A command line app to manage a todo list in a local file... work in progress

todo_app.rb

require "docopt"


##################################################
# Task object
##################################################
class Task
  attr_accessor :description, :creation_time, :completion_time, :completed

  def initialize(description)
    @description = description
    @creation_time = Time.new.to_s
    @completion_time = ""
    @completed = "not completed"
  end

  def in_words
    delim = "\t|\t"
    @description + delim + @creation_time.to_s + delim + @completion_time + delim + @completed + "\n"
  end

  def complete
    @completion_time = Time.new.to_s
    @completed = "completed!"
  end
end

##################################################
# Todo list
##################################################

class Todos
  def initialize
    @filename="todo_list.txt"
    task_list = File.readlines(@filename)
    @tasks = []
    if task_list[0].split("\t|\t").length >= 4 #We need a good way to keep track of columns from tasks
      task_list.each do |line|
        columns = line.split("\t|\t") # We need a good way to keep track of delimiters from tasks
        task = Task.new("")
        task.description = columns[0]
        task.creation_time = columns[1]
        task.completion_time = columns[2]
        task.completed = columns[3].delete "\n"
        @tasks << task
      end
    end
  end

  def add(description, where_to)
    task = Task.new(description)

    if where_to == "end"
      write_to_file(@tasks.insert(-1,task))
    else
      write_to_file(@tasks.insert(0,task))
    end
  end

  def list(order_by)
    if order_by == "completion time"
      puts @tasks.sort_by!{ |task| task.completion_time }.reverse!
      @tasks.each { |task| puts task.in_words }
    else
      @tasks.sort_by!{ |task| task.creation_time }.reverse!
      @tasks.each { |task| puts task.in_words }
    end
  end

  def delete(line_number)
    @tasks.delete_at(line_number.to_i - 1)
    write_to_file(@tasks)
  end

  def complete(line_number)
    @tasks[line_number.to_i - 1].complete
    write_to_file(@tasks)
  end

  # Should this be private?  It's kind of dangerous.
  def write_to_file(task_objects_array)
    words = []
    task_objects_array.each do |line|
      words << line.in_words
    end
    File.open(@filename, "w").puts(words)
  end
end

##################################################
# We initialize the task list each time we run todo_app.rb
##################################################

todos = Todos.new

##################################################
# This takes care of our command line parsing.
##################################################
doc = "Usage: ruby todo_app.rb [option] <arguments>...

       Options:
        -a   TASK       Adds a task to the end of your todo list.
        --ab TASK       Adds a task to the beginning of your list.
        -l              Print a list of your todo tasks ordered by creation date.
        --lc            Print a list of your todo tasks ordered by completion date.
        -d   TASK_NUM   Delete a task item from your todo list according to line number.
        -c   TASK_NUM   Complete a task item in your todo list according to line number.
        -h              Prints the help documentation.
        -v              Prints the app version.
      "

if __FILE__ == $0
  command = ARGV[0]
  command_arg = ARGV[1]
  options = Docopt(doc, '0.0.1', true)

  case command
    when '-a'  then todos.add(command_arg, "end")
    when '--ab' then todos.add(command_arg, "beginning")
    when '-l'  then todos.list("creation time")
    when '--lc' then todos.list("completion time")
    when '-d'  then todos.delete(command_arg)
    when '-c'  then todos.complete(command_arg)
    else
      puts "Sorry, I don't know how to (#{command}).  Try typing -h to get some help."
  end
end