//! Multi-language code symbol index — functions, classes, variables, structs,
//! enums, interfaces, traits, modules across all major programming languages.
//!
//! # Flow
//!
//! `rebuild(workspace)` → walk files by extension → dispatch to per-language
//! extractor → merge into `SymbolIndex` → `search(query)` or `list()`.
//!
//! # Supported Languages
//!
//! | Language    | Extensions         | Symbols extracted                          |
//! |-------------|-------------------|--------------------------------------------|
//! | Rust        | `.rs`             | fn, struct, enum, trait, mod, impl, type, const, macro |
//! | TypeScript  | `.ts`, `.tsx`     | function, class, interface, type, enum, const, variable |
//! | JavaScript  | `.js`, `.jsx`, `.mjs` | function, class, const, variable, module exports |
//! | Python      | `.py`             | def, async def, class, module-level assignment |
//! | Go          | `.go`             | func, type, struct, interface, const, var |
//! | Generic     | `.c`, `.h`, `.cpp`, `.hpp`, `.java`, `.rb`, `.rs` fallback | line-based heuristic |

use crate::tools::{Tool, ToolCtx};
use anyhow::Result;
use regex::Regex;
use serde::{Deserialize, Serialize};
use serde_json::{json, Value};
use std::collections::HashMap;
use std::sync::Mutex;
use tracing::{debug, info, instrument};

// ---------------------------------------------------------------------------
//  Language & SymbolKind enums
// ---------------------------------------------------------------------------

/// Programming language of a code symbol.
#[derive(Debug, Clone, Serialize, Deserialize, Hash, PartialEq, Eq)]
pub enum Language {
    Rust,
    TypeScript,
    JavaScript,
    Python,
    Go,
    Other,
}

impl std::fmt::Display for Language {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            Language::Rust => write!(f, "rust"),
            Language::TypeScript => write!(f, "typescript"),
            Language::JavaScript => write!(f, "javascript"),
            Language::Python => write!(f, "python"),
            Language::Go => write!(f, "go"),
            Language::Other => write!(f, "other"),
        }
    }
}

/// The kind of a code symbol.
#[derive(Debug, Clone, Serialize, Deserialize, Hash, PartialEq, Eq)]
pub enum SymbolKind {
    Function,
    Struct,
    Enum,
    Trait,
    /// module, namespace, package
    Module,
    /// impl block (Rust-specific)
    Impl,
    /// type alias
    Type,
    /// const value
    Constant,
    Macro,
    /// Class (TS/JS/Python/Go)
    Class,
    /// Interface (TS/Go)
    Interface,
    /// Variable (top-level let/var/assignment)
    Variable,
    Other,
}

impl std::fmt::Display for SymbolKind {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            SymbolKind::Function => write!(f, "fn"),
            SymbolKind::Struct => write!(f, "struct"),
            SymbolKind::Enum => write!(f, "enum"),
            SymbolKind::Trait => write!(f, "trait"),
            SymbolKind::Module => write!(f, "mod"),
            SymbolKind::Impl => write!(f, "impl"),
            SymbolKind::Type => write!(f, "type"),
            SymbolKind::Constant => write!(f, "const"),
            SymbolKind::Macro => write!(f, "macro"),
            SymbolKind::Class => write!(f, "class"),
            SymbolKind::Interface => write!(f, "interface"),
            SymbolKind::Variable => write!(f, "var"),
            SymbolKind::Other => write!(f, "symbol"),
        }
    }
}

/// A single code symbol entry in the index.
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct CodeSymbol {
    /// Symbol name (e.g. "run_agent", "AppStateRest", "main").
    pub name: String,
    /// Kind of symbol.
    pub kind: SymbolKind,
    /// Language this symbol was extracted from.
    pub language: Language,
    /// File path relative to workspace root.
    pub file: String,
    /// Line number (1-indexed).
    pub line: usize,
    /// Parent symbol (e.g. struct name for impl methods).
    pub parent: Option<String>,
    /// Doc comment or leading comment text, if any.
    pub doc_comment: Option<String>,
    /// Short context (the declaration line).
    pub context: String,
}

/// The in-memory symbol index, shared via a global static.
static SYMBOL_INDEX: Mutex<Option<SymbolIndex>> = Mutex::new(None);

// ---------------------------------------------------------------------------
//  Language-specific regexes (lazily compiled)
// ---------------------------------------------------------------------------

struct LangRegexes {
    // Rust
    rust_fn: Regex,
    rust_struct: Regex,
    rust_enum: Regex,
    rust_trait: Regex,
    rust_mod: Regex,
    rust_impl: Regex,
    rust_type: Regex,
    rust_const: Regex,
    rust_macro: Regex,
    // TypeScript / JavaScript
    ts_fn: Regex,
    ts_class: Regex,
    ts_interface: Regex,
    ts_type: Regex,
    ts_enum: Regex,
    ts_var_export: Regex,
    // Python
    py_def: Regex,
    py_class: Regex,
    py_async_def: Regex,
    // Go
    go_func: Regex,
    go_type: Regex,
    go_struct: Regex,
    go_interface: Regex,
    go_const: Regex,
    go_var: Regex,
}

impl LangRegexes {
    fn new() -> Self {
        LangRegexes {
            // Rust
            rust_fn: Regex::new(
                r"(?m)^\s*(?:pub\s+)?(?:(?:unsafe\s+)?async\s+)?fn\s+(\w+)",
            )
            .expect("rust fn regex"),
            rust_struct: Regex::new(r"(?m)^\s*(?:pub\s+)?struct\s+(\w+)")
                .expect("rust struct regex"),
            rust_enum: Regex::new(r"(?m)^\s*(?:pub\s+)?enum\s+(\w+)")
                .expect("rust enum regex"),
            rust_trait: Regex::new(
                r"(?m)^\s*(?:pub\s+)?(?:(?:unsafe\s+)?)?trait\s+(\w+)",
            )
            .expect("rust trait regex"),
            rust_mod: Regex::new(r"(?m)^\s*(?:pub\s+)?mod\s+(\w+)")
                .expect("rust mod regex"),
            rust_impl: Regex::new(
                r"(?m)^\s*(?:pub\s+)?(?:unsafe\s+)?impl(?:\s*<[^>]*>)?\s+(?:for\s+)?(\w+)",
            )
            .expect("rust impl regex"),
            rust_type: Regex::new(r"(?m)^\s*(?:pub\s+)?type\s+(\w+)")
                .expect("rust type regex"),
            rust_const: Regex::new(r"(?m)^\s*(?:pub\s+)?const\s+(\w+)")
                .expect("rust const regex"),
            rust_macro: Regex::new(
                r"(?m)^\s*(?:pub\s+)?macro_rules!\s*\(\s*(\w+)",
            )
            .expect("rust macro regex"),

