todo

#!/bin/bash -e

todo_flag=' '
done_flag='+'
todo_color='91'
done_color='92'
today_highlight_color='33'
todo_file_fmt='%Y-%m-%d'
todo_item_time_fmt='%H:%M'
list_file_delimiter="\\n"
todo_folder="${HOME}/.todo"
todo_file="${todo_folder}/$(date +${todo_file_fmt}).txt"

command_name="$1"
date_params=""
if [ -n "$command_name" ]; then
    shift 1
fi
while getopts ":d:" opt; do
    case $opt in
	d )
	    date_params=$(date -d "$OPTARG" +${todo_file_fmt})
	    if [ -n "$date_params" ]; then
		todo_file=""${todo_folder}/${date_params}.txt""
	    fi
	    ;;
    esac
done
shift $(($OPTIND - 1))
command_params="${@#$0}"

usage () {
    cat <<EOF | xargs -I{} echo -e {}
Usage: $0 [ COMMAND ] [ OPTIONS ] [ PARAMETERS ]
COMMANDS:
\\\\t \\\e[2mcommand      parameters\\\e[0m
\\\\t \\\e[1madd    | a\\\e[0m   \\\e[4mCONTENT\\\e[0m       add CONTENT to todo file.
\\\\t \\\e[1mlist   | ls\\\e[0m  [ \\\e[4mFILE\\\e[0m ]      show FILE\'s todo items, defaul is today\'s todo file.
\\\\t \\\e[1mremove | rm\\\e[0m  [ \\\e[4mN\\\e[0m ] ...     remove todo item of line N, default is all lines.
\\\\t \\\e[1mmark   | m\\\e[0m   [ \\\e[4mN\\\e[0m ] ...     mark todo item of line N as completed, default is all lines.
\\\\t \\\e[1munmark | um\\\e[0m  [ \\\e[4mN\\\e[0m ] ...     mark todo itemof line N as uncompleted. default is all lines.
\\\\t \\\e[1mls-file| sf\\\e[0m  [ \\\e[4mN\\\e[0m ]         show latest N todo files.

OPTIONS:
\\\\t -d  \\\e[4m DATE \\\e[0m  which day to be operated, default is today.
DESCRIPTION:
\\\\t \\\e[4mDATE\\\e[0m        DATE is like '"'today'"' '"'tomorrow'"' '"'last 2 days'"' '"'2017-11-11'"' etc,
\\\\t """"""     """"""""       which can be recognized be GNU date program.
\\\\t \\\e[4mN\\\e[0m           N is a positive number.
\\\\t \\\e[4mFILE\\\e[0m        FILE is a filename of todo list files, just name with suffix without path name.
EXAMPLES:
\\\\t todo add 'go shopping'
\\\\t todo add -d 'tomorrow' 'fix bugs'
\\\\t todo ls
\\\\t todo ls -d 'last 2 days'
\\\\t todo rm 2
\\\\t todo m -d 'last day' 2, 3
\\\\t todo um -d '2017-11-11' 1
EOF
}

echo_today_highlight () {
    if [ -n "$today_highlight_color" ]; then
	echo -en "\e[${today_highlight_color}m${@}\e[0m"
    else
	echo -en "$@"
    fi
}

get_todo_folder () {
    if ! [ -d "$todo_folder" ]; then
	mkdir -p "$todo_folder"
    fi
}

get_todo_file () {
    get_todo_folder
    if ! [ -f "$todo_file" ]; then
	touch "$todo_file"
    fi
}

get_line_number () {
    echo "$command_params" |sed -rn '/^( *[1-9]+)((,? *| +)[1-9]+)* *$/p' |sed 's/,/ /g'
}

trunc_array () {
    local array=($1)
    local newArr=()
    for (( i=0; i<$2; i++)); do
	newArr[${i}]=${array[${i}]}
    done
    echo -n "${newArr[*]}"
}

