module SpreadsheetModel

# File lib/spreadsheet_model.rb, line 16
def self.attr_accessor(*args)
  super
  @accessors = args
end

# File lib/spreadsheet_model.rb, line 127
def self.cache
  @@cache = Rails.cache if defined? Rails
  @@cache ||= ActiveSupport::Cache::MemoryStore.new
end

# File lib/spreadsheet_model.rb, line 72
def self.cached?
  !!read_cache('__spreadsheetmodel_cached')
end

# File lib/spreadsheet_model.rb, line 81
def self.column_names
  import unless cached?
  @column_names
end

# File lib/spreadsheet_model.rb, line 67
def self.find(*args)
  import unless cached?
  find_with_ids(*args)
end

# File lib/spreadsheet_model.rb, line 110
def self.find_one(id)
  rows = read_cache(id)

  return nil unless rows
  row_to_instance(rows[0])
end

# File lib/spreadsheet_model.rb, line 119
def self.find_some(ids)
  records = ids.map do |id|
    read_cache(id).map do |row|
      row_to_instance(row)
    end
  end.flatten
end

# File lib/spreadsheet_model.rb, line 90
def self.find_with_ids(*ids)
  expects_array = ids.first.kind_of?(Array)
  ids = ids.flatten.compact.uniq

  case ids.size
  when 0
    return nil
  when 1
    if expects_array
      result = find_some([ids.first])
    else
      result = find_one(ids.first)
    end
  else
    find_some(ids)
  end
end

# File lib/spreadsheet_model.rb, line 35
def self.import
  title_regexp = /.*/
  title_regexp = self::SHEET_TITLE_REGEXP if defined? self::SHEET_TITLE_REGEXP

  sheets = worksheets(sheet_key).select do |sheet|
    sheet.title =~ title_regexp
  end

  keys = sheets.each_with_object([]) do |sheet, keys|
    rows = sheet.rows.dup
    @column_names = rows.shift

    store_hash = rows.each_with_object({}) do |row, store_hash|
      row_hash = Hash[*@column_names.zip(row).flatten]
      row_hash = @import_callback.call(row_hash) if @import_callback
      write_rows = [store_hash[row[0]], row_hash].compact.flatten
      store_hash[row[0]] = write_rows
      store_hash
    end

    store_hash.each do |k, v|
      write_cache(k, v)
      keys << k
    end
    keys
  end
  write_cache('__spreadsheetmodel_keys', keys)
  write_cache('__spreadsheetmodel_cached', true)
end

# File lib/spreadsheet_model.rb, line 76
def self.keys
  import unless cached?
  read_cache('__spreadsheetmodel_keys')
end

# File lib/spreadsheet_model.rb, line 12
def self.on_import(&block)
  @import_callback = block
end

# File lib/spreadsheet_model.rb, line 132
def self.read_cache(key)
  cache.read "#{name}::#{key}"
end

# File lib/spreadsheet_model.rb, line 158
def self.row_to_instance(row)
  return nil unless row
  attributes = row.select { |key, _| @accessors.try(:include?, key.to_sym) }
  if row['type'].to_s.present?
    instance = attributes['type'].constantize.new(attributes)
  else
    instance = self.new(attributes)
  end

  instance.instance_variable_set(:@__row, row)
  instance
end

# File lib/spreadsheet_model.rb, line 29
def self.sheet_key
  sheet_key = ENV["GOOGLE_DRIVE_#{name.demodulize.underscore.upcase}_SHEET_KEY"]
  sheet_key = self::SHEET_KEY if defined? self::SHEET_KEY
  sheet_key
end

# File lib/spreadsheet_model.rb, line 140
def self.worksheets(sheet_key)
  client = ::OAuth2::Client.new(
    ENV['GOOGLE_DRIVE_CLIENT_ID'],
    ENV['GOOGLE_DRIVE_CLIENT_SECRET'],
    site: 'https://accounts.google.com',
    token_url: '/o/oauth2/token',
    authorize_url: '/o/oauth2/auth'
  )
  auth_options = {
    refresh_token: ENV['GOOGLE_DRIVE_REFRESH_TOKEN'],
    expires_at: 3600
  }
  auth_token = ::OAuth2::AccessToken.from_hash(client, auth_options)
  auth_token = auth_token.refresh!
  session = ::GoogleDrive.login_with_oauth(auth_token.token)
  session.spreadsheet_by_key(sheet_key).worksheets
end

# File lib/spreadsheet_model.rb, line 136
def self.write_cache(key, value)
  cache.write "#{name}::#{key}", value
end

# File lib/spreadsheet_model.rb, line 21
def [](name)
  @__row[name]
end

# File lib/spreadsheet_model.rb, line 25
def []=(name, value)
  @__row[name] = value
end