const express = require('express');
const fs = require('fs').promises;
const path = require('path');
const { google } = require('googleapis');
const { Resend } = require('resend');

const app = express();
const PORT = process.env.PORT || 3000;
const DATA_DIR = process.env.DATA_DIR || './data';
const REGISTRATIONS_FILE = path.join(DATA_DIR, 'registrations.json');

// Initialize Resend for emails
const resend = process.env.RESEND_API_KEY ? new Resend(process.env.RESEND_API_KEY) : null;

// Google Sheets configuration
const GOOGLE_SHEET_ID = process.env.GOOGLE_SHEET_ID;
const GOOGLE_CREDENTIALS = process.env.GOOGLE_CREDENTIALS ? JSON.parse(process.env.GOOGLE_CREDENTIALS) : null;

// Initialize Google Sheets API
let sheets = null;
if (GOOGLE_CREDENTIALS && GOOGLE_SHEET_ID) {
    const auth = new google.auth.GoogleAuth({
        credentials: GOOGLE_CREDENTIALS,
        scopes: ['https://www.googleapis.com/auth/spreadsheets'],
    });
    sheets = google.sheets({ version: 'v4', auth });
    console.log('Google Sheets integration enabled');
}

// Middleware
app.use(express.json());
app.use(express.static('.'));

// Ensure data directory exists
async function ensureDataDir() {
    try {
        await fs.mkdir(DATA_DIR, { recursive: true });
        try {
            await fs.access(REGISTRATIONS_FILE);
        } catch {
            await fs.writeFile(REGISTRATIONS_FILE, '[]');
        }
    } catch (error) {
        console.error('Error creating data directory:', error);
    }
}

// Load registrations
async function loadRegistrations() {
    try {
        const data = await fs.readFile(REGISTRATIONS_FILE, 'utf8');
        return JSON.parse(data);
    } catch {
        return [];
    }
}

// Save registrations
async function saveRegistrations(registrations) {
    await fs.writeFile(REGISTRATIONS_FILE, JSON.stringify(registrations, null, 2));
}

// Append registration to Google Sheet
async function appendToGoogleSheet(registration) {
    if (!sheets || !GOOGLE_SHEET_ID) {
        console.log('Google Sheets not configured, skipping...');
        return;
    }

    try {
        const values = [[
            registration.registeredAt,
            registration.firstName,
            registration.lastName,
            registration.email,
            registration.location,
            registration.role,
            Array.isArray(registration.interests) ? registration.interests.join(', ') : registration.interests,
            registration.contribute,
            registration.message,
            registration.id
        ]];

        await sheets.spreadsheets.values.append({
            spreadsheetId: GOOGLE_SHEET_ID,
            range: 'Registrations!A:J',
            valueInputOption: 'USER_ENTERED',
            insertDataOption: 'INSERT_ROWS',
            requestBody: { values },
        });

        console.log(`Added registration to Google Sheet: ${registration.email}`);
    } catch (error) {
        console.error('Error appending to Google Sheet:', error.message);
    }
}

// Send confirmation email
async function sendConfirmationEmail(registration) {
    if (!resend) {
        console.log('Resend not configured, skipping email...');
        return;
    }

    try {
        const interestsText = Array.isArray(registration.interests) && registration.interests.length > 0
            ? registration.interests.map(i => {
                const labels = {
                    'reality': '🎭 Playing with Reality',
                    'fiction': '✒️ Science Fictions',
                    'worlding': '🛠 Guerrilla Futuring',
                    'games': '🎲 Game Commons',
                    'infrastructure': '🌱 Infrastructures'
                };
                return labels[i] || i;
            }).join(', ')
            : 'Not specified';

