/**
 * Style Dictionary configuration for FA Design System (v4)
 *
 * Transforms W3C DTCG token JSON into:
 * - CSS custom properties (for runtime theming)
 * - JavaScript ES6 module (for MUI theme consumption)
 * - Tailwind token module (for tailwind.config.js consumption)
 * - JSON (for Penpot import)
 */

import StyleDictionary from 'style-dictionary';
import { readFileSync, writeFileSync } from 'fs';

const sd = new StyleDictionary({
  source: ['tokens/**/*.json'],
  usesDtcg: true,

  platforms: {
    css: {
      transformGroup: 'css',
      prefix: 'fa',
      buildPath: 'src/theme/generated/',
      files: [{
        destination: 'tokens.css',
        format: 'css/variables',
        options: {
          outputReferences: true,
        },
      }],
    },

    js: {
      transformGroup: 'js',
      buildPath: 'src/theme/generated/',
      files: [{
        destination: 'tokens.js',
        format: 'javascript/es6',
      }],
    },

    json: {
      transformGroup: 'js',
      buildPath: 'tokens/export/',
      files: [{
        destination: 'tokens-flat.json',
        format: 'json/flat',
      }],
    },
  },
});

await sd.buildAllPlatforms();

// Generate TypeScript declarations for the JS token output
const jsPath = 'src/theme/generated/tokens.js';
const dtsPath = 'src/theme/generated/tokens.d.ts';

const jsContent = readFileSync(jsPath, 'utf-8')
  .replace(/=\n\s+/g, '= ');

const declarations = ['/**', ' * Do not edit directly, this file was auto-generated.', ' */'];

for (const line of jsContent.split('\n')) {
  const m = line.match(/^export const (\w+)\s*=\s*(.+?)\s*;/);
  if (!m) continue;
  const [, name, val] = m;
  const isNum = !val.startsWith('"') && !val.startsWith("'") && !isNaN(Number(val));
  declarations.push(`export declare const ${name}: ${isNum ? 'number' : 'string'};`);
}

writeFileSync(dtsPath, declarations.join('\n') + '\n');
console.log(`✓ Generated ${declarations.length - 3} TypeScript declarations`);

// Generate Tailwind token module from the flat JSON export
// Keys are PascalCase: ColorBrand500, Spacing4, FontFamilyBody, etc.
const flatTokens = JSON.parse(readFileSync('tokens/export/tokens-flat.json', 'utf-8'));

const twColors = {};
const twSpacing = {};
const twBorderRadius = {};
const twFontFamily = {};
const twFontSize = {};
const twFontWeight = {};
const twLineHeight = {};
const twLetterSpacing = {};

// Helper: split PascalCase into parts, e.g. "ColorBrand500" → ["Color", "Brand", "500"]
function splitPascal(str) {
  return str.match(/[A-Z][a-z]*|\d+/g) || [];
}

for (const [key, value] of Object.entries(flatTokens)) {
  // Primitive colour tokens: ColorBrand500 → brand.500
  const colorMatch = key.match(/^Color(Brand|Sage|Neutral|Red|Amber|Green|Blue)(\d+)$/);
  if (colorMatch) {
    const group = colorMatch[1].toLowerCase();
    const shade = colorMatch[2];
    if (!twColors[group]) twColors[group] = {};
    twColors[group][shade] = value;
    continue;
  }
  // Single-value colors: ColorWhite, ColorBlack
  if (key === 'ColorWhite') { twColors['white'] = value; continue; }
  if (key === 'ColorBlack') { twColors['black'] = value; continue; }

  // Primitive spacing: Spacing1, Spacing0-5, Spacing16, etc.
  const spacingMatch = key.match(/^Spacing(\d+)$/);
  if (spacingMatch) {
    twSpacing[spacingMatch[1]] = value;
    continue;
  }
  if (key === 'Spacing05') { twSpacing['0.5'] = value; continue; }

  // Primitive border radius: BorderRadiusSm, BorderRadiusMd, etc.
  const radiusMatch = key.match(/^BorderRadius(\w+)$/);
  if (radiusMatch) {
    twBorderRadius[radiusMatch[1].toLowerCase()] = value;
    continue;
  }

  // Font family: FontFamilyBody, FontFamilyDisplay, FontFamilyMono
  const fontFamilyMatch = key.match(/^FontFamily(\w+)$/);
  if (fontFamilyMatch) {
    twFontFamily[fontFamilyMatch[1].toLowerCase()] = value;
    continue;
  }

  // Primitive font size: FontSize2xs, FontSizeBase, etc. (skip mobile/display)
  const fontSizeMatch = key.match(/^FontSize(2xs|Xs|Sm|Base|Md|Lg|Xl|2xl|3xl|4xl)$/i);
  if (fontSizeMatch) {
    twFontSize[fontSizeMatch[1].toLowerCase()] = value;
    continue;
  }

  // Font weight: FontWeightRegular, FontWeightMedium, etc.
  const fontWeightMatch = key.match(/^FontWeight(\w+)$/);
  if (fontWeightMatch) {
    twFontWeight[fontWeightMatch[1].toLowerCase()] = value;
    continue;
  }

  // Line height: LineHeightTight, LineHeightNormal, etc.
  const lineHeightMatch = key.match(/^LineHeight(\w+)$/);
  if (lineHeightMatch) {
    twLineHeight[lineHeightMatch[1].toLowerCase()] = value;
    continue;
  }

  // Letter spacing: LetterSpacingTight, LetterSpacingNormal, etc.
  const letterSpacingMatch = key.match(/^LetterSpacing(\w+)$/);
  if (letterSpacingMatch) {
    twLetterSpacing[letterSpacingMatch[1].toLowerCase()] = value;
    continue;
  }
}

const tailwindTokens = {
  colors: twColors,
  spacing: twSpacing,
  borderRadius: twBorderRadius,
  fontFamily: twFontFamily,
  fontSize: twFontSize,
  fontWeight: twFontWeight,
  lineHeight: twLineHeight,
  letterSpacing: twLetterSpacing,
};

const twOutput = `/**\n * Auto-generated Tailwind tokens from Style Dictionary.\n * Do not edit directly — edit tokens/*.json and run npm run build:tokens.\n */\nmodule.exports = ${JSON.stringify(tailwindTokens, null, 2)};\n`;

writeFileSync('src/theme/generated/tailwind-tokens.js', twOutput);
console.log(`✓ Generated Tailwind token module`);