class Todo
	def initialize(*argv)
		@argv = argv

		begin
			send(@argv[0])
		rescue TypeError
			list
		rescue NoMethodError
			puts "Command #{@argv[0]} not found.\n\n"
			help
		end
	end

	# Lists help information
	def help
		puts <<-help
Commands for Todo.rb:
   add [task name] - Add a new task
   list - Lists all tasks
   done [task id] - Complete a task
   help - Prints out this information
help
	end

	# Add task
	def add
		unless @argv[1]
			puts "Lacking argument [name]"
			exit
		end

		# Append task to file
		contents = File.read('todo.td')

		File.open('todo.td', 'w') do |f|
			todo = contents + @argv[1] + "\n"
			f.write(todo)
		end
	end

	# List all tasks
	def list
		# Read content
		contents = File.read('todo.td')
		puts "No tasks" unless contents

		# Show it with ids
		i = 0
		contents.each_line do |todo|
			i += 1
			puts "##{i} - #{todo}"
		end
	end

	# Finished a task
	def done
		unless @argv[1]
			puts "Lacking argument [id]"
			exit
		end

		# Put tasks into an array
		todos = File.read('todo.td').split("\n")

		unless todos
			puts "No tasks"
			exit
		end

		puts "Completed task: " + todos[@argv[1].to_i - 1]

		# Delete task from array and make string
		todos.delete_at(@argv[1].to_i - 1)
		content = todos.join("\n")

		# Update file
		File.open('todo.td', 'w') do |f|
			f.write(content)
		end
	end
end

todo = Todo.new(*ARGV)