ニコニコの動画IDからコメントを取得して保存するrubyスクリプト

get_nico_comments_by_movie_id.rb

require 'json'
require 'open-uri'
require 'net/https'

class NicovideoAPIWrapper
    def login(mail, password)
        #ログインを試みる
        https = Net::HTTP.new('secure.nicovideo.jp', 443)
        https.use_ssl = true
        https.verify_mode = OpenSSL::SSL::VERIFY_NONE
        response = https.start{|https|
            https.post('/secure/login?site=niconico', "mail=#{mail}&password=#{password}")
        }

        #set-cookieには複数のcookieが設定されている。
        #user_sessionがdeletedでない最初のcookieを探す。
        user_session = nil
        response.get_fields('set-cookie').each {|cookie|
            cookie.split('; ').each {|param|
                pair = param.split('=')
                if pair[0] == 'user_session' then
                    user_session = pair[1] if pair[1] != 'deleted'
                    break
                end
            }
            break unless user_session.nil?
        }
        @session_id = user_session
        return user_session
    end

    # getflvから動画情報取得
    def get_flv_info(movie_id)
      host = 'flapi.nicovideo.jp'
      path = "/api/getflv/#{movie_id}"

      response = Net::HTTP.new(host).start { |http|
        request = Net::HTTP::Get.new(path)
        request['cookie'] = "user_session=#{@session_id}"
        http.request(request)
      }

      flv_info = {}
      response.body.split('&').each do |st|
        stt = st.split('=')
        flv_info[stt[0].to_sym] = stt[1]
      end
      flv_info[:ms] =~ /(http%3A%2F%2Fmsg\.nicovideo\.jp%2F)(.*?)(%2Fapi%2F)/
      flv_info[:msg] = $2

      return flv_info
    end

    # 与えられた動画IDの情報を返す
    def get_movie_info(movie_id, max_num = 100)
    	flv_info       = get_flv_info(movie_id)
    	msg_server_url = URI.unescape( flv_info[:ms] ).gsub("/api/", "")
    	thread_id      = flv_info[:thread_id]
    	movie_info_url = "#{msg_server_url}/api.json/thread?version=20090904&thread=#{thread_id}&res_from=-#{max_num}"
    	JSON.load( open(movie_info_url).read )
    end

	# 与えられた動画IDのコメント情報を返す
    def get_comments_info(movie_id, max_num = 100)
    	movie_info =  get_movie_info(movie_id, max_num)
		comments_info = []
		movie_info.each do |v|
			comments_info << v["chat"] if v.has_key?("chat")
		end
		comments_info
	end

	# 与えられたコメント情報からコメントを抜き出す
	def extract_comments(infos)
		infos.map { |info| info["content"] }
	end

	# 与えられた動画IDからコメントを返す
	def get_comments(movie_id, max_num = 100)
		comments_info = get_comments_info(movie_id, max_num)
		extract_comments(comments_info)
	end
end

# 配列の要素一つを一行としてファイルに保存する
def save_array arr, dst_pass
	File.write(dst_pass, arr.join("\n"))
end

# main
NICO_MAIL  = ARGV[0]
NICO_PASS  = ARGV[1]
MOVIE_ID   = ARGV[2]
DST_DIR    = "comments"

Dir.mkdir(DST_DIR) unless File.exists?(DST_DIR)

nico = NicovideoAPIWrapper.new
nico.login(NICO_MAIL, NICO_PASS)
comments = nico.get_comments(MOVIE_ID)
save_array(comments, "#{DST_DIR}/#{MOVIE_ID}_comments.csv")