import http from "node:http";
import type { ConnectionManager } from "../connections.js";
import type { ICookieStore, IDeviceStore, IAdminStore, DbConfig } from "../db/types.js";
import { saveDbConfig, loadDbConfig, createStores } from "../db/index.js";
import type { RelayServer } from "../server.js";

export interface AdminDeps {
  adminStore: IAdminStore;
  connections: ConnectionManager;
  cookieStore: ICookieStore;
  deviceRegistry: IDeviceStore;
  server: RelayServer;
}

/**
 * Handle /admin/* routes. Returns true if the route was handled.
 */
export function handleAdminRoute(
  req: http.IncomingMessage,
  res: http.ServerResponse,
  deps: AdminDeps,
): boolean {
  const url = req.url ?? "";
  const method = req.method ?? "";

  if (!url.startsWith("/admin/")) return false;

  // --- Public routes (no auth) ---

  if (method === "GET" && url === "/admin/setup/status") {
    const dbConfig = loadDbConfig();
    json(res, 200, {
      isSetUp: deps.adminStore.isSetUp,
      dbConfigured: dbConfig !== null,
      dbType: dbConfig?.type ?? null,
    });
    return true;
  }

  if (method === "POST" && url === "/admin/setup/init") {
    handleSetupInit(req, res, deps);
    return true;
  }

  if (method === "POST" && url === "/admin/auth/login") {
    handleLogin(req, res, deps);
    return true;
  }

  // --- Protected routes ---

  const user = authenticate(req, deps.adminStore);
  if (!user) {
    json(res, 401, { error: "Unauthorized" });
    return true;
  }

  if (method === "POST" && url === "/admin/auth/logout") {
    json(res, 200, { ok: true });
    return true;
  }

  if (method === "GET" && url === "/admin/auth/me") {
    const info = deps.adminStore.getUser();
    json(res, 200, info);
    return true;
  }

  if (method === "GET" && url === "/admin/dashboard") {
    handleDashboard(res, deps);
    return true;
  }

  // Cookie management
  if (method === "GET" && url.startsWith("/admin/cookies")) {
    handleCookieList(req, res, deps);
    return true;
  }
  if (method === "DELETE" && url.startsWith("/admin/cookies/")) {
    handleCookieDeleteById(req, res, deps);
    return true;
  }
  if (method === "DELETE" && url === "/admin/cookies") {
    handleCookieBatchDelete(req, res, deps);
    return true;
  }

  // Device management
  if (method === "GET" && url === "/admin/devices") {
    handleDeviceList(res, deps);
    return true;
  }
  if (method === "POST" && url.match(/^\/admin\/devices\/[^/]+\/revoke$/)) {
    handleDeviceRevoke(req, res, deps);
    return true;
  }

  // Settings
  if (method === "GET" && url === "/admin/settings") {
    json(res, 200, deps.adminStore.getSettings());
    return true;
  }
  if (method === "PATCH" && url === "/admin/settings") {
    handleSettingsUpdate(req, res, deps);
    return true;
  }

  json(res, 404, { error: "Admin route not found" });
  return true;
}

// --- Auth helpers ---

function authenticate(
  req: http.IncomingMessage,
  store: IAdminStore,
): { sub: string; role: string } | null {
  const auth = req.headers.authorization;
  if (!auth?.startsWith("Bearer ")) return null;
  try {
    return store.verifyToken(auth.slice(7));
  } catch {
    return null;
  }
}

// --- Route handlers ---

function handleSetupInit(
  req: http.IncomingMessage,
  res: http.ServerResponse,
  deps: AdminDeps,
): void {
  readBody(req, async (body) => {
    try {
      const { username, password, dbConfig } = JSON.parse(body) as {
        username: string;
        password: string;
        dbConfig?: DbConfig;
      };
      if (!username || !password) {
        json(res, 400, { error: "Missing username or password" });
        return;
      }

      // If a database config is provided, initialize the database first
      if (dbConfig) {
        try {
          const stores = await createStores(dbConfig);
          saveDbConfig(dbConfig);
          deps.server.replaceStores(stores);
          // Update deps references to point to new stores
          deps.adminStore = stores.adminStore;
          deps.cookieStore = stores.cookieStore;
          deps.deviceRegistry = stores.deviceStore;
        } catch (err) {
          json(res, 500, { error: `Database connection failed: ${err instanceof Error ? err.message : String(err)}` });
          return;
        }
      }

      if (deps.adminStore.isSetUp) {
        json(res, 409, { error: "Already configured" });
        return;
      }
      await deps.adminStore.setup(username, password);
      const token = await deps.adminStore.login(username, password);
      json(res, 201, { token, username });
    } catch {
      json(res, 400, { error: "Invalid request" });
    }
  });
}

function handleLogin(
  req: http.IncomingMessage,
  res: http.ServerResponse,
  deps: AdminDeps,
): void {
  readBody(req, async (body) => {
    try {
      const { username, password } = JSON.parse(body);
      if (!username || !password) {
        json(res, 400, { error: "Missing username or password" });
        return;
      }
      const token = await deps.adminStore.login(username, password);
      json(res, 200, { token });
    } catch {
      json(res, 401, { error: "Invalid credentials" });
    }
  });
}

