libr-2/app/controllers/api/v1/likes_controller.rb

class Api::V1::LikesController < Api::V1::ApplicationController

  before_action :load_post, only: [:like, :unlike]
  before_action :load_comment, only: [:comment_like, :comment_unlike]

  def like
    if @current_user.likes.where(likable_id: @target_post, likable_type: Post).present?
      render json: {msg: '你已经喜欢过该文章了'}, status: 400
    else
      @current_user.likes.create likable: @target_post
      @current_user.timeline_sources.create! post_id: @target_post.id, action_type: 'like'
      render json:{msg: 'done', likes_count: @target_post.likes_count}
    end
  end

  def unlike
    like = @current_user.likes.find_by(likable_id: @target_post, likable_type: Post)
    if like.present?
      like.destroy!
      render json:{msg: 'done', likes_count: @target_post.likes_count}
    else
      render json: {msg: '不能进行该操作'}, status: 400
    end
  end

  def comment_like
    if @current_user.likes.where(likable_id: @target_comment, likable_type: Comment).present?
      render json: {msg: '你已经喜欢过该评论了'}, status: 400
    else
      @current_user.likes.create likable: @target_comment
      render json:{msg: 'done', likes_count: @target_comment.likes_count}
    end
  end

  def comment_unlike
    like = @current_user.likes.find_by(likable_id: @target_comment, likable_type: Comment)
    if like.present?
      like.destroy!
      render json:{msg: 'done', likes_count: @target_comment.likes_count}
    else
      render json: {msg: '不能进行该操作'}, status: 400
    end
  end

  private

  def load_comment
    @target_comment = Comment.find_by id: params[:comment_id]
    render json: {msg: '不能找到该评论'}, status: 404 unless @target_comment
  end

end