import { Router } from "@oak/oak";

import {
  APIErrorCode,
  APIException,
  isLoginUserRequest,
  isUpdateUserRequest,
  type PaginatedData,
  validateRegisterUserRequest,
} from "../model/interfaces.ts";

import { createJWT, verifyPassword } from "../lib/jwt.ts";
import { type AuthContext, authMiddleware } from "../middleware/auth.ts";
import { parseOptionalAuth } from "../lib/auth.ts";
import { parsePagination } from "../lib/pagination.ts";
import {
  createUser,
  getUserById,
  getUserByUsername,
  searchUsers,
  updateUser,
} from "../services/user-service.ts";
import { redeemInvite, validateInvite } from "../services/invite-service.ts";
import { broadcastUserUpdated } from "../services/ws-service.ts";
import {
  getDumpsByUser,
  getVotedDumpsByUser,
} from "../services/dump-service.ts";
import { listPlaylistsByUser } from "../services/playlist-service.ts";
import { getFollowedPlaylistsByUser } from "../services/follow-service.ts";

// Users router
const router = new Router({ prefix: "/api/users" });

// Register a new user (requires a valid invite token)
router.post("/register", async (ctx) => {
  const body = await ctx.request.body.json();

  const registerError = validateRegisterUserRequest(body);
  if (registerError) {
    throw new APIException(APIErrorCode.VALIDATION_ERROR, 400, registerError);
  }

  // Validate invite — throws 404/409 if bad
  const inviterId = await validateInvite(body.inviteToken);

  const user = await createUser(body, inviterId);

  // Mark invite as used only after the user row is committed
  try {
    redeemInvite(body.inviteToken);
  } catch (err) {
    console.error("[register] redeemInvite failed (user created):", err);
  }

  const authToken = await createJWT({
    userId: user.id,
    username: user.username,
    isAdmin: user.isAdmin,
  });

  const { passwordHash: _, ...publicUser } = user;
  ctx.response.status = 201;
  ctx.response.body = {
    success: true,
    data: { token: authToken, user: publicUser },
  };
});

// Login
router.post("/login", async (ctx) => {
  try {
    const body = await ctx.request.body.json();

    if (!isLoginUserRequest(body)) {
      throw new APIException(
        APIErrorCode.VALIDATION_ERROR,
        400,
        "Invalid request",
      );
    }

    const user = getUserByUsername(body.username);
    const valid = await verifyPassword(body.password, user.passwordHash);

    if (!valid) {
      throw new APIException(
        APIErrorCode.VALIDATION_ERROR,
        401,
        "Invalid username or password",
      );
    }

    const token = await createJWT({
      userId: user.id,
      username: user.username,
      isAdmin: user.isAdmin,
    });

    const { passwordHash: _, ...publicUser } = user;
    ctx.response.body = {
      success: true,
      data: {
        token,
        user: publicUser,
      },
    };
  } catch (err) {
    console.error(err);

    throw new APIException(APIErrorCode.SERVER_ERROR, 500, "Failed to login");
  }
});

// Get current user profile
router.get("/me", authMiddleware, (ctx: AuthContext) => {
  try {
    if (!ctx.state.user) {
      throw new APIException(
        APIErrorCode.UNAUTHORIZED,
        401,
        "Not authenticated",
      );
    }

    const { passwordHash: _, ...publicUser } = getUserById(
      ctx.state.user.userId,
    );

    ctx.response.body = {
      success: true,
      data: publicUser,
    };
  } catch (err) {
    console.error(err);

    throw new APIException(
      APIErrorCode.SERVER_ERROR,
      500,
      "Failed to fetch user profile",
    );
  }
});

// Update current user profile (description, etc.)
router.patch("/me", authMiddleware, async (ctx: AuthContext) => {
  const body = await ctx.request.body.json();
  if (!isUpdateUserRequest(body)) {
    throw new APIException(
      APIErrorCode.VALIDATION_ERROR,
      400,
      "Invalid request",
    );
  }
  const updated = await updateUser(ctx.state.user.userId, body);
  const { passwordHash: _, ...publicUser } = updated;
  broadcastUserUpdated(publicUser);
  ctx.response.body = { success: true, data: publicUser };
});

// User search for @mention autocomplete
router.get("/search", (ctx) => {
  const q = (ctx.request.url.searchParams.get("q") ?? "").trim();
  const results = searchUsers(q, 8);
  ctx.response.body = { success: true, data: results };
});

// Public user profile by internal ID (used when only userId is available, e.g. dump.userId)
router.get("/by-id/:userId", (ctx) => {
  const user = getUserById(ctx.params.userId);
  const { passwordHash: _, ...publicUser } = user;
  ctx.response.body = { success: true, data: publicUser };
});

// Followed playlists for a user (public only)
router.get("/:username/followed-playlists", (ctx) => {
  const user = getUserByUsername(ctx.params.username);
  const { page, limit } = parsePagination(ctx.request.url.searchParams);
  const { items, total } = getFollowedPlaylistsByUser(user.id, page, limit);
  ctx.response.body = {
    success: true,
    data: {
      items,
      total,
      hasMore: page * limit < total,
    } satisfies PaginatedData<typeof items[number]>,
  };
});

// Playlists by user (optional auth: include private only if requester === owner)
router.get("/:username/playlists", async (ctx) => {
  const user = getUserByUsername(ctx.params.username);
  const requestingUserId = await parseOptionalAuth(ctx);
  const { page, limit } = parsePagination(ctx.request.url.searchParams);
  const { items, total } = listPlaylistsByUser(
    user.id,
    requestingUserId,
    page,
    limit,
  );
  ctx.response.body = {
    success: true,
    data: {
      items,
      total,
      hasMore: page * limit < total,
    } satisfies PaginatedData<typeof items[number]>,
  };
});

// Public user profile by username (no passwordHash)
router.get("/:username", (ctx) => {
  const user = getUserByUsername(ctx.params.username);
  const { passwordHash: _, ...publicUser } = user;
  ctx.response.body = { success: true, data: publicUser };
});

// Dumps posted by user (optional auth: owner sees their private dumps)
router.get("/:username/dumps", async (ctx) => {
  const user = getUserByUsername(ctx.params.username);
  const requestingUserId = await parseOptionalAuth(ctx);
  const { page, limit } = parsePagination(ctx.request.url.searchParams);
  const includePrivate = requestingUserId === user.id;
  const { items, total } = getDumpsByUser(user.id, page, limit, includePrivate);
  ctx.response.body = {
    success: true,
    data: {
      items,
      total,
      hasMore: page * limit < total,
    } satisfies PaginatedData<typeof items[number]>,
  };
});

// Dumps upvoted by user (optional auth: hide private dump entries for non-owners)
router.get("/:username/votes", async (ctx) => {
  const user = getUserByUsername(ctx.params.username);
  const requestingUserId = await parseOptionalAuth(ctx);
  const { page, limit } = parsePagination(ctx.request.url.searchParams);
  const { items, total } = getVotedDumpsByUser(
    user.id,
    page,
    limit,
    requestingUserId,
  );
  ctx.response.body = {
    success: true,
    data: {
      items,
      total,
      hasMore: page * limit < total,
    } satisfies PaginatedData<typeof items[number]>,
  };
});

export default router;