#!/usr/bin/bash
# video demo at: http://www.youtube.com/watch?v=90xoathBYfk

# augmented by barbuk: https://github.com/BarbUk/dotfiles/blob/master/bin/snippy
#  . restore current clipboard
#  . {clipboard} placeholder to use current clipboard in snippet
#  . {cursor} placeholder to place the cursor
#    . go left to the correct position for cli and gui paste
#    . go up for block snippet for gui paste
#  . ##noparse header in snippet to not parse
#  . ##tmpfile header in snippet to replace $tmpfile by the temp filename used in the script
#  . ##richsnippet header in snippet to use paste buffer in rich mode (To copy html content in gui)
#  . execute command begining by $
#  . execute bash script in $snippets_directory/scripts
#
# augmented by "opennomad": https://gist.github.com/opennomad/15c4d624dce99066a82d
# originally written by "mhwombat": https://bbs.archlinux.org/viewtopic.php?id=71938&p=2
# Based on "snippy" by "sessy"
# (https://bbs.archlinux.org/viewtopic.php?id=71938)
#
# You will also need "dmenu", "zenity", "xsel", "sponge" and "xdotool". Get them from your linux
# distro in the usual way.
#
# To use:
# 1. Create the directory ~/.snippy
#
# 2. Create a file in that directory for each snippet that you want.
#    The filename will be used as a menu item, so you might want to
#    omit the file extension when you name the file.
#
#    TIP: If you have a lot of snippets, you can organise them into
#    subdirectories under ~/.snippy.
#
#    TIP: The contents of the file will be pasted asis, so if you
#    don't want a newline at the end when the text is pasted, don't
#    put one in the file.
#
# 3. Bind a convenient key combination to this script.
#
#    TIP: If you're using XMonad, add something like this to xmonad.hs
#      ((mod4Mask, xK_s), spawn "/path/to/snippy")
#

readonly snippets_directory=${HOME}/.snippy
readonly MENU_ENGINE="rofi"
readonly DMENU_ARGS='-dmenu -i -sort'

# if nothing happens, try "xdotool click 2", "xdotool key ctrl+v" or "xdotool key ctrl+shift+v"
readonly GUIPASTE="xdotool key ctrl+v"
readonly CLIPASTE="xdotool key ctrl+shift+v"

readonly MENU_ARGS=${DMENU_ARGS}
readonly cursor_placeholder="{cursor}"
readonly clipboard_placeholder="{clipboard}"

readonly tmpfile=$(mktemp)
trap 'rm -f $tmpfile' EXIT HUP INT TRAP TERM

# smarty like template engine which executes inline bash in (bashdown) strings (replaces variables with values e.g.)
# @link http://github.com/coderofsalvation/bashdown
# @dependancies: sed cat
# @example: echo 'hi $NAME it is $(date)' | bashdown
# fetches a document and interprets bashsyntax in string (bashdown) templates
# @param string - string with bash(down) syntax (usually surrounded by ' quotes instead of ")
bashdown() {
    while IFS= read -r line; do
        line="$(eval "printf -- \"$( printf "%s" "$line" | sed 's/"/\\"/g' )\"")";
        echo -e "$line"
    done
}

# Simplified version of bashdown, use echo and bash var search and replace
# Better handling of symbol char
bashdown_simple() {
  while IFS= read -r line; do
    line="$(eval "echo \"${line//\"/\\\"}\"")"
    echo "$line"
  done
}

# Detect if focused app is a terminal or a gui
is_gui() {
    name="$(xprop -id "$(xdotool getwindowfocus)" WM_CLASS | cut -d'"' -f2 | tr '[:upper:]' '[:lower:]')"
    [[ "$name" =~ term|tilda|kitty|alacritty ]] && return 1
    return 0
}

# Find the index of a string in a string
strindex() {
    x="${1%%$2*}"
    [[ "$x" = "$1" ]] && echo -1 || echo "${#x}"
}

is_rich_snippet() {
    file="$1"
    grep -q "##richsnippet" "$file"
}

# Move the cursor up or left
move_cursor() {
    local key=$1
    local count=$2
    local keys="End "
    if [[ $count -gt 0 ]]; then
        until [  "$count" -eq 0 ]; do
            keys+="${key} "
            ((count-=1))
        done
        # shellcheck disable=SC2086
        xdotool key --delay 0.1 $keys
    fi
}

run() {
    cd "${snippets_directory}" || exit

    local current_clipboard cursor_line cursor_line_position cursor_line cursor_position cursor_line_lenght

