require "devise"
require_dependency "think_feel_do_engine/application_controller"

module ThinkFeelDoEngine
  # Uses the Navigator to direct a participant"s flow through the site.
  class NavigatorController < ApplicationController
    include Concerns::NavigatorEnabled
    before_action :authenticate_participant!, :instantiate_navigator

    URL_GENERATION_ALERT = "We're sorry, the content you were looking "\
                           " for couldn't be found."
    FIRST_CONTENT_POSITION = 1

    layout "tool"

    def show_context
      context_name = params[:context_name] || home_tool.try(:title)
      @navigator.initialize_context(context_name)

      render "show_content"
    end

    def show_location
      @navigator.initialize_location(
        module_id: params[:module_id],
        provider_id: params[:provider_id],
        content_position: params[:content_position]
      )

      complete_task_status(params[:module_id],
                           params[:provider_id],
                           params[:content_position])

      render "show_content"
    rescue ActiveRecord::RecordNotFound, ActionView::Template::Error
      @navigator.initialize_context(home_tool.title)
      flash[:alert] = "Unable to find that module."
      render "show_content"
    end

    def show_next_content
      mark_engagement_completed
      @navigator.fetch_next_content

      if @navigator.current_module
        redirect_to navigator_location_path(
          module_id: @navigator.current_module.try(:id),
          provider_id: @navigator.current_content_provider
                         .try(:id),
          content_position: @navigator.content_position)
      else
        next_content_not_found
      end
    end

    def show_previous_content
      @navigator.fetch_previous_content
      redirect_to navigator_location_path(
        module_id: @navigator.current_module.try(:id),
        provider_id: @navigator.current_content_provider.try(:id),
        content_position: @navigator.content_position
      )
    end

    # Seek and redirect to the next content provider in order.
    def show_next_provider
      current_provider = @navigator.current_content_provider
      next_provider = current_provider

      while next_provider == current_provider
        @navigator.fetch_next_content
        next_provider = @navigator.current_content_provider
      end

      redirect_to navigator_location_path(
        module_id: @navigator.current_module.try(:id),
        provider_id: @navigator.current_content_provider.try(:id),
        content_position: @navigator.content_position
      )
    end

    private

    def last_engagement
      current_participant
        .active_membership
        .task_statuses
        .for_content_module(navigator_content_module)
        .try(:last)
        .try(:engagements)
        .try(:last)
    end

    def complete_task_status(module_id, provider_id, content_id)
      content_module = BitCore::ContentModule.find(module_id)
      membership = current_participant
                   .active_membership
      @task_status = membership
                     .task_statuses
                     .most_recent_for_content_module(content_module,
                                                     membership.day_in_study)
                     .first
      if @task_status &&
         (!content_specified?(provider_id, content_id) ||
         first_content_slide?(content_module, provider_id, content_id))
        @task_status
          .engagements
          .build
      end
      @task_status.mark_complete unless @task_status.nil?
    end

    def first_content_slide?(content_module, provider_id, content_id)
      first_content_provider = content_module
                               .content_providers
                               .order(:position)
                               .first
      provider_id == first_content_provider.id.to_s &&
        content_id == FIRST_CONTENT_POSITION.to_s
    end

    def mark_engagement_completed
      if navigator_content_module && last_engagement &&
         !@navigator.current_content_provider.exists?(
           @navigator.content_position + 1)
        last_engagement.update_attributes(completed_at: DateTime.current)
      end
    end

    def content_specified?(provider_id, content_id)
      !provider_id.blank? && !content_id.blank?
    end

    def module_exist?
      @navigator
        .current_module
        .provider_exists?(@navigator.provider_position + 1)
    end

    def navigator_content_module
      @navigator.current_module || @navigator
        .current_content_provider
        .content_module
    end

    def provider_exist?
      @navigator
        .current_content_provider
        .exists?(@navigator.content_position + 1)
    end

    def home_tool
      current_participant.current_group
        .arm
        .bit_core_tools.find_by_type("Tools::Home")
    end

    def next_content_not_found
      Raven.capture_message "URL Generation error in NavigatorController",
                            extra: {
                              participant_id: current_participant.try(:id),
                              params: params
                            } if defined?(Raven)
      redirect_to main_app.root_path, alert: URL_GENERATION_ALERT
    end
  end
end