# coding: utf-8
require 'json'
require 'time'
require 'digest/md5'

srand(0)

data = JSON.load(open("#{__dir__}/checkins.json").read)
output_file = "#{__dir__}/checkins.ics"

open(output_file, 'w'){|f|

  header = <<"EOS"
BEGIN:VCALENDAR
PRODID: 4sq checkins
VERSION:2.0
CALSCALE:GREGORIAN
METHOD:PUBLISH
X-WR-CALNAME:y_benjo
X-WR-TIMEZONE:Asia/Tokyo
BEGIN:VTIMEZONE
TZID:Asia/Tokyo
X-LIC-LOCATION:Asia/Tokyo
BEGIN:STANDARD
TZOFFSETFROM:+0900
TZOFFSETTO:+0900
TZNAME:JST
DTSTART:19700101T000000
END:STANDARD
END:VTIMEZONE
EOS

  f.puts header

  data['items'].each do |elem|
    next if elem['venue'].nil?

    text = elem['shout']
    text.gsub!(/\n/, '') unless text.nil?
    poi = elem['venue']['name']
    timestamp = elem['createdAt'].to_i
    t = Time.at(timestamp)
    t_str = t.gmtime.strftime("%Y%m%dT%H%M00Z")

    f.puts 'BEGIN:VEVENT'
    f.puts "DTSTART:#{t_str}"
    f.puts "DTEND:#{t_str}"
    f.puts "DTSTAMP:#{t_str}"

    # generate random UID
    uid = Digest::MD5.hexdigest(rand().to_s)[0...26] + '@google.com'
    f.puts "UID:#{uid}"
    f.puts "CREATED:#{t_str}"
    f.puts "DESCRIPTION:#{text}"
    f.puts "LAST-MODIFIED:#{t_str}"
    f.puts 'LOCATION:'
    f.puts 'SEQUENCE:0'
    f.puts 'STATUS:CONFIRMED'
    f.puts "SUMMARY:@ #{poi}"
    f.puts 'TRANSP:OPAQUE'
    f.puts 'END:VEVENT'
  end

  f.puts 'END:VCALENDAR'
}