namespace :nico do
  desc 'ニコニコ DB 同期'
  task sync: :environment do
    require 'json'
    require 'nokogiri'
    require 'open-uri'
    require 'open3'
    require 'set'
    require 'time'

    fetch_thumbnail = -> url do
      html = URI.open(url, read_timeout: 60, 'User-Agent' => 'Mozilla/5.0').read
      doc = Nokogiri::HTML(html)

      doc.at('meta[name="thumbnail"]')&.[]('content').presence
    end

    def sync_post_tags! post, desired_tag_ids, current_tag_ids: nil
      current_tag_ids ||= PostTag.where(post_id: post.id).pluck(:tag_id).to_set
      desired_tag_ids = desired_tag_ids.compact.to_set

      to_add = desired_tag_ids - current_tag_ids
      to_remove = current_tag_ids - desired_tag_ids

      Tag.where(id: to_add.to_a).find_each do |tag|
        begin
          PostTag.create!(post:, tag:)
        rescue ActiveRecord::RecordNotUnique
          ;
        end
      end

      PostTag.where(post_id: post.id, tag_id: to_remove.to_a).find_each(&:destroy!)
    end

    def sync_post_external_tags! post, desired_external_tag_ids, current_external_tag_ids: nil
      current_external_tag_ids ||=
          PostExternalTag.where(post_id: post.id).pluck(:external_tag_id).to_set
      desired_external_tag_ids = desired_external_tag_ids.compact.to_set

      to_add = desired_external_tag_ids - current_external_tag_ids
      to_remove = current_external_tag_ids - desired_external_tag_ids

      ExternalTag.where(id: to_add.to_a).find_each do |external_tag|
        begin
          PostExternalTag.create!(post:, external_tag:)
        rescue ActiveRecord::RecordNotUnique
          ;
        end
      end

      PostExternalTag
          .where(post_id: post.id, external_tag_id: to_remove.to_a)
          .find_each(&:destroy!)
    end

    mysql_user = ENV['MYSQL_USER']
    mysql_pass = ENV['MYSQL_PASS']
    nizika_nico_path = ENV['NIZIKA_NICO_PATH']
    stdout, stderr, status = Open3.capture3(
        { 'MYSQL_USER' => mysql_user, 'MYSQL_PASS' => mysql_pass },
        'python3', "#{ nizika_nico_path }/get_videos.py")

    unless status.success?
      warn stderr
      abort
    end

    data = JSON.parse(stdout)
    data.each do |datum|
      code = datum['code']
      post =
          Post
          .where('url REGEXP ?', "nicovideo\\.jp/watch/#{ Regexp.escape(code) }([^0-9]|$)")
          .first

      title = datum['title']
      original_created_at = datum['uploaded_at'] &&
          Time.strptime(datum['uploaded_at'], '%Y-%m-%d %H:%M:%S')
      original_created_from = original_created_at&.change(sec: 0)
      original_created_before = original_created_from&.+(1.minute)

      post_created = false
      post_changed = false

      if post
        attrs = { title:, original_created_from:, original_created_before: }

        unless post.thumbnail.attached?
          thumbnail_base = fetch_thumbnail.(post.url) rescue nil
          if thumbnail_base.present?
            attrs[:thumbnail_base] = thumbnail_base
            begin
              post.attach_thumbnail_from_url!(thumbnail_base)
            rescue Post::RemoteThumbnailFetchFailed => e
              payload = {
                  post_id: post.id,
                  thumbnail_base:,
                  error: e.class.name,
                  message: e.message }
              Rails.logger.info("nico_sync_thumbnail_fetch_failed #{ payload.to_json }")
            end
          end
        end

        post.assign_attributes(attrs)
        post_changed = post.changed?
        if post_changed
          post.save!
        end
      else
        post_created = true
        url = "https://www.nicovideo.jp/watch/#{ code }"
        thumbnail_base = fetch_thumbnail.(url) rescue nil
        post = Post.new(title:, url:, thumbnail_base:, uploaded_user: nil,
                        original_created_from:, original_created_before:)
        if thumbnail_base.present?
          begin
            post.attach_thumbnail_from_url!(thumbnail_base)
          rescue Post::RemoteThumbnailFetchFailed => e
            payload = {
                post_id: nil,
                thumbnail_base:,
                error: e.class.name,
                message: e.message }
            Rails.logger.info("nico_sync_thumbnail_fetch_failed #{ payload.to_json }")
          end
        end
        post.save!
        sync_post_tags!(post, [Tag.tagme.id, Tag.bot.id, Tag.niconico.id, Tag.video.id])
      end

      # 既存のタグ Id. 集合
      kept_tag_ids = post.tags.pluck(:id).to_set

      # 既存の外部タグ Id. 集合
      kept_external_tag_ids = post.external_tags.nico.pluck(:id).to_set

      # 記載すべき外部タグ Id. のリスト
      desired_external_tag_ids = []

      # 記載すべき内部タグ Id. のリスト
      desired_tag_ids = kept_tag_ids.to_a

      datum['tags'].each do |raw|
        name = TagNameSanitisationRule.sanitise(raw)
        tag = ExternalTag.find_or_create_by!(platform: :nico, name:)

        unless tag.nico_tag_versions.exists?
          NicoTagVersionRecorder.record!(external_tag: tag,
                                         event_type: :create,
                                         created_by_user: nil)
        end

        desired_external_tag_ids << tag.id

        # 新たに記載される外部タグと連携される内部タグを記載
        # 連携タグは記載すれども消除せず．
        unless tag.id.in?(kept_external_tag_ids)
          desired_tag_ids.concat(tag.linked_tags.pluck(:id))
        end
      end

      deerjikist = Deerjikist.find_by(platform: :nico, code: datum['user'])
      if deerjikist
        desired_tag_ids << deerjikist.tag_id
      elsif !(Tag.where(id: kept_tag_ids).where(category: :deerjikist).exists?)
        desired_tag_ids << Tag.no_deerjikist.id
      end

      desired_external_tag_ids.uniq!
      desired_tag_ids.uniq!

      # 外部タグの記載に際しては “bot 操作” タグを記載しなぃ．
      if kept_tag_ids != desired_tag_ids.to_set
        desired_tag_ids << Tag.bot.id
        desired_tag_ids.uniq!
      end

      tags_changed =
          kept_tag_ids != desired_tag_ids.to_set ||
          kept_external_tag_ids != desired_external_tag_ids.to_set

      sync_post_tags!(post, desired_tag_ids, current_tag_ids: kept_tag_ids)
      sync_post_external_tags!(post, desired_external_tag_ids,
                               current_external_tag_ids: kept_external_tag_ids)

      if post_created
        PostVersionRecorder.record!(post:, event_type: :create, created_by_user: nil)
      elsif post_changed || tags_changed
        PostVersionRecorder.ensure_snapshot!(post, created_by_user: nil)
        PostVersionRecorder.record!(post:, event_type: :update, created_by_user: nil)
      end
    end
  end
end