harpoon

#!/bin/sh

get_default_cache_dir() {
	if [ -n "$XDG_CACHE_HOME" ]; then
		echo "$XDG_CACHE_HOME"
	elif [ "$(uname)" = "Darwin" ]; then
		echo "$HOME/Library/Caches"
	else
		echo "$HOME/.cache"
	fi
}

cachefile="$(get_default_cache_dir)/.tmux-harpoon-sessions"

help() {
	echo
	echo "Usage:"
	echo "    ${0##*/} [options] [args]"
	echo "Options:"
	echo "    -a                    Track current tmux session"
	echo "    -A                    Track pane within current tmux session"
	echo "    -r <index>            Replace tracked entry at index with current session"
	echo "    -R <index>            Replace tracked entry at index with current pane within session"
	echo "    -d [session_name]     Stop tracking session with session name. If"
	echo "                          session_name is not passed then remove current session"
	echo "    -l                    List tracked sessions"
	echo "    -s <index>            Switch to the session at the specified index in the"
	echo "                          list of tracked sessions"
	echo "    -e                    Edit the sessions file"
	echo "    -h                    Display this help message"
}

remove() {
	session_name="$1"
	sed -i "/^$session_name/d" "$cachefile"
}

view() {
	FZF_CMD="$(_getFZFCmd)"
	entry="$(awk -v home="$HOME" -v bold="$(tput setaf 4)" -v sgr0="$(tput sgr0)" '{
        split($0, parts, "=")
        key = parts[1]
        value = parts[2]
        sub(home "/", "", value)
        printf "%s%s%s %s\n", bold, key, sgr0, value
    }' "$cachefile" | $FZF_CMD --ansi)"
	name="$(echo "$entry" | cut -d ' ' -f 1)"
	path="$HOME/$(echo "$entry" | rev | cut -d ' ' -f 1 | rev)"
	{ [ -z "$name" ] || [ -z "$path" ]; } && exit 0
	_switch "$name" "$path"
}

_getFZFCmd() {
	! type fzf >/dev/null 2>&1 && echo "Harpoon depends on fzf" && exit 1
	FZF_VERSION=$(fzf --version | cut -d ' ' -f1)
	REQUIRED_VERSION="0.53.0"

	version_gt() { [ "$(printf '%s\n' "$@" | sort -V | head -n1)" != "$1" ] || [ "$1" = "$2" ]; }

	if version_gt "$FZF_VERSION" "$REQUIRED_VERSION"; then
		echo "fzf --tmux 50%"
		return 0
	fi
	if type fzf-tmux >/dev/null 2>&1; then
		echo "fzf-tmux -p '50%,50%'"
		return 0
	fi
	echo "fzf"
	return 0
}

_getBookmark() {
	extended=$1

	base_info='#{session_name}=#{session_path}'
	pane_info=':#{window_index}.#{pane_index}'
	tmux display -p "$base_info$([ "$extended" = true ] && echo "$pane_info")"
}

_dedupe() {
	tmpfile="$(mktemp)"
	command cat -n "$cachefile" | sort -uk2 | sort -n | cut -f2- >"$tmpfile"
	mv "$tmpfile" "$cachefile"
	rm "$tmpfile"
}

replace() {
	bookmark=$(_getBookmark "$1")
	index=$2

	linenumbers=$(wc -l <"$cachefile")
	if [ "$linenumbers" -ge "$index" ]; then
		escaped_bookmark=$(echo "$bookmark" | sed 's/\//\\\//g')
		sed -i "${index}s/.*/$escaped_bookmark/" "$cachefile"
	else
		echo "$bookmark" >>"$cachefile"
	fi

	_dedupe
	exec tmux display "Tracking session #{session_name} in index $index"
}

add() {
	bookmark=$(_getBookmark "$1")
	echo "$bookmark" >>"$cachefile"
	_dedupe
	exec tmux display 'Tracking session #{session_name}'
}

_switch() {
	name="$1"
	path="$2"
	dirpath="${path%%:*}"
	pane="${path#*:}"
	[ "$dirpath" = "$pane" ] && pane=""
	if ! sessions_has_match "$name=$dirpath"; then
		if [ "$(uname)" = "Darwin" ]; then sedi="sed -i ''"; else sedi="sed -i"; fi
		$sedi "s|^$name=.*|$name=$dirpath:1.1|" "$cachefile"
		tmux new -ds "$name" -c "$dirpath"
	fi
	exec tmux switch-client -t "$name:$pane"
}

switch() {
	index="$1"
	count=1
	while IFS='=' read -r name path; do
		if [ "$count" = "$index" ]; then
			_switch "$name" "$path"
		fi
		count=$((count + 1))
	done <"$cachefile"
}

edit_file() { exec tmux popup -E "$EDITOR $cachefile"; }

sessions_has_match() { list_sessions | grep -wq "^$1"; }

list_sessions() { tmux ls -F '#{session_name}=#{session_path}'; }

bold() { printf "\033[1m%s\033[0m\n" "$*"; }

main() {
	! [ -f "$cachefile" ] && touch "$cachefile"
	while getopts ":haAr:R:d:ls:e" opt; do
		case "$opt" in
		h | :) help && exit 0 ;;
		a) add false ;;
		A) add true ;;
		r) replace false "$OPTARG" ;;
		R) replace true "$OPTARG" ;;
		d) remove "$OPTARG" ;;
		l) view ;;
		s) switch "$OPTARG" ;;
		e) edit_file ;;
		\?) help && exit 1 ;;
		esac
	done
}

main "$@"