const couchdbService = require("../services/couchdbService");

class Comment {
  static async create(commentData) {
    const { user, post, content } = commentData;
    
    // Get user data for embedding
    const userDoc = await couchdbService.findUserById(user);
    if (!userDoc) {
      throw new Error("User not found");
    }

    // Get post data for embedding
    const postDoc = await couchdbService.getById(post);
    if (!postDoc) {
      throw new Error("Post not found");
    }

    const comment = {
      _id: `comment_${Date.now()}_${Math.random().toString(36).substr(2, 9)}`,
      type: "comment",
      user: {
        userId: user,
        name: userDoc.name,
        profilePicture: userDoc.profilePicture || ""
      },
      post: {
        postId: post,
        content: postDoc.content,
        userId: postDoc.user.userId
      },
      content: content.trim(),
      createdAt: new Date().toISOString(),
      updatedAt: new Date().toISOString()
    };

    const createdComment = await couchdbService.create(comment);

    // Update post's comment count
    await couchdbService.updatePost(post, {
      commentsCount: (postDoc.commentsCount || 0) + 1
    });

    return createdComment;
  }

  static async findById(commentId) {
    return await couchdbService.getById(commentId);
  }

  static async find(query = {}) {
    const couchQuery = {
      selector: {
        type: "comment",
        ...query
      }
    };
    return await couchdbService.find(couchQuery);
  }

  static async findByPostId(postId, options = {}) {
    const { skip = 0, limit = 50, sort = { createdAt: -1 } } = options;
    
    const query = {
      selector: {
        type: "comment",
        "post.postId": postId
      },
      sort: Object.keys(sort).map(key => [key, sort[key] === -1 ? "desc" : "asc"]),
      skip,
      limit
    };

    return await couchdbService.find(query);
  }

  static async countDocuments(query = {}) {
    const couchQuery = {
      selector: {
        type: "comment",
        ...query
      },
      fields: ["_id"]
    };
    const docs = await couchdbService.find(couchQuery);
    return docs.length;
  }

  static async deleteComment(commentId) {
    const comment = await couchdbService.getById(commentId);
    if (!comment) {
      throw new Error("Comment not found");
    }

    // Update post's comment count
    if (comment.post && comment.post.postId) {
      const postDoc = await couchdbService.getById(comment.post.postId);
      if (postDoc) {
        await couchdbService.updatePost(comment.post.postId, {
          commentsCount: Math.max(0, (postDoc.commentsCount || 0) - 1)
        });
      }
    }

    return await couchdbService.delete(commentId);
  }

  static async findByUserId(userId, options = {}) {
    const { skip = 0, limit = 50 } = options;
    
    const query = {
      selector: {
        type: "comment",
        "user.userId": userId
      },
      sort: [["createdAt", "desc"]],
      skip,
      limit
    };

    return await couchdbService.find(query);
  }

  static async validateContent(content) {
    if (!content || content.trim().length === 0) {
      throw new Error("Comment content is required");
    }

    if (content.length > 500) {
      throw new Error("Comment content must be 500 characters or less");
    }

    return content.trim();
  }

  // Legacy compatibility methods for mongoose-like interface
  static async populate(comments, fields) {
    // In CouchDB, user and post data are already embedded in comments
    // This method is for compatibility with existing code
    if (fields) {
      if (fields.includes("user") || fields.includes("post")) {
        // Data is already embedded, so just return comments as-is
        return comments;
      }
    }
    return comments;
  }

  // Helper method to check if comment belongs to a post
  static async belongsToPost(commentId, postId) {
    const comment = await couchdbService.getById(commentId);
    return comment && comment.post && comment.post.postId === postId;
  }

  // Helper method to check if user owns comment
  static async isOwnedByUser(commentId, userId) {
    const comment = await couchdbService.getById(commentId);
    return comment && comment.user && comment.user.userId === userId;
  }
}

module.exports = Comment;