module KindleManager
  class HighlightsAdapter < BaseAdapter
    KINDLE_HIGHLIGHT_URL = "https://read.#{AmazonInfo.domain}/kp/notebook"

    attr_accessor :library_ids, :loaded_library_ids, :failed_library_ids

    def fetch
      go_to_kindle_highlights_page
      fetch_library_ids
      fetch_kindle_highlights
    end

    def go_to_kindle_highlights_page
      unless session.current_url == KINDLE_HIGHLIGHT_URL
        log "Visiting kindle highlights page"
        session.visit KINDLE_HIGHLIGHT_URL
      end
      wait_for_selector('#library')
      check_library_scroll
      snapshot_page
    end

    def fetch_library_ids
      last_scroll_top = check_library_scroll
      20.times do
        scroll_library_pane(last_scroll_top + 20000)
        sleep(2)
        new_scroll_top = check_library_scroll
        break if limit && limit < doc.css('#library #kp-notebook-library > .a-row').size
        break if last_scroll_top == new_scroll_top
        last_scroll_top = new_scroll_top
      end
      snapshot_page
      self.library_ids = doc.css('#library #kp-notebook-library > .a-row').map{|e| e['id'] }
      self.loaded_library_ids ||= []
      self.failed_library_ids ||= []
      log "Number of library ids is #{library_ids.size}"
    end

    def check_library_scroll
      if session.first('#library .kp-notebook-scroller-addon').present?
        scroll_top = session.evaluate_script("$('#library .kp-notebook-scroller-addon').get(0).scrollTop")
        scroll_height = session.evaluate_script("$('#library .kp-notebook-scroller-addon').get(0).scrollHeight")
        offset_height = session.evaluate_script("$('#library .kp-notebook-scroller-addon').get(0).offsetHeight")
        log "Scroll top:#{scroll_top} height:#{scroll_height} offset_height:#{offset_height}"
        scroll_top
      else
        log "Couldn't find the node '#library .kp-notebook-scroller-addon'"
        0
      end
    end

    def scroll_library_pane(target_scroll_top)
      session.evaluate_script("$('#library .kp-notebook-scroller-addon').get(0).scrollTop = #{target_scroll_top}")
    end

    def fetch_kindle_highlights
      library_ids.each_with_index do |library_id,i|
        break if limit && limit < i+1
        next if loaded_library_ids.include?(library_id)
        fetch_book_with_highlights(library_id)
      end
      report_failed_ids
      snapshot_page
    end

    def fetch_book_with_highlights(library_id)
      log "Fetching highlights for the book #{library_id}"
      session.first("##{library_id}").click
      wait_for_selector('#annotations .kp-notebook-annotation-container', wait_time: 10)
      title = doc.css('#annotations .kp-notebook-annotation-container h3.kp-notebook-metadata').try!(:text)
      highlights_count, notes_count = fetch_highlights_and_notes
      snapshot_page("Saving page for [#{title}] (#{library_id}) highlights:#{highlights_count} notes:#{notes_count}")
      if title.present?
        self.loaded_library_ids << library_id
      else
        self.failed_library_ids << library_id
        log "[ERROR] Failed to load #{library_id} or this book doesn't have any highlights and notes"
      end
    end

    def fetch_highlights_and_notes
      highlights_count = notes_count = nil
      10.times do
        sleep(1)
        highlights_count = doc.css('#annotations .kp-notebook-annotation-container #kp-notebook-highlights-count').try!(:text)
        notes_count = doc.css('#annotations .kp-notebook-annotation-container #kp-notebook-notes-count').try!(:text)
        break if highlights_count != '--' && notes_count != '--'
      end
      [highlights_count, notes_count]
    end

    def report_failed_ids
      log("May have failed with #{failed_library_ids.inspect}. Retry with client.adapter.session.first('#B000000000').click") if failed_library_ids.size > 0
    end

    def load
      books = []
      store.list_html_files.each do |file|
        parser = KindleManager::HighlightsParser.new(file)
        books += parser.parse
      end
      books.reject(&:invalid?).uniq(&:asin)
    end

    def snapshot_page(message = nil)
      store.record_page
      log(message.presence || "Saving page")
    end
  end
end