codive-lsp 0.1.0

//! LSP server definitions and spawning
//!
//! This module defines available language servers and how to spawn them.
//! Each server has a unique ID, supported file extensions, root detection logic,
//! and a spawn function.

use anyhow::{Context, Result};
use std::collections::HashMap;
use std::path::{Path, PathBuf};
use std::process::{Child, Command, Stdio};
use std::sync::Arc;
use tracing::{debug, info, warn};

/// Root detection function type
pub type RootDetector = Arc<dyn Fn(&Path) -> Option<PathBuf> + Send + Sync>;

/// Spawn function type
pub type SpawnFn = Arc<dyn Fn(&Path) -> Result<LspServerHandle> + Send + Sync>;

/// Handle to a spawned LSP server process
pub struct LspServerHandle {
    /// The child process
    pub process: Child,
    /// Custom initialization options to send to the server
    pub initialization: Option<serde_json::Value>,
}

/// Information about an LSP server
pub struct LspServerInfo {
    /// Unique identifier (e.g., "rust-analyzer", "typescript")
    pub id: String,
    /// File extensions this server handles (with leading dot)
    pub extensions: Vec<String>,
    /// Whether this is a global server (not project-specific)
    pub global: bool,
    /// Function to detect project root from a file path
    pub root_detector: RootDetector,
    /// Function to spawn the server
    pub spawn_fn: SpawnFn,
}

impl LspServerInfo {
    /// Create a new LSP server info
    pub fn new(
        id: impl Into<String>,
        extensions: Vec<&str>,
        root_detector: RootDetector,
        spawn_fn: SpawnFn,
    ) -> Self {
        Self {
            id: id.into(),
            extensions: extensions.into_iter().map(String::from).collect(),
            global: false,
            root_detector,
            spawn_fn,
        }
    }

    /// Check if this server handles a given file extension
    pub fn handles_extension(&self, ext: &str) -> bool {
        self.extensions.is_empty() || self.extensions.iter().any(|e| e == ext)
    }

    /// Detect the project root for a file
    pub fn detect_root(&self, file: &Path) -> Option<PathBuf> {
        (self.root_detector)(file)
    }

    /// Spawn the server for a project root
    pub fn spawn(&self, root: &Path) -> Result<LspServerHandle> {
        (self.spawn_fn)(root)
    }
}

/// Registry of available LSP servers
pub struct LspRegistry {
    servers: HashMap<String, LspServerInfo>,
}

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

impl LspRegistry {
    /// Create a new registry with default servers
    pub fn new() -> Self {
        let mut registry = Self {
            servers: HashMap::new(),
        };

        // Register built-in servers
        registry.register(Self::rust_analyzer());
        registry.register(Self::typescript());
        registry.register(Self::pyright());
        registry.register(Self::gopls());
        registry.register(Self::deno());
        registry.register(Self::clangd());
        registry.register(Self::lua_ls());
        registry.register(Self::css());
        registry.register(Self::html());
        registry.register(Self::json());
        registry.register(Self::yaml());
        registry.register(Self::vue());
        registry.register(Self::svelte());
        registry.register(Self::tailwindcss());
        registry.register(Self::eslint());
        registry.register(Self::ruby());
        registry.register(Self::php());
        registry.register(Self::zig());

        registry
    }

    /// Register a server
    pub fn register(&mut self, server: LspServerInfo) {
        info!(server_id = %server.id, "Registering LSP server");
        self.servers.insert(server.id.clone(), server);
    }

    /// Get a server by ID
    pub fn get(&self, id: &str) -> Option<&LspServerInfo> {
        self.servers.get(id)
    }

    /// Get all servers that handle a given file extension
    pub fn servers_for_extension(&self, ext: &str) -> Vec<&LspServerInfo> {
        self.servers
            .values()
            .filter(|s| s.handles_extension(ext))
            .collect()
    }

    /// Get all registered servers
    pub fn all_servers(&self) -> impl Iterator<Item = &LspServerInfo> {
        self.servers.values()
    }

    /// Get server IDs
    pub fn server_ids(&self) -> Vec<&str> {
        self.servers.keys().map(|s| s.as_str()).collect()
    }

