import { Client, Databases } from 'node-appwrite';

const APPWRITE_ENDPOINT = process.env.APPWRITE_ENDPOINT || process.env.APPWRITE_FUNCTION_ENDPOINT;
const APPWRITE_PROJECT_ID = process.env.APPWRITE_PROJECT_ID || process.env.APPWRITE_FUNCTION_PROJECT_ID;
const APPWRITE_API_KEY = process.env.APPWRITE_API_KEY;
const DATABASE_ID = process.env.APPWRITE_DATABASE_ID;

const githubHeaders = (token) => ({
  Authorization: `Bearer ${token}`,
  Accept: 'application/vnd.github+json',
  'User-Agent': 'appwrite-sync-github'
});

export default async function ({ req, res, log, error }) {
  try {
    if (!APPWRITE_ENDPOINT || !APPWRITE_PROJECT_ID || !APPWRITE_API_KEY || !DATABASE_ID) {
      return res.json({ error: 'Missing Appwrite environment configuration.' }, 500);
    }

    const payload = req.body ? JSON.parse(req.body) : {};
    const accountId = payload.accountId;
    const requesterId =
      (req.headers && (req.headers['x-appwrite-user-id'] || req.headers['x-appwrite-userid'])) ||
      process.env.APPWRITE_FUNCTION_USER_ID ||
      payload.userId;
    if (!accountId) {
      return res.json({ error: 'accountId is required in the request body.' }, 400);
    }

    const client = new Client()
      .setEndpoint(APPWRITE_ENDPOINT)
      .setProject(APPWRITE_PROJECT_ID)
      .setKey(APPWRITE_API_KEY);

    const databases = new Databases(client);
    const account = await databases.getDocument(DATABASE_ID, 'cloud_accounts', accountId);

    if (!account || account.provider !== 'github') {
      return res.json({ error: 'Cloud account not found or not a GitHub credential.' }, 404);
    }

    if (account.userId && requesterId && account.userId !== requesterId) {
      return res.json({ error: 'You are not allowed to use this credential.' }, 403);
    }

    const token = account.apiKey;
    if (!token) {
      return res.json({ error: 'GitHub token is missing for this account.' }, 400);
    }

    const githubResponse = await fetch('https://api.github.com/user/repos?per_page=100', {
      headers: githubHeaders(token)
    });

    if (!githubResponse.ok) {
      const body = await githubResponse.text();
      log(`GitHub API error: ${body}`);
      return res.json({ error: 'Failed to fetch repositories from GitHub.' }, githubResponse.status);
    }

    const repositories = await githubResponse.json();
    const simplified = repositories.map((repo) => ({
      id: repo.id,
      name: repo.name,
      fullName: repo.full_name,
      private: repo.private,
      url: repo.html_url,
      defaultBranch: repo.default_branch
    }));

    return res.json({ repositories: simplified }, 200);
  } catch (err) {
    error(err.message);
    return res.json({ error: 'Unexpected error while syncing with GitHub.' }, 500);
  }
}