#!/usr/bin/env node

/**
 * Wang Language Validator CLI
 * Usage: wang-validate <file.wang> [options]
 */

import { readFileSync } from 'fs';
import { resolve } from 'path';
import { WangValidator } from '../parser/wang-validator.js';

// Parse command line arguments
const args = process.argv.slice(2);

function showHelp() {
  console.log(`
Wang Language Validator

Usage: wang-validate <file> [options]

Options:
  --ast         Show the Abstract Syntax Tree
  --suggestions Show syntax improvement suggestions
  --quiet       Only show errors (exit code indicates success/failure)
  --help        Show this help message

Examples:
  wang-validate script.wang
  wang-validate script.wang --ast
  wang-validate script.wang --suggestions
  echo 'let x = 1' | wang-validate -
`);
}

async function main() {
  // Handle help flag
  if (args.includes('--help') || args.length === 0) {
    showHelp();
    process.exit(0);
  }

  const options = {
    showAST: args.includes('--ast'),
    showSuggestions: args.includes('--suggestions'),
    quiet: args.includes('--quiet'),
  };

  // Get the file path (first non-flag argument)
  const filePath = args.find((arg) => !arg.startsWith('--'));

  if (!filePath) {
    console.error('Error: No file specified');
    showHelp();
    process.exit(1);
  }

  try {
    // Read code from file or stdin
    let code: string;
    if (filePath === '-') {
      // Read from stdin
      code = await readStdin();
    } else {
      // Read from file
      const fullPath = resolve(process.cwd(), filePath);
      code = readFileSync(fullPath, 'utf-8');
    }

    // Validate the code
    const validator = new WangValidator();
    const result = validator.validate(code, { includeAST: options.showAST });

    if (result.valid) {
      if (!options.quiet) {
        console.log('✅ Valid Wang syntax');

        if (options.showAST && result.ast) {
          console.log('\\nAST:');
          console.log(JSON.stringify(result.ast, null, 2));
        }

        if (options.showSuggestions) {
          const suggestions = validator.suggestFixes(code);
          if (suggestions.length > 0) {
            console.log('\\nSuggestions:');
            suggestions.forEach((s) => console.log(`  • ${s}`));
          }
        }
      }
      process.exit(0);
    } else {
      // Invalid syntax
      if (!options.quiet) {
        console.error('❌ Invalid Wang syntax\\n');
      }

      if (result.error) {
        console.error(`Error at line ${result.error.line}, column ${result.error.column}:`);
        console.error(result.error.message);

        if (result.error.suggestion) {
          console.error(`\\n💡 Suggestion: ${result.error.suggestion}`);
        }
      }

      if (options.showSuggestions && !options.quiet) {
        const suggestions = validator.suggestFixes(code);
        if (suggestions.length > 0) {
          console.error('\\nAdditional suggestions:');
          suggestions.forEach((s) => console.error(`  • ${s}`));
        }
      }

      process.exit(1);
    }
  } catch (error: any) {
    console.error(`Error: ${error.message}`);
    process.exit(1);
  }
}

function readStdin(): Promise<string> {
  return new Promise((resolve, reject) => {
    let data = '';
    process.stdin.setEncoding('utf-8');

    process.stdin.on('data', (chunk) => {
      data += chunk;
    });

    process.stdin.on('end', () => {
      resolve(data);
    });

    process.stdin.on('error', reject);

    // Start reading
    process.stdin.resume();
  });
}

// Run the CLI
main().catch((error) => {
  console.error('Unexpected error:', error);
  process.exit(1);
});