class PostsController < ApplicationController
  before_action :authenticate_user!, only: [:create, :update, :destroy]

  def index
    posts = Post
      .select(
        :id,
        :title,
        :description,
        :post_status_id,
        'COUNT(DISTINCT likes.id) AS likes_count',
        'COUNT(DISTINCT comments.id) AS comments_count',
        '((LOG(COUNT(DISTINCT likes.id) + 1) + LOG(COUNT(DISTINCT comments.id) + 1)) + (EXTRACT(EPOCH FROM posts.created_at) / 45000)) AS hotness',
        "(SELECT COUNT(*) AS liked FROM likes WHERE likes.user_id=#{current_user ? current_user.id : -1} AND likes.post_id=posts.id)"
      )
      .left_outer_joins(:likes)
      .left_outer_joins(:comments)
      .group('posts.id')
      .where(filter_params)
      .search_by_name_or_description(params[:search])
      .order('hotness DESC')
      .page(params[:page])
    
    render json: posts
  end

  def create
    @post = Post.new
    @post.assign_attributes(post_create_params)

    if @post.save
      Follow.create(post_id: @post.id, user_id: current_user.id)
      
      render json: @post, status: :created
    else
      render json: {
        error: @post.errors.full_messages
      }, status: :unprocessable_entity
    end
  end

  def show
    @post = Post
      .select(
        :id,
        :title,
        :description,
        :board_id,
        :user_id,
        :post_status_id,
        :created_at,
        :updated_at,
        'users.email as user_email',
        'users.full_name as user_full_name'
      )
      .joins(:user)
      .find(params[:id])
    
    @post_statuses = PostStatus.select(:id, :name, :color).order(order: :asc)
    @board = @post.board

    respond_to do |format|
      format.html

      format.json { render json: @post }
    end
  end

  def update
    @post = Post.find(params[:id])
    authorize @post
    
    @post.assign_attributes(post_update_params)

    if @post.save
      if @post.post_status_id_previously_changed?
        PostStatusChange.create(
          user_id: current_user.id,
          post_id: @post.id,
          post_status_id: @post.post_status_id
        )
  
        UserMailer.notify_followers_of_post_status_change(post: @post).deliver_later
      end

      render json: @post
    else
      render json: {
        error: @post.errors.full_messages
      }, status: :unprocessable_entity
    end
  end

  def destroy
    @post = Post.find(params[:id])
    authorize @post

    if @post.destroy
      render json: {
        id: @post.id,
      }, status: :accepted
    else
      render json: {
        error: @post.errors.full_messages
      }, status: :unprocessable_entity
    end
  end

  private
  
    def filter_params
      defaults = Board.first ? { board_id: Board.first.id } : {}

      params
        .permit(:board_id, :post_status_id, :page, :search)
        .with_defaults(defaults)
        .except(:page, :search)
    end
    
    def post_create_params
      params
        .require(:post)
        .permit(policy(@post).permitted_attributes_for_create)
        .merge(user_id: current_user.id)
    end

    def post_update_params
      params
        .require(:post)
        .permit(policy(@post).permitted_attributes_for_update)
    end
end