import express from "express";
import http from "node:http";
import path from "node:path";
import cookieParser from "cookie-parser";
import { WebSocketServer } from "ws";
import type { BotManager } from "../bot/manager.js";
import type { MusicProvider } from "../music/provider.js";
import type { BotDatabase } from "../data/database.js";
import type { BotConfig } from "../data/config.js";
import type { Logger } from "../logger.js";
import type { CookieStore } from "../music/auth.js";
import type { AvatarStore } from "../data/avatars.js";
import { createBotRouter } from "./api/bot.js";
import { createMusicRouter } from "./api/music.js";
import { createPlayerRouter } from "./api/player.js";
import { createAuthRouter } from "./api/auth.js";
import { createSessionRouter } from "./api/session.js";
import { createUsersRouter } from "./api/users.js";
import { createAuditStore } from "../data/audit.js";
import { createAuditRouter } from "./api/audit.js";
import { setupWebSocket } from "./websocket.js";
import { createUserStore } from "../data/users.js";
import { createSessionStore } from "../data/sessions.js";
import { createRequireAuth } from "./middleware/requireAuth.js";
import { csrfOriginCheck } from "./middleware/csrf.js";
import { validateSessionFromHeaders } from "./auth/validateSession.js";

const SESSION_CLEANUP_INTERVAL_MS = 60 * 60 * 1000; // 1 hour

export interface WebServerOptions {
  port: number;
  botManager: BotManager;
  neteaseProvider: MusicProvider;
  qqProvider: MusicProvider;
  bilibiliProvider: MusicProvider;
  database: BotDatabase;
  config: BotConfig;
  configPath: string;
  logger: Logger;
  cookieStore?: CookieStore;
  avatarStore: AvatarStore;
  staticDir?: string;
}

export interface WebServer {
  start(): Promise<void>;
  stop(): void;
}

export function createWebServer(options: WebServerOptions): WebServer {
  const app = express();
  const server = http.createServer(app);
  const logger = options.logger.child({ component: "web" });

  if (options.config.trustProxy) {
    app.set("trust proxy", true);
  }

  app.use(express.json({ limit: "400kb" }));
  app.use(cookieParser());

  const users = createUserStore(options.database.db);
  const sessions = createSessionStore(options.database.db);
  const audit = createAuditStore(options.database.db);

  // ─── Public routes (no auth, no CSRF) ───────────────────────────────────
  app.get("/api/health", (_req, res) => {
    res.json({ status: "ok", version: "0.1.0" });
  });

  app.get("/api/config/public-url", (_req, res) => {
    const raw = (options.config.publicUrl ?? "").trim();
    res.json({ publicUrl: raw ? raw.replace(/\/+$/, "") : null });
  });

  app.use("/api/session", createSessionRouter(users, sessions, audit, logger));

  // ─── Gates for everything else under /api ───────────────────────────────
  const requireAuth = createRequireAuth(sessions);
  app.use("/api", csrfOriginCheck);
  app.use("/api", requireAuth);

  // ─── Protected routes ───────────────────────────────────────────────────
  app.use(
    "/api/bot",
    createBotRouter(
      options.botManager,
      options.config,
      options.configPath,
      logger,
      options.database,
      options.avatarStore,
    )
  );
  app.use(
    "/api/music",
    createMusicRouter(options.neteaseProvider, options.qqProvider, options.bilibiliProvider, logger)
  );
  app.use("/api/player", createPlayerRouter(
    options.botManager, logger, options.database,
    options.neteaseProvider, options.qqProvider, options.bilibiliProvider,
  ));
  app.use(
    "/api/auth",
    createAuthRouter(options.neteaseProvider, options.qqProvider, options.bilibiliProvider, logger, options.cookieStore)
  );
  app.use("/api/users", createUsersRouter(users, sessions, audit, logger));
  app.use("/api/audit", createAuditRouter(audit));

  // ─── Static SPA (public) ────────────────────────────────────────────────
  if (options.staticDir) {
    app.use(express.static(options.staticDir));
    app.get(/^(?!\/api|\/ws)/, (_req, res) => {
      res.sendFile(path.join(options.staticDir!, "index.html"));
    });
  }

  server.on("error", (err) => {
    logger.error({ err }, "HTTP server error");
  });

  // ─── WebSocket with manual upgrade auth ────────────────────────────────
  const wss = new WebSocketServer({ noServer: true });
  wss.on("error", (err) => {
    logger.error({ err }, "WebSocket server error");
  });
  server.on("upgrade", (req, socket, head) => {
    if (req.url !== "/ws") {
      socket.destroy();
      return;
    }
    const reqHost = req.headers.host;
    const originHeader = req.headers.origin;
    if (originHeader) {
      let originHost: string | null = null;
      try {
        originHost = new URL(originHeader).host;
      } catch {
        // fall through; treat as missing/invalid origin
      }
      if (!originHost || originHost !== reqHost) {
        socket.write("HTTP/1.1 403 Forbidden\r\nConnection: close\r\n\r\n");
        socket.destroy();
        return;
      }
    }
    const result = validateSessionFromHeaders(req.headers.cookie as string | undefined, sessions);
    if (!result) {
      socket.write("HTTP/1.1 401 Unauthorized\r\nConnection: close\r\n\r\n");
      socket.destroy();
      return;
    }
    wss.handleUpgrade(req, socket, head, (ws) => {
      (ws as unknown as { userId: string }).userId = result.userId;
      wss.emit("connection", ws, req);
    });
  });
  const cleanupWs = setupWebSocket(wss, options.botManager, logger);

  // ─── Session cleanup interval ──────────────────────────────────────────
  let cleanupTimer: ReturnType<typeof setInterval> | null = null;

  return {
    async start(): Promise<void> {
      return new Promise((resolve) => {
        server.listen(options.port, () => {
          logger.info({ port: options.port }, "Web server started");
          cleanupTimer = setInterval(() => {
            try {
              sessions.cleanupExpired();
            } catch (err) {
              logger.error({ err }, "session cleanup failed");
            }
          }, SESSION_CLEANUP_INTERVAL_MS);
          resolve();
        });
      });
    },
    stop(): void {
      if (cleanupTimer) {
        clearInterval(cleanupTimer);
        cleanupTimer = null;
      }
      cleanupWs();
      wss.close();
      server.close();
    },
  };
}