    # Use the filenames in the snippy directory as menu entries.
    # Get the menu selection from the user.
    # shellcheck disable=SC2086
    snippet=$( find -L .  -type f \
        | grep -v '^\.$' \
        | sed 's!\.\/!!' \
        | grep -vE '\.git/|\.gitconfig|\.gitkeep' \
        | ${MENU_ENGINE} ${MENU_ARGS} -p '❯ ')

    # just return if nothing was selected
    [[ -z "${snippet}" ]] && return 1

    if [ -f "${snippets_directory}/${snippet}" ]; then

        # Put the contents of the selected file into the paste buffer.
        # If file is empty, the content is the basename of the file
        if [ ! -s "${snippets_directory}/${snippet}" ]; then
            content="$(basename "${snippet}")"

        # don't parse file with the ##noparse header
        elif grep -qE "^##noparse" "${snippets_directory}/${snippet}"; then
            content="$( tail -n +2 "${snippets_directory}/${snippet}" )"

        # replace tmpfile for snippets with ##tmpfile header
        elif grep -qE "^##tmpfile" "${snippets_directory}/${snippet}"; then
            content="$( bashdown_simple <<< "$(tail -n +2 "${snippets_directory}/${snippet}" | sed "s%\$tmpfile%$tmpfile%g" )" )"

        # execute bash script in scripts dir
        elif [[ $(dirname "${snippet}") == 'scripts' ]] && grep -qE "^#!/bin/bash" "${snippets_directory}/${snippet}"; then
            content="$( bash "${snippets_directory}/${snippet}" )"

        # default action
        else
            content="$( bashdown_simple < "${snippets_directory}/${snippet}" )"
        fi

        if [ -n "$content" ]; then
            printf "%s" "$content" > "$tmpfile"
        fi

    else [[ ${snippet} =~ ^$ ]]
        ${snippet##*$} 2>/dev/null > "$tmpfile" # execute as bashcommand
    fi

    # if tmpfile is empty at this step, nothing to do.
    if [ ! -s "$tmpfile" ]; then
        return
    fi

    # save current clipboard
    current_clipboard=$(xsel -b)
    # replace {clipboard} by the clipboard content
    # use awk to handle correctly multiline clipboard
    if grep -q "$clipboard_placeholder" "$tmpfile"; then
        awk \
            -v clipboard="$current_clipboard" \
            -v placeholder="$clipboard_placeholder" \
            '{ gsub(placeholder, clipboard); print }' "$tmpfile" | sponge "$tmpfile"

        # remove last EOL
        perl -pi -e 'chomp if eof' "$tmpfile"
    fi


    # define cursor position and line at 0, we don't need to go up or left if there is no {cursor} placeholder
    cursor_line_position=0
    cursor_position=0

    # Check if there is a {cursor} placeholder
    if grep -qF $cursor_placeholder "$tmpfile"; then
        # retrieve the line number of the cursor placeholder
        cursor_line_position=$(grep -n "$cursor_placeholder" "$tmpfile" | cut -d: -f1)
        # retrieve the line
        cursor_line=$(grep $cursor_placeholder "$tmpfile")
        # calculate snippet total lines
        file_lines=$(wc -l < "$tmpfile")
        # determine the number of line to go up
        cursor_line_position=$(( file_lines - cursor_line_position + 1 ))
        # Extract cursor position
        cursor_position=$(strindex "$cursor_line" $cursor_placeholder)
        # total cursor line lenght
        cursor_line_lenght=${#cursor_line}
        # Compute the final cursor position ( 8 is the lenght of the placeholder {cursor} )
        cursor_position=$(( cursor_line_lenght - cursor_position - 8 ))
        # remove the placeholder
        sed -i -e "s/$cursor_placeholder//g" "$tmpfile"
    fi

    # Copy snippet in clipboard
    if is_rich_snippet "${snippets_directory}/${snippet}"; then
        xclip -t text/html -selection clipboard < "$tmpfile"
    else
        xclip -selection clipboard < "$tmpfile"
    fi

    # Paste into the current application.
    if is_gui; then
        # We need a little pause to handle the time to focus on the window
        sleep 0.17

        ${GUIPASTE}
        move_cursor "Up" $cursor_line_position
    else
        ${CLIPASTE}
    fi

    move_cursor "Left" $cursor_position

    # Restore current clipboard
    echo -ne "$current_clipboard" | xsel --clipboard --input
}

run