#!/bin/bash

# ================================================
#  SENTINELLA DI BACKUP (Gira su Pi-1 Master)
#  Controlla Pi-2 e attiva failover bundle IoT su Pi-1 se down.
# ================================================

LOOGLE_NOTIFY="/home/daniely/docker/loogle-casa/scripts/loogle-notify.sh"
HA_FAILOVER="/home/daniely/rete/scripts/ha-failover.sh"

if [[ ! -x "$LOOGLE_NOTIFY" ]]; then
    echo "Errore: loogle-notify non disponibile ($LOOGLE_NOTIFY)" >&2
    exit 1
fi

TARGET_IP="192.168.128.81"
TARGET_NAME="🍓 Pi-2 (Backup & Monitor)"
STATE_FILE="/mnt/ha-apps/.metadata/pi2-watchdog.state"
SIM_STATE="/mnt/ha-apps/.metadata/failover-sim.state"
LEGACY_STATE_FILE="/tmp/pi2_watchdog.state"
SSH_OPTS=(-o ConnectTimeout=5 -o BatchMode=yes -o StrictHostKeyChecking=accept-new)

if [[ -f "$SIM_STATE" ]] && [[ "$(cat "$SIM_STATE" 2>/dev/null)" != "none" ]]; then
    exit 0
fi

send_alert() {
    local title="$1"
    local body="$2"
    local severity="$3"
    "$LOOGLE_NOTIFY" --title "$title" --body "$body" --category watchdog_pi2 \
        --severity "$severity" &
}

pi2_reachable() {
    ping -c 3 -W 2 "$TARGET_IP" > /dev/null 2>&1 && return 0
    ssh "${SSH_OPTS[@]}" pi2 "exit 0" 2>/dev/null
}

if [ ! -f "$STATE_FILE" ]; then
    if [ -f "$LEGACY_STATE_FILE" ]; then
        cp "$LEGACY_STATE_FILE" "$STATE_FILE"
    else
        echo "UP" > "$STATE_FILE"
    fi
fi
LAST_STATE=$(cat "$STATE_FILE")

if pi2_reachable; then
    if [ "$LAST_STATE" == "DOWN" ]; then
        send_alert \
            "Pi-2 online" \
            "RISOLTO: $TARGET_NAME è tornato ONLINE! Failback bundle IoT in corso." \
            "info"
        echo "UP" > "$STATE_FILE"
        if [[ -x "$HA_FAILOVER" ]]; then
            sudo bash -c "\"$HA_FAILOVER\" stop-iot-bundle >> /var/log/ha-failover.log 2>&1 &"
        fi
    fi
else
    if [ "$LAST_STATE" == "UP" ]; then
        send_alert \
            "Pi-2 offline" \
            "ALLARME: $TARGET_NAME è OFFLINE! Avvio failover bundle IoT su Pi-1." \
            "warning"
        echo "DOWN" > "$STATE_FILE"
        if [[ -x "$HA_FAILOVER" ]]; then
            sudo bash -c "\"$HA_FAILOVER\" start-iot-bundle >> /var/log/ha-failover.log 2>&1 &"
        fi
    fi
fi