            // TypeScript/JavaScript
            ts_fn: Regex::new(
                r"(?m)^\s*(?:export\s+)?(?:(?:async\s+)?function\s+|(?:public|private|protected)\s+)?(\w+)\s*(?:\(|=\s*(?:async\s+)?\()",
            )
            .expect("ts fn regex"),
            ts_class: Regex::new(
                r"(?m)^\s*(?:export\s+)?(?:abstract\s+)?class\s+(\w+)",
            )
            .expect("ts class regex"),
            ts_interface: Regex::new(
                r"(?m)^\s*(?:export\s+)?interface\s+(\w+)",
            )
            .expect("ts interface regex"),
            ts_type: Regex::new(
                r"(?m)^\s*(?:export\s+)?type\s+(\w+)\s*=",
            )
            .expect("ts type regex"),
            ts_enum: Regex::new(r"(?m)^\s*(?:export\s+)?enum\s+(\w+)")
                .expect("ts enum regex"),
            ts_var_export: Regex::new(
                r"(?m)^\s*(?:export\s+)?(?:const|let|var)\s+(\w+)\s*(?::\s*\w+\s*)?=",
            )
            .expect("ts var regex"),

            // Python
            py_def: Regex::new(r"(?m)^\s*def\s+(\w+)").expect("py def regex"),
            py_class: Regex::new(r"(?m)^\s*class\s+(\w+)")
                .expect("py class regex"),
            py_async_def: Regex::new(r"(?m)^\s*async\s+def\s+(\w+)")
                .expect("py async def regex"),

            // Go
            go_func: Regex::new(
                r"(?m)^\s*func\s+(?:\([^)]*\)\s+)?(\w+)",
            )
            .expect("go func regex"),
            go_type: Regex::new(r"(?m)^\s*type\s+(\w+)")
                .expect("go type regex"),
            go_struct: Regex::new(r"(?m)^\s*type\s+(\w+)\s+struct")
                .expect("go struct regex"),
            go_interface: Regex::new(
                r"(?m)^\s*type\s+(\w+)\s+interface",
            )
            .expect("go interface regex"),
            go_const: Regex::new(r"(?m)^\s*const\s+(\w+)")
                .expect("go const regex"),
            go_var: Regex::new(r"(?m)^\s*var\s+(\w+)")
                .expect("go var regex"),
        }
    }
}

static LANG_REGEXES: std::sync::OnceLock<LangRegexes> = std::sync::OnceLock::new();

fn regexes() -> &'static LangRegexes {
    LANG_REGEXES.get_or_init(LangRegexes::new)
}

// ---------------------------------------------------------------------------
//  SymbolIndex
// ---------------------------------------------------------------------------

/// A symbol index cache.
#[derive(Debug, Clone)]
pub struct SymbolIndex {
    symbols: Vec<CodeSymbol>,
    workspace_path: Option<String>,
}

impl SymbolIndex {
    pub fn new() -> Self {
        SymbolIndex {
            symbols: Vec::new(),
            workspace_path: None,
        }
    }

    pub fn is_empty(&self) -> bool {
        self.symbols.is_empty()
    }

    pub fn len(&self) -> usize {
        self.symbols.len()
    }

    /// Rebuild the index by walking the workspace and extracting symbols
    /// from all supported languages.
    pub fn rebuild(&mut self, workspace: &str) -> Result<usize> {
        let path = std::path::Path::new(workspace);
        if !path.exists() {
            anyhow::bail!("workspace path does not exist: {workspace}");
        }

        let mut symbols = Vec::new();
        let walker = ignore::Walk::new(path);

        // Pre-compile per-extension dispatch table.
        type ExtDispatch = HashMap<&'static str, fn(&str, &str) -> Vec<CodeSymbol>>;
        let mut ext_dispatch = ExtDispatch::new();
        ext_dispatch.insert("rs", extract_rust);
        ext_dispatch.insert("ts", extract_typescript);
        ext_dispatch.insert("tsx", extract_typescript);
        ext_dispatch.insert("mts", extract_typescript);
        ext_dispatch.insert("js", extract_javascript);
        ext_dispatch.insert("jsx", extract_javascript);
        ext_dispatch.insert("mjs", extract_javascript);
        ext_dispatch.insert("py", extract_python);
        ext_dispatch.insert("go", extract_go);

        for entry in walker.flatten() {
            let file_path = entry.path();
            if !file_path.is_file() {
                continue;
            }

            let ext = file_path
                .extension()
                .and_then(|e| e.to_str())
                .unwrap_or("");
            let extractor = match ext_dispatch.get(ext) {
                Some(f) => f,
                _ => continue, // unsupported extension
            };

            let rel_path = file_path
                .strip_prefix(path)
                .unwrap_or(file_path)
                .display()
                .to_string();

            match std::fs::read_to_string(file_path) {
                Ok(content) => {
                    let file_symbols = extractor(&content, &rel_path);
                    symbols.extend(file_symbols);
                }
                Err(e) => {
                    debug!(file = %rel_path, error = %e, "failed to read file for indexing");
                }
            }
        }

        symbols.sort_by(|a, b| a.name.cmp(&b.name));
        self.symbols = symbols;
        self.workspace_path = Some(workspace.to_string());

        let count = self.symbols.len();
        info!(symbol_count = count, workspace = %workspace, "symbol index rebuilt");
        Ok(count)
    }

    /// Search indexed symbols by query.
    pub fn search(&self, query: &str, max_results: usize) -> Vec<&CodeSymbol> {
        if self.symbols.is_empty() {
            return Vec::new();
        }

        let query_lower = query.to_lowercase();
        let query_words: Vec<String> = query_lower
            .split_whitespace()
            .map(|s| s.to_string())
            .collect();

        let mut scored: Vec<(i32, &CodeSymbol)> = self
            .symbols
            .iter()
            .filter_map(|sym| {
                let score = score_symbol(sym, &query_lower, &query_words);
                if score > 0 {
                    Some((score, sym))
                } else {
                    None
                }
            })
            .collect();

        scored.sort_by(|a, b| b.0.cmp(&a.0).then_with(|| a.1.name.cmp(&b.1.name)));

        scored
            .into_iter()
            .take(max_results)
            .map(|(_, sym)| sym)
            .collect()
    }

    /// Return all indexed symbols, optionally filtered by language and/or kind.
    pub fn list(
        &self,
        language_filter: Option<Language>,
        kind_filter: Option<SymbolKind>,
        file_filter: Option<&str>,
        max_results: usize,
    ) -> Vec<&CodeSymbol> {
        let iter: Vec<&CodeSymbol> = self
            .symbols
            .iter()
            .filter(|s| {
                language_filter.as_ref().is_none_or(|l| s.language == *l)
                    && kind_filter.as_ref().is_none_or(|k| s.kind == *k)
                    && file_filter.is_none_or(|f| s.file.contains(f))
            })
            .take(max_results)
            .collect();
        iter
    }

