module Sources::Strategies
  class Tumblr < Base
    SIZES = %w[1280 640 540 500h 500 400 250 100]

    BASE_URL = %r!\Ahttps?://(?:[^/]+\.)*tumblr\.com!i
    DOMAIN = %r{(data|(\d+\.)?media)\.tumblr\.com}
    MD5 = %r{(?<md5>[0-9a-f]{32})}i
    FILENAME = %r{(?<filename>(tumblr_(inline_)?)?[a-z0-9]+(_r[0-9]+)?)}i
    EXT = %r{(?<ext>\w+)}
    IMAGE = %r!\Ahttps?://#{DOMAIN}/(?<dir>#{MD5}/)?#{FILENAME}_(?<size>\w+)\.#{EXT}\z!i
    VIDEO = %r!\Ahttps?://(?:vtt|ve\.media)\.tumblr\.com/!i
    POST = %r!\Ahttps?://(?<blog_name>[^.]+)\.tumblr\.com/(?:post|image)/(?<post_id>\d+)!i

    def self.enabled?
      Danbooru.config.tumblr_consumer_key.present?
    end

    def domains
      ["tumblr.com"]
    end

    def site_name
      "Tumblr"
    end

    def image_url
      return image_urls.first unless url.match?(IMAGE) || url.match?(VIDEO)
      find_largest(url)
    end

    def image_urls
      list = []

      case post[:type]
      when "photo"
        list += post[:photos].map { |photo| photo[:original_size][:url] }

      when "video"
        list += [post[:video_url]]

      # api response is blank (work is deleted or we were given a direct image with no referer url)
      when nil
        list += [url] if url.match?(IMAGE) || url.match?(VIDEO)
      end

      list += inline_images
      list.map { |url| find_largest(url) }
    end

    def preview_urls
      image_urls.map do |x|
        x.sub(%r!_1280\.(jpg|png|gif|jpeg)\z!, '_250.\1')
      end
    end

    def page_url
      return nil unless blog_name.present? && post_id.present?
      "https://#{blog_name}.tumblr.com/post/#{post_id}"
    end

    def canonical_url
      page_url
    end

    def profile_url
      return nil if artist_name.blank?
      "https://#{artist_name}.tumblr.com"
    end

    def artist_name
      post[:blog_name] || blog_name
    end

    def artist_commentary_title
      case post[:type]
      when "text", "link"
        post[:title]

      when "answer"
        "#{post[:asking_name]} asked: #{post[:question]}"

      else
        nil
      end
    end

    def artist_commentary_desc
      case post[:type]
      when "text"
        post[:body]

      when "link"
        post[:description]

      when "photo", "video"
        post[:caption]

      when "answer"
        post[:answer]

      else
        nil
      end
    end

    def tags
      post[:tags].to_a.map do |tag|
        [tag, "https://tumblr.com/tagged/#{CGI.escape(tag)}"]
      end.uniq
    end

    def normalize_tag(tag)
      tag = tag.tr("-", "_")
      super(tag)
    end

    def dtext_artist_commentary_desc
      DText.from_html(artist_commentary_desc).strip
    end

  public

    # Look for the biggest available version on media.tumblr.com. A bigger
    # version may or may not exist.
    #
    # https://40.media.tumblr.com/de018501416a465d898d24ad81d76358/tumblr_nfxt7voWDX1rsd4umo1_r23_1280.jpg
    # => https://media.tumblr.com/de018501416a465d898d24ad81d76358/tumblr_nfxt7voWDX1rsd4umo1_r23_raw.jpg
    #
    # https://68.media.tumblr.com/ee02048f5578595badc95905e17154b4/tumblr_inline_ofbr4452601sk4jd9_250.gif
    # => https://media.tumblr.com/ee02048f5578595badc95905e17154b4/tumblr_inline_ofbr4452601sk4jd9_500.gif
    #
    # https://25.media.tumblr.com/tumblr_m2dxb8aOJi1rop2v0o1_500.png
    # => https://media.tumblr.com/tumblr_m2dxb8aOJi1rop2v0o1_1280.png
    #
    # http://media.tumblr.com/0DNBGJovY5j3smfeQs8nB53z_400.jpg
    # => https://media.tumblr.com/0DNBGJovY5j3smfeQs8nB53z_500.jpg
    #
    # http://media.tumblr.com/tumblr_m24kbxqKAX1rszquso1_1280.jpg
    # => https://media.tumblr.com/tumblr_m24kbxqKAX1rszquso1_1280.jpg
    def find_largest(url, sizes: SIZES)
      return url unless url =~ IMAGE

      candidates = sizes.map do |size|
        "https://media.tumblr.com/#{$~[:dir]}#{$~[:filename]}_#{size}.#{$~[:ext]}"
      end

      candidates.find do |candidate|
        http_exists?(candidate, headers)
      end
    end

    def inline_images
      html = Nokogiri::HTML.fragment(artist_commentary_desc)
      html.css("img").map { |node| node["src"] }
    end

    def blog_name
      urls.map { |url| url[POST, :blog_name] }.compact.first
    end

    def post_id
      urls.map { |url| url[POST, :post_id] }.compact.first
    end

    def api_response
      return {} unless self.class.enabled?
      return {} unless blog_name.present? && post_id.present?

      body, code = HttpartyCache.get("/#{blog_name}/posts",
        params: { id: post_id, api_key: Danbooru.config.tumblr_consumer_key },
        base_uri: "https://api.tumblr.com/v2/blog/"
      )

      if code == 200
        return JSON.parse(body, symbolize_names: true)
      else
        Rails.logger.debug("TumblrApiClient call failed (code=#{code}, body=#{body}, blog_name=#{blog_name}, post_id=#{post_id})")
        return {}
      end
    end
    memoize :api_response

    def post
      api_response.dig(:response, :posts)&.first || {}
    end
  end
end