// main.js
import express from 'express';
import dotenv from 'dotenv';
import cors from 'cors'; // Import the cors middleware
import { fetchActivityData } from './engage-api/get-activity.mjs';
import { structActivityData } from './engage-api/struct-activity.mjs';
import { structStaffData } from './engage-api/struct-staff.mjs';

// Load environment variables from .env file
dotenv.config();

// --- Configuration ---
const USERNAME = process.env.API_USERNAME;
const PASSWORD = process.env.API_PASSWORD;
const PORT = process.env.PORT || 3000;
const FIXED_STAFF_ACTIVITY_ID = process.env.FIXED_STAFF_ACTIVITY_ID || '3350';
const allowedOriginsEnv = process.env.ALLOWED_ORIGINS || '*';

let corsOptions;

if (allowedOriginsEnv === '*') {
  corsOptions = { origin: '*' };
} else {
  // If ALLOWED_ORIGINS is a comma-separated list, split it into an array
  const originsArray = allowedOriginsEnv.split(',').map(origin => origin.trim());
  corsOptions = {
    origin: function (origin, callback) {
      // Allow requests with no origin (like mobile apps or curl requests)
      if (!origin) return callback(null, true);
      if (originsArray.indexOf(origin) !== -1 || originsArray.includes('*')) {
        callback(null, true);
      } else {
        callback(new Error('Not allowed by CORS'));
      }
    }
  };
}

// --- Initialize Express App ---
const app = express();

// Apply CORS middleware globally FIRST
// This will add the 'Access-Control-Allow-Origin' header to all responses
app.use(cors(corsOptions));

// Middleware to parse JSON request bodies
app.use(express.json());

// --- API Endpoints ---

// GET Endpoint: Welcome message
app.get('/', (req, res) => {
    res.send('Welcome to the DSAS CCA API!<br/><br/>\
        API Endpoints:<br/>\
        GET /v1/activity/:activityId (ID must be 1-4 digits)<br/>\
        GET /v1/staffs');
});

// GET Endpoint: Fetch structured activity data by ID
app.get('/v1/activity/:activityId', async (req, res) => {
    let { activityId } = req.params;

    if (!/^\d{1,4}$/.test(activityId)) {
        return res.status(400).json({
            error: 'Invalid Activity ID format. Activity ID must be 1 to 4 digits (e.g., 1, 0001, 9999).'
        });
    }

    if (!USERNAME || !PASSWORD) {
        console.error('API username or password not configured. Check .env file or environment variables.');
        return res.status(500).json({ error: 'Server configuration error.' });
    }

    console.log(`Workspaceing activity details for activity ID: ${activityId}`);
    try {
        const activityJson = await fetchActivityData(activityId, USERNAME, PASSWORD);
        if (activityJson) {
            const structuredActivity = await structActivityData(activityJson);
            res.json(structuredActivity);
        } else {
            res.status(404).json({ error: `Could not retrieve details for activity ${activityId}.` });
        }
    } catch (error) {
        console.error(`Error fetching activity ${activityId}:`, error);
        res.status(500).json({ error: 'An internal server error occurred while fetching activity data.' });
    }
});

// GET Endpoint: Fetch fixed structured staff data
app.get('/v1/staffs', async (req, res) => {
    if (!USERNAME || !PASSWORD) {
        console.error('API username or password not configured. Check .env file or environment variables.');
        return res.status(500).json({ error: 'Server configuration error.' });
    }

    console.log(`Workspaceing staff details (using fixed activity ID: ${FIXED_STAFF_ACTIVITY_ID})`);
    try {
        const activityJson = await fetchActivityData(FIXED_STAFF_ACTIVITY_ID, USERNAME, PASSWORD);
        if (activityJson) {
            const staffMap = await structStaffData(activityJson);
            const staffObject = Object.fromEntries(staffMap);
            res.json(staffObject);
        } else {
            res.status(404).json({ error: `Could not retrieve base data using activity ID ${FIXED_STAFF_ACTIVITY_ID} to get staff details.` });
        }
    } catch (error) {
        console.error(`Error fetching staff data (for fixed activity ID ${FIXED_STAFF_ACTIVITY_ID}):`, error);
        res.status(500).json({ error: 'An internal server error occurred while fetching staff data.' });
    }
});

// --- Start the Server ---
app.listen(PORT, () => {
    console.log(`Server is running on http://localhost:${PORT}`);
    console.log(`Allowed CORS origins: ${allowedOriginsEnv === '*' ? 'All (*)' : allowedOriginsEnv}`);
    console.log('API Endpoints:');
    console.log(`   GET /v1/activity/:activityId (ID must be 1-4 digits)`);
    console.log(`   GET /v1/staffs`);
    if (!USERNAME || !PASSWORD) {
        console.warn('Warning: API_USERNAME or API_PASSWORD is not set. Please configure them in your .env file or environment variables.');
    }
});

// Graceful shutdown
process.on('SIGINT', () => {
    console.log('Server shutting down...');
    process.exit(0);
});