    /// Count symbols by language.
    pub fn count_by_language(&self) -> Vec<(Language, usize)> {
        let mut counts: HashMap<Language, usize> = HashMap::new();
        for sym in &self.symbols {
            *counts.entry(sym.language.clone()).or_default() += 1;
        }
        let mut sorted: Vec<(Language, usize)> = counts.into_iter().collect();
        sorted.sort_by_key(|b| std::cmp::Reverse(b.1));
        sorted
    }

    /// Count symbols by kind.
    pub fn count_by_kind(&self) -> Vec<(SymbolKind, usize)> {
        let mut counts: HashMap<SymbolKind, usize> = HashMap::new();
        for sym in &self.symbols {
            *counts.entry(sym.kind.clone()).or_default() += 1;
        }
        let mut sorted: Vec<(SymbolKind, usize)> = counts.into_iter().collect();
        sorted.sort_by_key(|b| std::cmp::Reverse(b.1));
        sorted
    }
}

impl Default for SymbolIndex {
    fn default() -> Self {
        Self::new()
    }
}

/// Score a symbol against a search query.
fn score_symbol(sym: &CodeSymbol, query_lower: &str, query_words: &[String]) -> i32 {
    let name_lower = sym.name.to_lowercase();
    let mut score: i32 = 0;

    if name_lower == *query_lower {
        score += 1000;
    }
    if name_lower.starts_with(query_lower) {
        score += 500;
    }
    if name_lower.contains(query_lower) {
        score += 200;
    }
    for word in query_words {
        if name_lower.contains(word) {
            score += 50;
        }
    }
    if let Some(ref doc) = sym.doc_comment {
        let doc_lower = doc.to_lowercase();
        if doc_lower.contains(query_lower) {
            score += 30;
        }
        for word in query_words {
            if doc_lower.contains(word) {
                score += 10;
            }
        }
    }
    let context_lower = sym.context.to_lowercase();
    if context_lower.contains(query_lower) {
        score += 20;
    }
    score
}

// ---------------------------------------------------------------------------
//  Extract doc comments helper (Rust ///)
// ---------------------------------------------------------------------------

fn extract_doc_comments(lines: &[&str]) -> HashMap<usize, String> {
    let mut map = HashMap::new();
    let mut i = 0;
    while i < lines.len() {
        let line = lines[i].trim();
        if line.starts_with("///") {
            let mut doc = String::new();
            while i < lines.len() {
                let l = lines[i].trim();
                if l.starts_with("///") {
                    if !doc.is_empty() {
                        doc.push(' ');
                    }
                    doc.push_str(l.trim_start_matches("///").trim());
                    i += 1;
                } else {
                    break;
                }
            }
            let target_line = find_next_declaration_line(lines, i);
            if let Some(tl) = target_line {
                map.insert(tl + 1, doc);
            }
        } else {
            i += 1;
        }
    }
    map
}

fn find_next_declaration_line(lines: &[&str], start: usize) -> Option<usize> {
    lines[start..]
        .iter()
        .position(|line| {
            let trimmed = line.trim();
            !trimmed.is_empty()
                && !trimmed.starts_with("///")
                && !trimmed.starts_with("//!")
                && !trimmed.starts_with('#')
        })
        .map(|pos| start + pos)
}

// ---------------------------------------------------------------------------
//  Rust extractor
// ---------------------------------------------------------------------------

fn extract_rust(content: &str, rel_path: &str) -> Vec<CodeSymbol> {
    let r = regexes();
    let mut symbols = Vec::new();
    let lines: Vec<&str> = content.lines().collect();
    let doc_comments = extract_doc_comments(&lines);

    for (i, line) in lines.iter().enumerate() {
        let line_num = i + 1;
        let trimmed = line.trim();

        let entries: Vec<(Option<&str>, SymbolKind, &Regex)> = vec![
            (None, SymbolKind::Function, &r.rust_fn),
            (None, SymbolKind::Struct, &r.rust_struct),
            (None, SymbolKind::Enum, &r.rust_enum),
            (None, SymbolKind::Trait, &r.rust_trait),
            (None, SymbolKind::Module, &r.rust_mod),
            (None, SymbolKind::Type, &r.rust_type),
            (None, SymbolKind::Constant, &r.rust_const),
            (None, SymbolKind::Macro, &r.rust_macro),
        ];

        for (_parent, kind, re) in &entries {
            if let Some(caps) = re.captures(trimmed) {
                let name = caps
                    .get(1)
                    .expect("capture group 1 exists by regex")
                    .as_str()
                    .to_string();
                let doc = doc_comments.get(&line_num).cloned();
                symbols.push(CodeSymbol {
                    name,
                    kind: kind.clone(),
                    language: Language::Rust,
                    file: rel_path.to_string(),
                    line: line_num,
                    parent: None,
                    doc_comment: doc,
                    context: trimmed.to_string(),
                });
            }
        }

        // Parse impl blocks for methods
        if let Some(caps) = r.rust_impl.captures(trimmed) {
            let impl_for = caps
                .get(1)
                .expect("capture group 1 exists by regex")
                .as_str()
                .to_string();
            let mut brace_depth: i32 = 0;
            let mut started = false;
            for (j, l) in lines[i..].iter().enumerate() {
                for ch in l.chars() {
                    match ch {
                        '{' => {
                            brace_depth += 1;
                            started = true;
                        }
                        '}' => {
                            brace_depth -= 1;
                        }
                        _ => {}
                    }
                }
                if started && brace_depth <= 0 && j > 1 {
                    break;
                }
                if j > 0 {
                    let inner_line = l.trim();
                    if let Some(mcaps) = r.rust_fn.captures(inner_line) {
                        let method_name = mcaps
                            .get(1)
                            .expect("capture group 1 exists by regex")
                            .as_str()
                            .to_string();
                        let abs_line = i + j + 1;
                        let doc = doc_comments.get(&abs_line).cloned();
                        symbols.push(CodeSymbol {
                            name: format!("{impl_for}::{method_name}"),
                            kind: SymbolKind::Function,
                            language: Language::Rust,
                            file: rel_path.to_string(),
                            line: abs_line,
                            parent: Some(impl_for.clone()),
                            doc_comment: doc,
                            context: inner_line.to_string(),
                        });
                    }
                }
            }
        }
    }

    symbols
}

// ---------------------------------------------------------------------------
//  TypeScript extractor
// ---------------------------------------------------------------------------

fn extract_typescript(content: &str, rel_path: &str) -> Vec<CodeSymbol> {
    let r = regexes();
    let mut symbols = Vec::new();
    let lines: Vec<&str> = content.lines().collect();

    // Extract leading JSDoc/TSDoc comments
    let doc_comments = extract_ts_doc(&lines);

    for (i, line) in lines.iter().enumerate() {
        let line_num = i + 1;
        let trimmed = line.trim();
        let doc = doc_comments.get(&line_num).cloned();

