// Game state
let gameActive = false;
let stockCharts = {};

// Format large numbers: add commas for thousands
function formatNumber(value) {
    const num = Number(value);
    if (isNaN(num)) return value;
    if (Number.isInteger(num)) return num.toLocaleString();
    return num.toLocaleString(undefined, { minimumFractionDigits: 2, maximumFractionDigits: 2 });
}
async function startGame() {
    const daysInput = document.getElementById('daysInput');
    const days = parseInt(daysInput.value);

    if (!days || days < 1) {
        alert('Please enter a valid number of days');
        return;
    }

    try {
        const response = await fetch('/api/start', {
            method: 'POST',
            headers: {
                'Content-Type': 'application/json'
            },
            body: JSON.stringify({ days: days })
        });

        if (!response.ok) throw new Error('Failed to start game');

        gameActive = true;
        document.getElementById('startScreen').classList.add('hidden');
        document.getElementById('gameScreen').classList.remove('hidden');
        document.getElementById('totalDays').textContent = days;

        await updateGameDisplay();
        populateStockSelect();
    } catch (error) {
        alert('Error starting game: ' + error.message);
    }
}

async function updateGameDisplay() {
    try {
        const response = await fetch('/api/game-state');
        if (!response.ok) throw new Error('Failed to fetch game state');

        const data = await response.json();

        document.getElementById('balance').textContent = formatNumber(data.balance);
        document.getElementById('day').textContent = data.day;
        document.getElementById('index').textContent = formatNumber(data.index);

        displayStocks(data.stocks);
        displayHoldings(data.holdings);
        displayMessage(data.message);
        updateCharts(data.priceHistory, data.stocks, data.day);
    } catch (error) {
        console.error('Error updating game display:', error);
    }
}

function displayStocks(stocks) {
    const stocksList = document.getElementById('stocksList');
    stocksList.innerHTML = '';

    stocks.forEach(stock => {
        const div = document.createElement('div');
        div.className = 'stock-item';
        div.innerHTML = `<span>${stock.name}</span><span>$${formatNumber(stock.price)}</span>`;
        stocksList.appendChild(div);
    });
}

function displayHoldings(holdings) {
    const holdingsList = document.getElementById('holdingsList');
    holdingsList.innerHTML = '';

    holdings.forEach(holding => {
        const div = document.createElement('div');
        div.className = 'holding-item';
        div.innerHTML = `<span>${holding.name}</span><span>${holding.amount} shares</span>`;
        holdingsList.appendChild(div);
    });
}

function displayMessage(message) {
    const messageDiv = document.getElementById('message');
    if (message) {
        messageDiv.textContent = message;
        messageDiv.classList.add('show');
        messageDiv.classList.remove('error');
    } else {
        messageDiv.classList.remove('show');
    }
}

function populateStockSelect() {
    // Fetch the current game state to get the actual stocks
    fetch('/api/game-state')
        .then(response => response.json())
        .then(data => {
            const stocks = data.stocks;
            const select = document.getElementById('stockSelect');
            select.innerHTML = '';
            stocks.forEach(stock => {
                const option = document.createElement('option');
                option.value = stock.id;
                option.textContent = `${stock.name}`;
                select.appendChild(option);
            });
        })
        .catch(error => console.error('Error populating stock select:', error));
}

async function buyStock() {
    if (!gameActive) return;

    const stockId = parseInt(document.getElementById('stockSelect').value);
    const amount = parseInt(document.getElementById('amountInput').value);

    if (!amount || amount < 1) {
        showError('Please enter a valid amount');
        return;
    }

    try {
        const response = await fetch('/api/buy', {
            method: 'POST',
            headers: {
                'Content-Type': 'application/json'
            },
            body: JSON.stringify({
                stock_id: stockId,
                amount: amount
            })
        });

        const data = await response.json();

        if (!response.ok) {
            showError(data.error);
            return;
        }

        document.getElementById('amountInput').value = '1';
        await updateGameDisplay();
    } catch (error) {
        showError('Error buying stock: ' + error.message);
    }
}