ls_file () {
    local show_amount=$(echo $command_params |sed -rn '/^ *[0-9]+ *$/p')||0
    if [ -z "$show_amount" ]; then show_amount=0; fi
    if [ -d "$todo_folder" ]; then
	local file_list=($(ls -Cr $todo_folder))
	if [ $show_amount -gt 0 ]; then
	    file_list=($(trunc_array "${file_list[*]}" $show_amount))
	fi
	local filename
        for filename in "${file_list[@]}"; do
	    if [ "${filename%.txt}" = "$(date +${todo_file_fmt})" ]; then
		echo_today_highlight "$filename${list_file_delimiter}"
	    else
		echo -en "$filename${list_file_delimiter}"
	    fi
	done
	if [ $(echo -e "$list_file_delimiter" |awk "END { print NR }") -eq 1 ]; then
	    echo
	fi
    fi
}

print_item () {
    cat <<<"$@" |
    awk -f <(cat <<EOF
BEGAIN { done_count = 0; todo_count = 0 }
{
  is_item_done = (\$0 ~ /^${done_flag}/)
  line_color = is_item_done ? "$done_color" : "$todo_color"

  if (is_item_done) done_count += 1
  else todo_count += 1

  color_str = line_color ? "\\033[" line_color "m" : ""
  printf("%s%s  %s %s \n", color_str, NR, \$0, "\\033[0m")
}
END {
  format = ":todo %d   :done %d"
  printf(format, todo_count, done_count)
}
EOF
	    ) |
    xargs -I{} echo -e {}
}

ls_item () {
    local is_other_ls=$(( $1 + 0))
    local target_file="$todo_file"
    if [ -n "$command_params" ]; then
	local specific_file="${todo_folder}/$command_params"
	if [ -f "$specific_file" ]; then
	    target_file="$specific_file"
	elif [ -f "${specific_file}.txt" ]; then
	    echo -ne "Did you mean '${command_params}.txt'? [Y, N]: ";
	    local choice
	    read choice
	    case "$choice" in
		y | Y | yes | YES | Yes )
		    target_file="${specific_file}.txt"
		    ;;
		* )
		    exit 0
		    ;;
	    esac
	elif [ $is_other_ls -eq 0 ]; then
	    echo "File \"$command_params\" doesn't exist."
	    exit 0
	fi
    fi
    if [ -f "$target_file" ]; then
	if [ -z "$(cat $target_file)" ]; then
	    exit 0
	fi
	print_item "$(cat $target_file)"
    fi
}

add_item () {
    get_todo_file
    local content="$todo_flag $command_params"
    if [ -n "$command_params" ]; then
	if [ -z "$(cat $todo_file)" ]; then
	    echo -e "$content" > "$todo_file"
	else
	    echo -e "$content" >> "$todo_file"
	fi
    else
	usage
    fi
}

op_item () {
    get_todo_file
    local line_number_array=$(get_line_number)
    if [ -z "$command_params" ]; then
	line_number_array=()
    else
	if [ -z "${line_number_array[*]}" ]; then
	    usage
	fi
    fi
    local content
    local sed_line_numbers=$(echo ${line_number_array[*]} |sed -r 's/ +/,/g')
    case "$1" in
	mark )
	    content=$(sed -r "${sed_line_numbers}s/^${todo_flag}/${done_flag}/" $todo_file)
	    ;;
	remove )
	    content=$(sed "${sed_line_numbers}d" $todo_file)
	    ;;
	unmark )
	    content=$(sed -r "${sed_line_numbers}s/^\\${done_flag}/${todo_flag}/" $todo_file)
	    ;;
	* )
	    usage
    esac
    if [ -z "${line_number_array[*]}" ]; then
	ls_item
	echo -ne "Are you really want to $1 all todo items ? [Y, N]: "
	local choice_action
	read choice_action
	case "$choice_action" in
	    Y | y | Yes | YES | yes )
		echo -e "$content" > "$todo_file"
		;;
	    N | n | No | NO | * )
		exit 0
		;;
	esac
    else
	echo -e "$content" > "$todo_file"
    fi
    ls_item 1
}

if [ -z "$command_name" ]; then
    ls_item
    exit 0
fi

case "$command_name" in
    a | add )
	add_item
	;;
    ls | list)
	ls_item
	;;
    rm | remove)
	op_item remove
	;;
    m | mark )
	op_item mark
	;;
    um | unmark )
	op_item unmark
	;;
    lf | ls-file )
	ls_file
	;;
    sf | show-folder )
	echo "$todo_folder"
	;;
    lt | ls-todo )
	ls_todo
	;;
    * )
	usage
	;;
esac