todo.sh

#!/bin/bash

if ! type peco > /dev/null 2>&1; then
  echo 'peco not found'
  exit 1;
fi

COMMAND=$1
[ -v $COMMAND ]  && COMMAND="edit"
[ -v $TODO_DIR ] && TODO_DIR="$HOME/.todo"

set -eu

# init
if [ ! -d $TODO_DIR ]; then
  mkdir $TODO_DIR
fi

# functions
_generate_path () {
  echo "$TODO_DIR/$1.md"
}

_copy_from_latest_file () {
  dst=$1
  src=$(_generate_path $(ls $TODO_DIR | sed 's/.md//' | tail -n1))
  cp $src $dst
}

_todo_edit () {
  file_path=$(_generate_path $(date +%F))

  if [ ! -f $file_path ]; then
    echo 'Copy from the latest file?' 
    echo -n '[y/n] ' && read yn

    if [ "$yn" = "y" ]; then
      _copy_from_latest_file $file_path
    else
      touch $file_path
    fi
  fi

  $EDITOR $file_path
}

_todo_history () {
  file_name=$(ls $TODO_DIR | tac | sed 's/.md//' | peco)
  $EDITOR $(_generate_path $file_name)
}

_todo_help () {
  echo 'Help'
  exit
}

# commands
case $COMMAND in
  edit)       _todo_edit ;;
  history)    _todo_history ;;
  *)          _todo_help ;;
esac