async function sellStock() {
    if (!gameActive) return;

    const stockId = parseInt(document.getElementById('stockSelect').value);
    const amount = parseInt(document.getElementById('amountInput').value);

    if (!amount || amount < 1) {
        showError('Please enter a valid amount');
        return;
    }

    try {
        const response = await fetch('/api/sell', {
            method: 'POST',
            headers: {
                'Content-Type': 'application/json'
            },
            body: JSON.stringify({
                stock_id: stockId,
                amount: amount
            })
        });

        const data = await response.json();

        if (!response.ok) {
            showError(data.error);
            return;
        }

        document.getElementById('amountInput').value = '1';
        await updateGameDisplay();
    } catch (error) {
        showError('Error selling stock: ' + error.message);
    }
}

async function buyAll() {
    if (!gameActive) return;

    const stockId = parseInt(document.getElementById('stockSelect').value);
    
    try {
        const gameStateResponse = await fetch('/api/game-state');
        const gameStateData = await gameStateResponse.json();
        
        const stocks = gameStateData.stocks;
        const balance = gameStateData.balance;
        const stockPrice = stocks[stockId - 1]['price'];
        
        // Calculate maximum amount we can buy
        const maxAmount = Math.min(Math.floor(balance / stockPrice), 999999999999999999);
        
        if (maxAmount <= 0) {
            showError('Insufficient funds to buy any shares of this stock');
            return;
        }
        
        try {
            const response = await fetch('/api/buy', {
                method: 'POST',
                headers: {
                    'Content-Type': 'application/json'
                },
                body: JSON.stringify({
                    stock_id: stockId,
                    amount: maxAmount
                })
            });

            const data = await response.json();

            if (!response.ok) {
                showError(data.error);
                return;
            }

            document.getElementById('amountInput').value = '1';
            await updateGameDisplay();
        } catch (error) {
            showError('Error buying stock: ' + error.message);
        }
    } catch (error) {
        showError('Error fetching game state: ' + error.message);
    }
}

async function sellAll() {
    if (!gameActive) return;

    const stockId = parseInt(document.getElementById('stockSelect').value);
    
    try {
        const gameStateResponse = await fetch('/api/game-state');
        const gameStateData = await gameStateResponse.json();
        
        const holdings = gameStateData.holdings;
        const amountToSell = Math.min(holdings[stockId - 1]['amount'], 999999999999999999);
        
        if (amountToSell <= 0) {
            showError('You do not own any shares of this stock');
            return;
        }
        
        try {
            const response = await fetch('/api/sell', {
                method: 'POST',
                headers: {
                    'Content-Type': 'application/json'
                },
                body: JSON.stringify({
                    stock_id: stockId,
                    amount: amountToSell
                })
            });

            const data = await response.json();

            if (!response.ok) {
                showError(data.error);
                return;
            }

            document.getElementById('amountInput').value = '1';
            await updateGameDisplay();
        } catch (error) {
            showError('Error selling stock: ' + error.message);
        }
    } catch (error) {
        showError('Error fetching game state: ' + error.message);
    }
}

async function nextDay() {
    if (!gameActive) return;

    try {
        const response = await fetch('/api/next-day', {
            method: 'POST'
        });

        const data = await response.json();

        if (data.game_over) {
            await endGame();
            return;
        }

        await updateGameDisplay();
    } catch (error) {
        showError('Error advancing to next day: ' + error.message);
    }
}

async function endGame() {
    try {
        const response = await fetch('/api/end-game');
        if (!response.ok) throw new Error('Failed to fetch end game stats');

        const data = await response.json();

        document.getElementById('startBalance').textContent = formatNumber(data.starting_balance);
        document.getElementById('endBalance').textContent = formatNumber(data.ending_balance);
        document.getElementById('netWorth').textContent = formatNumber(data.total_net_worth);
        document.getElementById('profit').textContent = formatNumber(data.profit);

        // Color profit red or green
        const profitText = document.getElementById('profitText');
        if (data.profit >= 0) {
            profitText.style.color = '#4caf50';
        } else {
            profitText.style.color = '#f44336';
        }

