## Usage
# gem install oauth2
# ruby checkins.rb
#
## .env
# https://foursquare.com/developers/apps
# ENV["4SQ_CLIENT_ID"] = ""
# ENV["4SQ_CLIENT_SECRET"] = ""
# ENV["4SQ_REDIRECT_URI"] = "http://localhost"
#
## Save access_token after running this script
# ENV["4SQ_ACCESS_TOKEN"] = ""
#
## Import CSV to Google Calendar
# https://calendar.google.com/calendar/u/0/r/settings/export

require "oauth2"
require "csv"
begin load ".env"; rescue LoadError; nil; end

client_id = ENV["4SQ_CLIENT_ID"]
client_secret = ENV["4SQ_CLIENT_SECRET"]
redirect_uri = ENV["4SQ_REDIRECT_URI"]
access_token = ENV["4SQ_ACCESS_TOKEN"]
csv_path = "./#{Time.now.strftime("%Y%m%d%H%M")}.csv"
accept_language = "ja",
client = OAuth2::Client.new(client_id, client_secret, {
  site: "https://foursquare.com",
  authorize_url: "oauth2/authenticate",
  token_url: "oauth2/access_token"
})

if access_token.nil? || access_token.empty?
  authorize_url = client.auth_code.authorize_url(redirect_uri: redirect_uri)
  puts "Open url below and copy a code from callback url:\n#{authorize_url}"
  puts "Paste the code:"
  code = gets.chomp
  token = client.auth_code.get_token(code, redirect_uri: redirect_uri)
  access_token = token.token
  puts "Save access_token if you want: #{access_token}"
end

offset = 0
limit = 250
items = []

loop do
  puts "Fetching: #{offset}..#{offset + limit}"

  response = client.request(
    :get,
    "https://api.foursquare.com/v2/users/self/checkins",
    params: {
      v: 20210514,
      limit: limit,
      offset: offset,
      oauth_token: access_token,
      headers: { "Accept-Language" => accept_language }
    }
  )

  checkins = response.parsed.dig("response", "checkins")
  items += checkins["items"]
  offset += limit
  break if checkins["count"] < offset
end

rows = items.map do |item|
  created_at = Time.at(item["createdAt"] + item["timeZoneOffset"] * 60, in: "UTC")
  start_date = created_at.strftime("%-m/%-d/%Y")
  start_time = created_at.strftime("%H:%M %p")
  venue = item.dig("venue")
  location = venue["location"]
  formattedAddress = location["formattedAddress"] || []

  if location["cc"] == "JP"
    case formattedAddress.size
    when 2
      index = -1
    when 3
      index = -2
    end

    if index
      address = formattedAddress[index].split(", ").reverse.join
      address += formattedAddress[0]
    end
  else
    address = formattedAddress.join(", ")
  end

  {
    "Subject" => venue["name"],
    "Start Date" => start_date,
    "Start Time" => start_time,
    "End Date" => start_date,
    "End Time" => start_time,
    "All Day Event" => "False",
    "Description" => item["shout"],
    "Location" => address,
    "Private" => "False"
  }
end

CSV.open(csv_path, "wb", converters: nil) do |csv|
  csv << rows.first.keys
  rows.each { |row| csv << row.values }
end