import 'package:flutter/material.dart';
import '../domain/label_document.dart';

class PrintCompiler {
  /// Compiles a LabelDocument into printer commands according to the chosen language
  static String compile({
    required LabelDocument document,
    String? overrideLanguage,
    int copies = 1,
  }) {
    final language = (overrideLanguage ?? document.config.printerLanguage).toUpperCase();
    switch (language) {
      case 'TSPL':
        return TsplCompiler.compile(document, copies: copies);
      case 'ZPL':
      default:
        return ZplCompiler.compile(document, copies: copies);
    }
  }
}

class ZplCompiler {
  static String compile(LabelDocument doc, {int copies = 1}) {
    final buffer = StringBuffer();
    final cfg = doc.config;

    // Convert total web width (accounting for 1-Up, 2-Up, etc.) to printer dots
    final totalWebWidthDots = cfg.totalWebWidthDots;
    final heightDots = cfg.heightDots;

    buffer.writeln('^XA'); // Start of Label
    buffer.writeln('^PW$totalWebWidthDots'); // Print Width across entire roll
    buffer.writeln('^LL$heightDots'); // Label Length
    buffer.writeln('^LS0'); // Label Shift
    buffer.writeln('^LH0,0'); // Label Home
    buffer.writeln('^CI28'); // UTF-8 Encoding

    // Sort elements by zIndex
    final sortedElements = List<LabelElement>.from(doc.elements)
      ..sort((a, b) => a.zIndex.compareTo(b.zIndex));

    // Iterate across each column in the multi-up row (1-Up, 2-Up, 3-Up)
    final cols = cfg.columnsAcross.clamp(1, 4);
    for (int col = 0; col < cols; col++) {
      final colOffsetMm = col * (cfg.widthMm + cfg.horizontalGapMm);
      final colOffsetDots = cfg.mmToDots(colOffsetMm);

      for (final elem in sortedElements) {
        final xDots = cfg.mmToDots(elem.xMm) + colOffsetDots;
        final yDots = cfg.mmToDots(elem.yMm);
        final wDots = cfg.mmToDots(elem.widthMm);
        final hDots = cfg.mmToDots(elem.heightMm);

        if (elem is TextElement) {
          _compileText(buffer, elem, cfg, xDots, yDots, wDots);
        } else if (elem is DynamicTextElement) {
          // In design mode or unresolved templates, output the placeholder
          final textElem = TextElement(
            id: elem.id,
            xMm: elem.xMm,
            yMm: elem.yMm,
            widthMm: elem.widthMm,
            heightMm: elem.heightMm,
            text: elem.placeholder,
            fontFamily: elem.fontFamily,
            fontSizePt: elem.fontSizePt,
            isBold: elem.isBold,
            isItalic: elem.isItalic,
            alignment: elem.alignment,
          );
          _compileText(buffer, textElem, cfg, xDots, yDots, wDots);
        } else if (elem is BarcodeElement) {
          _compileBarcode(buffer, elem, cfg, xDots, yDots, wDots, hDots);
        } else if (elem is QrCodeElement) {
          _compileQrCode(buffer, elem, cfg, xDots, yDots, wDots);
        } else if (elem is RectangleElement) {
          _compileRectangle(buffer, elem, cfg, xDots, yDots, wDots, hDots);
        } else if (elem is LineElement) {
          _compileLine(buffer, elem, cfg, xDots, yDots, wDots, hDots);
        }
      }
    }

    if (copies > 1) {
      buffer.writeln('^PQ$copies');
    }

    buffer.writeln('^XZ'); // End of Label
    return buffer.toString();
  }

  static void _compileText(
    StringBuffer buf,
    TextElement elem,
    LabelConfiguration cfg,
    int xDots,
    int yDots,
    int wDots,
  ) {
    // Standard font height calculation based on point size & DPI
    // 1 pt = 1/72 inch. dots = pt / 72 * DPI
    final fontHeightDots = ((elem.fontSizePt / 72.0) * cfg.dpi * 1.33).round().clamp(14, 300);
    final fontWidthDots = (fontHeightDots * 0.85).round();

    final alignCode = switch (elem.alignment) {
      TextAlign.center => 'C',
      TextAlign.right => 'R',
      TextAlign.justify => 'J',
      _ => 'L',
    };

    // Replace unicode Rupee sign with 'Rs. ' as printer internal font 0 does not have U+20B9
    final printableText = elem.text.replaceAll('₹', 'Rs. ');

