#!/usr/bin/env bash
set -o errexit

#
# n! (nexclamation or nfactorial) -- command line note taking.
# Homepage: <http://nixhacks.net/nexclamation>
#
# COPYING
#
# MIT License
#
# Copyright (c) 2021-2022 ge <http://nixhacks.net/nexclamation>
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

n_version=0.0.11  # Current n! version.

# Defaults.
# All of them can be overrided in $n_config.

# Main config.
n_last_opened=$HOME/.local/share/nexclamation/last_opened

# Path ot save notes.
NPATH="${NPATH:-$HOME/.local/share/nexclamation/notes}"

# Editor.
# User's default editor. Set this value for override.
NEDITOR="${NEDITOR:-$EDITOR}"
# Quick note filename.
NQNOTENAME="${NQNOTENAME:-NOTE}"

# Color scheme.
R="\e[31m"  # red
B="\e[34m"  # blue
N="\e[0m"   # no color
b="\e[1m"   # bold font

n_version() {
cat << EOF
n! (nexclamation or 'n factorial') $n_version
Copyright (C) 2021-2022 ge <http://nixhacks.net/nexclamation>
License MIT: <https://opensource.org/licenses/MIT>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
EOF
exit 0
}

n_help() {
cat << EOF
Command line note taking.

Usage: n! [-v|--version] [-h|--help] [<command>] [<args>...]

Commands and options:
    q, quick [<name>]       take a quick note in current directory.
    s, search <query>       search in notes via grep.
    l, last                 open last opened file in editor.
    mkdir <dir>             add new directory. Creates new dir in NPATH.
    ls [<dir>]              list all notes, or notes from <dir> in NPATH.
    lsd                     list dirs in NPATH (empty dirs too).
    rm [-f|--force] <file>  remove notes or directories.
    i, info [<file>]        print info about notes and configuration.
    -h, --help              print this help message and exit.
    -v, --version           print version and exit.

Examples:

Take a new note or open existing note:
    n! [<note>]
Take new note in 'work' directory:
    n! work/my_note

Environment:

n! uses user's default editor. You can specify editor in EDITOR environment
variable in your .bashrc or .bash_profile, or select default editor by 'select-editor'
command.

Also you can set specific editor for nexclamation in ~/.nexclamation file. For example:
    NEDITOR=/usr/bin/vim.tiny

Other configuration options:
    NPATH           path to save notes. Default: $HOME/.local/share/nexclamation/notes
    NQNOTENAME      default file name for quick notes. Default: NOTE
EOF
exit 0
}

n_err() {
    echo -e "$1" >&2
    echo -e "See 'n! --help' or 'nexclamation --help' for info." >&2
    exit 1
}

# ------------------------------------------------------------------------- #
#   App init                                                                #
# ------------------------------------------------------------------------- #

n_initialise() {
    # Make $NPATH if not exists.
    if [ ! -d "$NPATH" ]; then
        mkdir -p "$NPATH" 2>/dev/null
    fi

    # Set editor.
    n_set_editor
}

n_set_editor() {

    get_selected_editor() {
        # shellcheck source=/dev/null
        source "$HOME/.selected_editor"
        echo "$SELECTED_EDITOR"
    }

    # Detect default editor.
    # Do nothing if editor is set in $n_config
    if [ -z "$EDITOR" ]; then
        NEDITOR="$(get_selected_editor)"
    elif [ -f /usr/bin/select-editor ]; then
        select-editor
        NEDITOR="$(get_selected_editor)"
    else
        NEDITOR=/usr/bin/vi
    fi
}

# ------------------------------------------------------------------------- #
#   Functions                                                               #
# ------------------------------------------------------------------------- #

n_take_note() {
    # Take a note.
    #
    # Arguments:
    #   $@ -- file names
    # Examples of $1:
    #   my_note.txt
    #   some_dir/my_note.txt

    if [[ -n "$*" ]]; then
        for file in "$@"; do
            if [[ "$file" =~ .+/.+ ]]; then
            # if filename contains path
                if [ -d "$NPATH/${file%/*}" ]; then
                    files+=("$NPATH/$file")
                else
                    echo -n "${0##*/}: $NPATH/${file%/*}" >&2
                    echo ": destination does not exist" >&2
                    echo "Run 'n! mkdir <dir>' to create new directory." >&2
                    exit 1
                fi
            else
                files+=("$NPATH/$file")
            fi
        done
        "$NEDITOR" "${files[@]}"
    else
        cd "$NPATH" || { echo "${0##*/}: Cannot cd into $NPATH"; exit 1; }
        "$NEDITOR"
        cd - >/dev/null || { echo "${0##*/}: Cannot cd into $OLDPWD"; exit 1; }
    fi
}

n_quick_note() {
    # Take note in current working directory.
    #
    # Default $NQNOTENAME can be set in ~/.nexclamation file.

