module RelatonItu
  class DataFetcher
    def initialize(output, format)
      @output = output
      @format = format
      @ext = format.sub "bibxml", "xml"
    end

    def files
      @files ||= []
    end

    def index
      @index ||= Relaton::Index.find_or_create :itu, file: "index-v1.yaml"
    end

    # @return agent [Mechanize]
    def agent
      @agent ||= Mechanize.new
    end

    # @return workers [RelatonBib::WorkersPool]
    def workers
      return @workers if @workers

      @workers = RelatonBib::WorkersPool.new 10
      @workers.tap do |w|
        w.worker { |row| parse_page(*row) }
      end
    end

    # @param url [String]
    # @param type [String]
    def parse_page(url, type)
      doc = agent.get url
      bib = DataParserR.parse doc, url, type
      write_file bib
    rescue => e # rubocop:disable Style/RescueStandardError
      warn e.message
      warn e.backtrace
    end

    def self.fetch(output: "data", format: "yaml")
      t1 = Time.now
      puts "Started at: #{t1}"
      FileUtils.mkdir_p output
      new(output, format).fetch
      t2 = Time.now
      puts "Stopped at: #{t2}"
      puts "Done in: #{(t2 - t1).round} sec."
    end

    def fetch
      fetch_recommendation
      fetch_question
      fetch_report
      fetch_handbook
      fetch_resolution
      workers.end
      workers.result
      index.save
    end

    def fetch_recommendation
      url = "https://extranet.itu.int/brdocsearch/_layouts/15/inplview.aspx?" \
            "List=%7B0661B581-2413-4E84-BAB2-77E6DB27AF7F%7D&" \
            "View=%7BC81191DD-48C4-4881-9CB7-FB61C683FE98%7D&" \
            "ViewCount=123&" \
            "IsXslView=TRUE&" \
            "IsCSR=TRUE&" \
            "ListViewPageUrl=https%3A%2F%2Fextranet.itu.int%2Fbrdocsearch%2FR-REC%2FForms%2Ffolders_inforce.aspx&" \
            "FolderCTID=0x012001"
      json_index url, "recommendation"
    end

    def fetch_question
      url = "https://extranet.itu.int/brdocsearch/R-QUE/Forms/folders_inforce.aspx"
      html_index url, "question"
    end

    def fetch_report
      url = "https://extranet.itu.int/brdocsearch/_layouts/15/inplview.aspx?" \
            "List=%7B82E4A13D-C7F3-4844-9E8A-2463C4B7784F%7D&" \
            "View=%7B94CC1561-E4AC-4317-B402-AA0AADD7F414%7D&" \
            "ViewCount=407&" \
            "IsXslView=TRUE&" \
            "IsCSR=TRUE&" \
            "ListViewPageUrl=https%3A%2F%2Fextranet.itu.int%2Fbrdocsearch%2FR-REP%2FForms%2FFolders%2520InForce.aspx&" \
            "FolderCTID=0x012001"
      json_index url, "technical-report"
    end

    def fetch_handbook
      url = "https://extranet.itu.int/brdocsearch/R-HDB/Forms/Folders%20InForce.aspx"
      html_index url, "handbook"
    end

    def fetch_resolution
      url = "https://extranet.itu.int/brdocsearch/R-RES/Forms/Folders%20InForce.aspx"
      html_index url, "resolution"
    end

    # #param url [String]
    # @param type [String]
    def json_index(url, type) # rubocop:disable Metrics/AbcSize
      result = agent.post url
      json = JSON.parse result.body
      json["Row"].each { |row| workers << [row["serverurl.progid"].sub(/^1/, ""), type] }
      return unless json["NextHref"]

      nexturl = url.sub(/(Paged|FolderCTID)=.+/, json["NextHref"].match(/(?<=aspx\?).+/).to_s)
      json_index nexturl, type
    end

    # #param url [String]
    # @param type [String]
    def html_index(url, type)
      resp = agent.get url
      result = Nokogiri::HTML resp.body
      result.xpath("//table//table/tr[position() > 1]").each do |hit|
        url = hit.at("td/a")[:onclick].match(%r{https://[^']+}).to_s
        workers << [url, type]
      end
    end

    # @param bib [RelatonItu::ItuBibliographicItem]
    def write_file(bib) # rubocop:disable Metrics/AbcSize
      id = bib.docidentifier[0].id.gsub(/[\s.]/, "_")
      file = "#{@output}/#{id}.#{@ext}"
      if files.include? file
        warn "File #{file} exists."
      else
        files << file
      end
      index.add_or_update bib.docidentifier[0].id, file
      File.write file, content(bib), encoding: "UTF-8"
    end

    def content(bib)
      case @format
      when "yaml" then bib.to_hash.to_yaml
      when "xml" then bib.to_xml bibdata: true
      when "bibxml" then bib.to_bibxml
      end
    end
  end
end