    // ========================================================================
    // Built-in Server Definitions
    // ========================================================================

    /// rust-analyzer for Rust
    fn rust_analyzer() -> LspServerInfo {
        LspServerInfo::new(
            "rust-analyzer",
            vec![".rs"],
            Arc::new(|file| find_project_root(file, &["Cargo.toml"])),
            Arc::new(|root| {
                let binary = which::which("rust-analyzer")
                    .context("rust-analyzer not found in PATH")?;

                debug!(binary = ?binary, root = ?root, "Spawning rust-analyzer");

                let process = Command::new(binary)
                    .current_dir(root)
                    .stdin(Stdio::piped())
                    .stdout(Stdio::piped())
                    .stderr(Stdio::null())
                    .spawn()
                    .context("Failed to spawn rust-analyzer")?;

                Ok(LspServerHandle {
                    process,
                    initialization: Some(serde_json::json!({
                        "checkOnSave": {
                            "command": "clippy"
                        }
                    })),
                })
            }),
        )
    }

    /// typescript-language-server for TypeScript/JavaScript
    fn typescript() -> LspServerInfo {
        LspServerInfo::new(
            "typescript",
            vec![".ts", ".tsx", ".js", ".jsx", ".mjs", ".cjs", ".mts", ".cts"],
            Arc::new(|file| {
                // Exclude if deno.json exists (use Deno LSP instead)
                if find_project_root(file, &["deno.json", "deno.jsonc"]).is_some() {
                    return None;
                }
                find_project_root(
                    file,
                    &[
                        "package-lock.json",
                        "bun.lockb",
                        "bun.lock",
                        "pnpm-lock.yaml",
                        "yarn.lock",
                        "package.json",
                    ],
                )
            }),
            Arc::new(|root| {
                // Try to find typescript-language-server
                let binary = which::which("typescript-language-server")
                    .context("typescript-language-server not found in PATH")?;

                debug!(binary = ?binary, root = ?root, "Spawning typescript-language-server");

                let process = Command::new(binary)
                    .arg("--stdio")
                    .current_dir(root)
                    .stdin(Stdio::piped())
                    .stdout(Stdio::piped())
                    .stderr(Stdio::null())
                    .spawn()
                    .context("Failed to spawn typescript-language-server")?;

                Ok(LspServerHandle {
                    process,
                    initialization: None,
                })
            }),
        )
    }

    /// Pyright for Python
    fn pyright() -> LspServerInfo {
        LspServerInfo::new(
            "pyright",
            vec![".py", ".pyi"],
            Arc::new(|file| {
                find_project_root(
                    file,
                    &[
                        "pyproject.toml",
                        "setup.py",
                        "setup.cfg",
                        "requirements.txt",
                        "pyrightconfig.json",
                    ],
                )
            }),
            Arc::new(|root| {
                // Try pyright-langserver first (npm package), then pyright
                let binary = which::which("pyright-langserver")
                    .or_else(|_| which::which("pyright"))
                    .context("pyright not found in PATH")?;

                debug!(binary = ?binary, root = ?root, "Spawning pyright");

                let process = Command::new(binary)
                    .arg("--stdio")
                    .current_dir(root)
                    .stdin(Stdio::piped())
                    .stdout(Stdio::piped())
                    .stderr(Stdio::null())
                    .spawn()
                    .context("Failed to spawn pyright")?;

                Ok(LspServerHandle {
                    process,
                    initialization: None,
                })
            }),
        )
    }

    /// gopls for Go
    fn gopls() -> LspServerInfo {
        LspServerInfo::new(
            "gopls",
            vec![".go"],
            Arc::new(|file| find_project_root(file, &["go.mod", "go.work"])),
            Arc::new(|root| {
                let binary =
                    which::which("gopls").context("gopls not found in PATH")?;

                debug!(binary = ?binary, root = ?root, "Spawning gopls");

                let process = Command::new(binary)
                    .current_dir(root)
                    .stdin(Stdio::piped())
                    .stdout(Stdio::piped())
                    .stderr(Stdio::null())
                    .spawn()
                    .context("Failed to spawn gopls")?;

