#!/usr/bin/env node
const path = require('node:path');
const fs = require('node:fs');
const vm = require('node:vm');
const http = require('node:http');
const url = require('node:url');
const { parseArgs } = require('node:util');

// ============================================================================
// CONSTANTS
// ============================================================================

const CONFIG = {
  host: '127.0.0.1',
  port: 12667,
  paths: {
    css: path.join(__dirname, 'fonts', 'ficons.css'),
    webfonts: path.join(__dirname, 'fonts', 'webfonts'),
    explorer: path.join(__dirname, 'explorer.html'),
    iconData: path.join(__dirname, 'data', 'all_icons.js')
  }
};

const MIME_TYPES = {
  '.html': 'text/html',
  '.js': 'text/javascript',
  '.css': 'text/css',
  '.json': 'application/json',
  '.woff': 'font/woff',
  '.woff2': 'font/woff2',
  '.ttf': 'font/ttf',
};

const COMMANDS = {
  EXPLORE: 'explore',
  SEARCH: 'search'
};

const EXIT_CODES = {
  SUCCESS: 0,
  ERROR: 1
};

// ============================================================================
// ICON DATA LAYER
// ============================================================================

class IconLoader {
  constructor(dataPath) {
    this.dataPath = dataPath;
    this._cache = null;
  }

  load() {
    if (this._cache) {
      return this._cache;
    }

    const source = fs.readFileSync(this.dataPath, 'utf8');
    const sandbox = { window: {} };
    vm.createContext(sandbox);
    vm.runInContext(source, sandbox);

    const icons = sandbox.window.FICONS_DATA;
    if (!Array.isArray(icons)) {
      throw new Error('Icon data was not loaded correctly.');
    }

    this._cache = icons;
    return icons;
  }

  getPrefixes() {
    return new Set(this.load().map(icon => icon.prefix));
  }
}

class IconSearcher {
  constructor(icons) {
    this.icons = icons;
  }

  search(query, variation = null) {
    const terms = this._parseQuery(query);
    return this.icons.filter(icon =>
      this._matches(icon, terms) && this._matchesVariation(icon, variation)
    );
  }

  _parseQuery(query) {
    return query.toLowerCase().split(/\s+/).filter(Boolean);
  }

  _matches(icon, terms) {
    const haystack = `${icon.name} ${icon.tags || ''}`.toLowerCase();
    return terms.every(term => haystack.includes(term));
  }

  _matchesVariation(icon, variation) {
    return !variation || icon.prefix === variation;
  }
}

class ResultFormatter {
  static formatJson(matches) {
    const grouped = this._groupByIconName(matches);

    if (grouped.size === 0) {
      return '{}';
    }

    const entries = Array.from(grouped.entries())
      .map(([name, variations]) => {
        const sortedVariations = Array.from(variations).sort();
        const variationsJson = JSON.stringify(sortedVariations);
        return `  ${JSON.stringify(name)}: ${variationsJson}`;
      });

    return `{\n${entries.join(',\n')}\n}`;
  }

  static _groupByIconName(matches) {
    const grouped = new Map();
    for (const icon of matches) {
      if (!grouped.has(icon.name)) {
        grouped.set(icon.name, new Set());
      }
      grouped.get(icon.name).add(icon.prefix);
    }
    return grouped;
  }
}

// ============================================================================
// HTTP SERVER LAYER
// ============================================================================

class FileServer {
  constructor(rootDir) {
    this.rootDir = rootDir;
  }

  serve(req, res) {
    const requestPath = this._sanitizePath(req.url);
    const fullPath = path.join(this.rootDir, requestPath);

    this._serveFile(fullPath, req, res);
  }

  _sanitizePath(urlPath) {
    const parsed = url.parse(urlPath);
    let pathname = parsed.pathname;

    if (pathname === '/') {
      return '/explorer.html';
    }

    return pathname;
  }

  _serveFile(filepath, req, res) {
    fs.stat(filepath, (err, stats) => {
      if (err || !stats.isFile()) {
        this._send404(res);
        return;
      }
      this._sendFile(filepath, res);
    });
  }

  _sendFile(filepath, res) {
    fs.readFile(filepath, (err, data) => {
      if (err) {
        this._send404(res);
        return;
      }

      const mimeType = this._getMimeType(filepath);
      res.writeHead(200, {
        'Content-Type': mimeType,
        'Cache-Control': 'no-cache'
      });
      res.end(data);
    });
  }

