/**
 * Dashboard JavaScript functionality
 */

let productivityChart = null;
let toolsChart = null;

async function loadDashboardData() {
    try {
        // Show loading state
        showLoadingState();
        
        // Load data in parallel
        const [
            analyticsSummary,
            productivityMetrics,
            toolUsageStats,
            recentProjects
        ] = await Promise.all([
            apiClient.getAnalyticsSummary(),
            apiClient.getProductivityMetrics(null, 30),
            apiClient.getToolUsageStats(null, null, 30),
            apiClient.getProjects(5, 0)
        ]);
        
        // Update summary cards
        updateSummaryCards(analyticsSummary);
        
        // Update engagement metrics
        updateEngagementMetrics(productivityMetrics);
        
        // Update charts
        updateProductivityChart(productivityMetrics.productivity_trends);
        updateToolsChart(toolUsageStats);
        
        // Update recent projects
        updateRecentProjects(recentProjects);
        
        // Update quick stats
        updateQuickStats(analyticsSummary);
        
    } catch (error) {
        console.error('Failed to load dashboard data:', error);
        showErrorState('Failed to load dashboard data. Please try refreshing the page.');
    }
}

function showLoadingState() {
    // Update cards with loading state
    document.getElementById('total-sessions').textContent = '-';
    document.getElementById('total-time').textContent = '-';
    document.getElementById('active-projects').textContent = '-';
    document.getElementById('productivity-score').textContent = '-';
}

function showErrorState(message) {
    // Show error message
    const alertHtml = `
        <div class="alert alert-warning alert-dismissible fade show" role="alert">
            <i class="fas fa-exclamation-triangle me-2"></i>
            ${message}
            <button type="button" class="btn-close" data-bs-dismiss="alert"></button>
        </div>
    `;
    
    const container = document.querySelector('.container');
    container.insertAdjacentHTML('afterbegin', alertHtml);
}

function updateSummaryCards(summary) {
    const overview = summary.overview || {};
    
    document.getElementById('total-sessions').textContent = 
        overview.total_sessions?.toLocaleString() || '0';
    
    document.getElementById('total-time').textContent = 
        overview.total_time_hours?.toFixed(1) || '0';
    
    document.getElementById('active-projects').textContent = 
        overview.projects_tracked?.toLocaleString() || '0';
    
    document.getElementById('productivity-score').textContent = 
        overview.productivity_indicators?.productivity_score?.toFixed(0) || '0';
}

function updateEngagementMetrics(metrics) {
    document.getElementById('engagement-score').textContent = 
        metrics.engagement_score?.toFixed(0) || '-';
    
    document.getElementById('avg-session-length').textContent = 
        metrics.average_session_length?.toFixed(0) || '-';
    
    document.getElementById('think-time').textContent = 
        metrics.think_time_average?.toFixed(0) || '-';
}

function updateProductivityChart(trendsData) {
    const ctx = document.getElementById('productivityChart').getContext('2d');
    
    // Destroy existing chart
    if (productivityChart) {
        productivityChart.destroy();
    }
    
    const labels = trendsData.map(item => {
        const date = new Date(item.date);
        return date.toLocaleDateString('en-US', { month: 'short', day: 'numeric' });
    });
    
    const data = trendsData.map(item => item.score);
    
    productivityChart = new Chart(ctx, {
        type: 'line',
        data: {
            labels: labels,
            datasets: [{
                label: 'Productivity Score',
                data: data,
                borderColor: '#007bff',
                backgroundColor: 'rgba(0, 123, 255, 0.1)',
                borderWidth: 2,
                fill: true,
                tension: 0.4
            }]
        },
        options: {
            responsive: true,
            maintainAspectRatio: false,
            plugins: {
                legend: {
                    display: false
                }
            },
            scales: {
                y: {
                    beginAtZero: true,
                    max: 100,
                    ticks: {
                        callback: function(value) {
                            return value + '%';
                        }
                    }
                },
                x: {
                    ticks: {
                        maxTicksLimit: 7
                    }
                }
            }
        }
    });
}

function updateToolsChart(toolsData) {
    const ctx = document.getElementById('toolsChart').getContext('2d');
    
    // Destroy existing chart
    if (toolsChart) {
        toolsChart.destroy();
    }
    
