window.ChartManager = {
    charts: {},

    init(containerId, chartData, options = {}) {
        const container = document.getElementById(containerId);
        if (!container) return;

        const ctx = container.getContext('2d');

        if (this.charts[containerId]) {
            this.charts[containerId].destroy();
        }

        const defaultOptions = {
            responsive: true,
            maintainAspectRatio: false,
            plugins: {
                legend: {
                    position: 'top',
                }
            }
        };

        this.charts[containerId] = new Chart(ctx, {
            type: options.type || 'line',
            data: chartData,
            options: { ...defaultOptions, ...options }
        });

        return this.charts[containerId];
    },

    createTrendChart(containerId, labels, datasets) {
        return this.init(containerId, {
            labels,
            datasets: datasets.map((ds, i) => ({
                label: ds.label || `Control ${i + 1}`,
                data: ds.data,
                borderColor: ds.color || this.getColor(i),
                backgroundColor: this.getColor(i, 0.1),
                tension: 0.3,
                fill: true,
                pointRadius: 4,
                pointHoverRadius: 6
            }))
        }, {
            type: 'line',
            plugins: {
                title: {
                    display: true,
                    text: 'Monthly QC Trend'
                }
            }
        });
    },

    createComparisonChart(containerId, labels, datasets) {
        return this.init(containerId, {
            labels,
            datasets: datasets.map((ds, i) => ({
                label: ds.label || `Control ${i + 1}`,
                data: ds.data,
                backgroundColor: this.getColor(i, 0.6),
                borderColor: this.getColor(i),
                borderWidth: 1
            }))
        }, {
            type: 'bar',
            plugins: {
                title: {
                    display: true,
                    text: 'Control Comparison'
                }
            }
        });
    },

    createViolationChart(containerId, labels, datasets) {
        return this.init(containerId, {
            labels,
            datasets: datasets.map((ds, i) => ({
                label: ds.label || `Control ${i + 1}`,
                data: ds.data,
                backgroundColor: ds.data.map(v => v > 100 ? 'rgba(239, 68, 68, 0.6)' : 'rgba(34, 197, 94, 0.6)'),
                borderColor: ds.data.map(v => v > 100 ? 'rgb(239, 68, 68)' : 'rgb(34, 197, 94)'),
                borderWidth: 1
            }))
        }, {
            type: 'bar',
            plugins: {
                title: {
                    display: true,
                    text: 'QC Violations (Values > 100)'
                }
            }
        });
    },

    getColor(index, alpha = 1) {
        const colors = [
            `rgba(59, 130, 246, ${alpha})`,
            `rgba(16, 185, 129, ${alpha})`,
            `rgba(245, 158, 11, ${alpha})`,
            `rgba(239, 68, 68, ${alpha})`,
            `rgba(139, 92, 246, ${alpha})`,
            `rgba(236, 72, 153, ${alpha})`
        ];
        return colors[index % colors.length];
    },

    destroy(containerId) {
        if (this.charts[containerId]) {
            this.charts[containerId].destroy();
            delete this.charts[containerId];
        }
    },

    destroyAll() {
        Object.keys(this.charts).forEach(id => this.destroy(id));
    }
};

document.addEventListener('DOMContentLoaded', () => {
    const chartsContainer = document.getElementById('charts-container');
    if (chartsContainer && typeof initReportCharts === 'function') {
        initReportCharts();
    }
});