                Ok(LspServerHandle {
                    process,
                    initialization: None,
                })
            }),
        )
    }

    /// Deno LSP for Deno projects
    fn deno() -> LspServerInfo {
        LspServerInfo::new(
            "deno",
            vec![".ts", ".tsx", ".js", ".jsx", ".mjs", ".mts"],
            Arc::new(|file| {
                // Only activate if deno.json exists
                find_project_root(file, &["deno.json", "deno.jsonc"])
            }),
            Arc::new(|root| {
                let binary = which::which("deno").context("deno not found in PATH")?;

                debug!(binary = ?binary, root = ?root, "Spawning deno lsp");

                let process = Command::new(binary)
                    .arg("lsp")
                    .current_dir(root)
                    .stdin(Stdio::piped())
                    .stdout(Stdio::piped())
                    .stderr(Stdio::null())
                    .spawn()
                    .context("Failed to spawn deno lsp")?;

                Ok(LspServerHandle {
                    process,
                    initialization: Some(serde_json::json!({
                        "enable": true,
                        "lint": true,
                        "unstable": false
                    })),
                })
            }),
        )
    }

    /// clangd for C/C++
    fn clangd() -> LspServerInfo {
        LspServerInfo::new(
            "clangd",
            vec![".c", ".h", ".cpp", ".hpp", ".cc", ".hh", ".cxx", ".hxx", ".C", ".H"],
            Arc::new(|file| {
                find_project_root(
                    file,
                    &["compile_commands.json", "CMakeLists.txt", "Makefile", ".clangd"],
                )
            }),
            Arc::new(|root| {
                let binary = which::which("clangd").context("clangd not found in PATH")?;

                debug!(binary = ?binary, root = ?root, "Spawning clangd");

                let process = Command::new(binary)
                    .arg("--background-index")
                    .current_dir(root)
                    .stdin(Stdio::piped())
                    .stdout(Stdio::piped())
                    .stderr(Stdio::null())
                    .spawn()
                    .context("Failed to spawn clangd")?;

                Ok(LspServerHandle {
                    process,
                    initialization: None,
                })
            }),
        )
    }

    /// lua-language-server for Lua
    fn lua_ls() -> LspServerInfo {
        LspServerInfo::new(
            "lua-language-server",
            vec![".lua"],
            Arc::new(|file| {
                find_project_root(file, &[".luarc.json", ".luarc.jsonc", ".luacheckrc"])
                    .or_else(|| file.parent().map(|p| p.to_path_buf()))
            }),
            Arc::new(|root| {
                let binary = which::which("lua-language-server")
                    .context("lua-language-server not found in PATH")?;

                debug!(binary = ?binary, root = ?root, "Spawning lua-language-server");

                let process = Command::new(binary)
                    .current_dir(root)
                    .stdin(Stdio::piped())
                    .stdout(Stdio::piped())
                    .stderr(Stdio::null())
                    .spawn()
                    .context("Failed to spawn lua-language-server")?;

                Ok(LspServerHandle {
                    process,
                    initialization: None,
                })
            }),
        )
    }

    /// CSS Language Server
    fn css() -> LspServerInfo {
        LspServerInfo::new(
            "css",
            vec![".css", ".scss", ".sass", ".less"],
            Arc::new(|file| {
                find_project_root(file, &["package.json"]).or_else(|| file.parent().map(|p| p.to_path_buf()))
            }),
            Arc::new(|root| {
                // Try vscode-css-language-server or css-languageserver
                let binary = which::which("vscode-css-language-server")
                    .or_else(|_| which::which("css-languageserver"))
                    .context("css language server not found in PATH")?;

                debug!(binary = ?binary, root = ?root, "Spawning CSS language server");

                let process = Command::new(binary)
                    .arg("--stdio")
                    .current_dir(root)
                    .stdin(Stdio::piped())
                    .stdout(Stdio::piped())
                    .stderr(Stdio::null())
                    .spawn()
                    .context("Failed to spawn CSS language server")?;

                Ok(LspServerHandle {
                    process,
                    initialization: None,
                })
            }),
        )
    }

