#!/bin/bash
#shellcheck disable=SC2155,SC2207
set -eo pipefail

NOTES_DIR="$HOME/notes"
EDITOR="${EDITOR:-nano}"
mkdir -p "$NOTES_DIR"

show_usage() {
    cat <<EOF
Usage: $(basename "$0") <command> [options]

Commands:
    add         Create a new note
    edit        Open a note in editor
    rm          Remove a note
    list        List all notes

Options for 'add':
    -n, --name <name>    Custom note name (default: <unixtime>-untitled-note.md)
    -t, --title <title>  Custom note title (default: "Untitled note")
    --no-time            Don't add creation timestamp
    --no-edit            Don't open editor

Options for 'edit':
    <name>               Note filename to edit

Options for 'rm':
    <name>               Note filename to remove

Options for 'list':
    (none)

EOF
}

cmd_add() {
    local name="untitled-note"
    local title="Untitled note"
    local add_time=true
    local new_edit=true

    while [[ $# -gt 0 ]]; do
        case "$1" in
            -n|--name) name="$2"; shift 2 ;;
            -t|--title) title="$2"; shift 2 ;;
            --no-time) add_time=false; shift ;;
            --no-edit) new_edit=false; shift ;;
            *)
                echo "Unknown option: $1"
                show_usage
                exit 1
                ;;
        esac
    done

    local filename="$(date +%s)-${name}.md"
    local filepath="$NOTES_DIR/$filename"

    {
        echo "# $title"
        echo
        if [[ "$add_time" == true ]]; then
            echo
            echo "Created at $(date '+%Y-%m-%d %H:%M:%S')"
            echo
        fi
        echo "---"
        echo
    } > "$filepath"

    echo "Created note: $filepath"

    if [[ "$new_edit" == true ]]; then
        $EDITOR "$filepath"
    fi
}

cmd_edit() {
    if [[ $# -lt 1 ]]; then
        echo "Error: Note name required"
        show_usage
        exit 1
    fi

    local filename="$1"
    local filepath="$NOTES_DIR/$filename"

    if [[ ! -f "$filepath" ]]; then
        echo "Error: Note not found: $filename"
        exit 1
    fi

    $EDITOR "$filepath"
}

cmd_rm() {
    if [[ $# -lt 1 ]]; then
        echo "Error: Note name required"
        show_usage
        exit 1
    fi

    local filename="$1"
    local filepath="$NOTES_DIR/$filename"

    if [[ ! -f "$filepath" ]]; then
        echo "Error: Note not found: $filename"
        exit 1
    fi

    rm -v "$filepath"
}

cmd_list() {
    local count=0
    printf "%-40s %s\n" "Filename" "Title"
    printf "%-40s %s\n" "--------" "-----"

    # Use nullglob to handle empty directory case
    local shopt_save
    shopt_save=$(shopt -p nullglob)
    shopt -s nullglob

    local files=("$NOTES_DIR"/*.md)

    # Restore original nullglob setting
    eval "$shopt_save"

    for file in "${files[@]}"; do
        if [[ -f "$file" ]]; then
            local filename=$(basename "$file")
            local title=$(sed -n 's/^# \([^#].*\)/\1/p' "$file" | head -n1)

            if [[ -z "$title" ]]; then
                title="Untitled note"
            fi

            printf "%-40s # %s\n" "$filename" "$title"
            ((count++))
        fi
    done

    if [[ $count -eq 0 ]]; then
        echo "No notes found"
    else
        echo ""
        echo "Total: $count note(s)"
    fi
}

if [[ $# -lt 1 ]]; then
    cmd_list "$@"
    exit 0
fi

command="$1"
shift

case "$command" in
    add) cmd_add "$@"          ;;
    edit) cmd_edit "$@"        ;;
    rm) cmd_rm "$@"            ;;
    list) cmd_list "$@"        ;;
    -h|--help|help) show_usage ;;
    *)
        echo "Unknown command: $command"
        show_usage
        exit 1
        ;;
esac