        // Functions: `function name(` or `async function name(` or `name = function(`
        if let Some(caps) = r.ts_fn.captures(trimmed) {
            let name = caps.get(1).unwrap().as_str().to_string();
            // Skip arrow lambda captures that aren't function names
            if !name.starts_with('(') && name != "function" && name != "async" {
                symbols.push(CodeSymbol {
                    name,
                    kind: SymbolKind::Function,
                    language: Language::TypeScript,
                    file: rel_path.to_string(),
                    line: line_num,
                    parent: None,
                    doc_comment: doc.clone(),
                    context: trimmed.to_string(),
                });
            }
            continue;
        }

        // Classes
        if let Some(caps) = r.ts_class.captures(trimmed) {
            symbols.push(CodeSymbol {
                name: caps.get(1).unwrap().as_str().to_string(),
                kind: SymbolKind::Class,
                language: Language::TypeScript,
                file: rel_path.to_string(),
                line: line_num,
                parent: None,
                doc_comment: doc.clone(),
                context: trimmed.to_string(),
            });
            continue;
        }

        // Interfaces
        if let Some(caps) = r.ts_interface.captures(trimmed) {
            symbols.push(CodeSymbol {
                name: caps.get(1).unwrap().as_str().to_string(),
                kind: SymbolKind::Interface,
                language: Language::TypeScript,
                file: rel_path.to_string(),
                line: line_num,
                parent: None,
                doc_comment: doc.clone(),
                context: trimmed.to_string(),
            });
            continue;
        }

        // Type aliases
        if let Some(caps) = r.ts_type.captures(trimmed) {
            symbols.push(CodeSymbol {
                name: caps.get(1).unwrap().as_str().to_string(),
                kind: SymbolKind::Type,
                language: Language::TypeScript,
                file: rel_path.to_string(),
                line: line_num,
                parent: None,
                doc_comment: doc.clone(),
                context: trimmed.to_string(),
            });
            continue;
        }

        // Enums
        if let Some(caps) = r.ts_enum.captures(trimmed) {
            symbols.push(CodeSymbol {
                name: caps.get(1).unwrap().as_str().to_string(),
                kind: SymbolKind::Enum,
                language: Language::TypeScript,
                file: rel_path.to_string(),
                line: line_num,
                parent: None,
                doc_comment: doc.clone(),
                context: trimmed.to_string(),
            });
            continue;
        }

        // Const/let/var (module-level variables)
        if let Some(caps) = r.ts_var_export.captures(trimmed) {
            let name = caps.get(1).unwrap().as_str().to_string();
            // Only capture top-level (indentation 0) or exported
            let is_top_level = line.starts_with(|c: char| !c.is_whitespace())
                || trimmed.starts_with("export");
            if is_top_level {
                let kind = if trimmed.contains("const ") {
                    SymbolKind::Constant
                } else {
                    SymbolKind::Variable
                };
                symbols.push(CodeSymbol {
                    name,
                    kind,
                    language: Language::TypeScript,
                    file: rel_path.to_string(),
                    line: line_num,
                    parent: None,
                    doc_comment: doc,
                    context: trimmed.to_string(),
                });
            }
        }
    }

    symbols
}

/// Extract leading `/** ... */` JSDoc or `///` comments.
fn extract_ts_doc(lines: &[&str]) -> HashMap<usize, String> {
    let mut map = HashMap::new();
    let mut i = 0;
    while i < lines.len() {
        let line = lines[i].trim();
        if line.starts_with("/**") || line.starts_with("///") {
            let mut doc = String::new();
            let mut in_block = line.starts_with("/**");
            if in_block {
                // Single-line /** ... */
                if line.ends_with("*/") && line.len() > 4 {
                    let content = line.trim_start_matches("/**").trim_end_matches("*/").trim();
                    if !content.is_empty() {
                        doc.push_str(content);
                    }
                    in_block = false;
                }
                while in_block && i < lines.len() {
                    let l = lines[i].trim();
                    let l = l.trim_start_matches('*').trim();
                    if l.ends_with("*/") {
                        doc.push_str(l.trim_end_matches("*/").trim());
                        break;
                    }
                    doc.push(' ');
                    doc.push_str(l);
                    i += 1;
                }
            } else {
                // /// style
                while i < lines.len() {
                    let l = lines[i].trim();
                    if l.starts_with("///") {
                        if !doc.is_empty() {
                            doc.push(' ');
                        }
                        doc.push_str(l.trim_start_matches("///").trim());
                        i += 1;
                    } else {
                        break;
                    }
                }
            }
            let target_line = find_next_declaration_line(lines, i);
            if let Some(tl) = target_line {
                map.insert(tl + 1, doc);
            }
        } else {
            i += 1;
        }
    }
    map
}

// ---------------------------------------------------------------------------
//  JavaScript extractor (subset of TypeScript, no TS-specific syntax)
// ---------------------------------------------------------------------------

fn extract_javascript(content: &str, rel_path: &str) -> Vec<CodeSymbol> {
    let r = regexes();
    let mut symbols = Vec::new();
    let lines: Vec<&str> = content.lines().collect();

    for (i, line) in lines.iter().enumerate() {
        let line_num = i + 1;
        let trimmed = line.trim();

        // Functions
        if let Some(caps) = r.ts_fn.captures(trimmed) {
            let name = caps.get(1).unwrap().as_str().to_string();
            if !name.starts_with('(') && name != "function" && name != "async" {
                symbols.push(CodeSymbol {
                    name,
                    kind: SymbolKind::Function,
                    language: Language::JavaScript,
                    file: rel_path.to_string(),
                    line: line_num,
                    parent: None,
                    doc_comment: None,
                    context: trimmed.to_string(),
                });
            }
            continue;
        }

        // Classes
        if let Some(caps) = r.ts_class.captures(trimmed) {
            symbols.push(CodeSymbol {
                name: caps.get(1).unwrap().as_str().to_string(),
                kind: SymbolKind::Class,
                language: Language::JavaScript,
                file: rel_path.to_string(),
                line: line_num,
                parent: None,
                doc_comment: None,
                context: trimmed.to_string(),
            });
            continue;
        }

        // Module-level const/let/var
        if let Some(caps) = r.ts_var_export.captures(trimmed) {
            let name = caps.get(1).unwrap().as_str().to_string();
            let is_top_level = line.starts_with(|c: char| !c.is_whitespace());
            if is_top_level {
                let kind = if trimmed.contains("const ") {
                    SymbolKind::Constant
                } else {
                    SymbolKind::Variable
                };
                symbols.push(CodeSymbol {
                    name,
                    kind,
                    language: Language::JavaScript,
                    file: rel_path.to_string(),
                    line: line_num,
                    parent: None,
                    doc_comment: None,
                    context: trimmed.to_string(),
                });
            }
        }
    }

    symbols
}

// ---------------------------------------------------------------------------
//  Python extractor
// ---------------------------------------------------------------------------

fn extract_python(content: &str, rel_path: &str) -> Vec<CodeSymbol> {
    let r = regexes();
    let mut symbols = Vec::new();
    let lines: Vec<&str> = content.lines().collect();

