const express = require('express');
const router = express.Router();
const path = require('path');
const fs = require('fs').promises;
const fsStandard = require('fs');
const mime = require('mime-types');
const { logger, ErrorLogger } = require('../config/logs');
const bcrypt = require('bcrypt');
const compression = require('compression');
const { pipeline } = require('stream/promises'); // Utilisation du pipeline moderne
const baseDir = 'cdn-files';

// Middleware de compression gzip
router.use(compression());

async function getSamAccountNameFromUserId(userId) {
    const data = await fs.readFile(path.join(__dirname, '../data', 'user.json'), 'utf8');
    const users = JSON.parse(data);
    const user = users.find(user => user.id === userId);
    if (user) {
        return user.name;
    } else {
        throw new Error('User not found');
    }
}

async function findFileInUserDir(userId, filename) {
    const samaccountname = await getSamAccountNameFromUserId(userId);
    const userDir = path.join(baseDir, samaccountname);
    return findFileInDir(userDir, filename);
}

async function findFileInDir(dir, filename) {
    let files;
    try {
        files = await fs.readdir(dir, { withFileTypes: true });
    } catch (err) {
        return null; // Directory does not exist
    }

    for (const file of files) {
        const filePath = path.join(dir, file.name);

        if (file.name === filename && file.isFile()) {
            return filePath;
        } else if (file.isDirectory()) {
            const found = await findFileInDir(filePath, filename);
            if (found) {
                return found;
            }
        }
    }

    return null;
}

router.get('/:userId', (req, res) => {
    res.render('unauthorized');
});

router.get('/:userId/:filename', async (req, res) => {
    const { userId, filename } = req.params;

    try {
        const filePath = await findFileInUserDir(userId, filename);
        if (!filePath) {
            return res.render('file-not-found');
        }

        const data = await fs.readFile(path.join(__dirname, '../data', 'file_info.json'), 'utf8');
        const fileInfoArray = JSON.parse(data);

        const fileInfo = fileInfoArray.find(info => info.fileName === filename && info.Id === userId);
        if (fileInfo) {
            const expiryDate = new Date(fileInfo.expiryDate);
            const now = new Date();

            if (expiryDate < now) {
                await fs.unlink(filePath);
                return res.render('file-expired');
            }

            if (fileInfo.password && !req.session.passwordVerified) {
                return res.render('password-check', { userId, filename });
            }
        }

        const mimeType = mime.lookup(filePath) || 'application/octet-stream';
        const range = req.headers.range;
        const stats = await fs.stat(filePath);
        const fileSize = stats.size;

        if (range) {
            const [start, end] = range.replace(/bytes=/, '').split('-');
            const chunkStart = parseInt(start, 10);
            const chunkEnd = end ? parseInt(end, 10) : fileSize - 1;

            if (chunkStart >= fileSize || chunkEnd >= fileSize) {
                res.setHeader('Content-Range', `bytes */${fileSize}`);
                return res.status(416).send('Requested Range Not Satisfiable');
            }

            res.status(206);
            res.setHeader('Content-Range', `bytes ${chunkStart}-${chunkEnd}/${fileSize}`);
            res.setHeader('Accept-Ranges', 'bytes');
            res.setHeader('Content-Length', chunkEnd - chunkStart + 1);
            res.setHeader('Content-Type', mimeType);

            const readStream = fsStandard.createReadStream(filePath, { start: chunkStart, end: chunkEnd });
            await pipeline(readStream, res); // Utilisation de pipeline avec await pour éviter les erreurs
        } else {
            res.setHeader('Content-Length', fileSize);
            res.setHeader('Content-Type', mimeType);

            const readStream = fsStandard.createReadStream(filePath);
            await pipeline(readStream, res);
        }
    } catch (err) {
        ErrorLogger.error('Error handling request:', err);
        if (!res.headersSent) {
            res.status(500).send('Error reading file.');
        }
    }
});

router.post('/:userId/:filename', async (req, res) => {
    const { userId, filename } = req.params;
    const enteredPassword = req.body.password;

    try {
        const data = await fs.readFile(path.join(__dirname, '../data', 'file_info.json'), 'utf8');
        const fileInfoArray = JSON.parse(data);

        const fileInfo = fileInfoArray.find(info => info.fileName === filename && info.Id === userId);

        if (!fileInfo) {
            return res.json({ success: false, message: 'File not found' });
        }

        const passwordMatch = await bcrypt.compare(enteredPassword, fileInfo.password);
        if (passwordMatch) {
            req.session.passwordVerified = true;

            const filePath = await findFileInUserDir(userId, filename);
            const mimeType = mime.lookup(filePath) || 'application/octet-stream';
            const readStream = fsStandard.createReadStream(filePath);

            let fileContent = '';
            for await (const chunk of readStream) {
                fileContent += chunk.toString('base64');
            }

            res.json({ success: true, fileContent, mimeType });
        } else {
            res.json({ success: false, message: 'Incorrect password' });
        }
    } catch (err) {
        ErrorLogger.error('Error reading file:', err);
        if (!res.headersSent) {
            res.status(500).send('Error reading file.');
        }
    }
});

module.exports = router;