session_persistence.rb

# require 'pg'


# class SessionPersistance
#   def initialize(session)
#     @session = session
#     @session[:lists] ||= []
#   end

#   def find_list(id)
#     @session[:lists].find { |list| list[:id] == id }
#   end

#   def all_lists
#     @session[:lists]
#   end

#   def create_new_list(list_name)
#     id = next_element_id(all_lists)
#     all_lists << { id: id, name: list_name, todos: [] } 
#   end

#   def delete_list(id)
#     all_lists.reject! { |list| list[:id] == id }
#   end

#   def update_list_name(list_id, new_name)
#     list = find_list(list_id)
#     list[:name] = new_name
#   end

#   def create_new_todo(list_id, todo_name)
#     list = find_list(list_id)
#     id = next_element_id(list[:todos])
#     list[:todos] <<  {id: id, name: todo_name, completed: false}
#   end

#   def delete_todo_from_list(list_id, todo_id)
#     list = find_list(list_id)
#     list[:todos].reject! { |todo| todo[:id] == todo_id }
#   end

#   def update_todo_status(list_id, todo_id, new_status)
#     list = find_list(list_id)
#     todo = list[:todos].find {|todo| todo[:id] == todo_id }
  
#     todo[:completed] = new_status 
#   end

#   def mark_all_todos_as_completed(list_id)
#     list = find_list(list_id)
#     list[:todos].each {|todo| todo[:completed] = true }
#   end

#   private
  
#   def next_element_id(elements)
#     max = elements.map {|element| element[:id] }.max || 0
#     max + 1
#   end
# end