#!/bin/sh
# Build the socktop display session: one tmux window per GROUP, one pane per
# host inside it. Window order and pane index order together are the swipe
# order (see socktop-swipe).
set -eu

# shellcheck source=config.env
for c in /usr/local/etc/socktop-swipe.env "$(dirname "$0")/config.env"; do
	[ -r "$c" ] && . "$c" && break
done

: "${SOCKTOP_GROUPS:=}"
: "${SOCKTOP_HOSTS:=}"
: "${SOCKTOP_SESSION:=socktop4}"
: "${SOCKTOP_BIN:=socktop}"

# Legacy form: SOCKTOP_HOSTS alone is a single tiled group.
if [ -z "$SOCKTOP_GROUPS" ]; then
	: "${SOCKTOP_HOSTS:?no SOCKTOP_GROUPS or SOCKTOP_HOSTS -- is the config installed?}"
	SOCKTOP_GROUPS=$SOCKTOP_HOSTS
fi

tmux kill-session -t "$SOCKTOP_SESSION" 2>/dev/null || true

# Pane titles are set on the session, so do it up front; windows inherit.
build_group() {
	# $1 = window name, remaining args = host names and an optional @layout
	name=$1
	shift
	layout=tiled
	hosts=
	for tok in "$@"; do
		case "$tok" in
		@*) layout=${tok#@} ;;
		*) hosts="$hosts $tok" ;;
		esac
	done
	# shellcheck disable=SC2086
	set -- $hosts
	[ $# -gt 0 ] || return 0

	if ! tmux has-session -t "$SOCKTOP_SESSION" 2>/dev/null; then
		tmux new-session -d -s "$SOCKTOP_SESSION" -n "$name" "$SOCKTOP_BIN -P $1"
	else
		tmux new-window -d -t "$SOCKTOP_SESSION" -n "$name" "$SOCKTOP_BIN -P $1"
	fi
	win="$SOCKTOP_SESSION:$name"
	tmux select-pane -t "$win.0" -T "$1"
	shift
	for h in "$@"; do
		# Split the most recently created pane so creation order == index order.
		tmux split-window -t "$win" "$SOCKTOP_BIN -P $h"
		tmux select-pane -t "$win.$(tmux display-message -t "$win" -p '#{pane_index}')" -T "$h"
	done
	tmux select-layout -t "$win" "$layout"
	tmux select-pane -t "$win.0"
}

n=0
old_ifs=$IFS
IFS=';'
for group in $SOCKTOP_GROUPS; do
	IFS=$old_ifs
	# shellcheck disable=SC2086
	build_group "g$n" $group
	n=$((n + 1))
	IFS=';'
done
IFS=$old_ifs

tmux select-window -t "$SOCKTOP_SESSION:g0"

tmux set-option -t "$SOCKTOP_SESSION" pane-border-status top
tmux set-option -t "$SOCKTOP_SESSION" pane-border-format ' #{pane_title} '
tmux set-option -t "$SOCKTOP_SESSION" status off

# Keep dead panes so pane indices stay stable if a socktop exits.
tmux set-option -t "$SOCKTOP_SESSION" remain-on-exit on

# Mouse mode MUST stay off. With it on, every touch swipe is ALSO delivered to
# tmux as a click-drag: dragging across a pane border resizes it and taps
# reselect panes, which fights the gesture daemon. See README, "Why no tapping".
tmux set-option -t "$SOCKTOP_SESSION" mouse off

exec tmux attach -t "$SOCKTOP_SESSION"