    if [[ -n "$*" ]]; then
        local temp="$*"
        NQNOTENAME="${temp%% *}"
    fi

    echo "${PWD}/${NQNOTENAME}" > "$n_last_opened"
    "$NEDITOR" "$NQNOTENAME"
    exit 0  # Prevent new note taking
}

n_last() {
    # Open last opened file.
    #
    # Filename is saved in service file $n_last_opened

    if [ -f "$n_last_opened" ]; then
        local file
        file="$(cat "$n_last_opened")"
    else
        echo "${0##*/}: No opened files yet" >&2; exit 1
    fi

    if [ -f "$file" ]; then
        "$NEDITOR" "$file"; exit 0
    else
        echo "${0##*/}: $file: No such file" >&2; exit 1
    fi
}

n_search() {
    # Search in notes.
    #
    # $1 is search query.

    while (( "$#" )); do
        case "$1" in
            -h|--help) n_help;;
            -v|--version) n_version;;
            -*) n_err "${0##*/}: $1: Unknown option";;
            *) local q="$1"; shift;;
        esac
    done

    cd "$NPATH" || { echo "${0##*/}: Cannot cd into $NPATH"; exit 1; }
    grep --recursive --ignore-case --line-number --color=auto "$q"
    cd - >/dev/null || { echo "${0##*/}: Cannot cd into $OLDPWD"; exit 1; }
}

n_mkdir() {
    # Create new directory in $NPATH
    #
    #   $1 -- dirname

    while (( "$#" )); do
        case "$1" in
            -h|--help) n_help;;
            -v|--version) n_version;;
            -*) n_err "${0##*/}: $1: Unknown option";;
            *) local dir="$1"; shift;;
        esac
    done

    mkdir -p "${NPATH}/${dir}" 2>/dev/null
    echo -e "${b}Created:${N} ${NPATH}/${B}${b}${dir}/${N}"
    exit 0
}

n_list() {
    # List files from dir or dirs.

    while (( "$#" )); do
        case "$1" in
            -d|--dirs) list_dirs=1; shift;;
            -h|--help) n_help;;
            -v|--version) n_version;;
            -*) n_err "${0##*/}: $1: Unknown option";;
            *) local dir="$1"; shift;;
        esac
    done

    if [ ${#dir[@]} -gt 1 ]; then
        echo -e "${0##*/}: too many arguments" >&2; exit 1
    fi

    if [ ! -d "${NPATH}/${dir}" ]; then
        echo -e \
        "${0##*/}: ${NPATH}/${dir}: No such directory" >&2
        exit 1
    fi

    if [ -n "$list_dirs" ]; then  # list only dirs (append / for coloring)
        list="$(find "$NPATH" -type d -exec echo {}/ \;)"
    elif [ "$dir" ]; then      # list files from specific directory
        list="$(find "${NPATH}/${dir}" -type f)"
    else                       # list all of files and dirs
        list="$(find "$NPATH" -type f)"
    fi

    # Print output.
    for path in $(echo "$list" | sed -E "s%${NPATH}/?%%g;/^$/d"); do
        # Add color for dirs (blue) with brainfucking parameter expansion
        local temp
        temp="${path//\//\\/}" # Escape slashes
        # shellcheck disable=SC2059
        echo "${path}" | sed "/${temp%\\*}\//s//$(printf "${B}${b}${temp%/*}\/${N}")/"
    done | sort
    exit 0
}

n_remove() {
    # Remove files or directories.