    // Track current class for method nesting
    // Reset when we see a non-indented line outside a class.
    let mut current_class: Option<String> = None;

    for (i, line) in lines.iter().enumerate() {
        let line_num = i + 1;
        let trimmed = line.trim();
        let indent = line.len() - trimmed.len();

        // Reset class tracking when we leave its indentation level.
        if current_class.is_some() && indent == 0 && !trimmed.is_empty() {
            current_class = None;
        }

        // Class
        if let Some(caps) = r.py_class.captures(trimmed) {
            let name = caps.get(1).unwrap().as_str().to_string();
            current_class = Some(name.clone());
            symbols.push(CodeSymbol {
                name,
                kind: SymbolKind::Class,
                language: Language::Python,
                file: rel_path.to_string(),
                line: line_num,
                parent: None,
                doc_comment: None,
                context: trimmed.to_string(),
            });
            continue;
        }

        // Async def
        if let Some(caps) = r.py_async_def.captures(trimmed) {
            let name = caps.get(1).unwrap().as_str().to_string();
            let full_name = current_class
                .as_ref()
                .map(|c| format!("{c}.{name}"))
                .unwrap_or_else(|| name.clone());
            symbols.push(CodeSymbol {
                name: full_name,
                kind: SymbolKind::Function,
                language: Language::Python,
                file: rel_path.to_string(),
                line: line_num,
                parent: current_class.clone(),
                doc_comment: None,
                context: trimmed.to_string(),
            });
            continue;
        }

        // Def
        if let Some(caps) = r.py_def.captures(trimmed) {
            let name = caps.get(1).unwrap().as_str().to_string();
            // Detect __init__ or other dunder methods
            let full_name = current_class
                .as_ref()
                .map(|c| format!("{c}.{name}"))
                .unwrap_or_else(|| name.clone());
            symbols.push(CodeSymbol {
                name: full_name,
                kind: SymbolKind::Function,
                language: Language::Python,
                file: rel_path.to_string(),
                line: line_num,
                parent: current_class.clone(),
                doc_comment: None,
                context: trimmed.to_string(),
            });
            continue;
        }

        // Module-level variable assignment: `NAME = value` (UPPER_CASE = constant)
        let is_top_level = line.starts_with(|c: char| !c.is_whitespace())
            && !trimmed.starts_with('#')
            && !trimmed.starts_with("def ")
            && !trimmed.starts_with("class ")
            && !trimmed.starts_with("import ")
            && !trimmed.starts_with("from ")
            && !trimmed.starts_with("@")
            && !trimmed.starts_with("return")
            && !trimmed.starts_with("if ")
            && !trimmed.starts_with("elif ")
            && !trimmed.starts_with("else:")
            && !trimmed.starts_with("for ")
            && !trimmed.starts_with("while ")
            && !trimmed.starts_with("try:")
            && !trimmed.starts_with("except")
            && !trimmed.starts_with("with ")
            && !trimmed.starts_with("raise")
            && !trimmed.starts_with("pass")
            && !trimmed.starts_with("self.")
            && !trimmed.starts_with("cls.")
            && trimmed.contains(" = ")
            && !trimmed.contains("==");
        if is_top_level {
            let name = trimmed.split('=').next().unwrap_or("").trim().to_string();
            if !name.is_empty()
                && !name.starts_with('_')
                && !name.contains(' ')
            {
                let kind = if name.chars().all(|c| c.is_uppercase() || c == '_') {
                    SymbolKind::Constant
                } else {
                    SymbolKind::Variable
                };
                symbols.push(CodeSymbol {
                    name,
                    kind,
                    language: Language::Python,
                    file: rel_path.to_string(),
                    line: line_num,
                    parent: None,
                    doc_comment: None,
                    context: trimmed.to_string(),
                });
            }
        }
    }

    symbols
}

// ---------------------------------------------------------------------------
//  Go extractor
// ---------------------------------------------------------------------------

fn extract_go(content: &str, rel_path: &str) -> Vec<CodeSymbol> {
    let r = regexes();
    let mut symbols = Vec::new();
    let lines: Vec<&str> = content.lines().collect();

    for (i, line) in lines.iter().enumerate() {
        let line_num = i + 1;
        let trimmed = line.trim();

        // Struct: `type Name struct {`
        if let Some(caps) = r.go_struct.captures(trimmed) {
            symbols.push(CodeSymbol {
                name: caps.get(1).unwrap().as_str().to_string(),
                kind: SymbolKind::Struct,
                language: Language::Go,
                file: rel_path.to_string(),
                line: line_num,
                parent: None,
                doc_comment: None,
                context: trimmed.to_string(),
            });
            continue;
        }

        // Interface: `type Name interface {`
        if let Some(caps) = r.go_interface.captures(trimmed) {
            symbols.push(CodeSymbol {
                name: caps.get(1).unwrap().as_str().to_string(),
                kind: SymbolKind::Interface,
                language: Language::Go,
                file: rel_path.to_string(),
                line: line_num,
                parent: None,
                doc_comment: None,
                context: trimmed.to_string(),
            });
            continue;
        }

        // Type alias: `type Name Xxx`
        if let Some(caps) = r.go_type.captures(trimmed) {
            let name = caps.get(1).unwrap().as_str().to_string();
            // Skip if already captured as struct/interface
            if !trimmed.contains(" struct") && !trimmed.contains(" interface") {
                symbols.push(CodeSymbol {
                    name,
                    kind: SymbolKind::Type,
                    language: Language::Go,
                    file: rel_path.to_string(),
                    line: line_num,
                    parent: None,
                    doc_comment: None,
                    context: trimmed.to_string(),
                });
            }
            continue;
        }

        // Func
        if let Some(caps) = r.go_func.captures(trimmed) {
            let name = caps.get(1).unwrap().as_str().to_string();
            symbols.push(CodeSymbol {
                name,
                kind: SymbolKind::Function,
                language: Language::Go,
                file: rel_path.to_string(),
                line: line_num,
                parent: None,
                doc_comment: None,
                context: trimmed.to_string(),
            });
            continue;
        }

        // Const
        if let Some(caps) = r.go_const.captures(trimmed) {
            symbols.push(CodeSymbol {
                name: caps.get(1).unwrap().as_str().to_string(),
                kind: SymbolKind::Constant,
                language: Language::Go,
                file: rel_path.to_string(),
                line: line_num,
                parent: None,
                doc_comment: None,
                context: trimmed.to_string(),
            });
            continue;
        }

        // Var
        if let Some(caps) = r.go_var.captures(trimmed) {
            symbols.push(CodeSymbol {
                name: caps.get(1).unwrap().as_str().to_string(),
                kind: SymbolKind::Variable,
                language: Language::Go,
                file: rel_path.to_string(),
                line: line_num,
                parent: None,
                doc_comment: None,
                context: trimmed.to_string(),
            });
        }
    }

    symbols
}

// ---------------------------------------------------------------------------
//  Format indexed symbols as a system-prompt-style listing
// ---------------------------------------------------------------------------

