import fs from 'fs-extra';
import path from 'path';
import { logStep, logSuccess } from '../utils/logger';
import type { SwaggerAnalysis, GenerationReport } from '../types';

/** Counts files ending with `.mock.ts` in a directory (returns 0 if directory does not exist). */
function countMockFiles(dir: string): number {
  try {
    return fs.readdirSync(dir).filter((f) => f.endsWith('.mock.ts')).length;
  } catch {
    return 0;
  }
}

/** Counts files ending with `.spec.ts` in a directory (returns 0 if directory does not exist). */
function countSpecFiles(dir: string): number {
  try {
    return fs.readdirSync(dir).filter((f) => f.endsWith('.spec.ts')).length;
  } catch {
    return 0;
  }
}

/** Generates and persists the `generation-report.json` file with process statistics. */
export function generateReport(outputDir: string, analysis: SwaggerAnalysis): GenerationReport {
  logStep('Generating report...');

  const report: GenerationReport = {
    timestamp: new Date().toISOString(),
    tags: analysis.tags.length,
    endpoints: Object.keys(analysis.paths).length,
    outputDirectory: outputDir,
    structure: {
      dtos: fs.readdirSync(path.join(outputDir, 'data/dtos')).length,
      repositories: fs.readdirSync(path.join(outputDir, 'data/repositories')).length,
      mappers: fs.readdirSync(path.join(outputDir, 'data/mappers')).length,
      useCases: fs.readdirSync(path.join(outputDir, 'domain/use-cases')).length,
      providers:
        fs.readdirSync(path.join(outputDir, 'di/repositories')).length +
        fs.readdirSync(path.join(outputDir, 'di/use-cases')).length,
      mocks:
        countMockFiles(path.join(outputDir, 'data/dtos')) +
        countMockFiles(path.join(outputDir, 'data/repositories')) +
        countMockFiles(path.join(outputDir, 'di/repositories')) +
        countMockFiles(path.join(outputDir, 'di/use-cases')) +
        countMockFiles(path.join(outputDir, 'domain/use-cases')) +
        countMockFiles(path.join(outputDir, 'entities/models')),
      specs:
        countSpecFiles(path.join(outputDir, 'entities/models')) +
        countSpecFiles(path.join(outputDir, 'data/mappers')) +
        countSpecFiles(path.join(outputDir, 'data/repositories')) +
        countSpecFiles(path.join(outputDir, 'domain/use-cases'))
    }
  };

  const reportPath = path.join(process.cwd(), 'generation-report.json');
  fs.writeJsonSync(reportPath, report, { spaces: 2 });

  logSuccess(`Report saved to: ${reportPath}`);

  return report;
}