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

const app = express();
app.use(cors());
app.use(express.json());

const LEADERBOARD_FILE = './leaderboard.json';
const INACTIVE_DAYS = 30;  // Completely remove from JSON after 30 days
const LEADERBOARD_VISIBLE_DAYS = 5;  // Only show on leaderboard if active within 5 days

// Load leaderboard from file
function loadLeaderboard() {
    try {
        return JSON.parse(fs.readFileSync(LEADERBOARD_FILE, 'utf8'));
    } catch (e) {
        return [];
    }
}

// Save leaderboard to file
function saveLeaderboard(data) {
    fs.writeFileSync(LEADERBOARD_FILE, JSON.stringify(data, null, 2));
}

// Clean up inactive players (remove from JSON after 30 days)
function cleanupInactive(leaderboard) {
    const thirtyDaysAgo = Date.now() - (INACTIVE_DAYS * 24 * 60 * 60 * 1000);
    const beforeCount = leaderboard.length;

    const active = leaderboard.filter(player => player.lastSeen > thirtyDaysAgo);

    if (active.length < beforeCount) {
        console.log(`Permanently removed ${beforeCount - active.length} players (>30 days inactive)`);
    }

    return active;
}

// Filter players visible on leaderboard (active within 5 days)
function getVisiblePlayers(leaderboard) {
    const fiveDaysAgo = Date.now() - (LEADERBOARD_VISIBLE_DAYS * 24 * 60 * 60 * 1000);
    const visible = leaderboard.filter(player => player.lastSeen > fiveDaysAgo);
    return visible;
}

// Submit checkpoint
app.post('/api/checkpoint', (req, res) => {
    const { playerId, name, mass, playTime, levels } = req.body;

    // Basic validation
    if (!playerId || mass < 0 || playTime < 0) {
        return res.status(400).json({ error: 'Invalid data' });
    }

    let leaderboard = loadLeaderboard();

    // Clean up players inactive for 30+ days
    leaderboard = cleanupInactive(leaderboard);

    const now = Date.now();

    // Find or create player
    let player = leaderboard.find(p => p.id === playerId);
    if (player) {
        // Update existing player
        player.mass = Math.max(player.mass, mass);
        player.playTime = Math.max(player.playTime, playTime);
        player.level = Math.max(player.level, levels?.total || 0);
        player.name = name || player.name;
        player.lastSeen = now;

        // Calculate hole age (time since first seen)
        player.holeAge = now - player.firstSeen;
    } else {
        // New player
        leaderboard.push({
            id: playerId,
            name: name || 'Anonymous',
            mass: mass,
            playTime: playTime,
            level: levels?.total || 0,
            firstSeen: now,
            lastSeen: now,
            holeAge: 0
        });
    }

    // Sort by mass and keep top 100 (in JSON file)
    leaderboard.sort((a, b) => b.mass - a.mass);
    leaderboard = leaderboard.slice(0, 100);

    saveLeaderboard(leaderboard);

    res.json({ success: true });
});

// Get leaderboard
app.get('/api/leaderboard', (req, res) => {
    const type = req.query.type || 'mass';
    const requesterId = req.query.playerId; // Get player ID from query parameter

    let leaderboard = loadLeaderboard();

    // Clean up players inactive for 30+ days
    leaderboard = cleanupInactive(leaderboard);

    // Update hole ages and online status
    const now = Date.now();
    const fifteenMinutes = 15 * 60 * 1000;

    leaderboard.forEach(player => {
        player.holeAge = now - player.firstSeen;
        player.isOnline = (now - player.lastSeen) < fifteenMinutes;
    });

    // Filter to only show players active within 5 days
    let visiblePlayers = getVisiblePlayers(leaderboard);

    // Sort by requested type
    if (type === 'age') {
        visiblePlayers.sort((a, b) => b.holeAge - a.holeAge);
    } else if (type === 'time') {
        visiblePlayers.sort((a, b) => b.playTime - a.playTime);
    } else if (type === 'level') {
        visiblePlayers.sort((a, b) => b.level - a.level);
    } else {
        visiblePlayers.sort((a, b) => b.mass - a.mass);
    }

    // Log who opened the leaderboard
    if (requesterId) {
        const requester = leaderboard.find(p => p.id === requesterId);
        const requesterName = requester ? requester.name : 'Unknown';
	const timestamp = new Date().toLocaleString();
        console.log(`${timestamp} Score requested by: ${requesterName} (${requesterId.slice(-5)})`);
    }

    // Save the full leaderboard (including hidden players)
    saveLeaderboard(leaderboard);

    // Return only visible players (top 50)
    res.json(visiblePlayers.slice(0, 50));
});

// Get player info (works even if not visible on leaderboard)
app.get('/api/player/:playerId', (req, res) => {
    const playerId = req.params.playerId;
    let leaderboard = loadLeaderboard();

    const player = leaderboard.find(p => p.id === playerId);

    if (!player) {
        return res.status(404).json({ error: 'Player not found' });
    }

    // Update hole age
    player.holeAge = Date.now() - player.firstSeen;

    // Calculate days since last seen
    player.daysSinceLastSeen = Math.floor((Date.now() - player.lastSeen) / (24 * 60 * 60 * 1000));
    
    // Check if visible on leaderboard
    const fiveDaysAgo = Date.now() - (LEADERBOARD_VISIBLE_DAYS * 24 * 60 * 60 * 1000);
    player.visibleOnLeaderboard = player.lastSeen > fiveDaysAgo;

    res.json(player);
});

// Manual cleanup endpoint (optional - for maintenance)
app.post('/api/cleanup', (req, res) => {
    let leaderboard = loadLeaderboard();
    const beforeCount = leaderboard.length;

    leaderboard = cleanupInactive(leaderboard);
    saveLeaderboard(leaderboard);

    res.json({
        removed: beforeCount - leaderboard.length,
        remaining: leaderboard.length
    });
});

// Stats endpoint (optional - see how many are hidden vs visible)
app.get('/api/stats', (req, res) => {
    let leaderboard = loadLeaderboard();
    const visiblePlayers = getVisiblePlayers(leaderboard);
    
    res.json({
        totalPlayers: leaderboard.length,
        visiblePlayers: visiblePlayers.length,
        hiddenPlayers: leaderboard.length - visiblePlayers.length
    });
});

const PORT = process.env.PORT || 3000;
app.listen(PORT, () => {
    console.log(`Server running on port ${PORT}`);
    console.log(`Players hidden from leaderboard after ${LEADERBOARD_VISIBLE_DAYS} days inactive`);
    console.log(`Players permanently removed after ${INACTIVE_DAYS} days inactive`);
});