export interface ExportColumn {
  header: string;
  key: string;
  format?: (value: any, row: any) => string;
}

export interface ExportDataOptions {
  title: string;
  subtitle?: string;
  filename: string;
  columns: ExportColumn[];
  data: any[];
}

/**
 * Converts dataset into standard CSV string and triggers browser download
 */
export function exportToSpreadsheet({ filename, columns, data }: ExportDataOptions): void {
  if (!data || data.length === 0) return;

  const headers = columns.map((col) => `"${(col.header || '').replace(/"/g, '""')}"`).join(',');
  const rows = data.map((row) =>
    columns
      .map((col) => {
        let val: any;
        if (col.format) {
          val = col.format(row[col.key], row);
        } else {
          val = row[col.key];
        }
        if (val === null || val === undefined) val = '';
        const strVal = String(val).replace(/"/g, '""');
        return `"${strVal}"`;
      })
      .join(',')
  );

  const csvContent = '\uFEFF' + [headers, ...rows].join('\r\n');
  const blob = new Blob([csvContent], { type: 'text/csv;charset=utf-8;' });
  const url = URL.createObjectURL(blob);
  const link = document.createElement('a');
  link.setAttribute('href', url);
  link.setAttribute('download', `${filename.replace(/\.csv$/i, '')}.csv`);
  document.body.appendChild(link);
  link.click();
  document.body.removeChild(link);
  URL.revokeObjectURL(url);
}

/**
 * Draws the high-visibility official PFM vector brand insignia onto the jsPDF document.
 */
function drawPfmLogo(doc: any, x: number, y: number, size: number): void {
  const scale = size / 64;
  doc.saveGraphicsState();

  // Dark foundation disc
  doc.setFillColor(9, 13, 22);
  doc.circle(x + 32 * scale, y + 32 * scale, 31 * scale, 'F');
  doc.setDrawColor(30, 41, 59);
  doc.setLineWidth(1 * scale);
  doc.circle(x + 32 * scale, y + 32 * scale, 30 * scale, 'S');

  // Cyan/Blue Outer hexagonal shield ring
  doc.setDrawColor(59, 130, 246);
  doc.setLineWidth(1.2 * scale);
  (doc as any).polygon(
    [
      { x: x + 32 * scale, y: y + 6.5 * scale },
      { x: x + 53.5 * scale, y: y + 19 * scale },
      { x: x + 56 * scale, y: y + 23.2 * scale },
      { x: x + 56 * scale, y: y + 40.8 * scale },
      { x: x + 53.5 * scale, y: y + 45 * scale },
      { x: x + 32 * scale, y: y + 57.5 * scale },
      { x: x + 27 * scale, y: y + 57.5 * scale },
      { x: x + 5.5 * scale, y: y + 45 * scale },
      { x: x + 3 * scale, y: y + 40.8 * scale },
      { x: x + 3 * scale, y: y + 23.2 * scale },
      { x: x + 5.5 * scale, y: y + 19 * scale },
      { x: x + 27 * scale, y: y + 6.5 * scale },
    ],
    'S'
  );

  // Top Facet - Indigo/Violet Governance Canopy
  doc.setFillColor(99, 102, 241);
  doc.triangle(
    x + 32 * scale,
    y + 9 * scale,
    x + 51.5 * scale,
    y + 20.2 * scale,
    x + 43 * scale,
    y + 25.2 * scale,
    'F'
  );
  doc.triangle(
    x + 32 * scale,
    y + 9 * scale,
    x + 43 * scale,
    y + 25.2 * scale,
    x + 21 * scale,
    y + 25.2 * scale,
    'F'
  );
  doc.triangle(
    x + 32 * scale,
    y + 9 * scale,
    x + 21 * scale,
    y + 25.2 * scale,
    x + 12.5 * scale,
    y + 20.2 * scale,
    'F'
  );

  // Left Facet - Electric Sapphire Capital Vault
  doc.setFillColor(37, 99, 235);
  doc.triangle(
    x + 10 * scale,
    y + 23 * scale,
    x + 19.2 * scale,
    y + 28.4 * scale,
    x + 19.2 * scale,
    y + 44.5 * scale,
    'F'
  );
  doc.triangle(
    x + 10 * scale,
    y + 23 * scale,
    x + 19.2 * scale,
    y + 44.5 * scale,
    x + 30 * scale,
    y + 50.8 * scale,
    'F'
  );

  // Right Facet - Cyan/Emerald Performance Wing
  doc.setFillColor(6, 182, 212);
  doc.triangle(
    x + 54 * scale,
    y + 23 * scale,
    x + 44.8 * scale,
    y + 28.4 * scale,
    x + 44.8 * scale,
    y + 44.5 * scale,
    'F'
  );
  doc.triangle(
    x + 54 * scale,
    y + 23 * scale,
    x + 44.8 * scale,
    y + 44.5 * scale,
    x + 34 * scale,
    y + 50.8 * scale,
    'F'
  );

