#!/usr/bin/env bash

# green: gpiochip3 line 13 / LED1_GREEN (0 = on, 1 = off, active-low)
# red:   gpiochip3 line 14 / LED2_RED  (0 = on, 1 = off, active-low)
#
# gpioset v2 holds the line until the process exits, so each LED is driven
# by a background process. We kill and replace it to change state.

CHIP=/dev/gpiochip3
GREEN_PIN=13
RED_PIN=14

green_pid=""
red_pid=""

set_led() {
    local pin=$1 val=$2 pid_var=$3
    kill "${!pid_var}" 2>/dev/null || true
    gpioset --chip "$CHIP" "${pin}=${val}" &
    printf -v "$pid_var" '%s' "$!"
}

cleanup() {
    kill "$green_pid" "$red_pid" 2>/dev/null || true
}
trap 'cleanup; exit 0' INT TERM
trap cleanup EXIT

# release any lines left held by a previous run of this script
pkill -f "gpioset.*$CHIP" 2>/dev/null || true

green_state=0  # start ON

while true; do
    green_state=$(( 1 - green_state ))
    set_led "$GREEN_PIN" "$green_state" green_pid

    if ping -q -c 1 -W 1 8.8.8.8 >/dev/null 2>&1; then
        set_led "$RED_PIN" 1 red_pid
    else
        set_led "$RED_PIN" 0 red_pid
    fi

    sleep 2
done