/**
 * Performance Chart Component
 *
 * Professional Chart.js implementation for Core Web Vitals and performance metrics
 *
 * @package ThinkRank
 * @since 1.0.0
 */

import { Line } from 'react-chartjs-2';

// Chart.js is loaded separately via charts.js entry point
// Components are registered globally by the charts bundle

/**
 * Performance Chart Component
 */
const PerformanceChart = ({ 
    title, 
    data, 
    unit = '', 
    thresholds = {}, 
    height = 300,
    showArea = true,
    color = '#0073aa'
}) => {
    // Prepare chart data
    const chartData = {
        labels: data.map((_, index) => {
            const daysAgo = data.length - 1 - index;
            const date = new Date();
            date.setDate(date.getDate() - daysAgo);
            return date.toLocaleDateString('en-US', { month: 'short', day: 'numeric' });
        }),
        datasets: [
            {
                label: title,
                data: data.map(point => point.value),
                borderColor: color,
                backgroundColor: showArea ? `${color}20` : 'transparent',
                borderWidth: 2,
                fill: showArea,
                tension: 0.4,
                pointBackgroundColor: color,
                pointBorderColor: '#ffffff',
                pointBorderWidth: 2,
                pointRadius: 4,
                pointHoverRadius: 6,
                pointHoverBackgroundColor: color,
                pointHoverBorderColor: '#ffffff',
                pointHoverBorderWidth: 2,
            }
        ]
    };

    // Chart options
    const options = {
        responsive: true,
        maintainAspectRatio: false,
        plugins: {
            legend: {
                display: false
            },
            title: {
                display: true,
                text: title,
                font: {
                    size: 16,
                    weight: '600'
                },
                color: '#1e1e1e',
                padding: {
                    bottom: 20
                }
            },
            tooltip: {
                backgroundColor: '#ffffff',
                titleColor: '#1e1e1e',
                bodyColor: '#1e1e1e',
                borderColor: '#e0e0e0',
                borderWidth: 1,
                cornerRadius: 8,
                displayColors: false,
                callbacks: {
                    label: function(context) {
                        const value = context.parsed.y;
                        const formattedValue = unit === 's' ? 
                            `${value.toFixed(2)}s` : 
                            unit === 'ms' ? 
                                `${Math.round(value)}ms` : 
                                value.toFixed(3);
                        
                        return `${title}: ${formattedValue}`;
                    }
                }
            }
        },
        scales: {
            x: {
                grid: {
                    color: '#f0f0f0',
                    borderColor: '#e0e0e0'
                },
                ticks: {
                    color: '#666666',
                    font: {
                        size: 12
                    }
                }
            },
            y: {
                beginAtZero: true,
                grid: {
                    color: '#f0f0f0',
                    borderColor: '#e0e0e0'
                },
                ticks: {
                    color: '#666666',
                    font: {
                        size: 12
                    },
                    callback: function(value) {
                        if (unit === 's') {
                            return `${value.toFixed(1)}s`;
                        } else if (unit === 'ms') {
                            return `${Math.round(value)}ms`;
                        } else {
                            return value.toFixed(2);
                        }
                    }
                }
            }
        },
        interaction: {
            intersect: false,
            mode: 'index'
        },
        elements: {
            point: {
                hoverRadius: 8
            }
        }
    };

    // Add threshold lines if provided
    if (thresholds.good || thresholds.needs_improvement) {
        options.plugins.annotation = {
            annotations: {}
        };

        if (thresholds.good) {
            options.plugins.annotation.annotations.goodThreshold = {
                type: 'line',
                yMin: thresholds.good,
                yMax: thresholds.good,
                borderColor: '#34a853',
                borderWidth: 2,
                borderDash: [5, 5],
                label: {
                    content: 'Good',
                    enabled: true,
                    position: 'end'
                }
            };
        }

        if (thresholds.needs_improvement) {
            options.plugins.annotation.annotations.improvementThreshold = {
                type: 'line',
                yMin: thresholds.needs_improvement,
                yMax: thresholds.needs_improvement,
                borderColor: '#fbbc04',
                borderWidth: 2,
                borderDash: [5, 5],
                label: {
                    content: 'Needs Improvement',
                    enabled: true,
                    position: 'end'
                }
            };
        }
    }

    return (
        <div style={{ height: `${height}px`, width: '100%' }}>
            <Line data={chartData} options={options} />
        </div>
    );
};

export default PerformanceChart;