    // Text block with field formatting
    buf.writeln('^FO$xDots,$yDots');
    buf.writeln('^A0N,$fontHeightDots,$fontWidthDots');
    buf.writeln('^FB$wDots,2,0,$alignCode,0');
    buf.writeln('^FD$printableText^FS');
  }

  static void _compileBarcode(
    StringBuffer buf,
    BarcodeElement elem,
    LabelConfiguration cfg,
    int xDots,
    int yDots,
    int wDots,
    int hDots,
  ) {
    final barcodeVal = (elem.valueType == 'dynamic' && elem.staticValue.isEmpty)
        ? elem.placeholder
        : elem.staticValue;

    // Module width: 2 dots for 203 DPI, 3 dots for 300 DPI (Citizen CL-E331) for readable scanning
    final moduleWidth = (cfg.dpi >= 300) ? 3 : 2;
    final barHeight = (hDots * (elem.showText ? 0.82 : 0.95)).round().clamp(24, 600);
    final showTextChar = elem.showText ? 'Y' : 'N';

    buf.writeln('^FO$xDots,$yDots');
    buf.writeln('^BY$moduleWidth,3,$barHeight');

    switch (elem.barcodeType) {
      case BarcodeType.ean13:
        buf.writeln('^BEN,$barHeight,$showTextChar,N');
        break;
      case BarcodeType.code39:
        buf.writeln('^B3N,N,$barHeight,$showTextChar,N');
        break;
      case BarcodeType.upca:
        buf.writeln('^BUN,$barHeight,$showTextChar,N,N');
        break;
      case BarcodeType.code128:
      default:
        buf.writeln('^BCN,$barHeight,$showTextChar,N,N');
        break;
    }

    buf.writeln('^FD$barcodeVal^FS');
  }

  static void _compileQrCode(
    StringBuffer buf,
    QrCodeElement elem,
    LabelConfiguration cfg,
    int xDots,
    int yDots,
    int wDots,
  ) {
    final qrVal = (elem.valueType == 'dynamic' && elem.staticValue.isEmpty)
        ? elem.placeholder
        : elem.staticValue;
    // Magnification factor (1 to 10)
    final mag = (wDots / 30).round().clamp(2, 8);

    buf.writeln('^FO$xDots,$yDots');
    buf.writeln('^BQN,2,$mag');
    buf.writeln('^FDQA,$qrVal^FS');
  }

  static void _compileRectangle(
    StringBuffer buf,
    RectangleElement elem,
    LabelConfiguration cfg,
    int xDots,
    int yDots,
    int wDots,
    int hDots,
  ) {
    final borderDots = cfg.mmToDots(elem.borderWidthMm).clamp(1, 40);
    final cornerDots = cfg.mmToDots(elem.cornerRadiusMm).clamp(0, 8);
    buf.writeln('^FO$xDots,$yDots^GB$wDots,$hDots,$borderDots,B,$cornerDots^FS');
  }

  static void _compileLine(
    StringBuffer buf,
    LineElement elem,
    LabelConfiguration cfg,
    int xDots,
    int yDots,
    int wDots,
    int hDots,
  ) {
    final thickDots = cfg.mmToDots(elem.thicknessMm).clamp(1, 30);
    if (elem.isVertical) {
      buf.writeln('^FO$xDots,$yDots^GB$thickDots,$hDots,$thickDots^FS');
    } else {
      buf.writeln('^FO$xDots,$yDots^GB$wDots,$thickDots,$thickDots^FS');
    }
  }
}

class TsplCompiler {
  static String compile(LabelDocument doc, {int copies = 1}) {
    final buffer = StringBuffer();
    final cfg = doc.config;
    final cols = cfg.columnsAcross.clamp(1, 4);

    buffer.writeln('SIZE ${cfg.totalWebWidthMm} mm, ${cfg.heightMm} mm');
    buffer.writeln('GAP ${cfg.verticalGapMm.toStringAsFixed(cfg.verticalGapMm % 1 == 0 ? 0 : 1)} mm, 0 mm');
    buffer.writeln('DIRECTION 1');
    buffer.writeln('CLS');

    for (int col = 0; col < cols; col++) {
      final colOffsetMm = col * (cfg.widthMm + cfg.horizontalGapMm);
      final colOffsetDots = cfg.mmToDots(colOffsetMm);

      for (final elem in doc.elements) {
        final xDots = cfg.mmToDots(elem.xMm) + colOffsetDots;
        final yDots = cfg.mmToDots(elem.yMm);

        if (elem is TextElement) {
          buffer.writeln('TEXT $xDots,$yDots,"3",0,1,1,"${elem.text}"');
        } else if (elem is BarcodeElement) {
          final val = elem.valueType == 'dynamic' ? elem.placeholder : elem.staticValue;
          final hDots = cfg.mmToDots(elem.heightMm);
          buffer.writeln('BARCODE $xDots,$yDots,"128",$hDots,${elem.showText ? 1 : 0},0,2,2,"$val"');
        }
      }
    }

    buffer.writeln('PRINT $copies,1');
    return buffer.toString();
  }
}