    /// HTML Language Server
    fn html() -> LspServerInfo {
        LspServerInfo::new(
            "html",
            vec![".html", ".htm"],
            Arc::new(|file| {
                find_project_root(file, &["package.json"]).or_else(|| file.parent().map(|p| p.to_path_buf()))
            }),
            Arc::new(|root| {
                let binary = which::which("vscode-html-language-server")
                    .or_else(|_| which::which("html-languageserver"))
                    .context("HTML language server not found in PATH")?;

                debug!(binary = ?binary, root = ?root, "Spawning HTML language server");

                let process = Command::new(binary)
                    .arg("--stdio")
                    .current_dir(root)
                    .stdin(Stdio::piped())
                    .stdout(Stdio::piped())
                    .stderr(Stdio::null())
                    .spawn()
                    .context("Failed to spawn HTML language server")?;

                Ok(LspServerHandle {
                    process,
                    initialization: None,
                })
            }),
        )
    }

    /// JSON Language Server
    fn json() -> LspServerInfo {
        LspServerInfo::new(
            "json",
            vec![".json", ".jsonc"],
            Arc::new(|file| file.parent().map(|p| p.to_path_buf())),
            Arc::new(|root| {
                let binary = which::which("vscode-json-language-server")
                    .or_else(|_| which::which("json-languageserver"))
                    .context("JSON language server not found in PATH")?;

                debug!(binary = ?binary, root = ?root, "Spawning JSON language server");

                let process = Command::new(binary)
                    .arg("--stdio")
                    .current_dir(root)
                    .stdin(Stdio::piped())
                    .stdout(Stdio::piped())
                    .stderr(Stdio::null())
                    .spawn()
                    .context("Failed to spawn JSON language server")?;

                Ok(LspServerHandle {
                    process,
                    initialization: None,
                })
            }),
        )
    }

    /// YAML Language Server
    fn yaml() -> LspServerInfo {
        LspServerInfo::new(
            "yaml",
            vec![".yaml", ".yml"],
            Arc::new(|file| file.parent().map(|p| p.to_path_buf())),
            Arc::new(|root| {
                let binary =
                    which::which("yaml-language-server").context("yaml-language-server not found in PATH")?;

                debug!(binary = ?binary, root = ?root, "Spawning YAML language server");

                let process = Command::new(binary)
                    .arg("--stdio")
                    .current_dir(root)
                    .stdin(Stdio::piped())
                    .stdout(Stdio::piped())
                    .stderr(Stdio::null())
                    .spawn()
                    .context("Failed to spawn yaml-language-server")?;

                Ok(LspServerHandle {
                    process,
                    initialization: None,
                })
            }),
        )
    }

    /// Vue Language Server (Volar)
    fn vue() -> LspServerInfo {
        LspServerInfo::new(
            "vue",
            vec![".vue"],
            Arc::new(|file| find_project_root(file, &["package.json", "vue.config.js", "vite.config.js"])),
            Arc::new(|root| {
                // Try vue-language-server (Volar)
                let binary = which::which("vue-language-server")
                    .or_else(|_| which::which("volar-server"))
                    .context("Vue language server not found in PATH")?;

                debug!(binary = ?binary, root = ?root, "Spawning Vue language server");

                let process = Command::new(binary)
                    .arg("--stdio")
                    .current_dir(root)
                    .stdin(Stdio::piped())
                    .stdout(Stdio::piped())
                    .stderr(Stdio::null())
                    .spawn()
                    .context("Failed to spawn Vue language server")?;

                Ok(LspServerHandle {
                    process,
                    initialization: None,
                })
            }),
        )
    }

    /// Svelte Language Server
    fn svelte() -> LspServerInfo {
        LspServerInfo::new(
            "svelte",
            vec![".svelte"],
            Arc::new(|file| find_project_root(file, &["package.json", "svelte.config.js"])),
            Arc::new(|root| {
                let binary = which::which("svelteserver")
                    .or_else(|_| which::which("svelte-language-server"))
                    .context("Svelte language server not found in PATH")?;

                debug!(binary = ?binary, root = ?root, "Spawning Svelte language server");

                let process = Command::new(binary)
                    .arg("--stdio")
                    .current_dir(root)
                    .stdin(Stdio::piped())
                    .stdout(Stdio::piped())
                    .stderr(Stdio::null())
                    .spawn()
                    .context("Failed to spawn Svelte language server")?;

