class ThreadPostsController < ApplicationController
  before_action :set_thread

  # GET /api/threads/:thread_id/posts
  def index
    sort = params[:sort].presence_in(['created_at', 'score']) || 'created_at'
    order = params[:order].presence_in(['asc', 'desc']) || 'desc'

    posts = @thread.posts
            .select('posts.*, (good - bad) AS score')
            .order("#{ sort } #{ order }")

    render json: posts.map { |post|
      post.as_json.merge(image_url: (
          if post.image.attached?
            Rails.application.routes.url_helpers.rails_blob_url(post.image, only_path: true)
          else
            nil
          end))
    }
  end

  # POST /api/threads/:thread_id/posts
  def create
    post = @thread.posts.new(post_params)
    if post.save
      render json: post.as_json.merge(image_url: (
          if post.image.attached?
            Rails.application.routes.url_helpers.rails_blob_url(post.image, only_path: true)
          else
            nil
          end)), status: :created
    else
      render json: { errors: post.errors.full_messages }, status: :unprocessable_entity
    end
  end

  private

  def set_thread
    @thread = Topic.find(params[:thread_id])
  end

  def post_params
    params.permit(:name, :message, :password, :image).transform_values { |v|
      v.presence
    }
  end
end