GamedayParser.rb

class GamedayParser
  require 'nokogiri'
  require 'zip/zipfilesystem'

  require './app/models/team'
  require './app/models/stadium'
  require './app/models/player'
  require './app/models/game'
  require './app/models/at_bat'
  require './app/models/pitch'


  def parse_days(league, start_date, end_date)
    for date in start_date..end_date
      parse_day(league, date.year, date.month, date.day)
    end
  end

  private

  def parse_day(league, year, month, day)
    month = month.to_s.rjust(2,'0')
    day = day.to_s.rjust(2,'0')

    day_zip = "data/components/game/#{league}/year_#{year}/month_#{month}/day_#{day}.zip"
    zipfile = Zip::ZipFile.open(day_zip)
    zipfile.dir.entries('.').each do |game_dir|
      parse_game_dir(zipfile, game_dir) if game_dir.start_with? 'gid'
    end
  end

  def parse_game_dir(zipfile, game_dir)
    print "Reading game directory #{game_dir}..."

    game = parse_linescore_xml(zipfile.file.read("#{game_dir}/linescore.xml"))
    return if game.status != 'Final'

    parse_inning_all_xml(game, zipfile.file.read("#{game_dir}/inning/inning_all.xml"))
    parse_game_xml(zipfile.file.read("#{game_dir}/game.xml"))

    zipfile.dir.entries("#{game_dir}/batters").each do |f|
      parse_batter_or_pitcher_xml(zipfile.file.read("#{game_dir}/batters/#{f}"))
    end
    zipfile.dir.entries("#{game_dir}/pitchers").each do |f|
      parse_batter_or_pitcher_xml(zipfile.file.read("#{game_dir}/pitchers/#{f}"))
    end
  end

  def xml_attributes_to_model_attributes(xml_node, model_class)
    Hash[xml_node.attributes.map {|k,v| [v.name, v.value]}].slice(*model_class.column_names)
  end

  def update_model_from_xml_node(model_class, xml_node)
    return if xml_node.nil?
    node_attributes = xml_attributes_to_model_attributes(xml_node, model_class)
    instance = model_class.find_or_initialize_by(id: xml_node['id'])
    instance.update_attributes(node_attributes)
  end

  def parse_game_xml(xml)
    xml = Nokogiri::XML(xml)
    team_xml_nodes = xml.xpath('//team')
    for team_xml_node in team_xml_nodes
      update_model_from_xml_node(Team, team_xml_node)
    end
    stadium_xml_node = xml.xpath('//stadium').first
    update_model_from_xml_node(Stadium, stadium_xml_node)
  end

  def parse_batter_or_pitcher_xml(xml)
    xml = Nokogiri::XML(xml)
    player_xml_node = xml.xpath('//Player').first
    update_model_from_xml_node(Player, player_xml_node)
  end

  def parse_inning_all_xml(game, xml)
    xml = Nokogiri::XML(xml)
    atbat_xml_nodes = xml.xpath('//atbat')
    for atbat_xml_node in atbat_xml_nodes
      atbat_attributes = xml_attributes_to_model_attributes(atbat_xml_node, AtBat)
      atbat = AtBat.find_or_initialize_by_game_id_and_num(game.id, atbat_attributes['num'])
      atbat.update_attributes(atbat_attributes)

      pitch_xml_nodes = atbat_xml_node.xpath('.//pitch')
      for pitch_xml_node in pitch_xml_nodes
        print '.'

        pitch_xml_node['pitch_type'] = pitch_xml_node.remove_attribute('type').value
        pitch_xml_node['ingame_id'] = pitch_xml_node.remove_attribute('id').value
        pitch_attributes = xml_attributes_to_model_attributes(pitch_xml_node, Pitch)
        pitch = Pitch.find_or_initialize_by(at_bat_id: atbat.id, ingame_id: pitch_attributes['ingame_id'])
        pitch.update_attributes(pitch_attributes)
      end
    end
  end

  def parse_linescore_xml(xml)
    xml = Nokogiri::XML(xml)
    game_xml_node = xml.xpath('//game').first
    game_xml_node['mlbam_id'] = game_xml_node.remove_attribute('id').value
    game_attributes = xml_attributes_to_model_attributes(game_xml_node, Game)
    game = Game.find_or_initialize_by_mlbam_id(game_xml_node['mlbam_id'])
    game.update_attributes(game_attributes)
    return game
  end
end