/// Format the entire symbol index as a compact, prompt-friendly listing.
///
/// The output is a markdown table grouped by language then file:
///
/// ```text
/// ## Indexed Symbols (342 total)
///
/// ### rust (210)
/// apps/domain/src/core/message.rs
///   fn user, fn assistant, fn system, fn tool, fn tool_result
///   enum Role
///   struct ChatMessage
/// ...
/// ```
pub fn format_symbol_listing(index: &SymbolIndex) -> String {
    let mut out = String::new();
    let total = index.len();
    out.push_str(&format!("## Indexed Symbols ({total} total)\n\n"));

    let by_lang = index.count_by_language();
    if by_lang.is_empty() {
        out.push_str("_No symbols indexed. Rebuild the index first._\n");
        return out;
    }

    // Group by language → file → symbol
    let mut by_lang_file: std::collections::BTreeMap<
        String,
        std::collections::BTreeMap<String, Vec<&CodeSymbol>>,
    > = std::collections::BTreeMap::new();

    for sym in &index.symbols {
        let lang_str = sym.language.to_string();
        by_lang_file
            .entry(lang_str)
            .or_default()
            .entry(sym.file.clone())
            .or_default()
            .push(sym);
    }

    for (lang, files) in &by_lang_file {
        let count: usize = files.values().map(|v| v.len()).sum();
        out.push_str(&format!("### {lang} ({count})\n"));

        for (file, syms) in files {
            out.push_str(&format!("  {file}\n"));

            // Group by kind for compact listing
            let mut by_kind: std::collections::BTreeMap<String, Vec<&str>> =
                std::collections::BTreeMap::new();
            for sym in syms {
                let kind_str = sym.kind.to_string();
                by_kind
                    .entry(kind_str)
                    .or_default()
                    .push(sym.name.as_str());
            }
            for (kind, names) in &by_kind {
                out.push_str(&format!("    {kind}: {}\n", names.join(", ")));
            }
        }
        out.push('\n');
    }

    out
}

// ---------------------------------------------------------------------------
//  Tool: SemanticSearch — search the symbol index
// ---------------------------------------------------------------------------

/// Search for code symbols across all indexed languages.
///
/// Flow: ensure index is built → search by query → return formatted results.
pub struct SemanticSearch;

impl Tool for SemanticSearch {
    fn name(&self) -> &'static str {
        "semantic_search"
    }

    fn description(&self) -> &'static str {
        "Search for code symbols (functions, structs, classes, interfaces, variables) \
         by name, concept, or meaning across Rust, TypeScript, JavaScript, Python, and Go"
    }

    fn parameters(&self) -> Value {
        json!({
            "type": "object",
            "properties": {
                "query": {
                    "type": "string",
                    "description": "Search query — symbol name, concept, or meaning"
                },
                "kind": {
                    "type": "string",
                    "enum": ["fn", "class", "struct", "enum", "interface", "trait", "const", "var", "mod", "all"],
                    "description": "Filter by symbol kind (default: all)",
                    "default": "all"
                },
                "language": {
                    "type": "string",
                    "enum": ["rust", "typescript", "javascript", "python", "go", "all"],
                    "description": "Filter by language (default: all)",
                    "default": "all"
                },
                "max_results": {
                    "type": "integer",
                    "description": "Maximum results (default 10, max 30)",
                    "default": 10
                },
                "rebuild_index": {
                    "type": "boolean",
                    "description": "Force rebuild the symbol index before searching (default false)",
                    "default": false
                }
            },
            "required": ["query"]
        })
    }

    #[instrument(skip(self, ctx, args))]
    fn run(&self, ctx: &ToolCtx, args: &Value) -> Result<String> {
        let query = crate::tools::arg_str(args, "query")?;
        let kind_filter = args.get("kind").and_then(|v| v.as_str()).unwrap_or("all");
        let lang_filter = args
            .get("language")
            .and_then(|v| v.as_str())
            .unwrap_or("all");
        let max_results = args
            .get("max_results")
            .and_then(|v| v.as_u64())
            .unwrap_or(10)
            .min(30) as usize;
        let rebuild = args
            .get("rebuild_index")
            .and_then(|v| v.as_bool())
            .unwrap_or(false);

        let workspace = ctx
            .workspaces
            .first()
            .map(|p| p.to_string_lossy().to_string())
            .unwrap_or_else(|| ".".to_string());

        info!(
            query = %query,
            kind = %kind_filter,
            lang = %lang_filter,
            max_results,
            rebuild,
            "semantic search"
        );

        let mut guard = SYMBOL_INDEX
            .lock()
            .map_err(|e| anyhow::anyhow!("index lock failed: {e}"))?;
        let index = guard.get_or_insert_with(SymbolIndex::new);

        if rebuild || index.is_empty() {
            let count = index.rebuild(&workspace)?;
            debug!(symbol_count = count, "symbol index rebuilt");
        }

        // Map kind filter to enum
        let target_kind = match kind_filter {
            "fn" => Some(SymbolKind::Function),
            "class" => Some(SymbolKind::Class),
            "struct" => Some(SymbolKind::Struct),
            "enum" => Some(SymbolKind::Enum),
            "interface" => Some(SymbolKind::Interface),
            "trait" => Some(SymbolKind::Trait),
            "const" => Some(SymbolKind::Constant),
            "var" => Some(SymbolKind::Variable),
            "mod" => Some(SymbolKind::Module),
            _ => None,
        };

        let target_lang = match lang_filter {
            "rust" => Some(Language::Rust),
            "typescript" => Some(Language::TypeScript),
            "javascript" => Some(Language::JavaScript),
            "python" => Some(Language::Python),
            "go" => Some(Language::Go),
            _ => None,
        };

        let results = index.search(&query, max_results * 2);

        let filtered: Vec<&&CodeSymbol> = results
            .iter()
            .filter(|s| target_kind.as_ref().is_none_or(|k| s.kind == *k))
            .filter(|s| target_lang.as_ref().is_none_or(|l| s.language == *l))
            .take(max_results)
            .collect();

        if filtered.is_empty() {
            return Ok(format!(
                "No symbols found matching '{query}'.\n\
                 Try a different query, or use `rebuild_index: true` to rebuild the index first.\n\
                 Index has {} symbols across {} languages.",
                index.len(),
                index.count_by_language().len(),
            ));
        }

        let total = index.len();
        info!(matched = filtered.len(), total_indexed = total, "semantic search completed");

        let mut by_file: std::collections::BTreeMap<String, Vec<&&CodeSymbol>> =
            std::collections::BTreeMap::new();
        for sym in &filtered {
            by_file.entry(sym.file.clone()).or_default().push(*sym);
        }

