Solution for Ruby Todos

todos_3.rb

#!/usr/bin/env ruby
require "yaml"
require 'term/ansicolor'

class String
  include Term::ANSIColor
end

class List
  def initialize
    @tasks = []
    if File.exists?("todos.yml")
      loaded_list
    else
      dumped_list
    end
  end

  def loaded_list
    @tasks = YAML.load_file("todos.yml")
  end

  def dumped_list
    File.open("todos.yml", "w") { |file| YAML.dump(@tasks, file) }
  end

  def show_list
    puts "\e[H\e[2J"
    divider_line = "".ljust(100, "-")
    puts "My Todo List\n#{divider_line}\n"
    puts "Description".ljust(30) + "Priority".ljust(10) + "Tags".ljust(15) + "Completion".ljust(15) + "Creation Date".ljust(30) + "Completion Date"
    @tasks.each_with_index do |task, index|
      if task.priority_level == 1
        puts "#{(index + 1).to_s.ljust(5)} #{task.description.ljust(25)} #{task.priority_level.to_s.ljust(5)} #{task.tags.join(",").ljust(20)} #{task.completed.to_s.ljust(10)} #{task.creation_date.to_s.ljust(20)} #{task.completion_date.to_s.ljust(15)}".on_red
      elsif task.priority_level == 2
        puts "#{(index + 1).to_s.ljust(5)} #{task.description.ljust(25)} #{task.priority_level.to_s.ljust(5)} #{task.tags.join(",").ljust(20)} #{task.completed.to_s.ljust(10)} #{task.creation_date.to_s.ljust(20)} #{task.completion_date.to_s.ljust(15)}".on_yellow
      else
        puts "#{(index + 1).to_s.ljust(5)} #{task.description.ljust(25)} #{task.priority_level.to_s.ljust(5)} #{task.tags.join(",").ljust(20)} #{task.completed.to_s.ljust(10)} #{task.creation_date.to_s.ljust(20)} #{task.completion_date.to_s.ljust(15)}".on_green
      end
    end
  end

  def priority_sorted_list
    @tasks.sort! {|a, b| a.priority_level <=> b.priority_level}
    show_list
    dumped_list
  end

  def priority_only(level)
    @tasks.keep_if {|t| t.priority_level == level}
    puts "here are the priority level tasks only: #{@tasks}"
    show_list
  end

  def completed_by_date
    @tasks.keep_if {|t| t.completed == true }
    @tasks.sort! {|a,b| a.completion_date <=> b.completion_date }
    show_list
  end

  def outstanding_by_date
    @tasks.keep_if {|t| t.completed == false }
    @tasks.sort! {|a,b| a.creation_date <=> b.creation_date }
    show_list
  end

  def filter_by_tag(tag)
    @tasks.keep_if {|t| t.tags.include?(tag) }
    show_list
  end

  def add_task(description, position = -1)
    @tasks.insert(position, Task.new(description))
    dumped_list
  end

  def delete_task(position)
    @tasks.delete_at(position)
    dumped_list
  end

  def complete_task(position)
    @tasks[position].complete!
    dumped_list
  end

  def add_tags(position, new_tags)
    old_tags = @tasks[position].tags
    if old_tags = []
      updated_tags = new_tags
    else
      old_tags.keep_if do |tag|
        new_tags.include?(tag) == false
        new_tags << tag
        updated_tags = new_tags
      end
    end
    @tasks[position].update_tags(updated_tags)
    dumped_list
  end

  def change_priority(position, new_level)
    @tasks[position].change_priority(new_level)
    dumped_list
  end

end
#####################################################################################################################
#####################################################################################################################
class Task
  attr_accessor :description, :completed, :completion_date, :priority_level, :tags
  attr_reader :creation_date
  def initialize(description)
    @description, @completed, @creation_date, @completion_date, @tags, @priority_level =
    description, false, Time.now, "", [], 3
  end

  def complete!
    @completed = true
    @completion_date = Time.now
  end

  def update_tags(updated_tags)
    @tags = updated_tags
  end

  def change_priority(new_level)
    @priority_level = new_level.to_i
  end

end
#####################################################################################################################
#####################################################################################################################
todo_list = List.new
#####################################################################################################################
#####################################################################################################################
case ARGV[0]
when "list"
  if ARGV[1] == nil
    todo_list.show_list
  elsif ARGV[1] == "prioritized"
    todo_list.priority_sorted_list
  elsif ARGV[1] == "priority"
    todo_list.priority_only(ARGV[2].to_i)
  elsif ARGV[1] == "completed"
    todo_list.completed_by_date
  elsif ARGV[1] == "outstanding"
    todo_list.outstanding_by_date
  elsif ARGV[1] == "tag"
    todo_list.filter_by_tag(ARGV[2])
  end
when "add"
  ####adding tasks
  if ARGV[1] == "first"
    position = 0
    ARGV.shift(2)
  elsif ARGV[1] == "last"
    position = -1
    ARGV.shift(2)
  else
    position = -1
    ARGV.shift(1)
  end
  content = ARGV.join(' ')
  todo_list.add_task(content, position)
  ####adding tags
when "tagging"
  item_pos = ARGV[1].to_i
  ARGV.shift(2)
  new_tags = ARGV
  todo_list.add_tags(item_pos - 1, new_tags)
when "delete"
  item_pos = ARGV[1].to_i
  todo_list.delete_task(item_pos - 1)
when "complete"
  item_pos = ARGV[1].to_i
  todo_list.complete_task(item_pos - 1)
when /\d/
  item_pos = ARGV[0].to_i
  if ARGV[1] == "prioritize"
    todo_list.change_priority(item_pos - 1, ARGV[2])
  end
end