/**
 * Simple Express server to display translated episodes with speaker colors.
 */

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

const app = express();
const PORT = process.env.PORT || 5000;

// Configuration
const TRANSLATED_DIR = path.join(__dirname, '..', '_translated');
const COLORS_FILE = path.join(__dirname, '..', '_colors.json');

// Set up EJS as templating engine
app.set('view engine', 'ejs');
app.set('views', path.join(__dirname, 'views'));

// Serve static files
app.use(express.static(path.join(__dirname, 'public')));

/**
 * Load speaker color mapping.
 */
function loadColors() {
    try {
        if (fs.existsSync(COLORS_FILE)) {
            const data = fs.readFileSync(COLORS_FILE, 'utf-8');
            return JSON.parse(data);
        }
    } catch (err) {
        console.error('Error loading colors:', err);
    }
    return {};
}

/**
 * Get list of all episodes from _translated folder.
 */
function getEpisodes() {
    const episodes = [];
    try {
        if (fs.existsSync(TRANSLATED_DIR)) {
            const files = fs.readdirSync(TRANSLATED_DIR);
            files
                .filter(f => f.endsWith('_translated.json'))
                .sort()
                .forEach(file => {
                    // Extract episode name from filename (e.g., "S02E01_translated.json" -> "S02E01")
                    const episodeId = file.replace('_translated.json', '');
                    episodes.push({
                        id: episodeId,
                        filename: file,
                        title: episodeId
                    });
                });
        }
    } catch (err) {
        console.error('Error reading episodes:', err);
    }
    return episodes;
}

/**
 * Load a specific episode's data.
 */
function loadEpisode(episodeId) {
    const jsonFile = path.join(TRANSLATED_DIR, `${episodeId}_translated.json`);
    try {
        if (fs.existsSync(jsonFile)) {
            const data = fs.readFileSync(jsonFile, 'utf-8');
            return JSON.parse(data);
        }
    } catch (err) {
        console.error('Error loading episode:', err);
    }
    return null;
}

/**
 * Escape HTML special characters.
 */
function escapeHtml(text) {
    if (!text) return '';
    return text
        .replace(/&/g, '&')
        .replace(/</g, '&lt;')
        .replace(/>/g, '&gt;')
        .replace(/"/g, '&quot;')
        .replace(/'/g, '&#039;');
}

// Make escapeHtml available to templates
app.locals.escapeHtml = escapeHtml;

// Routes
app.get('/', (req, res) => {
    const episodes = getEpisodes();
    if (episodes.length === 0) {
        return res.status(404).send('No episodes found');
    }

    // Get first episode data
    const firstEpisode = episodes[0];
    const lines = loadEpisode(firstEpisode.id);
    const colors = loadColors();

    res.render('episode', {
        episodes,
        currentEpisode: firstEpisode,
        lines,
        colors
    });
});

app.get('/episode/:episodeId', (req, res) => {
    const episodeId = req.params.episodeId;
    const lines = loadEpisode(episodeId);

    if (!lines) {
        return res.status(404).send('Episode not found');
    }

    const episodes = getEpisodes();
    const currentEpisode = {
        id: episodeId,
        filename: `${episodeId}_translated.json`,
        title: episodeId
    };
    const colors = loadColors();

    res.render('episode', {
        episodes,
        currentEpisode,
        lines,
        colors
    });
});

// Start server
app.listen(PORT, '0.0.0.0', () => {
    console.log(`Episode Web Viewer running at http://localhost:${PORT}`);
});