        // Display final holdings
        const finalHoldings = document.getElementById('finalHoldings');
        finalHoldings.innerHTML = '';
        data.holdings.forEach((holding, index) => {
            if (holding.amount > 0) {
                const div = document.createElement('div');
                div.className = 'holding-final';
                const stockPrice = Number(data.stocks[index].price);
                const value = holding.amount * stockPrice;
                div.innerHTML = `
                    <span>${holding.name}: ${holding.amount} shares</span>
                    <span>Value: $${formatNumber(value)}</span>
                `;
                finalHoldings.appendChild(div);
            }
        });

        // Fetch current game state to get price history for the chart
        const gameStateResponse = await fetch('/api/game-state');
        const gameStateData = await gameStateResponse.json();
        
        // Display the final price chart
        if (gameStateData.priceHistory) {
            createEndPriceChart(gameStateData.priceHistory);
        }

        gameActive = false;
        document.getElementById('gameScreen').classList.add('hidden');
        document.getElementById('endScreen').classList.remove('hidden');
    } catch (error) {
        showError('Error getting game stats: ' + error.message);
    }
}

function showError(message) {
    const messageDiv = document.getElementById('message');
    messageDiv.textContent = message;
    messageDiv.classList.add('show', 'error');
}

async function saveScore() {
    const playerName = document.getElementById('playerName').value.trim();
    
    if (!playerName) {
        alert('Please enter your name');
        return;
    }
    
    try {
        const response = await fetch('/api/save-score', {
            method: 'POST',
            headers: {
                'Content-Type': 'application/json'
            },
            body: JSON.stringify({ name: playerName })
        });
        
        const data = await response.json();
        
        if (data.success) {
            alert(`Score saved! You ranked #${data.rank} on the leaderboard!`);
            // Clear the name input
            document.getElementById('playerName').value = '';
        }
    } catch (error) {
        showError('Error saving score: ' + error.message);
    }
}

async function viewLeaderboard() {
    try {
        const response = await fetch('/api/leaderboard');
        const data = await response.json();
        
        document.getElementById('startScreen').classList.add('hidden');
        document.getElementById('leaderboardScreen').classList.remove('hidden');
        
        displayLeaderboard(data.scores);
    } catch (error) {
        showError('Error loading leaderboard: ' + error.message);
    }
}

function displayLeaderboard(scores) {
    const leaderboardList = document.getElementById('leaderboardList');
    const emptyMessage = document.getElementById('emptyLeaderboard');
    
    if (scores.length === 0) {
        leaderboardList.innerHTML = '';
        emptyMessage.style.display = 'block';
        return;
    }
    
    emptyMessage.style.display = 'none';
    leaderboardList.innerHTML = '';
    
    scores.forEach((score, index) => {
        const rank = index + 1;
        const div = document.createElement('div');
        div.className = `leaderboard-entry rank-${rank}`;
        
        const profitClass = score.profit >= 0 ? 'positive' : 'negative';
        const profitSign = score.profit >= 0 ? '+' : '';

        div.innerHTML = `
            <div class="leaderboard-rank">#${rank}</div>
            <div class="leaderboard-info">
                <div class="leaderboard-name">${score.name}</div>
                <div class="leaderboard-stats">Days: ${score.leaderboardDays} | Balance: $${formatNumber(score.final_balance)} | Net Worth: $${formatNumber(score.net_worth)} | ${score.timestamp}</div>
            </div>
            <div class="leaderboard-profit ${profitClass}">${profitSign}$${formatNumber(score.profit)}</div>
        `;
        
        leaderboardList.appendChild(div);
    });
}

function backToStart() {
    document.getElementById('leaderboardScreen').classList.add('hidden');
    document.getElementById('startScreen').classList.remove('hidden');
}

function createEndPriceChart(priceHistory) {
    // Define colors for stocks
    const colors = ['#667eea', '#764ba2', '#4caf50', '#ff9800', '#f44336', '#e91e63', '#9c27b0'];
    
