/**
 * @angular-modernizer/plugin-angular - Static Extract Transform Rule
 *
 * Extracts public static methods from stateful classes to module-level
 * exported functions placed immediately above the class declaration.
 *
 * @example
 * // Before
 * export class OrderService {
 *   private orders: Order[] = [];
 *   static validate(id: string): boolean { return id.length > 0; }
 *   addOrder(order: Order): void { this.orders.push(order); }
 * }
 *
 * // After
 * export function validate(id: string): boolean { return id.length > 0; }
 *
 * export class OrderService {
 *   private orders: Order[] = [];
 *   addOrder(order: Order): void { this.orders.push(order); }
 * }
 */
import type {
  TransformRule,
  TransformContext,
  TransformResult,
} from '@angular-modernizer/plugin-system';
import type { PublicApi } from '@angular-modernizer/api';
import { StaticExtractTransformOrchestrator } from '../orchestrators/static-extract-transform.orchestrator.js';

export class StaticExtractTransformRule implements TransformRule {
  public readonly id = 'angular:extract-static-from-stateful';
  public readonly name = 'Extract Static Methods from Stateful Class';
  public readonly description =
    'Extracts public static methods from classes with instance state to module-level functions';
  public readonly category = 'refactoring';
  public readonly tags = [
    'angular',
    'refactoring',
    'static',
    'tree-shaking',
    'architecture',
  ];

  private readonly orchestrator = new StaticExtractTransformOrchestrator();

  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 stats = this.orchestrator.run(context);
    const modified = sourceFile.getFullText() !== initialText;

    return {
      ruleId: this.id,
      modified,
      message: modified
        ? `Extracted ${stats.extractedCount} static method(s) to module level; ${stats.inFileRefsUpdated} in-file + ${stats.crossFileCallersUpdated} cross-file reference(s) updated`
        : 'No eligible static-in-stateful-class patterns found',
      filePath,
      changeCount: stats.extractedCount,
    };
  }
}