class TimelinesController < ApplicationController
  include ApplicationHelper

  before_action :authenticate_user!, except: [:show]
  before_action :set_timeline, only: [:show, :edit, :update, :destroy, :toggle_archive]

  before_action :set_navbar_color
  before_action :set_sidenav_expansion

  before_action :require_premium_plan, only: [:new, :create]
  before_action :require_timeline_read_permission, only: [:show]
  before_action :require_timeline_edit_permission, only: [:edit, :update]

  # GET /timelines
  def index
    cache_linkable_content_for_each_content_type

    # TODO: We SHOULD be just doing the below, but since it returns ContentPage stand-ins instead
    # of actual Timeline models, it's a bit wonky to get all the Timeline-specific logic in place
    # without reworking most of the views. For now, we're just grabbing timelines and contributable
    # timelines manually.
    # @timelines = @linkables_raw.fetch('Timeline', [])
    @timelines = current_user.timelines

    @page_title = "My timelines"

    if @universe_scope
      @timelines = Timeline.where(universe: @universe_scope)
    else
      # Add in all timelines from shared universes also
      @timelines += Timeline.where(universe_id: current_user.contributable_universe_ids)
                            .where.not(id: @timelines.pluck(:id))
    end

    @filtered_page_tags = []
    @page_tags = PageTag.where(
      page_type: Timeline.name,
      page_id:   @timelines.pluck(:id)
    ).order(:tag)
    if params.key?(:tag)
      @filtered_page_tags = @page_tags.where(slug: params[:tag])
      @timelines = @timelines.select { |timeline| @filtered_page_tags.pluck(:page_id).include?(timeline.id) }
    end

    # if params.key?(:favorite_only)
    #   @timelines.select!(&:favorite?)
    # end


    # New style, using content#index view (we can wipe unused stuff from above once this is finalized)
    @content_type_class = Timeline
    @content_type_name = @content_type_class.name
    @content = @timelines
    @total_content_count = @timelines.count
    
    # Set up pagination variables (no actual pagination for now, but template expects them)
    @current_page = 1
    @total_pages = 1
    
    @folders = []
    render 'content/index'
  end

  def show
    @page_title = @timeline.name
  end

  # GET /timelines/new
  def new
    timeline = current_user.timelines.create(name: 'Untitled Timeline', universe: @universe_scope).reload
    redirect_to edit_timeline_path(timeline)
  end

  # GET /timelines/1/edit
  def edit
    @page_title = "Editing #{@timeline.name}"
    @suggested_page_tags = []
    cache_linkable_content_for_each_content_type
    
    # Collect all unique tags from timeline events for filtering
    @timeline_event_tags = collect_timeline_event_tags
    
    # Get content already linked to other events in this timeline
    @timeline_linked_content = {}
    @timeline_content_summary = {}
    timeline_entity_ids = @timeline.timeline_events
                                   .joins(:timeline_event_entities)
                                   .pluck('timeline_event_entities.entity_type', 'timeline_event_entities.entity_id')
                                   .uniq
    
    timeline_entity_ids.group_by(&:first).each do |entity_type, entity_pairs|
      entity_ids = entity_pairs.map(&:last).uniq
      content_class = content_class_from_name(entity_type)
      next unless content_class
      
      # Original data for link modal
      @timeline_linked_content[entity_type] = content_class.where(id: entity_ids)
                                                          .where(user: current_user)
                                                          .limit(20)
      
      # Enhanced data for content summary sidebar
      all_content = content_class.where(id: entity_ids)
                                .where(user: current_user)
                                .order(:name)
      
      @timeline_content_summary[entity_type] = {
        count: all_content.count,
        items: all_content.limit(10), # Show first 10, with expansion option
        total_items: all_content.count,
        content_class: content_class
      }
    end
  end

  # POST /timelines
  def create
    @page_title = "Create a timeline"

    # TODO this endpoint is probably just API-only, right?
    @timeline = Timeline.new(timeline_params)

    if current_user.on_premium_plan? && @timeline.save
      redirect_to @timeline, notice: 'Timeline was successfully created.'
    else
      render :new
    end
  end

  # PATCH/PUT /timelines/1
  def update
    if @timeline.update(timeline_params)
      update_page_tags

      render status: 200, json: @timeline.reload
    else
      render status: 501, json: @timeline.errors
    end
  end

  # DELETE /timelines/1
  def destroy
    @timeline.destroy
    redirect_to timelines_url, notice: 'Timeline was successfully destroyed.'
  end

  # GET /timelines/1/toggle_archive
  def toggle_archive
    unless @timeline.updatable_by?(current_user)
      flash[:notice] = "You don't have permission to edit that!"
      return redirect_back fallback_location: @timeline
    end

    verb = nil
    success = if @timeline.archived?
      verb = "unarchived"
      @timeline.unarchive!
    else
      verb = "archived"
      @timeline.archive!
    end

    if success
      flash[:notice] = "Timeline #{verb} successfully!"
    else
      flash[:alert] = "Failed to #{verb.sub('ed', '')} timeline."
    end

    redirect_back fallback_location: edit_timeline_path(@timeline)
  end

  # GET /timelines/1/tag_suggestions
  def tag_suggestions
    # Get all unique tags from all of the current user's timelines
    user_timeline_tags = PageTag.where(
      user: current_user,
      page_type: 'Timeline'
    ).distinct.pluck(:tag).sort

    render json: {
      suggestions: user_timeline_tags
    }
  end

  private

  def require_timeline_read_permission
    return user_signed_in? && @timeline.readable_by?(current_user)
  end

  def require_timeline_edit_permission
    return user_signed_in? && @timeline.updatable_by?(current_user)
  end

  # TODO: move this (and the copy in ContentController) into the has_page_tags concern?
  def update_page_tags
    tag_list = page_tag_params.split(PageTag::SUBMISSION_DELIMITER)
    current_tags = @timeline.page_tags.pluck(:tag)

    tags_to_add    = tag_list - current_tags
    tags_to_remove = current_tags - tag_list

    tags_to_add.each do |tag|
      @timeline.page_tags.find_or_create_by(
        tag:  tag,
        slug: PageTagService.slug_for(tag),
        user: @timeline.user
      )
    end

    tags_to_remove.each do |tag|
      @timeline.page_tags.find_by(tag: tag).destroy
    end
  end

  # Use callbacks to share common setup or constraints between actions.
  def set_timeline
    @timeline = Timeline.find(params[:id])
  end

  # Only allow a trusted parameter "white list" through.
  def timeline_params
    params.require(:timeline).except(:page_tags).permit(:name, :subtitle, :description, :notes, :private_notes, :universe_id, :deleted_at, :archived_at, :privacy)
  end

  def page_tag_params
    params.require(:timeline).fetch(:page_tags, "")
  end

  def set_navbar_color
    @navbar_color = Timeline.hex_color.presence || '#2196F3'
  end

  def set_sidenav_expansion
    @sidenav_expansion = 'writing'
  end

  def collect_timeline_event_tags
    # Get all unique tags from timeline events with their usage counts
    tag_counts = @timeline.timeline_events
                          .joins(:page_tags)
                          .group('page_tags.tag')
                          .count
    
    # Return array of hashes with tag name and count for easy access in view
    tag_counts.map { |tag, count| { name: tag, count: count } }
              .sort_by { |tag_data| tag_data[:name].downcase }
  end
end