        const roleLabels = {
            'writer': 'Sci-Fi Writer / Storyteller',
            'gamemaker': 'Game Designer / Maker',
            'artist': 'Artist / Performer',
            'larper': 'LARPer / Roleplayer',
            'economist': 'Weird Economist / Commons Activist',
            'futurist': 'Futurist / Speculative Designer',
            'academic': 'Academic / Researcher',
            'tech': 'Technologist / Developer',
            'curious': 'Curious Explorer',
            'other': 'Other'
        };

        const contributeLabels = {
            'session': 'Pitch a session',
            'workshop': 'Run a workshop',
            'game': 'Share/playtest a game',
            'performance': 'Perform/facilitate',
            'collaborate': 'Collaborate on something',
            'participate': 'Participate',
            'unsure': 'Not sure yet'
        };

        await resend.emails.send({
            from: 'WORLDPLAY <hello@worldplay.art>',
            to: registration.email,
            subject: '🎭 Welcome to WORLDPLAY – Registration Confirmed',
            html: `
<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
</head>
<body style="font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif; background-color: #0a0a0f; color: #f0f0f5; padding: 40px 20px; margin: 0;">
    <div style="max-width: 600px; margin: 0 auto;">
        <div style="text-align: center; margin-bottom: 40px;">
            <h1 style="font-family: monospace; font-size: 32px; background: linear-gradient(135deg, #9d4edd 0%, #ff006e 100%); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; margin: 0;">WORLDPLAY</h1>
            <p style="color: #a0a0b0; font-style: italic; margin-top: 8px;">: To be Defined</p>
        </div>

        <div style="background-color: #12121a; border: 1px solid rgba(157, 78, 221, 0.3); border-radius: 12px; padding: 32px; margin-bottom: 24px;">
            <h2 style="color: #00d9ff; margin-top: 0; font-size: 20px;">Welcome, ${registration.firstName}! 🌟</h2>

            <p style="color: #a0a0b0; line-height: 1.7;">
                Thank you for registering your interest in <strong style="color: #f0f0f5;">WORLDPLAY</strong> – a pop-up physical hub for prefiguring and prehearsing postcapitalist futures through fiction, performance and play.
            </p>

            <p style="color: #a0a0b0; line-height: 1.7;">
                We've received your registration and will be in touch with next steps as we finalize the programme.
            </p>
        </div>

        <div style="background-color: #12121a; border: 1px solid rgba(157, 78, 221, 0.3); border-radius: 12px; padding: 32px; margin-bottom: 24px;">
            <h3 style="color: #9d4edd; margin-top: 0; font-size: 16px; text-transform: uppercase; letter-spacing: 0.1em;">Your Registration Details</h3>

            <table style="width: 100%; color: #a0a0b0; font-size: 14px;">
                <tr>
                    <td style="padding: 8px 0; border-bottom: 1px solid rgba(157, 78, 221, 0.1);"><strong style="color: #f0f0f5;">Name:</strong></td>
                    <td style="padding: 8px 0; border-bottom: 1px solid rgba(157, 78, 221, 0.1);">${registration.firstName} ${registration.lastName}</td>
                </tr>
                <tr>
                    <td style="padding: 8px 0; border-bottom: 1px solid rgba(157, 78, 221, 0.1);"><strong style="color: #f0f0f5;">Email:</strong></td>
                    <td style="padding: 8px 0; border-bottom: 1px solid rgba(157, 78, 221, 0.1);">${registration.email}</td>
                </tr>
                ${registration.location ? `
                <tr>
                    <td style="padding: 8px 0; border-bottom: 1px solid rgba(157, 78, 221, 0.1);"><strong style="color: #f0f0f5;">Location:</strong></td>
                    <td style="padding: 8px 0; border-bottom: 1px solid rgba(157, 78, 221, 0.1);">${registration.location}</td>
                </tr>
                ` : ''}
                ${registration.role ? `
                <tr>
                    <td style="padding: 8px 0; border-bottom: 1px solid rgba(157, 78, 221, 0.1);"><strong style="color: #f0f0f5;">Role:</strong></td>
                    <td style="padding: 8px 0; border-bottom: 1px solid rgba(157, 78, 221, 0.1);">${roleLabels[registration.role] || registration.role}</td>
                </tr>
                ` : ''}
                <tr>
                    <td style="padding: 8px 0; border-bottom: 1px solid rgba(157, 78, 221, 0.1);"><strong style="color: #f0f0f5;">Interests:</strong></td>
                    <td style="padding: 8px 0; border-bottom: 1px solid rgba(157, 78, 221, 0.1);">${interestsText}</td>
                </tr>
                ${registration.contribute ? `
                <tr>
                    <td style="padding: 8px 0; border-bottom: 1px solid rgba(157, 78, 221, 0.1);"><strong style="color: #f0f0f5;">Contribution:</strong></td>
                    <td style="padding: 8px 0; border-bottom: 1px solid rgba(157, 78, 221, 0.1);">${contributeLabels[registration.contribute] || registration.contribute}</td>
                </tr>
                ` : ''}
            </table>
        </div>