  // Center Plate
  doc.setFillColor(15, 23, 42);
  doc.setDrawColor(51, 65, 85);
  (doc as any).polygon(
    [
      { x: x + 22 * scale, y: y + 28.5 * scale },
      { x: x + 32 * scale, y: y + 22.8 * scale },
      { x: x + 42 * scale, y: y + 28.5 * scale },
      { x: x + 42 * scale, y: y + 35.5 * scale },
      { x: x + 32 * scale, y: y + 41.2 * scale },
      { x: x + 22 * scale, y: y + 35.5 * scale },
    ],
    'FD'
  );

  // Center Diamond Spark
  doc.setFillColor(255, 255, 255);
  doc.circle(x + 32 * scale, y + 32 * scale, 2.5 * scale, 'F');

  doc.restoreGraphicsState();
}

/**
 * Generates an executive-grade PDF document in LANDSCAPE mode with clear PFM logo visibility,
 * metadata header, and structured autoTable data.
 */
export async function exportToPdf({ title, subtitle, filename, columns, data }: ExportDataOptions): Promise<void> {
  if (!data || data.length === 0) return;

  const [{ jsPDF }, { default: autoTable }] = await Promise.all([
    import('jspdf'),
    import('jspdf-autotable'),
  ]);

  // Enforce Landscape orientation
  const doc = new jsPDF({
    orientation: 'landscape',
    unit: 'pt',
    format: 'a4',
  });

  const pageWidth = doc.internal.pageSize.getWidth();
  const pageHeight = doc.internal.pageSize.getHeight();
  const margin = 40;

  // Header background banner
  doc.setFillColor(13, 18, 31);
  doc.rect(0, 0, pageWidth, 72, 'F');
  doc.setDrawColor(30, 41, 59);
  doc.setLineWidth(1);
  doc.line(0, 72, pageWidth, 72);

  // Draw PFM Logo with clear visibility
  const logoSize = 44;
  drawPfmLogo(doc, margin, 14, logoSize);

  // PFM Branding Text next to Logo
  doc.setTextColor(255, 255, 255);
  doc.setFont('helvetica', 'bold');
  doc.setFontSize(14);
  doc.text('PFM Console', margin + logoSize + 12, 33);

  doc.setFont('helvetica', 'normal');
  doc.setFontSize(8);
  doc.setTextColor(56, 189, 248); // Cyan
  doc.text('POST-FUND MANAGEMENT SYSTEM  •  OFFICIAL REPORT', margin + logoSize + 12, 46);

  // Document Title & Subtitle in Header (Right aligned or center)
  doc.setFont('helvetica', 'bold');
  doc.setFontSize(13);
  doc.setTextColor(248, 250, 252);
  doc.text(title, pageWidth - margin, 32, { align: 'right' });

  doc.setFont('helvetica', 'normal');
  doc.setFontSize(8);
  doc.setTextColor(148, 163, 184);
  const nowStr = new Date().toLocaleString('en-GB', {
    dateStyle: 'medium',
    timeStyle: 'short',
  });
  doc.text(
    `${subtitle || 'Authoritative Register Export'}  •  Generated: ${nowStr}`,
    pageWidth - margin,
    46,
    { align: 'right' }
  );

  // Prepare table headers and rows
  const tableHeaders = [columns.map((c) => c.header)];
  const tableRows = data.map((row) =>
    columns.map((col) => {
      let val: any;
      if (col.format) {
        val = col.format(row[col.key], row);
      } else {
        val = row[col.key];
      }
      if (val === null || val === undefined) return '—';
      return String(val);
    })
  );

  // Render autoTable in landscape
  (autoTable as any)(doc, {
    head: tableHeaders,
    body: tableRows,
    startY: 86,
    margin: { left: margin, right: margin, bottom: 45 },
    theme: 'grid',
    styles: {
      fontSize: 8,
      cellPadding: 6,
      textColor: [30, 41, 59],
      lineColor: [226, 232, 240],
      lineWidth: 0.5,
      overflow: 'linebreak',
    },
    headStyles: {
      fillColor: [15, 23, 42],
      textColor: [255, 255, 255],
      fontStyle: 'bold',
      fontSize: 8,
    },
    alternateRowStyles: {
      fillColor: [248, 250, 252],
    },
    didDrawPage: (hookData: any) => {
      // Footer on every page
      const currentPg = hookData.pageNumber;
      doc.setFont('helvetica', 'normal');
      doc.setFontSize(8);
      doc.setTextColor(100, 116, 139);
      doc.text(
        `Post Fund Management (PFM) • Confidential & Authoritative • Page ${currentPg}`,
        margin,
        pageHeight - 20
      );
      doc.text(
        `Total Records: ${data.length} • Landscape Master Report`,
        pageWidth - margin,
        pageHeight - 20,
        { align: 'right' }
      );
    },
  });

  doc.save(`${filename.replace(/\.pdf$/i, '')}.pdf`);
}