        let mut output = format!(
            "## Semantic Search Results\n\n**Query:** {query}\n**Index size:** {total} symbols\n**Matches:** {}\n\n",
            filtered.len()
        );

        for (file, symbols) in &by_file {
            output.push_str(&format!("### `{file}`\n\n"));
            for sym in symbols {
                let lang_str = sym.language.to_string();
                let kind_str = sym.kind.to_string();
                let parent_str = sym
                    .parent
                    .as_ref()
                    .map(|p| format!(" [{p}]"))
                    .unwrap_or_default();
                let doc_str = sym
                    .doc_comment
                    .as_ref()
                    .map(|d| {
                        let truncated: String = d.chars().take(100).collect();
                        format!(" — {truncated}")
                    })
                    .unwrap_or_default();
                output.push_str(&format!(
                    "- `{kind_str}` **{}**{} `[{lang_str}]` at line {} `{}`{}{}\n",
                    sym.name,
                    parent_str,
                    sym.line,
                    sym.context.trim(),
                    doc_str,
                    if sym.context.trim().len() > 80 { "…" } else { "" }
                ));
            }
            output.push('\n');
        }

        output.push_str(&format!(
            "---\n*{} symbols indexed across {} languages. Use `rebuild_index: true` to refresh.*\n",
            total,
            index.count_by_language().len(),
        ));

        Ok(output)
    }
}

// ---------------------------------------------------------------------------
//  Tool: RebuildIndex — explicitly rebuild the symbol index
// ---------------------------------------------------------------------------

/// Rebuild the code symbol index for all supported languages.
pub struct RebuildIndex;

impl Tool for RebuildIndex {
    fn name(&self) -> &'static str {
        "rebuild_index"
    }

    fn description(&self) -> &'static str {
        "Rebuild the code symbol index for semantic search (supports Rust, TypeScript, JavaScript, Python, Go)"
    }

    fn parameters(&self) -> Value {
        json!({
            "type": "object",
            "properties": {}
        })
    }

    #[instrument(skip(self, ctx, _args))]
    fn run(&self, ctx: &ToolCtx, _args: &Value) -> Result<String> {
        let workspace = ctx
            .workspaces
            .first()
            .map(|p| p.to_string_lossy().to_string())
            .unwrap_or_else(|| ".".to_string());

        info!("rebuilding multi-language symbol index");

        let mut guard = SYMBOL_INDEX
            .lock()
            .map_err(|e| anyhow::anyhow!("index lock failed: {e}"))?;
        let index = guard.get_or_insert_with(SymbolIndex::new);
        let count = index.rebuild(&workspace)?;
        let by_lang = index.count_by_language();

        let mut out = format!(
            "Symbol index rebuilt successfully. {} symbols indexed.\n\n",
            count
        );
        out.push_str("By language:\n");
        for (lang, c) in &by_lang {
            out.push_str(&format!("  {lang}: {c}\n"));
        }

        Ok(out)
    }
}

// ---------------------------------------------------------------------------
//  Tool: ListSymbols — list all indexed symbols
// ---------------------------------------------------------------------------

/// List all indexed symbols grouped by language and file.
///
/// This is designed to provide a compact symbol listing for system-prompt
/// context so the AI agent knows what functions, variables, and types exist.
pub struct ListSymbols;

impl Tool for ListSymbols {
    fn name(&self) -> &'static str {
        "list_symbols"
    }

    fn description(&self) -> &'static str {
        "List all indexed code symbols (functions, classes, variables, structs, interfaces, \
         types, constants) across Rust, TypeScript, JavaScript, Python, and Go. \
         Optionally filter by language, kind, or file path."
    }

    fn parameters(&self) -> Value {
        json!({
            "type": "object",
            "properties": {
                "language": {
                    "type": "string",
                    "enum": ["rust", "typescript", "javascript", "python", "go", "all"],
                    "description": "Filter by language (default: all)",
                    "default": "all"
                },
                "kind": {
                    "type": "string",
                    "enum": ["fn", "class", "struct", "enum", "interface", "trait", "const", "var", "mod", "all"],
                    "description": "Filter by symbol kind (default: all)",
                    "default": "all"
                },
                "file": {
                    "type": "string",
                    "description": "Filter by file path substring (e.g. 'auth/', 'domain/')"
                },
                "max_results": {
                    "type": "integer",
                    "description": "Maximum symbols to list (default 50, max 200)",
                    "default": 50
                },
                "rebuild_index": {
                    "type": "boolean",
                    "description": "Force rebuild before listing (default false)",
                    "default": false
                }
            }
        })
    }

    #[instrument(skip(self, ctx, args))]
    fn run(&self, ctx: &ToolCtx, args: &Value) -> Result<String> {
        let lang_filter = args
            .get("language")
            .and_then(|v| v.as_str())
            .unwrap_or("all");
        let kind_filter = args.get("kind").and_then(|v| v.as_str()).unwrap_or("all");
        let file_filter = args.get("file").and_then(|v| v.as_str());
        let max_results = args
            .get("max_results")
            .and_then(|v| v.as_u64())
            .unwrap_or(50)
            .min(200) as usize;
        let rebuild = args
            .get("rebuild_index")
            .and_then(|v| v.as_bool())
            .unwrap_or(false);

        let workspace = ctx
            .workspaces
            .first()
            .map(|p| p.to_string_lossy().to_string())
            .unwrap_or_else(|| ".".to_string());

        let mut guard = SYMBOL_INDEX
            .lock()
            .map_err(|e| anyhow::anyhow!("index lock failed: {e}"))?;
        let index = guard.get_or_insert_with(SymbolIndex::new);

        if rebuild || index.is_empty() {
            let count = index.rebuild(&workspace)?;
            info!(symbol_count = count, "symbol index rebuilt for list");
        }

        let target_lang = match lang_filter {
            "rust" => Some(Language::Rust),
            "typescript" => Some(Language::TypeScript),
            "javascript" => Some(Language::JavaScript),
            "python" => Some(Language::Python),
            "go" => Some(Language::Go),
            _ => None,
        };

        let target_kind = match kind_filter {
            "fn" => Some(SymbolKind::Function),
            "class" => Some(SymbolKind::Class),
            "struct" => Some(SymbolKind::Struct),
            "enum" => Some(SymbolKind::Enum),
            "interface" => Some(SymbolKind::Interface),
            "trait" => Some(SymbolKind::Trait),
            "const" => Some(SymbolKind::Constant),
            "var" => Some(SymbolKind::Variable),
            "mod" => Some(SymbolKind::Module),
            _ => None,
        };

        let symbols = index.list(target_lang, target_kind, file_filter, max_results);

        let total = index.len();
        let by_lang = index.count_by_language();

        if symbols.is_empty() {
            return Ok(format!(
                "No symbols match the filters. Index has {total} total symbols.\n\
                 Languages: {}",
                by_lang
                    .iter()
                    .map(|(l, c)| format!("{l}: {c}"))
                    .collect::<Vec<_>>()
                    .join(", ")
            ));
        }

        let mut out = format!(
            "## Indexed Symbols\n\n**Total:** {total} | **Showing:** {} | **Filter:** lang={lang_filter}, kind={kind_filter}\n\n",
            symbols.len()
        );

