Add a terminal startup script

#!/bin/bash

set -eu

shopt -s extglob lastpipe

. ~/.shell/lib/shared.sh

declare -r CODE_HIGHLIGHT=$(tput setab 15; tput setaf 16)

declare -r CODE_RESET=$(tput sgr0)

declare -a OPTIONS=(

	ssh="SSH: connect to a remote host"

	tmux="Tmux: connect to local terminal multiplexer"

	shell="Shell: start a local shell ($SHELL)"

	manual="Enter command manually"

)

declare -i FOCUS=0

if [[ -v TMUX ]] || ! has tmux; then

	unset OPTIONS[1]

	OPTIONS=( "${OPTIONS[@]}" )

fi

_clear() { clear; echo; }

interact() {

	local STATE=ssh

	trap 'read -N1 -p "Press any key to exit"' EXIT

	while _clear && do_$STATE; do

		has do_$STATE || die "Unknown state: $STATE"

	done

	die "Command for the $STATE state failed: $_"

}

do_ssh() {

	local host

	while read -p 'Connect to SSH host [empty for other options]: ' host args; do

		[[ -z $host ]] && STATE=options && return

		exec ssh $host $args

	done

}

do_tmux() {

	exec tmux attach

}

do_shell() {

	exec -l $SHELL

}

do_manual() {

	read -e -p '> '

	eval $REPLY

	exit

}

do_options() {

	local SELECTION

	while [[ ! -v SELECTION ]]; do

		display_options

		process_keys

	done

	local opt=${OPTIONS[$SELECTION]}

	STATE=${opt%%=*}

}

display_options() {

	_clear

	echo "Options:${1+ $1}"

	for i in "${!OPTIONS[@]}"; do

		local prefix=" " suffix=

		local opt=${OPTIONS[$i]}

		local name=${opt%%=*} desc=${opt#*=}

		[[ $i -eq ${1-$FOCUS} ]] && prefix="$CODE_HIGHLIGHT>" suffix=$CODE_RESET

		local rhs=$(tput hpa $((COLUMNS-${#name}-2)))"[$name]"

		printf "$prefix %2d: %s%s$suffix\n" $i "$desc" "$rhs"

	done

	echo

}

select_from() {

	local choice=$1

	if [[ $choice =~ ^[0-9]+$ && -v OPTIONS[choice] ]]; then

		SELECTION=$choice

		return 0

	fi

	local i=0

	declare -gA named_options

	if [[ ! -v named_options ]]; then

		named_options=()

		for opt in "${OPTIONS[@]}"; do

			named_options[${opt%%=*}]=$((i++))

		done

	fi

	if [[ ! -v named_options[$choice] ]]; then

		echo >&2 "Unknown choice: $choice"

		return 1

	fi

	SELECTION=${named_options[$choice]}

}

process_keys() {

	local key choice

	while read -s -N1 key; do

		case $key in

			$'\n') SELECTION=$FOCUS; break ;;

			$'\e') process_esc_seq ;;

			*) read -ei "$key" choice; select_from "$choice" && break ;;

		esac

	done

}

process_esc_seq() {

	local buff=

	local opt_min=0

	local opt_max=$((${#OPTIONS[*]}-1))

	while read -rs -N1 key; do

		buff+=$key

		case $buff in

			# arrow keys

			[[O]A) let 'FOCUS=(--FOCUS>=opt_min)?FOCUS:opt_min'; break ;;

			[[O]B) let 'FOCUS=(++FOCUS<=opt_max)?FOCUS:opt_max'; break ;;

			# any other ESC input sequences

			\[*([0-;])[A-Z~]) return ;;

		esac

	done

	display_options

}

has_client() {

	tmux list-clients -F '#{client_termname}' | while read termname; do

		echo "$termname $TERM"

		if [[ $termname == $TERM ]]; then

			return 0

		fi

	done

	return 1

}

has_client && interact

# No other terms of this one's kind attached to Tmux, lets be the first

exec tmux attach