import { generateCuttingList } from './cuttingEngine.js';
import { collectHoleSpecsForPiece } from './holeSpecifications.js';
import { GROOVE, getBackGroovePlanOrientation } from '../../shared/manufacturing.js';

function toSafeNumber(value, fallback = 0) {
  const n = Number(value);
  return Number.isFinite(n) ? n : fallback;
}

function toLabel(value) {
  return String(value || '')
    .replace(/[^a-zA-Z0-9_\-]+/g, '_')
    .replace(/_+/g, '_')
    .replace(/^_+|_+$/g, '')
    .toUpperCase();
}

function emitPanelOutline(lines, widthMm, heightMm, safeZ, cutZ, feed) {
  lines.push(`G0 Z${safeZ.toFixed(3)}`);
  lines.push('G0 X0.000 Y0.000');
  lines.push(`G1 Z${cutZ.toFixed(3)} F${Math.round(feed)}`);
  lines.push(`G1 X${widthMm.toFixed(3)} Y0.000`);
  lines.push(`G1 X${widthMm.toFixed(3)} Y${heightMm.toFixed(3)}`);
  lines.push(`G1 X0.000 Y${heightMm.toFixed(3)}`);
  lines.push('G1 X0.000 Y0.000');
  lines.push(`G0 Z${safeZ.toFixed(3)}`);
}

function emitHole(lines, { xMm, yMm, diameterMm = 5, depthMm = 10, type = 'generic', face = 'face', end = null }) {
  let tail = `TYPE=${String(type)} FACE=${face}`;
  if (end) tail += ` END=${end}`;
  lines.push(
    `; HOLE X=${Number(xMm).toFixed(3)} Y=${Number(yMm).toFixed(3)} D=${Number(diameterMm).toFixed(3)} Z=${Number(depthMm).toFixed(3)} ${tail}`
  );
}

function emitPieceHoleComments(lines, piece, widthMm, heightMm, partIndex = 0) {
  const { specs, thicknessMm: _tm } = collectHoleSpecsForPiece(piece, widthMm, heightMm, partIndex);
  for (const spec of specs) {
    emitHole(lines, spec);
  }

  const m = piece?.machining || {};
  const orient = piece?.elementType ? getBackGroovePlanOrientation(piece.elementType) : null;
  if (m.groove && orient) {
    const gw = Number(m.groove.width ?? GROOVE.back.width);
    const gd = Number(m.groove.depth ?? GROOVE.back.depth);
    const ax = Number(m.groove.axisFromPanelEdge ?? m.groove.axisFromBackEdge ?? GROOVE.back.axisFromPanelEdge);
    lines.push(`; GROOVE BACK W=${gw.toFixed(3)} D=${gd.toFixed(3)} AXIS=${ax.toFixed(3)} ORIENT=${orient}`);
  }
}

export function generateCncProgram(config, modules = [], colors = {}) {
  const cuttingList = generateCuttingList(config, colors, modules);

  const safeZ = 10;
  const cutDepth = 3;
  const feedCut = 1800;

  const lines = [
    '%',
    '; APEX CNC ISO (G-code) - v1',
    `; Generated: ${new Date().toISOString()}`,
    `; Config: ${config.widthMm}x${config.heightMm}x${config.depthMm} mm`,
    'G21 ; metric units',
    'G90 ; absolute coordinates',
    'G17 ; XY plane',
    `G0 Z${safeZ.toFixed(3)}`
  ];

  let programPartCount = 0;

  for (const piece of cuttingList.pieces || []) {
    const widthMm = toSafeNumber(piece.rawCutWidthMm, piece.widthMm);
    const heightMm = toSafeNumber(piece.rawCutHeightMm, piece.heightMm);
    const qty = Math.max(1, Math.round(toSafeNumber(piece.quantity, 1)));
    const thickness = toSafeNumber(piece.thicknessMm, 19);
    const pieceName = toLabel(piece.description || piece.elementType || 'PIECE');
    const targetDepth = -Math.min(cutDepth, Math.max(1, thickness * 0.25));

    for (let i = 0; i < qty; i++) {
      programPartCount += 1;
      lines.push('');
      lines.push(`; --- PART ${programPartCount}: ${pieceName} #${i + 1} ---`);
      lines.push(`; SIZE_RAW: X=${widthMm.toFixed(3)} Y=${heightMm.toFixed(3)} T=${thickness.toFixed(3)}`);
      emitPieceHoleComments(lines, piece, widthMm, heightMm, i);
      emitPanelOutline(lines, widthMm, heightMm, safeZ, targetDepth, feedCut);
    }
  }

  lines.push('');
  lines.push(`G0 Z${safeZ.toFixed(3)}`);
  lines.push('G0 X0.000 Y0.000');
  lines.push('M30');
  lines.push('%');

  return {
    fileName: 'apex-program.nc',
    mimeType: 'text/plain; charset=utf-8',
    content: lines.join('\n'),
    metadata: {
      generatedAt: new Date().toISOString(),
      parts: programPartCount
    }
  };
}

export default {
  generateCncProgram
};