import cors from 'cors';
import dotenv from 'dotenv';
import express from 'express';
import { Client, Databases, Query } from 'node-appwrite';

dotenv.config();

const app = express();

app.use(cors());
app.use(express.json());

const requiredEnv = ['APPWRITE_ENDPOINT', 'APPWRITE_PROJECT_ID', 'APPWRITE_API_KEY'];
const missingEnv = requiredEnv.filter((key) => !process.env[key]);

const databaseId =
  process.env.APPWRITE_DATABASE_ID || process.env.VITE_APPWRITE_DATABASE_ID || '';

const collectionIds = {
  servers:
    process.env.APPWRITE_COLLECTION_SERVERS_ID ||
    process.env.VITE_APPWRITE_COLLECTION_SERVERS_ID ||
    '',
  githubRepos:
    process.env.APPWRITE_COLLECTION_GITHUB_REPOS_ID ||
    process.env.VITE_APPWRITE_COLLECTION_GITHUB_REPOS_ID ||
    '',
  auditLogs:
    process.env.APPWRITE_COLLECTION_AUDIT_LOGS_ID ||
    process.env.VITE_APPWRITE_COLLECTION_AUDIT_LOGS_ID ||
    '',
  cloudAccounts:
    process.env.APPWRITE_COLLECTION_CLOUDFLARE_ACCOUNTS_ID ||
    process.env.VITE_APPWRITE_COLLECTION_CLOUDFLARE_ACCOUNTS_ID ||
    '',
};

const client = new Client()
  .setEndpoint(process.env.APPWRITE_ENDPOINT || '')
  .setProject(process.env.APPWRITE_PROJECT_ID || '')
  .setKey(process.env.APPWRITE_API_KEY || '');

const databases = new Databases(client);

const getPaginationQueries = (request) => {
  const limit = Number.parseInt(request.query.limit ?? '25', 10);
  const offset = Number.parseInt(request.query.offset ?? '0', 10);

  const queries = [];

  if (!Number.isNaN(limit)) {
    queries.push(Query.limit(Math.min(Math.max(limit, 1), 100)));
  }

  if (!Number.isNaN(offset)) {
    queries.push(Query.offset(Math.max(offset, 0)));
  }

  return queries;
};

const listCollection = (collectionId, extraQueries = []) => async (request, response) => {
  if (missingEnv.length > 0) {
    return response.status(500).json({
      error: 'Missing required environment variables.',
      missing: missingEnv,
    });
  }

  if (!databaseId || !collectionId) {
    return response.status(500).json({
      error: 'Missing Appwrite database or collection configuration.',
      databaseId,
      collectionId,
    });
  }

  try {
    const documents = await databases.listDocuments(
      databaseId,
      collectionId,
      [...getPaginationQueries(request), ...extraQueries]
    );

    return response.json(documents);
  } catch (error) {
    return response.status(500).json({
      error: 'Failed to fetch Appwrite documents.',
      details: error.message,
    });
  }
};

app.get('/health', (request, response) => {
  response.json({ status: 'ok' });
});

app.get('/servers', listCollection(collectionIds.servers));
app.get('/github-repos', listCollection(collectionIds.githubRepos));
app.get('/cloud-accounts', listCollection(collectionIds.cloudAccounts));
app.get('/audit-logs', listCollection(collectionIds.auditLogs, [Query.orderDesc('timestamp')]));

const port = Number.parseInt(process.env.BACKEND_PORT ?? '4000', 10);

app.listen(port, () => {
  // eslint-disable-next-line no-console
  console.log(`Backend listening on http://localhost:${port}`);
});