  _send404(res) {
    res.writeHead(404, { 'Content-Type': 'text/plain' });
    res.end('Not Found');
  }

  _getMimeType(filepath) {
    const ext = path.extname(filepath).toLowerCase();
    return MIME_TYPES[ext] || 'application/octet-stream';
  }
}

class ExplorerServer {
  constructor(config) {
    this.config = config;
    this.fileServer = new FileServer(__dirname);
    this.server = null;
  }

  start() {
    this.server = http.createServer((req, res) => {
      this.fileServer.serve(req, res);
    });

    this.server.listen(this.config.port, this.config.host, () => {
      console.log(`Ficons Explorer running at http://${this.config.host}:${this.config.port}/`);
      console.log('Press Ctrl+C to stop the server');
    });

    this.server.on('error', (err) => this._handleError(err));
  }

  _handleError(err) {
    if (err.code === 'EADDRINUSE') {
      console.error(`Error: Port ${this.config.port} is already in use.`);
    } else {
      console.error('Server error:', err.message);
    }
    process.exit(EXIT_CODES.ERROR);
  }
}

// ============================================================================
// CLI LAYER
// ============================================================================

class CliParser {
  static parse(args) {
    if (args.length === 0) {
      return { error: 'No command provided' };
    }

    const { values, positionals } = parseArgs({
      args,
      options: {
        help: { type: 'boolean', short: 'h' },
        variation: { type: 'string', short: 'v' },
      },
      allowPositionals: true,
    });

    return {
      help: values.help,
      command: positionals[0]?.toLowerCase(),
      args: positionals.slice(1),
      variation: values.variation
    };
  }
}

class SearchCommand {
  constructor(iconLoader) {
    this.iconLoader = iconLoader;
  }

  execute(positionals, variation) {
    const { query, variation: detectedVariation } = this._parseInput(positionals, variation);

    if (!query) {
      console.error('Error: search command requires a query.');
      console.log('Usage: npx @invisi/ficons search <query> [options]');
      process.exit(EXIT_CODES.ERROR);
    }

    const icons = this.iconLoader.load();
    const searcher = new IconSearcher(icons);
    const matches = searcher.search(query, detectedVariation);

    console.log(ResultFormatter.formatJson(matches));
  }

  _parseInput(positionals, variation) {
    let effectiveVariation = variation;

    // Auto-detect variation from last positional arg
    if (!effectiveVariation && positionals.length > 1) {
      const prefixes = this.iconLoader.getPrefixes();
      const lastArg = positionals[positionals.length - 1].toLowerCase();

      if (prefixes.has(lastArg)) {
        effectiveVariation = lastArg;
        positionals.pop();
      }
    }

    return {
      query: positionals.join(' ').trim(),
      variation: effectiveVariation
    };
  }
}

class HelpPrinter {
  static print() {
    console.log('Usage: npx @invisi/ficons <command> [options]');
    console.log('');
    console.log('Commands:');
    console.log('  explore           Start local HTTP server and open icon explorer');
    console.log('  search <query>    Search for icons by name or tags');
    console.log('');
    console.log('Options:');
    console.log('  -v, --variation <prefix>  Filter by style variation (e.g., rs, rr, bs)');
    console.log('  -h, --help               Show this help message');
    console.log('');
    console.log('Examples:');
    console.log('  npx @invisi/ficons explore');
    console.log('  npx @invisi/ficons search camera');
    console.log('  npx @invisi/ficons search arrow rr');
    console.log('  npx @invisi/ficons search home --variation rs');
  }
}

class CliApplication {
  constructor() {
    this.iconLoader = new IconLoader(CONFIG.paths.iconData);
    this.searchCommand = new SearchCommand(this.iconLoader);
  }

  run(args) {
    const parsed = CliParser.parse(args);

    if (parsed.error || parsed.help) {
      HelpPrinter.print();
      process.exit(parsed.error ? EXIT_CODES.ERROR : EXIT_CODES.SUCCESS);
    }

    switch (parsed.command) {
      case COMMANDS.EXPLORE:
        new ExplorerServer(CONFIG).start();
        break;

      case COMMANDS.SEARCH:
        this.searchCommand.execute(parsed.args, parsed.variation);
        break;

      default:
        console.error(`Unknown command: ${parsed.command}`);
        console.log('Run "npx @invisi/ficons --help" for usage information.');
        process.exit(EXIT_CODES.ERROR);
    }
  }
}

// ============================================================================
// ENTRY POINT
// ============================================================================

const app = new CliApplication();
app.run(process.argv.slice(2));