async function handleDashboard(res: http.ServerResponse, deps: AdminDeps): Promise<void> {
  const devices = await deps.deviceRegistry.listAll();
  const onlineDeviceIds = devices
    .filter((d) => deps.connections.isOnline(d.deviceId))
    .map((d) => d.deviceId);

  const allCookies = await deps.cookieStore.getAll();

  const domains = new Set(allCookies.map((c) => c.domain));

  json(res, 200, {
    connections: deps.connections.connectedCount,
    totalDevices: devices.length,
    onlineDevices: onlineDeviceIds.length,
    totalCookies: allCookies.length,
    uniqueDomains: domains.size,
  });
}

async function handleCookieList(
  req: http.IncomingMessage,
  res: http.ServerResponse,
  deps: AdminDeps,
): Promise<void> {
  const parsed = new URL(req.url ?? "", `http://${req.headers.host}`);

  // Check if this is a single cookie detail request: /admin/cookies/:id
  const idMatch = parsed.pathname.match(/^\/admin\/cookies\/([a-f0-9]+)$/);
  if (idMatch) {
    const cookie = await deps.cookieStore.getById(idMatch[1]);
    if (!cookie) {
      json(res, 404, { error: "Cookie not found" });
      return;
    }
    json(res, 200, cookie);
    return;
  }

  const domain = parsed.searchParams.get("domain") ?? undefined;
  const search = parsed.searchParams.get("q") ?? undefined;
  const page = parseInt(parsed.searchParams.get("page") ?? "1", 10);
  const limit = Math.min(parseInt(parsed.searchParams.get("limit") ?? "50", 10), 200);

  let cookies = await deps.cookieStore.getAll();

  if (domain) {
    cookies = cookies.filter((c) => c.domain === domain);
  }
  if (search) {
    const q = search.toLowerCase();
    cookies = cookies.filter(
      (c) => c.domain.toLowerCase().includes(q) || c.cookieName.toLowerCase().includes(q),
    );
  }

  const total = cookies.length;
  const offset = (page - 1) * limit;
  const items = cookies.slice(offset, offset + limit);

  json(res, 200, { items, total, page, limit });
}

async function handleCookieDeleteById(
  _req: http.IncomingMessage,
  res: http.ServerResponse,
  deps: AdminDeps,
): Promise<void> {
  const parsed = new URL(_req.url ?? "", `http://${_req.headers.host}`);
  const idMatch = parsed.pathname.match(/^\/admin\/cookies\/([a-f0-9]+)$/);
  if (!idMatch) {
    json(res, 400, { error: "Invalid cookie ID" });
    return;
  }
  const deleted = await deps.cookieStore.deleteById(idMatch[1]);
  json(res, 200, { deleted });
}

function handleCookieBatchDelete(
  req: http.IncomingMessage,
  res: http.ServerResponse,
  deps: AdminDeps,
): void {
  readBody(req, async (body) => {
    try {
      const { ids } = JSON.parse(body) as { ids: string[] };
      if (!ids || !Array.isArray(ids)) {
        json(res, 400, { error: "Missing ids array" });
        return;
      }
      let count = 0;
      for (const id of ids) {
        if (await deps.cookieStore.deleteById(id)) count++;
      }
      json(res, 200, { deleted: count });
    } catch {
      json(res, 400, { error: "Invalid JSON" });
    }
  });
}

async function handleDeviceList(res: http.ServerResponse, deps: AdminDeps): Promise<void> {
  const devices = (await deps.deviceRegistry.listAll()).map((d) => ({
    deviceId: d.deviceId,
    name: d.name,
    platform: d.platform,
    createdAt: d.createdAt,
    online: deps.connections.isOnline(d.deviceId),
  }));
  json(res, 200, { devices });
}

async function handleDeviceRevoke(
  req: http.IncomingMessage,
  res: http.ServerResponse,
  deps: AdminDeps,
): Promise<void> {
  const parsed = new URL(req.url ?? "", `http://${req.headers.host}`);
  const match = parsed.pathname.match(/^\/admin\/devices\/([^/]+)\/revoke$/);
  if (!match) {
    json(res, 400, { error: "Invalid device ID" });
    return;
  }
  const deviceId = match[1];
  const revoked = await deps.deviceRegistry.revoke(deviceId);
  if (revoked) {
    deps.connections.disconnect(deviceId);
  }
  json(res, 200, { revoked });
}

function handleSettingsUpdate(
  req: http.IncomingMessage,
  res: http.ServerResponse,
  deps: AdminDeps,
): void {
  readBody(req, (body) => {
    try {
      const patch = JSON.parse(body);
      const updated = deps.adminStore.updateSettings(patch);
      json(res, 200, updated);
    } catch {
      json(res, 400, { error: "Invalid JSON" });
    }
  });
}

// --- Helpers ---

function json(res: http.ServerResponse, status: number, data: unknown): void {
  res.writeHead(status, { "Content-Type": "application/json" });
  res.end(JSON.stringify(data));
}

function readBody(req: http.IncomingMessage, cb: (body: string) => void): void {
  let data = "";
  req.on("data", (chunk: Buffer) => {
    data += chunk.toString();
    if (data.length > 64 * 1024) req.destroy();
  });
  req.on("end", () => cb(data));
}