/**
 * @angular-modernizer/plugin-angular - DTO Object Literal Transform Rule
 *
 * Rewrites direct `new X()` DTO instantiation followed by sequential property
 * assignments into typed object literals, making property mapping explicit and
 * type-safe.
 *
 * This transformation follows the "Thin Rule, Thick Orchestrator" pattern:
 * - Rule: Thin wrapper (≤50 lines) delegating to orchestrator
 * - Orchestrator: Contains all business logic for transformation
 *
 * Guarantees:
 * - Idempotent: Safe to run multiple times (no NewExpression remains after rewrite)
 * - Atomic: All or nothing per source file
 * - Reversible: Can be undone via git reset
 */
import type {
  TransformRule,
  TransformContext,
  TransformResult,
} from '@angular-modernizer/plugin-system';
import type { PublicApi } from '@angular-modernizer/api';
import {
  DtoObjectLiteralOrchestrator,
  type DtoDetectionConfig,
} from '../orchestrators/dto-object-literal.orchestrator.js';

const DEFAULT_CONFIG: DtoDetectionConfig = {
  classNamePatterns: [/.*Response$/, /.*Dto$/, /.*Result$/],
};

/**
 * DTO Object Literal Transform Rule — rewrites direct DTO instantiation to object literals.
 *
 * @example
 * ```typescript
 * // Before
 * const r = new UserResponse();
 * r.id = 1;
 * r.name = 'Alice';
 *
 * // After
 * const r = { id: 1, name: 'Alice' };
 * ```
 */
export class DtoObjectLiteralTransformRule implements TransformRule {
  public readonly id = 'angular:dto-object-literal-transform';
  public readonly name = 'DTO Object Literal Transform';
  public readonly description =
    'Rewrites direct new X() DTO instantiation with sequential property assignments into typed object literals';
  public readonly category = 'modernization';
  public readonly tags = ['angular', 'dto', 'object-literal', 'type-safety'];

  private readonly orchestrator = new DtoObjectLiteralOrchestrator();
  private readonly config: DtoDetectionConfig;

  constructor(config?: Partial<DtoDetectionConfig>) {
    this.config = { ...DEFAULT_CONFIG, ...config };
  }

  async transform(
    context: TransformContext<PublicApi>,
  ): Promise<TransformResult> {
    const { sourceFile, filePath } = context;

    if (filePath.endsWith('.d.ts')) {
      return {
        ruleId: this.id,
        modified: false,
        message: 'Skipped declaration file',
        filePath,
      };
    }

    const initialText = sourceFile.getFullText();
    const result = this.orchestrator.run(context, this.config);
    const modified = sourceFile.getFullText() !== initialText;

    return {
      ruleId: this.id,
      modified,
      message: modified
        ? `Rewrote ${result.changeCount} DTO instantiation(s) as object literals (${result.skippedCount} skipped)`
        : 'No DTO object literal changes needed',
      filePath,
      changeCount: result.changeCount,
    };
  }
}