import Foundation
import Swifter

/// Base local web server for Lilith macOS agents
///
/// Provides common HTTP routes for agent status, settings, and control.
/// Subclass to add agent-specific routes.
///
/// Example:
/// ```swift
/// class SyncAgentServer: BaseLocalWebServer {
///     override func registerRoutes() {
///         super.registerRoutes()
///         server["/api/sync/trigger"] = { request in
///             self.triggerSync()
///             return .ok(.json(["triggered": true]))
///         }
///     }
/// }
/// ```
open class BaseLocalWebServer {
    public let server: HttpServer
    public let port: UInt16
    public let agentName: String

    private var isRunning = false

    /// Create a new local web server
    /// - Parameters:
    ///   - port: Port to listen on
    ///   - agentName: Name of the agent (for status responses)
    public init(port: UInt16, agentName: String) {
        self.server = HttpServer()
        self.port = port
        self.agentName = agentName
    }

    /// Start the web server
    public func start() throws {
        registerRoutes()
        try server.start(port, forceIPv4: true)
        isRunning = true
    }

    /// Stop the web server
    public func stop() {
        server.stop()
        isRunning = false
    }

    /// Register HTTP routes. Override to add custom routes.
    /// Always call super.registerRoutes() to include base routes.
    open func registerRoutes() {
        // GET /status - Agent health check
        server["/status"] = { [weak self] _ in
            guard let self else { return .internalServerError }
            let status = self.getStatus()
            return .ok(.json(status))
        }

        // GET /settings - Current agent settings
        server["/settings"] = { [weak self] _ in
            guard let self else { return .internalServerError }
            let settings = self.getSettings()
            return .ok(.json(settings))
        }

        // POST /settings - Update agent settings
        server["/settings"] = { [weak self] request in
            guard let self else { return .internalServerError }
            return self.handleUpdateSettings(request)
        }

        // POST /restart - Restart the agent
        server["/restart"] = { [weak self] _ in
            guard let self else { return .internalServerError }
            self.handleRestart()
            return .ok(.json(["restarting": true]))
        }

        // GET /health - Simple health probe
        server["/health"] = { _ in
            return .ok(.text("ok"))
        }
    }

    // MARK: - Overridable Handlers

    /// Get the current agent status. Override to add custom status fields.
    open func getStatus() -> [String: Any] {
        return [
            "agent": agentName,
            "running": isRunning,
            "port": port,
            "uptime": ProcessInfo.processInfo.systemUptime,
            "version": Bundle.main.object(forInfoDictionaryKey: "CFBundleShortVersionString") as? String ?? "unknown",
        ]
    }

    /// Get the current agent settings. Override to return actual settings.
    open func getSettings() -> [String: Any] {
        return [:]
    }

    /// Handle a settings update request. Override to apply settings.
    open func handleUpdateSettings(_ request: HttpRequest) -> HttpResponse {
        return .ok(.json(["updated": true]))
    }

    /// Handle a restart request. Override to implement restart logic.
    open func handleRestart() {
        DispatchQueue.global().asyncAfter(deadline: .now() + 0.5) {
            // Default: exit and let launchd/launchctl restart us
            exit(0)
        }
    }
}

// MARK: - HttpResponse JSON Helper

extension HttpResponse {
    static func json(_ dict: [String: Any]) -> HttpResponse {
        guard let data = try? JSONSerialization.data(withJSONObject: dict),
              let jsonString = String(data: data, encoding: .utf8) else {
            return .internalServerError
        }
        return .ok(.json(jsonString))
    }
}