require 'flickraw'
require 'date'
require 'set'

# load conf and set API key and access token
# (ex)
# { "api_key": "xxxxxxx",
#  "shared_secret": "xxxxx",
#  "access_token": "xxxxxxx",
#  "access_secret": "xxxxxx"
# }
conf = nil
open('flickr.conf') { |f|
  conf = JSON.load(f)
}

FlickRaw.api_key = conf['api_key']
FlickRaw.shared_secret = conf['shared_secret']
flickr.access_token = conf['access_token']
flickr.access_secret = conf['access_secret']


def get_set_id_by_name(set_name)
  res = flickr.photosets.getList
  for set in res
    if set.title == set_name
      return set.id
    end
  end
  nil
end

def get_photos_in_a_set(photoset_id)
  page = 1
  pages = 1
  photo_ids = []
  while page <= pages
    res = flickr.photosets.getPhotos :photoset_id => photoset_id.to_s,
                                     :page => page.to_s
    photo_ids.concat res.photo.map { |photo| photo.id }

    page = res.page.to_i + 1
    pages = res.pages.to_i
  end
  { :id => res.id,
    :primary => res.primary, 
    :photo => photo_ids }
end

def log(str)
  puts "#{Time.now} #{str}"
end


def main(cur_set_id)
  # get set 'YYYY-MM-DD'
  new_set_name = Date::today.to_s
  new_set_id = get_set_id_by_name(new_set_name)
  if new_set_id.nil?
    log("set #{new_set_name} not found")
    exit
  end
  log("set #{new_set_name} found: #{new_set_id}")

  # Get set information
  cur_set = get_photos_in_a_set(cur_set_id)
  new_set = get_photos_in_a_set(new_set_id)
  log("current set has #{cur_set[:photo].length} photos")
  if new_set[:photo].length == 0
    log("no photo")
    exit
  end
  log("add #{new_set[:photo].length} photo(s) to it")

  # Create new photo_ids
  cur_photos_set = Set.new(cur_set[:photo])
  photos = cur_set[:photo].dup
  log("current photos: #{photos.join(',')}")
  modified = false
  for photo in new_set[:photo]
    if cur_photos_set.include? photo
      log("skip photo #{photo}")
    else
      log("add photo #{photo}")
      photos.unshift(photo) 
      modified = true
    end
  end
  log("new photos: #{photos.join(',')}")

  if modified
    log("editPhotos start")
    res = flickr.photosets.editPhotos :photoset_id => cur_set[:id],
                                      :primary_photo_id => cur_set[:primary],
                                      :photo_ids => photos.join(",")
    log("editPhotos finished")
  else
    log("editPhots skipped")
  end

  # delete set
  log("delete photoset start")
  flickr.photosets.delete :photoset_id => new_set_id
  log("delete photoset finished")
end


if ARGV.length < 1
  log("set_id not specified")
  log("ruby flickr_update.rb [set_id]")
  exit
end

begin
  main(ARGV[0])
rescue SystemExit
rescue Exception => e
  log("exception #{e.inspect}\n#{e.backtrace.join("\n")}")
end

$ ruby update_flickr.rb [set_id]