
            PatternCategory::Security => "🔒",
            PatternCategory::Performance => "⚡",
            PatternCategory::Testing => "🧪",
        }
    }
}

/// Location of a pattern match
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct PatternLocation {
    pub file: PathBuf,
    pub line: usize,
    pub snippet: String,
}

/// Pattern detector for code analysis
#[derive(Debug, Default)]
pub struct PatternDetector {
    /// Detected patterns
    patterns: Vec<CodePattern>,
    /// Pattern rules
    rules: Vec<PatternRule>,
}

/// Rule for detecting patterns
#[derive(Debug, Clone)]
pub struct PatternRule {
    /// Pattern name
    pub name: String,
    /// Category
    pub category: PatternCategory,
    /// Description
    pub description: String,
    /// Regex pattern
    pub regex: Regex,
}

impl PatternRule {
    /// Create a new rule
    pub fn new(
        name: &str,
        category: PatternCategory,
        description: &str,
        pattern: &str,
    ) -> Result<Self> {
        Ok(Self {
            name: name.to_string(),
            category,
            description: description.to_string(),
            regex: Regex::new(pattern)?,
        })
    }
}

impl PatternDetector {
    /// Create new detector with default rules
    pub fn new() -> Self {
        let mut detector = Self::default();
        detector.add_default_rules();
        detector
    }

    /// Add default pattern rules
    fn add_default_rules(&mut self) {
        // Unwrap usage (potential panic)
        if let Ok(rule) = PatternRule::new(
            "unwrap_usage",
            PatternCategory::AntiPattern,
            "Direct .unwrap() calls can panic",
            r"\.unwrap\(\)",
        ) {
            self.rules.push(rule);
        }

        // TODO comments
        if let Ok(rule) = PatternRule::new(
            "todo_comment",
            PatternCategory::Convention,
            "TODO comments indicate unfinished work",
            r"(?i)//\s*TODO:",
        ) {
            self.rules.push(rule);
        }

        // FIXME comments
        if let Ok(rule) = PatternRule::new(
            "fixme_comment",
            PatternCategory::Convention,
            "FIXME comments indicate bugs or issues",
            r"(?i)//\s*FIXME:",
        ) {
            self.rules.push(rule);
        }

        // Unsafe blocks
        if let Ok(rule) = PatternRule::new(
            "unsafe_block",
            PatternCategory::Security,
            "Unsafe blocks require careful review",
            r"unsafe\s*\{",
        ) {
            self.rules.push(rule);
        }

        // Clone in loop
        if let Ok(rule) = PatternRule::new(
            "clone_in_loop",
            PatternCategory::Performance,
            "Cloning in loops can be expensive",
            r"for\s+.*\{[^}]*\.clone\(\)",
        ) {
            self.rules.push(rule);
        }

        // Test function
        if let Ok(rule) = PatternRule::new(
            "test_function",
            PatternCategory::Testing,
            "Test functions",
            r"#\[test\]",
        ) {
            self.rules.push(rule);
        }
    }

    /// Analyze content for patterns
    pub fn analyze(&mut self, file: &Path, content: &str) {
        for rule in &self.rules {
            for (line_num, line) in content.lines().enumerate() {
                if rule.regex.is_match(line) {
                    // Find or create pattern
                    let pattern = self.patterns.iter_mut().find(|p| p.name == rule.name);

                    if let Some(pattern) = pattern {
                        pattern.add_location(file.to_path_buf(), line_num + 1, line.to_string());
                    } else {
                        let mut pattern = CodePattern::new(
                            rule.name.clone(),
                            rule.description.clone(),
                            rule.category.clone(),
                        );
                        pattern.add_location(file.to_path_buf(), line_num + 1, line.to_string());
                        self.patterns.push(pattern);
                    }
                }
            }
        }
    }

    /// Get all detected patterns
    pub fn patterns(&self) -> &[CodePattern] {
        &self.patterns
    }

    /// Get patterns by category
    pub fn by_category(&self, category: &PatternCategory) -> Vec<&CodePattern> {
        self.patterns
            .iter()
            .filter(|p| &p.category == category)
            .collect()
    }

    /// Get anti-patterns (issues to fix)
    pub fn anti_patterns(&self) -> Vec<&CodePattern> {
        self.by_category(&PatternCategory::AntiPattern)
    }

    /// Clear detected patterns
    pub fn clear(&mut self) {
        self.patterns.clear();
    }

    /// Add custom rule
    pub fn add_rule(&mut self, rule: PatternRule) {
        self.rules.push(rule);
    }