                Ok(LspServerHandle {
                    process,
                    initialization: None,
                })
            }),
        )
    }

    /// Tailwind CSS IntelliSense
    fn tailwindcss() -> LspServerInfo {
        LspServerInfo::new(
            "tailwindcss",
            vec![".html", ".jsx", ".tsx", ".vue", ".svelte"],
            Arc::new(|file| {
                // Only activate if tailwind config exists
                find_project_root(file, &["tailwind.config.js", "tailwind.config.ts", "tailwind.config.cjs"])
            }),
            Arc::new(|root| {
                let binary = which::which("tailwindcss-language-server")
                    .context("tailwindcss-language-server not found in PATH")?;

                debug!(binary = ?binary, root = ?root, "Spawning Tailwind CSS language server");

                let process = Command::new(binary)
                    .arg("--stdio")
                    .current_dir(root)
                    .stdin(Stdio::piped())
                    .stdout(Stdio::piped())
                    .stderr(Stdio::null())
                    .spawn()
                    .context("Failed to spawn tailwindcss-language-server")?;

                Ok(LspServerHandle {
                    process,
                    initialization: None,
                })
            }),
        )
    }

    /// ESLint Language Server
    fn eslint() -> LspServerInfo {
        LspServerInfo::new(
            "eslint",
            vec![".js", ".jsx", ".ts", ".tsx", ".mjs", ".cjs"],
            Arc::new(|file| {
                // Only activate if ESLint config exists
                find_project_root(
                    file,
                    &[
                        ".eslintrc",
                        ".eslintrc.js",
                        ".eslintrc.json",
                        ".eslintrc.yaml",
                        ".eslintrc.yml",
                        "eslint.config.js",
                        "eslint.config.mjs",
                    ],
                )
            }),
            Arc::new(|root| {
                let binary = which::which("vscode-eslint-language-server")
                    .or_else(|_| which::which("eslint-language-server"))
                    .context("ESLint language server not found in PATH")?;

                debug!(binary = ?binary, root = ?root, "Spawning ESLint language server");

                let process = Command::new(binary)
                    .arg("--stdio")
                    .current_dir(root)
                    .stdin(Stdio::piped())
                    .stdout(Stdio::piped())
                    .stderr(Stdio::null())
                    .spawn()
                    .context("Failed to spawn ESLint language server")?;

                Ok(LspServerHandle {
                    process,
                    initialization: Some(serde_json::json!({
                        "validate": "on",
                        "packageManager": "npm",
                        "codeActionOnSave": {
                            "enable": false
                        }
                    })),
                })
            }),
        )
    }

    /// Solargraph for Ruby
    fn ruby() -> LspServerInfo {
        LspServerInfo::new(
            "solargraph",
            vec![".rb", ".rake", ".gemspec"],
            Arc::new(|file| {
                find_project_root(file, &["Gemfile", ".solargraph.yml", "Rakefile"])
            }),
            Arc::new(|root| {
                let binary =
                    which::which("solargraph").context("solargraph not found in PATH")?;

                debug!(binary = ?binary, root = ?root, "Spawning Solargraph");

                let process = Command::new(binary)
                    .arg("stdio")
                    .current_dir(root)
                    .stdin(Stdio::piped())
                    .stdout(Stdio::piped())
                    .stderr(Stdio::null())
                    .spawn()
                    .context("Failed to spawn solargraph")?;

                Ok(LspServerHandle {
                    process,
                    initialization: None,
                })
            }),
        )
    }

    /// Intelephense for PHP
    fn php() -> LspServerInfo {
        LspServerInfo::new(
            "intelephense",
            vec![".php", ".phtml"],
            Arc::new(|file| {
                find_project_root(file, &["composer.json", "index.php"])
            }),
            Arc::new(|root| {
                let binary =
                    which::which("intelephense").context("intelephense not found in PATH")?;

                debug!(binary = ?binary, root = ?root, "Spawning Intelephense");

                let process = Command::new(binary)
                    .arg("--stdio")
                    .current_dir(root)
                    .stdin(Stdio::piped())
                    .stdout(Stdio::piped())
                    .stderr(Stdio::null())
                    .spawn()
                    .context("Failed to spawn intelephense")?;

