import { Router } from "@oak/oak";
import { authMiddleware } from "../middleware/auth.ts";
import { getUserById, updateUserAvatar } from "../services/user-service.ts";
import { updateClientAvatar } from "../services/ws-service.ts";
import { APIErrorCode, APIException } from "../model/interfaces.ts";
import {
  AVATARS_DIR,
  detectImageMime,
  MAX_IMAGE_SIZE,
  serveUploadedFile,
} from "../utils/upload.ts";

const router = new Router();

router.post("/api/avatars/me", authMiddleware, async (ctx) => {
  const authPayload = ctx.state.user;
  const contentType = ctx.request.headers.get("content-type") ?? "";
  if (!contentType.includes("multipart/form-data")) {
    throw new APIException(
      APIErrorCode.BAD_REQUEST,
      400,
      "Expected multipart/form-data",
    );
  }

  const body = await ctx.request.body.formData();
  const file = body.get("file");

  if (!(file instanceof File)) {
    throw new APIException(APIErrorCode.BAD_REQUEST, 400, "Missing file field");
  }

  if (file.size > MAX_IMAGE_SIZE) {
    throw new APIException(
      APIErrorCode.BAD_REQUEST,
      400,
      "File too large (max 5 MB)",
    );
  }

  const data = new Uint8Array(await file.arrayBuffer());

  const mime = detectImageMime(data);
  if (!mime) {
    throw new APIException(
      APIErrorCode.BAD_REQUEST,
      400,
      "File content is not a recognised image (JPEG, PNG, GIF, WebP)",
    );
  }

  await Deno.mkdir(AVATARS_DIR, { recursive: true });
  await Deno.writeFile(`${AVATARS_DIR}/${authPayload.userId}`, data);
  updateUserAvatar(authPayload.userId, mime);
  updateClientAvatar(authPayload.userId, mime);

  const user = getUserById(authPayload.userId);
  ctx.response.status = 200;
  ctx.response.body = { success: true, data: user };
});

router.get("/api/avatars/:userId", async (ctx) => {
  const { userId } = ctx.params;

  let user;
  try {
    user = getUserById(userId);
  } catch {
    ctx.response.status = 404;
    return;
  }

  if (!user.avatarMime) {
    ctx.response.status = 404;
    return;
  }

  await serveUploadedFile(ctx, `${AVATARS_DIR}/${userId}`, user.avatarMime);
});

export default router;