    // Get top 5 tools
    const topTools = toolsData.slice(0, 5);
    const labels = topTools.map(item => item.tool_name);
    const data = topTools.map(item => item.usage_count);
    
    const colors = [
        '#007bff', '#28a745', '#17a2b8', '#ffc107', '#dc3545'
    ];
    
    toolsChart = new Chart(ctx, {
        type: 'doughnut',
        data: {
            labels: labels,
            datasets: [{
                data: data,
                backgroundColor: colors,
                borderWidth: 2,
                borderColor: '#fff'
            }]
        },
        options: {
            responsive: true,
            maintainAspectRatio: false,
            plugins: {
                legend: {
                    position: 'bottom',
                    labels: {
                        padding: 20,
                        usePointStyle: true
                    }
                }
            }
        }
    });
}

function updateRecentProjects(projects) {
    const container = document.getElementById('recent-projects');
    
    if (!projects.length) {
        container.innerHTML = `
            <div class="text-center text-muted py-4">
                <i class="fas fa-folder-open fa-2x mb-2"></i>
                <p>No projects found</p>
            </div>
        `;
        return;
    }
    
    const projectsHtml = projects.map(project => `
        <div class="project-item fade-in">
            <div class="d-flex justify-content-between align-items-start">
                <div>
                    <div class="project-title">${project.name}</div>
                    <div class="project-path">${project.path}</div>
                    <div class="project-stats mt-2">
                        <span class="me-3">
                            <i class="fas fa-clock me-1"></i>
                            ${ApiUtils.formatDuration(project.total_time_minutes)}
                        </span>
                        <span class="me-3">
                            <i class="fas fa-play-circle me-1"></i>
                            ${project.total_sessions} sessions
                        </span>
                        ${project.languages ? `
                            <span>
                                <i class="fas fa-code me-1"></i>
                                ${project.languages.slice(0, 2).join(', ')}
                            </span>
                        ` : ''}
                    </div>
                </div>
                <small class="text-muted">
                    ${ApiUtils.formatRelativeTime(project.last_activity)}
                </small>
            </div>
        </div>
    `).join('');
    
    container.innerHTML = projectsHtml;
}

function updateQuickStats(summary) {
    const container = document.getElementById('quick-stats');
    const recent = summary.recent_activity || {};
    
    const statsHtml = `
        <div class="row g-3">
            <div class="col-sm-6">
                <div class="d-flex align-items-center">
                    <div class="flex-shrink-0">
                        <i class="fas fa-calendar-week fa-2x text-primary"></i>
                    </div>
                    <div class="flex-grow-1 ms-3">
                        <div class="fw-bold">${recent.sessions_last_7_days || 0}</div>
                        <small class="text-muted">Sessions this week</small>
                    </div>
                </div>
            </div>
            <div class="col-sm-6">
                <div class="d-flex align-items-center">
                    <div class="flex-shrink-0">
                        <i class="fas fa-clock fa-2x text-success"></i>
                    </div>
                    <div class="flex-grow-1 ms-3">
                        <div class="fw-bold">${(recent.time_last_7_days_hours || 0).toFixed(1)}h</div>
                        <small class="text-muted">Time this week</small>
                    </div>
                </div>
            </div>
            <div class="col-sm-6">
                <div class="d-flex align-items-center">
                    <div class="flex-shrink-0">
                        <i class="fas fa-chart-line fa-2x text-info"></i>
                    </div>
                    <div class="flex-grow-1 ms-3">
                        <div class="fw-bold">${(recent.daily_average_last_week || 0).toFixed(1)}</div>
                        <small class="text-muted">Daily average</small>
                    </div>
                </div>
            </div>
            <div class="col-sm-6">
                <div class="d-flex align-items-center">
                    <div class="flex-shrink-0">
                        <i class="fas fa-fire fa-2x text-warning"></i>
                    </div>
                    <div class="flex-grow-1 ms-3">
                        <div class="fw-bold">${summary.overview?.tracking_period_days || 0}</div>
                        <small class="text-muted">Days tracked</small>
                    </div>
                </div>
            </div>
        </div>
    `;
    
    container.innerHTML = statsHtml;
}

function refreshDashboard() {
    // Add visual feedback
    const refreshBtn = document.querySelector('[onclick="refreshDashboard()"]');
    const icon = refreshBtn.querySelector('i');
    
    icon.classList.add('fa-spin');
    refreshBtn.disabled = true;
    
    loadDashboardData().finally(() => {
        icon.classList.remove('fa-spin');
        refreshBtn.disabled = false;
    });
}

// Auto-refresh dashboard every 5 minutes
setInterval(() => {
    loadDashboardData();
}, 5 * 60 * 1000);

// Handle window resize for charts
window.addEventListener('resize', () => {
    if (productivityChart) {
        productivityChart.resize();
    }
    if (toolsChart) {
        toolsChart.resize();
    }
});