    /// Summary of findings
    pub fn summary(&self) -> HashMap<PatternCategory, usize> {
        let mut result = HashMap::new();
        for pattern in &self.patterns {
            *result.entry(pattern.category.clone()).or_insert(0) += pattern.locations.len();
        }
        result
    }
}

impl ProjectIntelligence {
    /// Create new intelligence for a project root
    pub fn new(root: PathBuf) -> Self {
        Self {
            root,
            symbols: Arc::new(RwLock::new(SymbolIndex::new())),
            dependencies: Arc::new(RwLock::new(DependencyGraph::new())),
            git_state: Arc::new(RwLock::new(GitState::new())),
            files: Arc::new(RwLock::new(FileIndex::new())),
            patterns: Arc::new(RwLock::new(PatternDetector::new())),
            last_update: Utc::now(),
        }
    }

    /// Get project root
    pub fn root(&self) -> &Path {
        &self.root
    }

    /// Get symbol index
    pub fn symbols(&self) -> &Arc<RwLock<SymbolIndex>> {
        &self.symbols
    }

    /// Get dependency graph
    pub fn dependencies(&self) -> &Arc<RwLock<DependencyGraph>> {
        &self.dependencies
    }

    /// Get git state
    pub fn git_state(&self) -> &Arc<RwLock<GitState>> {
        &self.git_state
    }

    /// Get file index
    pub fn files(&self) -> &Arc<RwLock<FileIndex>> {
        &self.files
    }

    /// Get pattern detector
    pub fn patterns(&self) -> &Arc<RwLock<PatternDetector>> {
        &self.patterns
    }

    /// Refresh all indexes
    pub fn refresh(&mut self) -> Result<()> {
        // Update git state
        if let Ok(mut git) = self.git_state.write() {
            let _ = git.update(&self.root);
        }

        // Parse Cargo.toml
        let cargo_path = self.root.join("Cargo.toml");
        if cargo_path.exists() {
            if let Ok(content) = std::fs::read_to_string(&cargo_path) {
                if let Ok(deps) = DependencyGraph::parse(&content) {
                    if let Ok(mut graph) = self.dependencies.write() {
                        *graph = deps;
                    }
                }
            }
        }

        // Index files
        self.index_files()?;

        self.last_update = Utc::now();
        Ok(())
    }

    /// Index all files in the project
    fn index_files(&mut self) -> Result<()> {
        use walkdir::WalkDir;

        let mut file_index = self
            .files
            .write()
            .map_err(|_| anyhow::anyhow!("Lock error"))?;
        let mut symbol_index = self
            .symbols
            .write()
            .map_err(|_| anyhow::anyhow!("Lock error"))?;
        let mut pattern_detector = self
            .patterns
            .write()
            .map_err(|_| anyhow::anyhow!("Lock error"))?;

        file_index.clear();
        symbol_index.clear();
        pattern_detector.clear();

        for entry in WalkDir::new(&self.root)
            .into_iter()
            .filter_entry(|e| {
                if e.depth() == 0 {
                    return true;
                }
                let name = e.file_name().to_string_lossy();
                !name.starts_with('.') && name != "target" && name != "node_modules"
            })
            .filter_map(|e| e.ok())
        {
            if entry.file_type().is_file() {
                let path = entry.path().to_path_buf();
                if let Ok(file_entry) = FileEntry::from_path(path.clone()) {
                    file_index.add(file_entry);

                    // Index Rust files for symbols and patterns
                    if path.extension().map(|e| e == "rs").unwrap_or(false) {
                        if let Ok(content) = std::fs::read_to_string(&path) {
                            self.index_rust_symbols(&mut symbol_index, &path, &content);
                            pattern_detector.analyze(&path, &content);
                        }
                    }
                }
            }
        }

        Ok(())
    }

    /// Index symbols from Rust source
    fn index_rust_symbols(&self, index: &mut SymbolIndex, file: &Path, content: &str) {
        for (line_num, line) in content.lines().enumerate() {
            let line_num = line_num + 1;