        <div style="background-color: #12121a; border: 1px solid rgba(157, 78, 221, 0.3); border-radius: 12px; padding: 32px; margin-bottom: 24px;">
            <h3 style="color: #9d4edd; margin-top: 0; font-size: 16px; text-transform: uppercase; letter-spacing: 0.1em;">Event Details</h3>

            <p style="color: #a0a0b0; margin: 0;">
                📅 <strong style="color: #f0f0f5;">June 7–13, 2026</strong><br>
                📍 <strong style="color: #f0f0f5;">Commons Hub</strong>, Hirschwang an der Rax, Austria<br>
                🏔️ Austrian Alps, ~1.5 hours from Vienna by train
            </p>
        </div>

        <div style="text-align: center; padding: 24px 0; border-top: 1px solid rgba(157, 78, 221, 0.2);">
            <p style="color: #a0a0b0; font-size: 14px; margin: 0;">
                Questions? Reply to this email or visit <a href="https://worldplay.art" style="color: #00d9ff;">worldplay.art</a>
            </p>
            <p style="color: #9d4edd; font-size: 12px; margin-top: 16px; font-style: italic;">
                Reality is a design space ✨
            </p>
        </div>
    </div>
</body>
</html>
            `,
        });

        console.log(`Confirmation email sent to: ${registration.email}`);
    } catch (error) {
        console.error('Error sending confirmation email:', error.message);
    }
}

// Registration endpoint
app.post('/api/register', async (req, res) => {
    try {
        const { firstName, lastName, email, location, role, interests, contribute, message } = req.body;

        // Validation
        if (!firstName || !lastName || !email) {
            return res.status(400).json({ error: 'First name, last name, and email are required' });
        }

        if (!email.match(/^[^\s@]+@[^\s@]+\.[^\s@]+$/)) {
            return res.status(400).json({ error: 'Please provide a valid email address' });
        }

        // Load existing registrations
        const registrations = await loadRegistrations();

        // Check for duplicate email
        if (registrations.some(r => r.email.toLowerCase() === email.toLowerCase())) {
            return res.status(400).json({ error: 'This email is already registered' });
        }

        // Create new registration
        const registration = {
            id: Date.now().toString(36) + Math.random().toString(36).substr(2),
            firstName: firstName.trim(),
            lastName: lastName.trim(),
            email: email.toLowerCase().trim(),
            location: location?.trim() || '',
            role: role || '',
            interests: interests || [],
            contribute: contribute || '',
            message: message?.trim() || '',
            registeredAt: new Date().toISOString(),
            ipAddress: req.ip || req.connection.remoteAddress
        };

        // Save registration locally
        registrations.push(registration);
        await saveRegistrations(registrations);

        console.log(`New registration: ${registration.firstName} ${registration.lastName} <${registration.email}>`);

        // Add to Google Sheet (async, don't block response)
        appendToGoogleSheet(registration).catch(err => console.error('Sheet error:', err));