    // Get the history for all stocks
    let history = [];
    const stockKeys = Object.keys(priceHistory);
    if (stockKeys.length > 0) {
        history = priceHistory[stockKeys[0]] || [];
    }
    const days = Array.from({ length: history.length }, (_, i) => i + 1);
    
    // Create datasets for each stock dynamically
    const datasets = stockKeys.map((key, index) => ({
        label: key.charAt(0).toUpperCase() + key.slice(1),
        data: priceHistory[key] || [],
        borderColor: colors[index % colors.length],
        backgroundColor: colors[index % colors.length] + '15',
        fill: false,
        tension: 0.4,
        borderWidth: 2,
        pointRadius: 3,
        pointHoverRadius: 5,
        pointBackgroundColor: colors[index % colors.length],
        pointBorderColor: '#fff',
        pointBorderWidth: 1
    }));
    
    const ctx = document.getElementById('endPriceChart');
    if (!ctx) return;
    
    new Chart(ctx, {
        type: 'line',
        data: {
            labels: days,
            datasets: datasets
        },
        options: {
            responsive: true,
            maintainAspectRatio: true,
            plugins: {
                legend: {
                    display: true,
                    position: 'top',
                    labels: {
                        font: { size: 12 },
                        padding: 15,
                        usePointStyle: true
                    }
                }
            },
            scales: {
                y: {
                    beginAtZero: false,
                    ticks: {
                        callback: function(value) {
                            return '$' + formatNumber(value);
                        }
                    }
                },
                x: {
                    title: {
                        display: true,
                        text: 'Day'
                    }
                }
            }
        }
    });
}

function updateCharts(priceHistory, stocks, currentDay) {
    // Define colors for stocks
    const colors = ['#667eea', '#764ba2', '#4caf50', '#ff9800', '#f44336', '#e91e63', '#9c27b0'];
    
    // Get the history for all stocks - use first stock to get day count
    let history = [];
    const priceHistoryKeys = Object.keys(priceHistory);
    if (priceHistoryKeys.length > 0) {
        history = priceHistory[priceHistoryKeys[0]] || [];
    }
    const days = Array.from({ length: history.length }, (_, i) => i + 1);
    
    // Create datasets for each stock dynamically
    const datasets = priceHistoryKeys.map((key, index) => {
        // Find the stock name from the stocks array that matches this key
        const matchingStock = stocks.find(s => s.name.toLowerCase().replace(/\s+/g, '').replace(/[^a-z0-9]/g, '') === key.toLowerCase());
        const label = matchingStock ? matchingStock.name : key.charAt(0).toUpperCase() + key.slice(1);
        
        return {
            label: label,
            data: priceHistory[key] || [],
            borderColor: colors[index % colors.length],
            backgroundColor: colors[index % colors.length] + '15',
            fill: false,
            tension: 0.4,
            borderWidth: 2,
            pointRadius: 3,
            pointHoverRadius: 5,
            pointBackgroundColor: colors[index % colors.length],
            pointBorderColor: '#fff',
            pointBorderWidth: 1
        };
    });
    
    const ctx = document.getElementById('priceChart');
    if (!ctx) return;
    
    if (stockCharts['combined']) {
        stockCharts['combined'].data.labels = days;
        stockCharts['combined'].data.datasets = datasets;
        stockCharts['combined'].update();
    } else {
        stockCharts['combined'] = new Chart(ctx, {
            type: 'line',
            data: {
                labels: days,
                datasets: datasets
            },
            options: {
                responsive: true,
                maintainAspectRatio: true,
                plugins: {
                    legend: {
                        display: true,
                        position: 'top',
                        labels: {
                            font: { size: 12 },
                            padding: 15,
                            usePointStyle: true
                        }
                    }
                },
                scales: {
                    y: {
                        beginAtZero: false,
                        ticks: {
                            callback: function(value) {
                                return '$' + formatNumber(value);
                            }
                        }
                    },
                    x: {
                        title: {
                            display: true,
                            text: 'Day'
                        }
                    }
                }
            }
        });
    }
}

// Initialize when page loads
document.addEventListener('DOMContentLoaded', () => {
    populateStockSelect();
});