/**
 * Small pdfkit helpers shared by the printable records (Stockkarte,
 * Bestandsbuch): dates, empty values and a table that repeats its header on
 * every page.
 */

export const PDF_MARGIN = 36;

export interface PdfColumn {
  header: string;
  width: number;
  /** Numbers read better right-aligned; the default is left. */
  align?: 'left' | 'right';
}

export interface DrawTableOptions {
  /** Draws the last row in bold, e.g. a totals row. */
  boldLastRow?: boolean;
}

export function formatDay(date: Date): string {
  return date.toLocaleDateString('de-DE', {
    day: '2-digit',
    month: '2-digit',
    year: 'numeric',
    timeZone: 'UTC',
  });
}

export function orDash(value: string | number | null | undefined): string {
  return value === null || value === undefined || value === ''
    ? '–'
    : String(value);
}

/** Widens the last column so the table fills the page width. */
export function fillWidth(
  doc: PDFKit.PDFDocument,
  columns: PdfColumn[],
): PdfColumn[] {
  const fixed = columns.slice(0, -1).reduce((sum, c) => sum + c.width, 0);
  const last = columns[columns.length - 1];
  return [
    ...columns.slice(0, -1),
    { ...last, width: doc.page.width - 2 * PDF_MARGIN - fixed },
  ];
}

export function drawSection(doc: PDFKit.PDFDocument, title: string): void {
  if (doc.y > doc.page.height - PDF_MARGIN - 80) doc.addPage();
  doc.moveDown(0.6);
  doc
    .font('Helvetica-Bold')
    .fontSize(11)
    .fillColor('#000000')
    .text(title, PDF_MARGIN);
  doc.moveDown(0.2);
}

/** Draws a simple table, repeating the header on every new page. */
export function drawTable(
  doc: PDFKit.PDFDocument,
  columns: PdfColumn[],
  rows: string[][],
  options: DrawTableOptions = {},
): void {
  const left = PDF_MARGIN;
  const bottomLimit = doc.page.height - PDF_MARGIN - 20;

  const drawRow = (cells: string[], isHeader: boolean, bold = isHeader) => {
    doc.font(bold ? 'Helvetica-Bold' : 'Helvetica').fontSize(8);
    const heights = cells.map((cell, index) =>
      doc.heightOfString(cell, { width: columns[index].width - 4 }),
    );
    const rowHeight = Math.max(...heights, 10) + 4;
    if (doc.y + rowHeight > bottomLimit) {
      doc.addPage();
      if (!isHeader) {
        drawRow(
          columns.map((c) => c.header),
          true,
        );
        doc.font(bold ? 'Helvetica-Bold' : 'Helvetica').fontSize(8);
      }
    }
    const top = doc.y;
    let x = left;
    cells.forEach((cell, index) => {
      doc.text(cell, x + 2, top + 2, {
        width: columns[index].width - 4,
        align: columns[index].align ?? 'left',
      });
      x += columns[index].width;
    });
    doc
      .moveTo(left, top + rowHeight)
      .lineTo(x, top + rowHeight)
      .lineWidth(0.3)
      .strokeColor('#999999')
      .stroke();
    doc.y = top + rowHeight;
  };

  drawRow(
    columns.map((c) => c.header),
    true,
  );
  if (rows.length === 0) {
    doc
      .font('Helvetica-Oblique')
      .fontSize(8)
      .text('Keine Einträge.', left + 2, doc.y + 2);
    doc.moveDown(0.5);
    return;
  }
  rows.forEach((row, index) =>
    drawRow(
      row,
      false,
      options.boldLastRow === true && index === rows.length - 1,
    ),
  );
  doc.moveDown(0.5);
}