// Copyright (c) 2026 Gordon Bolton. MIT License.
/**
 * Generates the merged OpenAPI spec by bootstrapping the Express app
 * and fetching the spec from /api/swagger.json.
 *
 * This ensures the generated spec matches exactly what users see in production.
 */

const { createApp } = require('../server/app.js');
const http = require('http');
const fs = require('fs');
const path = require('path');

const PORT = 34567; // Use a different port to avoid conflicts
const OUTPUT_DIR = path.join(process.cwd(), 'dist');
const OUTPUT_FILE = path.join(OUTPUT_DIR, 'openapi-merged.json');

async function generateOpenApiSpec() {
  // Ensure output directory exists
  if (!fs.existsSync(OUTPUT_DIR)) {
    fs.mkdirSync(OUTPUT_DIR, { recursive: true });
  }

  console.log('Bootstrapping Express app in test mode...');
  const app = createApp({ skipRateLimits: true });

  return new Promise((resolve, reject) => {
    const server = http.createServer(app);

    server.listen(PORT, () => {
      console.log(`Server listening on port ${PORT}`);

      // Fetch the merged spec
      const options = {
        hostname: 'localhost',
        port: PORT,
        path: '/api/swagger.json',
        method: 'GET'
      };

      const req = http.request(options, (res) => {
        let data = '';

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

        res.on('end', () => {
          try {
            const spec = JSON.parse(data);

            // Validate it's a proper OpenAPI spec
            if (!spec.openapi || !spec.info) {
              throw new Error('Invalid OpenAPI spec: missing openapi or info field');
            }

            // Write to file
            fs.writeFileSync(OUTPUT_FILE, JSON.stringify(spec, null, 2));
            console.log(`✓ OpenAPI spec written to ${OUTPUT_FILE}`);
            console.log(`  Version: ${spec.openapi}`);
            console.log(`  Title: ${spec.info.title}`);

            server.close(() => {
              resolve();
            });
          } catch (error) {
            console.error('Error processing OpenAPI spec:', error.message);
            server.close(() => {
              reject(error);
            });
          }
        });
      });

      req.on('error', (error) => {
        console.error('Error fetching spec:', error.message);
        server.close(() => {
          reject(error);
        });
      });

      req.end();
    });

    server.on('error', (error) => {
      if (error.code === 'EADDRINUSE') {
        reject(new Error(`Port ${PORT} is already in use`));
      } else {
        reject(error);
      }
    });
  });
}

// Run if executed directly
if (require.main === module) {
  generateOpenApiSpec()
    .then(() => {
      console.log('OpenAPI spec generation complete');
      process.exit(0);
    })
    .catch((error) => {
      console.error('Failed to generate OpenAPI spec:', error);
      process.exit(1);
    });
}

module.exports = { generateOpenApiSpec };