import QRCode from 'qrcode';

/**
 * QR Code generation and printing utilities
 */

export interface QRCodeOptions {
    width?: number;
    margin?: number;
    color?: {
        dark?: string;
        light?: string;
    };
    errorCorrectionLevel?: 'L' | 'M' | 'Q' | 'H';
}

const defaultOptions: QRCodeOptions = {
    width: 200,
    margin: 2,
    color: {
        dark: '#000000',
        light: '#ffffff',
    },
    errorCorrectionLevel: 'M',
};

/**
 * Generate QR code as data URL (PNG image)
 */
export async function generateQRCode(data: string, options: QRCodeOptions = {}): Promise<string> {
    const opts = { ...defaultOptions, ...options };

    try {
        return await QRCode.toDataURL(data, {
            width: opts.width,
            margin: opts.margin,
            color: opts.color,
            errorCorrectionLevel: opts.errorCorrectionLevel,
        });
    } catch (error) {
        console.error('QR Code generation failed:', error);
        throw error;
    }
}

/**
 * Generate QR code as SVG string
 */
export async function generateQRCodeSVG(data: string, options: QRCodeOptions = {}): Promise<string> {
    const opts = { ...defaultOptions, ...options };

    try {
        return await QRCode.toString(data, {
            type: 'svg',
            width: opts.width,
            margin: opts.margin,
            color: opts.color,
            errorCorrectionLevel: opts.errorCorrectionLevel,
        });
    } catch (error) {
        console.error('QR Code SVG generation failed:', error);
        throw error;
    }
}

/**
 * Generate batch QR code data
 */
export function generateBatchQRData(batchId: string, batchName?: string): string {
    const baseUrl = window.location.origin;
    return JSON.stringify({
        type: 'batch',
        id: batchId,
        name: batchName,
        url: `${baseUrl}/batches/${batchId}`,
        ts: Date.now(),
    });
}

/**
 * Generate plant QR code data
 */
export function generatePlantQRData(plantId: string, tagNumber: string, address: string): string {
    const baseUrl = window.location.origin;
    return JSON.stringify({
        type: 'plant',
        id: plantId,
        tag: tagNumber,
        address,
        url: `${baseUrl}/plants/${plantId}`,
        ts: Date.now(),
    });
}

/**
 * Generate visitor badge QR code data
 */
export function generateVisitorQRData(visitorId: string, badgeNumber: string, name: string): string {
    return JSON.stringify({
        type: 'visitor',
        id: visitorId,
        badge: badgeNumber,
        name,
        ts: Date.now(),
    });
}

/**
 * Generate room/zone QR code data
 */
export function generateRoomQRData(roomId: string, roomName: string): string {
    const baseUrl = window.location.origin;
    return JSON.stringify({
        type: 'room',
        id: roomId,
        name: roomName,
        url: `${baseUrl}/rooms/${roomId}`,
        ts: Date.now(),
    });
}

/**
 * Parse scanned QR code data
 */
export function parseQRData(data: string): {
    type: 'batch' | 'plant' | 'visitor' | 'room' | 'unknown';
    id?: string;
    url?: string;
    [key: string]: any;
} {
    try {
        const parsed = JSON.parse(data);
        return {
            type: parsed.type || 'unknown',
            ...parsed,
        };
    } catch {
        // If not JSON, try to extract URL
        if (data.startsWith('http')) {
            return { type: 'unknown', url: data };
        }
        return { type: 'unknown', raw: data };
    }
}

/**
 * Generate printable label HTML with QR code
 */
export async function generatePrintableLabel(params: {
    type: 'batch' | 'plant' | 'visitor' | 'room';
    title: string;
    subtitle?: string;
    details?: string[];
    qrData: string;
    size?: 'small' | 'medium' | 'large';
}): Promise<string> {
    const { type, title, subtitle, details = [], qrData, size = 'medium' } = params;

    const qrCodeDataUrl = await generateQRCode(qrData, {
        width: size === 'small' ? 100 : size === 'large' ? 300 : 200,
    });

    const sizes = {
        small: { width: '2in', fontSize: '8pt', qrSize: '1in' },
        medium: { width: '3in', fontSize: '10pt', qrSize: '1.5in' },
        large: { width: '4in', fontSize: '12pt', qrSize: '2in' },
    };

    const sizeConfig = sizes[size];

    return `
        <div style="
            width: ${sizeConfig.width};
            padding: 0.25in;
            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
            font-size: ${sizeConfig.fontSize};
            border: 1px solid #ccc;
            display: flex;
            align-items: center;
            gap: 0.25in;
        ">
            <img src="${qrCodeDataUrl}" style="width: ${sizeConfig.qrSize}; height: ${sizeConfig.qrSize};" />
            <div style="flex: 1;">
                <div style="font-weight: bold; font-size: 1.2em; margin-bottom: 4px;">
                    ${title}
                </div>
                ${subtitle ? `<div style="color: #666; margin-bottom: 4px;">${subtitle}</div>` : ''}
                ${details.map(d => `<div style="font-size: 0.9em;">${d}</div>`).join('')}
                <div style="font-size: 0.7em; color: #999; margin-top: 4px;">
                    ${type.toUpperCase()} • ${new Date().toLocaleDateString()}
                </div>
            </div>
        </div>
    `;
}

/**
 * Print label(s) using browser print dialog
 */
export function printLabels(labelsHtml: string[], title: string = 'Print Labels') {
    const printWindow = window.open('', '_blank');
    if (!printWindow) {
        alert('Please allow popups to print labels');
        return;
    }

    printWindow.document.write(`
        <!DOCTYPE html>
        <html>
        <head>
            <title>${title}</title>
            <style>
                @page { size: auto; margin: 0.5in; }
                @media print {
                    .label { page-break-inside: avoid; margin-bottom: 0.25in; }
                }
                body { margin: 0; padding: 0.5in; }
                .label { margin-bottom: 0.5in; }
            </style>
        </head>
        <body>
            ${labelsHtml.map(html => `<div class="label">${html}</div>`).join('')}
            <script>
                window.onload = function() {
                    window.print();
                    window.onafterprint = function() { window.close(); };
                };
            </script>
        </body>
        </html>
    `);
    printWindow.document.close();
}