            // Functions
            if let Some(caps) = FN_REGEX.captures(line) {
                let vis = Visibility::parse(caps.get(1).map(|m| m.as_str()).unwrap_or(""));
                if let Some(name_match) = caps.get(4) {
                    let symbol = Symbol::new(
                        name_match.as_str().to_string(),
                        SymbolKind::Function,
                        file.to_path_buf(),
                        line_num,
                    )
                    .with_visibility(vis)
                    .with_signature(line.trim().to_string());
                    index.add(symbol);
                }
            }
            // Structs
            else if let Some(caps) = STRUCT_REGEX.captures(line) {
                let vis = Visibility::parse(caps.get(1).map(|m| m.as_str()).unwrap_or(""));
                if let Some(name_match) = caps.get(3) {
                    let symbol = Symbol::new(
                        name_match.as_str().to_string(),
                        SymbolKind::Struct,
                        file.to_path_buf(),
                        line_num,
                    )
                    .with_visibility(vis)
                    .with_signature(line.trim().to_string());
                    index.add(symbol);
                }
            }
            // Enums
            else if let Some(caps) = ENUM_REGEX.captures(line) {
                let vis = Visibility::parse(caps.get(1).map(|m| m.as_str()).unwrap_or(""));
                if let Some(name_match) = caps.get(3) {
                    let symbol = Symbol::new(
                        name_match.as_str().to_string(),
                        SymbolKind::Enum,
                        file.to_path_buf(),
                        line_num,
                    )
                    .with_visibility(vis)
                    .with_signature(line.trim().to_string());
                    index.add(symbol);
                }
            }
            // Traits
            else if let Some(caps) = TRAIT_REGEX.captures(line) {
                let vis = Visibility::parse(caps.get(1).map(|m| m.as_str()).unwrap_or(""));
                if let Some(name_match) = caps.get(3) {
                    let symbol = Symbol::new(
                        name_match.as_str().to_string(),
                        SymbolKind::Trait,
                        file.to_path_buf(),
                        line_num,
                    )
                    .with_visibility(vis)
                    .with_signature(line.trim().to_string());
                    index.add(symbol);
                }
            }
            // Impls
            else if let Some(caps) = IMPL_REGEX.captures(line) {
                if let Some(name_match) = caps.get(2) {
                    let symbol = Symbol::new(
                        name_match.as_str().to_string(),
                        SymbolKind::Impl,
                        file.to_path_buf(),
                        line_num,
                    )
                    .with_signature(line.trim().to_string());
                    index.add(symbol);
                }
            }
            // Constants
            else if let Some(caps) = CONST_REGEX.captures(line) {
                let vis = Visibility::parse(caps.get(1).map(|m| m.as_str()).unwrap_or(""));
                if let Some(name_match) = caps.get(3) {
                    let symbol = Symbol::new(
                        name_match.as_str().to_string(),
                        SymbolKind::Const,
                        file.to_path_buf(),
                        line_num,
                    )
                    .with_visibility(vis)
                    .with_signature(line.trim().to_string());
                    index.add(symbol);
                }
            }
            // Type aliases
            else if let Some(caps) = TYPE_REGEX.captures(line) {
                let vis = Visibility::parse(caps.get(1).map(|m| m.as_str()).unwrap_or(""));
                if let Some(name_match) = caps.get(3) {
                    let symbol = Symbol::new(
                        name_match.as_str().to_string(),
                        SymbolKind::Type,
                        file.to_path_buf(),
                        line_num,
                    )
                    .with_visibility(vis)
                    .with_signature(line.trim().to_string());
                    index.add(symbol);
                }
            }
            // Macros
            else if let Some(caps) = MACRO_REGEX.captures(line) {
                let vis = Visibility::parse(caps.get(1).map(|m| m.as_str()).unwrap_or(""));
                if let Some(name_match) = caps.get(3) {
                    let symbol = Symbol::new(
                        name_match.as_str().to_string(),
                        SymbolKind::Macro,
                        file.to_path_buf(),
                        line_num,
                    )
                    .with_visibility(vis)
                    .with_signature(line.trim().to_string());
                    index.add(symbol);
                }
            }
            // Modules
            else if let Some(caps) = MOD_REGEX.captures(line) {
                let vis = Visibility::parse(caps.get(1).map(|m| m.as_str()).unwrap_or(""));
                if let Some(name_match) = caps.get(3) {
                    // Skip module declarations that just reference other files
                    if !line.contains(';') || line.contains('{') {
                        let symbol = Symbol::new(
                            name_match.as_str().to_string(),
                            SymbolKind::Module,
                            file.to_path_buf(),
                            line_num,
                        )
                        .with_visibility(vis)
                        .with_signature(line.trim().to_string());
                        index.add(symbol);
                    }
                }
            }
        }
    }

    /// Get last update time
    pub fn last_update(&self) -> DateTime<Utc> {
        self.last_update
    }

    /// Quick search across all indexes using BM25 ranking
    pub fn search(&self, query: &str) -> Vec<SearchResult> {
        let mut results = Vec::new();

        // Search symbols (needs write lock for BM25 lazy rebuild)
        if let Ok(mut symbols) = self.symbols.write() {
            for symbol in symbols.search(query) {
                results.push(SearchResult::Symbol(symbol.clone()));
            }
        }

        // Search files
        if let Ok(files) = self.files.read() {
            let query_lower = query.to_lowercase();
            for (path, entry) in &files.files {
                if path.to_string_lossy().to_lowercase().contains(&query_lower) {
                    results.push(SearchResult::File(entry.clone()));
                }
            }
        }

        results
    }
}

/// Search result types
#[derive(Debug, Clone)]
pub enum SearchResult {
    Symbol(Symbol),
    File(FileEntry),
    Pattern(CodePattern),
}

impl SearchResult {
    /// Display the result
    pub fn display(&self) -> String {
        match self {
            SearchResult::Symbol(s) => s.display(),
            SearchResult::File(f) => format!("📄 {}", f.path.display()),
            SearchResult::Pattern(p) => format!(
                "{} {} ({} matches)",
                p.category.icon(),
                p.name,
                p.locations.len()
            ),
        }
    }
}

#[cfg(test)]
#[path = "../../tests/unit/cognitive/intelligence/intelligence_test.rs"]
mod tests;