import { Injectable, signal, computed } from '@angular/core';

export interface Comment {
  id: string;
  blockId: string;
  author: string;
  text: string;
  createdAt: Date;
  resolved?: boolean;
}

@Injectable({
  providedIn: 'root'
})
export class CommentService {
  private comments = signal<Comment[]>([]);

  /**
   * Get all comments for a specific block
   */
  getCommentsForBlock(blockId: string): Comment[] {
    return this.comments().filter(c => c.blockId === blockId);
  }

  /**
   * Get comment count for a specific block
   */
  getCommentCount(blockId: string): number {
    return this.comments().filter(c => c.blockId === blockId && !c.resolved).length;
  }

  /**
   * Add a comment to a block
   */
  addComment(blockId: string, text: string, author: string = 'User'): void {
    const newComment: Comment = {
      id: this.generateId(),
      blockId,
      author,
      text,
      createdAt: new Date()
    };
    this.comments.update(comments => [...comments, newComment]);
  }

  /**
   * Delete a comment
   */
  deleteComment(commentId: string): void {
    this.comments.update(comments => comments.filter(c => c.id !== commentId));
  }

  /**
   * Mark comment as resolved
   */
  resolveComment(commentId: string): void {
    this.comments.update(comments => 
      comments.map(c => c.id === commentId ? { ...c, resolved: true } : c)
    );
  }

  /**
   * Get all comments
   */
  getAllComments(): Comment[] {
    return this.comments();
  }

  private generateId(): string {
    return Math.random().toString(36).substring(2, 11);
  }

  /**
   * Add test comments to specific blocks (for demo purposes)
   */
  addTestComments(blockIds: string[]): void {
    blockIds.forEach((blockId, index) => {
      // Add 1-3 random comments per block
      const commentCount = Math.floor(Math.random() * 3) + 1;
      for (let i = 0; i < commentCount; i++) {
        this.addComment(
          blockId,
          `Test comment ${i + 1} for block`,
          `User ${index + 1}`
        );
      }
    });
  }
}