                Ok(LspServerHandle {
                    process,
                    initialization: None,
                })
            }),
        )
    }

    /// ZLS for Zig
    fn zig() -> LspServerInfo {
        LspServerInfo::new(
            "zls",
            vec![".zig"],
            Arc::new(|file| {
                find_project_root(file, &["build.zig", "zls.json"])
            }),
            Arc::new(|root| {
                let binary = which::which("zls").context("zls not found in PATH")?;

                debug!(binary = ?binary, root = ?root, "Spawning ZLS");

                let process = Command::new(binary)
                    .current_dir(root)
                    .stdin(Stdio::piped())
                    .stdout(Stdio::piped())
                    .stderr(Stdio::null())
                    .spawn()
                    .context("Failed to spawn zls")?;

                Ok(LspServerHandle {
                    process,
                    initialization: None,
                })
            }),
        )
    }
}

// ============================================================================
// Helper Functions
// ============================================================================

/// Find a project root by searching upward for marker files
pub fn find_project_root(file: &Path, markers: &[&str]) -> Option<PathBuf> {
    let start_dir = if file.is_file() {
        file.parent()?
    } else {
        file
    };

    let mut current = start_dir;
    loop {
        for marker in markers {
            if current.join(marker).exists() {
                return Some(current.to_path_buf());
            }
        }

        match current.parent() {
            Some(parent) => current = parent,
            None => break,
        }
    }

    None
}

/// Find a project root, stopping at a specific directory
pub fn find_project_root_with_stop(
    file: &Path,
    markers: &[&str],
    stop_at: &Path,
) -> Option<PathBuf> {
    let start_dir = if file.is_file() {
        file.parent()?
    } else {
        file
    };

    let mut current = start_dir;
    loop {
        // Stop if we've reached the boundary
        if current == stop_at {
            break;
        }

        for marker in markers {
            if current.join(marker).exists() {
                return Some(current.to_path_buf());
            }
        }

        match current.parent() {
            Some(parent) => current = parent,
            None => break,
        }
    }

    None
}

#[cfg(test)]
mod tests {
    use super::*;
    use std::fs;
    use tempfile::tempdir;

    #[test]
    fn test_find_project_root() {
        let temp = tempdir().unwrap();
        let project_dir = temp.path().join("my-project");
        let src_dir = project_dir.join("src");
        let nested_dir = src_dir.join("nested");

        fs::create_dir_all(&nested_dir).unwrap();
        fs::write(project_dir.join("Cargo.toml"), "").unwrap();

        let file = nested_dir.join("main.rs");
        fs::write(&file, "").unwrap();

        let root = find_project_root(&file, &["Cargo.toml"]);
        assert_eq!(root, Some(project_dir));
    }

    #[test]
    fn test_find_project_root_not_found() {
        let temp = tempdir().unwrap();
        let file = temp.path().join("orphan.rs");
        fs::write(&file, "").unwrap();

        let root = find_project_root(&file, &["Cargo.toml"]);
        assert_eq!(root, None);
    }

    #[test]
    fn test_registry_default_servers() {
        let registry = LspRegistry::new();

        assert!(registry.get("rust-analyzer").is_some());
        assert!(registry.get("typescript").is_some());
        assert!(registry.get("pyright").is_some());
        assert!(registry.get("gopls").is_some());
    }

    #[test]
    fn test_servers_for_extension() {
        let registry = LspRegistry::new();

        let rust_servers = registry.servers_for_extension(".rs");
        assert_eq!(rust_servers.len(), 1);
        assert_eq!(rust_servers[0].id, "rust-analyzer");

        let ts_servers = registry.servers_for_extension(".ts");
        assert_eq!(ts_servers.len(), 1);
        assert_eq!(ts_servers[0].id, "typescript");
    }
}