        // Send confirmation email (async, don't block response)
        sendConfirmationEmail(registration).catch(err => console.error('Email error:', err));

        res.json({
            success: true,
            message: 'Registration successful',
            id: registration.id
        });

    } catch (error) {
        console.error('Registration error:', error);
        res.status(500).json({ error: 'An error occurred. Please try again.' });
    }
});

// Admin endpoint to view registrations (protected by simple token)
app.get('/api/registrations', async (req, res) => {
    const token = req.headers['x-admin-token'] || req.query.token;
    const adminToken = process.env.ADMIN_TOKEN || 'worldplay-admin-2026';

    if (token !== adminToken) {
        return res.status(401).json({ error: 'Unauthorized' });
    }

    try {
        const registrations = await loadRegistrations();
        res.json({
            count: registrations.length,
            registrations: registrations.map(r => ({
                ...r,
                ipAddress: undefined // Don't expose IP in admin view
            }))
        });
    } catch (error) {
        res.status(500).json({ error: 'Failed to load registrations' });
    }
});

// Export registrations as CSV
app.get('/api/registrations/export', async (req, res) => {
    const token = req.headers['x-admin-token'] || req.query.token;
    const adminToken = process.env.ADMIN_TOKEN || 'worldplay-admin-2026';

    if (token !== adminToken) {
        return res.status(401).json({ error: 'Unauthorized' });
    }

    try {
        const registrations = await loadRegistrations();

        const headers = ['ID', 'First Name', 'Last Name', 'Email', 'Location', 'Role', 'Interests', 'Contribute', 'Message', 'Registered At'];
        const rows = registrations.map(r => [
            r.id,
            r.firstName,
            r.lastName,
            r.email,
            r.location,
            r.role,
            Array.isArray(r.interests) ? r.interests.join('; ') : r.interests,
            r.contribute,
            r.message.replace(/"/g, '""'),
            r.registeredAt
        ]);

        const csv = [
            headers.join(','),
            ...rows.map(row => row.map(cell => `"${cell}"`).join(','))
        ].join('\n');

        res.setHeader('Content-Type', 'text/csv');
        res.setHeader('Content-Disposition', 'attachment; filename=worldplay-registrations.csv');
        res.send(csv);
    } catch (error) {
        res.status(500).json({ error: 'Failed to export registrations' });
    }
});

// Health check
app.get('/health', (req, res) => {
    res.json({ status: 'ok', timestamp: new Date().toISOString() });
});

// Stats endpoint
app.get('/api/stats', async (req, res) => {
    try {
        const registrations = await loadRegistrations();

        const stats = {
            totalRegistrations: registrations.length,
            byRole: {},
            byInterest: {},
            byContribute: {}
        };

        registrations.forEach(r => {
            // Count by role
            if (r.role) {
                stats.byRole[r.role] = (stats.byRole[r.role] || 0) + 1;
            }

            // Count by interest
            if (Array.isArray(r.interests)) {
                r.interests.forEach(interest => {
                    stats.byInterest[interest] = (stats.byInterest[interest] || 0) + 1;
                });
            }

            // Count by contribute
            if (r.contribute) {
                stats.byContribute[r.contribute] = (stats.byContribute[r.contribute] || 0) + 1;
            }
        });

        res.json(stats);
    } catch (error) {
        res.status(500).json({ error: 'Failed to calculate stats' });
    }
});

// Start server
ensureDataDir().then(() => {
    app.listen(PORT, '0.0.0.0', () => {
        console.log(`WORLDPLAY server running on port ${PORT}`);
        console.log(`Admin token: ${process.env.ADMIN_TOKEN || 'worldplay-admin-2026'}`);
        console.log(`Google Sheets: ${sheets ? 'enabled' : 'disabled'}`);
        console.log(`Email notifications: ${resend ? 'enabled' : 'disabled'}`);
    });
});