const fs = require('fs');
const path = require('path');

function splitByGroup(filePath) {
    const content = fs.readFileSync(filePath, 'utf8');
    const lines = content.split('\n');
    
    // Create groups directory if it doesn't exist
    const groupsDir = path.join(path.dirname(filePath), 'countries');
    if (!fs.existsSync(groupsDir)) {
        fs.mkdirSync(groupsDir);
    }
    
    // Get existing country files
    const existingFiles = fs.readdirSync(groupsDir)
        .filter(file => file.endsWith('.m3u'))
        .map(file => file.toLowerCase());
    
    const groups = {};
    let currentExtinf = null;
    
    // First line should be #EXTM3U
    const header = lines[0];
    if (!header.startsWith('#EXTM3U')) {
        throw new Error('Invalid M3U file: Missing #EXTM3U header');
    }
    
    // Process each line
    lines.forEach(line => {
        line = line.trim();
        if (!line) return;
        
        if (line.startsWith('#EXTINF')) {
            currentExtinf = line;
            const groupMatch = line.match(/group-title="([^"]*)"/);
            const groupTitle = groupMatch ? groupMatch[1] : 'Unknown';
            
            if (!groups[groupTitle]) {
                groups[groupTitle] = ['#EXTM3U'];
            }
            groups[groupTitle].push(line);
        } else if (currentExtinf && !line.startsWith('#')) {
            // This is a URL line
            const groupMatch = currentExtinf.match(/group-title="([^"]*)"/);
            const groupTitle = groupMatch ? groupMatch[1] : 'Unknown';
            groups[groupTitle].push(line);
            currentExtinf = null;
        }
    });
    
    // Get list of current group files that should exist
    const currentGroupFiles = Object.keys(groups).map(groupTitle => 
        `${groupTitle.replace(/[^a-z0-9]/gi, '_').toLowerCase()}.m3u`
    );
    
    // Remove files for groups that no longer exist
    existingFiles.forEach(existingFile => {
        if (!currentGroupFiles.includes(existingFile)) {
            const fileToRemove = path.join(groupsDir, existingFile);
            fs.unlinkSync(fileToRemove);
            console.log(`Removed obsolete group playlist: ${existingFile}`);
        }
    });
    
    // Write each group to a separate file
    Object.entries(groups).forEach(([groupTitle, groupLines]) => {
        const safeGroupTitle = groupTitle.replace(/[^a-z0-9]/gi, '_').toLowerCase();
        const groupFilePath = path.join(groupsDir, `${safeGroupTitle}.m3u`);
        fs.writeFileSync(groupFilePath, groupLines.join('\n') + '\n');
        console.log(`Created/updated group playlist: ${groupFilePath}`);
    });
    
    // Create a summary of the split
    const summary = Object.entries(groups).map(([group, lines]) => {
        const channelCount = (lines.length - 1) / 2; // Subtract header and divide by 2 (EXTINF + URL)
        return `${group}: ${channelCount} channels`;
    });
    
    console.log('\nPlaylist split summary:');
    console.log(summary.join('\n'));
}

const filePath = process.argv[2];
if (!filePath) {
    console.error('Please provide the path to mystique.m3u');
    process.exit(1);
}

try {
    splitByGroup(filePath);
} catch (error) {
    console.error('Error splitting mystique.m3u:', error.message);
    process.exit(1);
}