#!/usr/bin/env node

/**
 * Theme Build Script
 *
 * This script generates CSS variables from TOML theme configurations.
 * It can be run manually or integrated into the build pipeline.
 */

const fs = require('fs');
const path = require('path');

// Simple TOML parser for basic key-value pairs
function parseSimpleToml(content) {
  const result = {};
  let currentSection = null;

  const lines = content.split('\n');

  for (const line of lines) {
    const trimmed = line.trim();

    // Skip empty lines and comments
    if (!trimmed || trimmed.startsWith('#')) continue;

    // Section headers [section]
    if (trimmed.startsWith('[') && trimmed.endsWith(']')) {
      currentSection = trimmed.slice(1, -1);
      if (!result[currentSection]) {
        result[currentSection] = {};
      }
      continue;
    }

    // Key-value pairs
    if (trimmed.includes('=')) {
      const [key, ...valueParts] = trimmed.split('=');
      let value = valueParts.join('=').trim();

      // Handle quoted values vs unquoted values
      if (value.startsWith('"') && value.includes('"', 1)) {
        // Extract value between first and last quotes, ignoring comments after closing quote
        const firstQuote = value.indexOf('"');
        const lastQuote = value.indexOf('"', firstQuote + 1);
        if (lastQuote !== -1) {
          value = value.substring(firstQuote + 1, lastQuote);
        }
      } else {
        // For unquoted values, remove inline comments
        if (value.includes('#')) {
          value = value.split('#')[0].trim();
        }
      }

      if (currentSection) {
        result[currentSection][key.trim()] = value;
      } else {
        result[key.trim()] = value;
      }
    }
  }

  return result;
}

// Generate CSS variables from theme config
function generateCssVariables(themeConfig) {
  let css = `:root {\n`;

  // Colors
  if (themeConfig.colors) {
    css += `  /* Colors */\n`;
    for (const [key, value] of Object.entries(themeConfig.colors)) {
      const cssVar = key.replace(/_/g, '-');
      css += `  --color-${cssVar}: ${value};\n`;
    }
    css += `\n`;
  }

  // Typography
  if (themeConfig.typography) {
    css += `  /* Typography */\n`;
    for (const [key, value] of Object.entries(themeConfig.typography)) {
      const cssVar = key.replace(/_/g, '-');
      css += `  --${cssVar}: ${value};\n`;
    }
    css += `\n`;
  }

  // Spacing
  if (themeConfig.spacing) {
    css += `  /* Spacing */\n`;
    for (const [key, value] of Object.entries(themeConfig.spacing)) {
      const cssVar = key.replace(/_/g, '-');
      css += `  --space-${cssVar}: ${value};\n`;
    }
    css += `\n`;
  }

  // Border Radius
  if (themeConfig.radius) {
    css += `  /* Border Radius */\n`;
    for (const [key, value] of Object.entries(themeConfig.radius)) {
      const cssVar = key.replace(/_/g, '-');
      css += `  --radius-${cssVar}: ${value};\n`;
    }
    css += `\n`;
  }

  // Component specific
  if (themeConfig.components) {
    css += `  /* Component Tokens */\n`;
    if (themeConfig.components.button) {
      css += `  --btn-border-radius: ${themeConfig.components.button.border_radius};\n`;
    }
    if (themeConfig.components.card) {
      css += `  --card-border-radius: ${themeConfig.components.card.border_radius};\n`;
    }
    if (themeConfig.components.input) {
      css += `  --input-border-radius: ${themeConfig.components.input.border_radius};\n`;
    }
    css += `\n`;
  }

  // Animations
  if (themeConfig.animations) {
    css += `  /* Animations */\n`;
    for (const [key, value] of Object.entries(themeConfig.animations)) {
      const cssVar = key.replace(/_/g, '-');
      css += `  --${cssVar}: ${value};\n`;
    }
  }

  css += `}\n`;
  return css;
}

// Main function
function buildTheme(themeName = 'default') {
  try {
    console.log(`Building theme: ${themeName}`);

    // Read theme TOML file from new assets location
    const themePath = path.join(__dirname, '..', 'assets', 'styles', 'themes', `${themeName}.toml`);

    if (!fs.existsSync(themePath)) {
      console.error(`Theme file not found: ${themePath}`);
      process.exit(1);
    }

    const themeContent = fs.readFileSync(themePath, 'utf8');
    const themeConfig = parseSimpleToml(themeContent);

    // Generate CSS
    const css = generateCssVariables(themeConfig);

    // Write CSS file
    const outputPath = path.join(__dirname, '..', 'public', 'styles', `theme-${themeName}.css`);

    // Ensure directory exists
    const outputDir = path.dirname(outputPath);
    if (!fs.existsSync(outputDir)) {
      fs.mkdirSync(outputDir, { recursive: true });
    }

    // Write file with header
    const header = `/* Theme Variables - ${themeName} */\n/* Generated from ${path.basename(themePath)} */\n/* Do not edit manually */\n\n`;

    fs.writeFileSync(outputPath, header + css);

    console.log(`✅ Theme built successfully: ${outputPath}`);

    // Also update the main theme variables file if this is the default theme
    if (themeName === 'default') {
      const mainThemePath = path.join(__dirname, '..', 'public', 'styles', 'theme-variables.css');
      fs.writeFileSync(mainThemePath, header + css);
      console.log(`✅ Updated main theme variables: ${mainThemePath}`);
    }

  } catch (error) {
    console.error('Error building theme:', error.message);
    process.exit(1);
  }
}

// CLI handling
if (require.main === module) {
  const themeName = process.argv[2] || 'default';
  buildTheme(themeName);
}

module.exports = { buildTheme, generateCssVariables, parseSimpleToml };