import { execSync } from 'child_process';
import fs from 'fs-extra';
import path from 'path';
import { logStep, logSuccess, logError, logInfo } from '../utils/logger';

/** Invokes `openapi-generator-cli` to generate DTOs into a temporary directory. */
export function generateCode(swaggerFile: string, templatesDir: string): string {
  logStep('Generating code from OpenAPI spec...');

  const tempDir = path.join(process.cwd(), '.temp-generated');

  if (fs.existsSync(tempDir)) {
    fs.removeSync(tempDir);
  }

  try {
    const command = `openapi-generator-cli generate \
      -i "${swaggerFile}" \
      -g typescript-angular \
      --global-property models \
      -t "${templatesDir}" \
      -o "${tempDir}" \
      --additional-properties=ngVersion=17.0.0,modelFileSuffix=.dto,modelNameSuffix=Dto`;

    execSync(command, { stdio: 'inherit' });
    logSuccess('Code generated successfully');

    return tempDir;
  } catch (_error) {
    logError('Error generating code');
    if (fs.existsSync(tempDir)) {
      fs.removeSync(tempDir);
    }
    process.exit(1);
  }
}

/** Copies the generated DTOs from the temporary directory to the output directory. */
export function organizeFiles(tempDir: string, outputDir: string): void {
  logStep('Organising generated DTO files...');

  const sourceDir = path.join(tempDir, 'model');
  const destDir = path.join(outputDir, 'data/dtos');
  let filesMoved = 0;

  if (fs.existsSync(sourceDir)) {
    fs.ensureDirSync(destDir);

    const files = fs.readdirSync(sourceDir).filter((file) => file.endsWith('.dto.ts'));

    files.forEach((file) => {
      const sourcePath = path.join(sourceDir, file);
      const destPath = path.join(destDir, file);

      fs.copySync(sourcePath, destPath);
      filesMoved++;
      logInfo(`  ${file} → ${path.relative(process.cwd(), destPath)}`);
    });
  }

  logSuccess(`${filesMoved} DTOs moved successfully`);
}

/** Post-processes the generated DTOs: adds cross-DTO imports and normalises Array<T> → T[]. */
export function addDtoImports(outputDir: string): void {
  logStep('Post-processing generated DTOs...');

  const dtosDir = path.join(outputDir, 'data/dtos');

  if (!fs.existsSync(dtosDir)) return;

  const files = fs.readdirSync(dtosDir).filter((f) => f.endsWith('.dto.ts'));

  // Build a map of DTO classname → file base name (without .ts)
  const dtoMap: Record<string, string> = {};
  files.forEach((file) => {
    const content = fs.readFileSync(path.join(dtosDir, file), 'utf8');
    const match = content.match(/export interface (\w+)/);
    if (match) {
      dtoMap[match[1]] = file.replace('.ts', '');
    }
  });

  let filesProcessed = 0;

  files.forEach((file) => {
    const filePath = path.join(dtosDir, file);
    const originalContent = fs.readFileSync(filePath, 'utf8');
    let content = originalContent;

    const selfMatch = content.match(/export interface (\w+)/);
    const selfName = selfMatch ? selfMatch[1] : '';

    // Normalize Array<T> → T[] (openapi-generator-cli always outputs Array<T>)
    content = content.replace(/Array<(\w+)>/g, '$1[]');

    // Find all Dto type references in the file body (excluding the interface name itself)
    const references = new Set<string>();
    const typeRegex = /\b(\w+Dto)\b/g;
    let match;
    while ((match = typeRegex.exec(content)) !== null) {
      if (match[1] !== selfName) {
        references.add(match[1]);
      }
    }

    // Build import lines for each referenced type that exists in the dtoMap
    const imports: string[] = [];
    references.forEach((ref) => {
      if (dtoMap[ref]) {
        imports.push(`import { ${ref} } from './${dtoMap[ref]}';`);
      }
    });

    if (imports.length > 0) {
      content = imports.join('\n') + '\n' + content;
    }

    if (content !== originalContent) {
      fs.writeFileSync(filePath, content);
      filesProcessed++;
      logInfo(`  Procesado ${file}`);
    }
  });

  logSuccess(`${filesProcessed} DTOs post-processed`);
}