# frozen_string_literal: true

module YiffRocks
  class HomeController < ApplicationController
    include ::ApplicationController::ReadonlyMethods
    before_action :handle_ratelimit, only: %i[create update destroy]
    before_action :validate_api_key_required, only: %i[create update destroy]
    before_action :validate_shortener_access, only: %i[create update destroy]
    before_action :load_shorturl, only: %i[update destroy]
    before_action :ensure_edit_access, only: %i[update destroy]
    before_action -> { track_usage("shortener") }, except: %i[index]
    wrap_parameters format: :json, name: "short_url"

    def index
    end

    def show
      code = params[:code]
      preview = code.ends_with?("+")
      code = code[..-2] if preview
      if params[:format] == "json"
        return if handle_ratelimit && performed?
        return if validate_api_key_required && performed?
        return if validate_shortener_access && performed?
        @short = ShortUrl.find_by(code: code)
        return render_error(YiffyAPIErrorCodes::SHORTENER_NOT_FOUND, error: "A short url with that code was not found.") if @short.nil?
        return render(json: {
          success: true,
          data:    @short,
        })
      end
      @short = ShortUrl.find_by(code: code)
      return render(plain: "Unknown short url code.", status: 404) if @short.nil?
      return render("preview") if preview
      redirect_to(@short.url, allow_other_host: true)
    end

    def create
      @short_url = ShortUrl.create(creator_ua: request.headers["User-Agent"], **short_url_params(:create))

      handle_errors
      return if performed?

      render(json: @short_url)
    end

    def update
      @short_url.update(short_url_params(:update))

      handle_errors
      return if performed?

      return render_error(YiffyAPIErrorCodes::SHORTENER_NO_CHANGES, message: "No changes were detected.") unless @short_url.saved_change_to_url? || @short_url.saved_change_to_creator_name?

      render(json: @short_url)
    end

    def destroy
      @short_url.destroy
    end

    private

    def short_url_params(context = nil)
      permitted_params = %i[url credit creator_name]
      permitted_params += %i[code] if context == :create
      params.require(:short_url).permit(permitted_params)
    end

    def handle_errors
      if @short_url.errors.any?
        @short_url.errors.full_messages.each do |error|
          return render_error(YiffyAPIErrorCodes::SHORTENER_CODE_TOO_LONG, message: error, errors: @short_url.errors.full_messages) if error.to_s =~ /Code is too long/
          return render_error(YiffyAPIErrorCodes::SHORTENER_INVALID_CODE, message: error, errors: @short_url.errors.full_messages) if error.to_s =~ /Code is invalid/
          return render_error(YiffyAPIErrorCodes::SHORTENER_INVALID_URL, message: error, errors: @short_url.errors.full_messages) if error.to_s =~ /Url is invalid/
          return render_error(YiffyAPIErrorCodes::SHORTENER_URL_TOO_LONG, message: error, errors: @short_url.errors.full_messages) if error.to_s =~ /Url is too long/
          return render_error(YiffyAPIErrorCodes::SHORTENER_CREDIT_TOO_LONG, message: error, errors: @short_url.errors.full_messages) if error.to_s =~ /Creator name is too long/
          return render_error(YiffyAPIErrorCodes::SHORTENER_CODE_IN_USE, message: error, errors: @short_url.errors.full_messages) if error.to_s =~ /Code has already been taken/
          @short_url.save! # Make further failed validations raise
        end
      end
    end

    def load_shorturl
      @short_url = ShortUrl.find_by(code: params[:code])
      render_error(YiffyAPIErrorCodes::SHORTENER_NOT_FOUND, message: "A short url with that code was not found.") if @short_url.nil?
    end

    def ensure_edit_access
      management_code = params.fetch(:short_url, {}).permit(:managementCode)[:managementCode]
      params[:short_url].delete(:managementCode) if management_code.present?

      if CurrentUser.user.id != @short_url.creator_id
        return render_error(YiffyAPIErrorCodes::SHORTENER_NO_MANAGEMENT_CODE, message: "That short url cannot be edited by you.") if @short_url.management_code.blank? || management_code.blank?
        render_error(YiffyAPIErrorCodes::SHORTENER_MANAGEMENT_CODE_MISMATCH, message: "That management code does not match this short url.") if management_code != @short_url.management_code
      end
    end
  end
end