        // Group by language
        let mut by_lang_map: std::collections::BTreeMap<String, Vec<&CodeSymbol>> =
            std::collections::BTreeMap::new();
        for sym in &symbols {
            by_lang_map
                .entry(sym.language.to_string())
                .or_default()
                .push(*sym);
        }

        for (lang, syms) in &by_lang_map {
            out.push_str(&format!("### {lang}\n\n"));

            let mut by_file: std::collections::BTreeMap<String, Vec<&CodeSymbol>> =
                std::collections::BTreeMap::new();
            for sym in syms {
                by_file.entry(sym.file.clone()).or_default().push(*sym);
            }

            for (file, file_syms) in &by_file {
                out.push_str(&format!("`{file}`:\n"));
                for sym in file_syms {
                    out.push_str(&format!(
                        "  `{}` {}  L{}\n",
                        sym.kind,
                        sym.name,
                        sym.line,
                    ));
                }
            }
            out.push('\n');
        }

        out.push_str("---\n");
        out.push_str(&format!(
            "By language: {}\n",
            by_lang
                .iter()
                .map(|(l, c)| format!("{l}: {c}"))
                .collect::<Vec<_>>()
                .join(", ")
        ));
        out.push_str(&format!(
            "By kind: {}\n",
            index
                .count_by_kind()
                .iter()
                .map(|(k, c)| format!("{k}: {c}"))
                .collect::<Vec<_>>()
                .join(", ")
        ));

        Ok(out)
    }
}

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

    #[test]
    fn test_extract_rust_functions() {
        let content = "pub fn hello() {}\nfn world() {}\n";
        let symbols = extract_rust(content, "test.rs");
        assert_eq!(symbols.len(), 2);
        assert_eq!(symbols[0].name, "hello");
        assert_eq!(symbols[1].name, "world");
    }

    #[test]
    fn test_extract_rust_struct() {
        let content = "pub struct MyStruct {}\nstruct Private;\n";
        let symbols = extract_rust(content, "test.rs");
        assert!(symbols.iter().any(|s| s.name == "MyStruct"));
        assert!(symbols.iter().any(|s| s.name == "Private"));
    }

    #[test]
    fn test_extract_typescript_function_and_class() {
        let content = "function hello() {}\nexport class User {}\ninterface Person {}\n";
        let symbols = extract_typescript(content, "test.ts");
        assert!(symbols.iter().any(|s| s.name == "hello" && s.kind == SymbolKind::Function));
        assert!(symbols.iter().any(|s| s.name == "User" && s.kind == SymbolKind::Class));
        assert!(symbols.iter().any(|s| s.name == "Person" && s.kind == SymbolKind::Interface));
    }

    #[test]
    fn test_extract_typescript_const() {
        let content = "export const API_URL = 'http://example.com';\nconst MAX_RETRIES = 3;\n";
        let symbols = extract_typescript(content, "test.ts");
        assert!(symbols.iter().any(|s| s.name == "API_URL" && s.kind == SymbolKind::Constant));
        assert!(symbols.iter().any(|s| s.name == "MAX_RETRIES" && s.kind == SymbolKind::Constant));
    }

    #[test]
    fn test_extract_python_def_and_class() {
        let content = "class MyClass:\n    def method(self):\n        pass\n\ndef top_func():\n    pass\n";
        let symbols = extract_python(content, "test.py");
        assert!(symbols.iter().any(|s| s.name == "MyClass" && s.kind == SymbolKind::Class));
        assert!(symbols.iter().any(|s| s.name == "MyClass.method" && s.kind == SymbolKind::Function));
        assert!(symbols.iter().any(|s| s.name == "top_func" && s.kind == SymbolKind::Function));
    }

    #[test]
    fn test_extract_python_variable() {
        let content = "DATABASE_URL = 'postgres://localhost'\nconfig_path = '/etc/app'\n";
        let symbols = extract_python(content, "test.py");
        assert!(symbols.iter().any(|s| s.name == "DATABASE_URL" && s.kind == SymbolKind::Constant));
        assert!(symbols.iter().any(|s| s.name == "config_path" && s.kind == SymbolKind::Variable));
    }

    #[test]
    fn test_extract_go_func_and_struct() {
        let content = "func main() {}\nfunc (s *Server) Serve() {}\ntype Config struct {\n    Name string\n}\n";
        let symbols = extract_go(content, "test.go");
        assert!(symbols.iter().any(|s| s.name == "main" && s.kind == SymbolKind::Function));
        assert!(symbols.iter().any(|s| s.name == "Serve" && s.kind == SymbolKind::Function));
        assert!(symbols.iter().any(|s| s.name == "Config" && s.kind == SymbolKind::Struct));
    }

    #[test]
    fn test_extract_go_const_and_var() {
        let content = "const VERSION = \"1.0\"\nvar DefaultPort = 8080\n";
        let symbols = extract_go(content, "test.go");
        assert!(symbols.iter().any(|s| s.name == "VERSION" && s.kind == SymbolKind::Constant));
        assert!(symbols.iter().any(|s| s.name == "DefaultPort" && s.kind == SymbolKind::Variable));
    }

    #[test]
    fn test_index_rebuild_and_search() {
        let dir = std::env::temp_dir().join(format!("sstest_{}", uuid::Uuid::new_v4()));
        std::fs::create_dir_all(&dir).unwrap();
        std::fs::write(dir.join("test.rs"), "pub fn search_me() {}\n").unwrap();
        std::fs::write(dir.join("test.ts"), "export const FOO = 42;\n").unwrap();

        let mut index = SymbolIndex::new();
        let count = index
            .rebuild(&dir.to_string_lossy())
            .expect("rebuild should succeed");
        assert!(count >= 2, "should index at least 2 symbols, got {count}");

        let results = index.search("search_me", 10);
        assert!(!results.is_empty(), "should find search_me");

        let results = index.search("FOO", 10);
        assert!(!results.is_empty(), "should find FOO");

        let by_lang = index.count_by_language();
        assert!(
            by_lang.iter().any(|(l, _)| *l == Language::Rust),
            "should have Rust symbols"
        );
        assert!(
            by_lang.iter().any(|(l, _)| *l == Language::TypeScript),
            "should have TypeScript symbols"
        );
    }

    #[test]
    fn test_empty_extraction() {
        let symbols = extract_rust("// just a comment\n", "empty.rs");
        assert!(symbols.is_empty());
    }

    #[test]
    fn test_search_empty_index() {
        let index = SymbolIndex::new();
        assert!(index.search("anything", 10).is_empty());
    }
}