    while (( "$#" )); do
        case "$1" in
            -f|--force) forced=1; shift;;
            -h|--help) n_help;;
            -v|--version) n_version;;
            -*) n_err "${0##*/}: $1: Unknown option";;
            *) local files+=("$1"); shift;;
        esac
    done

    if [ ${#files[@]} -eq 0 ]; then
        echo -e "${0##*/}: Nothing to remove" >&2; exit 1
    fi

    if [ ! "$forced" ]; then
        echo -e "These files will be removed: ${R}${files[*]}${N}" | fmt -t

        while [ -z "$answer" ]; do
            echo -en "Remove files permanently? (y/n) "
            read -r reply
            case "${reply,,}" in
                y|yes) answer=1;;
                n|no)   echo "Abort"; exit 1;;
                *) echo 'Please, answer y or n';;
            esac
        done
    fi

    for file in "${files[@]}"; do
        file="${NPATH}/${file}"
        if [ -d "$file" ]; then
            rm -rf "$file"
            echo -e "${b}Removed:${N} $file"
        elif [ -f "$file" ]; then
            rm -f "$file"
            echo -e "${b}Removed:${N} $file"
        else
            echo "${0##*/}: $file: No such file or directory" >&2; exit 1
        fi
    done
    exit 0
}

n_info() {
    # Show information about notes and configuration.

    while (( "$#" )); do
        case "$1" in
            -h|--help) n_help;;
            -v|--version) n_version;;
            -*) n_err "${0##*/}: $1: Unknown option";;
            *) local file="$1"; shift;;
        esac
    done

    if [ -n "$file" ]; then
        file="$NPATH/$file"
        if [ ! -f "$file" ]; then
            echo "${0##*/}: $file: No such file" >&2; exit 1
        fi
        {
            echo -e "${b}Lines:${N}|$(wc -l "$file" |
                tail -n 1 | awk '{print $1}')"
            echo -e "${b}Words:${N}|$(wc -w "$file" |
                tail -n 1 | awk '{print $1}')"
            echo -e "${b}Size:${N}|$(du -hs "$file" | cut -f 1)"
        } | column -t -s '|'
        exit 0
    fi

    local all_files
    local all_dirs
    all_files="$(find "$NPATH" -type f)"
    all_dirs="$(find "$NPATH" -type d)"
    {
        echo -e "${b}Editor:${N}|${NEDITOR}"
        echo -e "${b}Quick notes:${N}|${NQNOTENAME}"
        echo -e "${b}Notes save path:${N}|${NPATH}"
        echo -e "${b}Dirs:${N}|$(<<< "$all_dirs" wc -l)"
        echo -e "${b}Files:${N}|$(<<< "$all_files" wc -l)"
        # shellcheck disable=SC2001
        echo -e "${b}Total lines:${N}|$(<<< "$all_files" sed 's/.*/"&"/' |
            xargs  wc -l | tail -n 1 | awk '{print $1}')"
        # shellcheck disable=SC2001
        echo -e "${b}Total words:${N}|$(<<< "$all_files" sed 's/.*/"&"/' |
            xargs  wc -w | tail -n 1 | awk '{print $1}')"
        echo -e "${b}Total size:${N}|$(du -hs "$NPATH" | cut -f 1)"
        echo -e "${b}Last opened:${N}|$([ -f "$n_last_opened" ] && \
            cat "$n_last_opened" || echo 'no opened files yet')"
    } | column -t -s '|'
    exit 0
}

# ------------------------------------------------------------------------- #
#   n!                                                                      #
# ------------------------------------------------------------------------- #

n_checkopt() {
    if [ "$2" ]; then
        return 0
    else
        n_err "${0##*/}: Missing argument for $1"
    fi
}

n_initialise

while (( "$#" )); do
    case "$1" in
        q|quick)    shift; n_quick_note "$@"; shift "$#";;
        l|last)     n_last;;
        s|search)   n_checkopt "$1" "$2"; n_search "$2"; exit 0;;
        mkdir)      n_checkopt "$1" "$2"; n_mkdir "$2"; exit 0;;
        ls)         shift; n_list "$@"; shift "$#";;
        lsd)        shift; n_list -d; shift "$#";;
        rm)         shift; n_remove "$@"; shift "$#";;
        i|info)     shift; n_info "$@"; shift "$#";;
        -v|--version)   n_version;;
        -h|--help)      n_help;;
        -*) n_err "${0##*/}: $1: Unknown option";;
        *)  pos_args+=("$1"); shift;;
    esac
done

if [ "${#pos_args[@]}" -gt 0 ]; then
    echo "${NPATH}/${pos_args[-1]}" > "$n_last_opened"
fi

n_take_note "${pos_args[@]}"