class Crawler

# File lib/gsv_downloader/crawler.rb, line 6
def initialize (area_validator, db)
  @metadata_downloader  = MetaDataDownloader.new
      @stats = Statistics.new
      @db = db
  @area_validator = area_validator
  @max = 200
end

# File lib/gsv_downloader/crawler.rb, line 21
def crawl(panoID)

  @db.mark_to_crawl(panoID)

  @metadata_downloader.download(panoID) do | response|

    json = extract_json(response)
    panoID = json["Location"]["panoId"]
    @stats.count

    unless @db.crawled?(panoID)
      @db.mark_as_crawled(panoID)

      # if inside the area
      if @area_validator.call(json)
        @db.add_pano(panoID, response) #TODO to save to save or whatever

        # for each valid and new link, crawl it
        extract_valid_links(json) do |link_id|
          crawl(link_id)
        end
      end
    end
  end
end

# File lib/gsv_downloader/crawler.rb, line 14
def start(pano_ids)
  pano_ids.each do |pano_id|
    crawl(pano_id)
  end
  @metadata_downloader.start()
end

# File lib/gsv_downloader/crawler.rb, line 49
def extract_json(data)
  result = JSON.parse(data)
  #p result
  raise "web service error" if result.has_key? 'Error'
  result
end

# File lib/gsv_downloader/crawler.rb, line 56
def extract_valid_links(json)
  json["Links"].each do |link_json|
    link_id = link_json["panoId"]
    if (link_json["scene"] == "0") and (@db.to_crawl?(link_id)) and (!@db.crawled?(link_id))
      yield(link_id)
    end
  end
end