#!/bin/bash
# =============================================================================
# health-check.sh - Surveillance de sante du photomaton
# =============================================================================
# Usage: bash health-check.sh
# Appele regulierement par le timer systemd photobooth-watchdog.timer
# =============================================================================

set -uo pipefail

LOG_TAG="photomaton-watchdog"
PHOTOBOOTH_URL="http://localhost:8083"
MAX_RESTART_ATTEMPTS=3
RESTART_COUNT_FILE="/tmp/photomaton-restart-count"

log_info()  { logger -t "$LOG_TAG" "[INFO] $1";  echo "[INFO] $1"; }
log_warn()  { logger -t "$LOG_TAG" "[WARN] $1";  echo "[WARN] $1"; }
log_error() { logger -t "$LOG_TAG" "[ERROR] $1"; echo "[ERROR] $1"; }

# Initialiser le compteur de redemarrage
if [ ! -f "$RESTART_COUNT_FILE" ]; then
    echo "0" > "$RESTART_COUNT_FILE"
fi

restart_service() {
    local service="$1"
    local count
    count=$(cat "$RESTART_COUNT_FILE" 2>/dev/null || echo 0)

    if [ "$count" -ge "$MAX_RESTART_ATTEMPTS" ]; then
        log_error "Service $service: trop de redemarrages ($count). Intervention manuelle requise."
        return 1
    fi

    log_warn "Redemarrage de $service (tentative $((count + 1))/$MAX_RESTART_ATTEMPTS)..."
    echo "$((count + 1))" > "$RESTART_COUNT_FILE"

    systemctl --user restart "$service" 2>/dev/null || \
    systemctl restart "$service" 2>/dev/null || true

    sleep 5
}

# Reset le compteur si l'app tourne bien depuis plus de 10 minutes
reset_restart_counter() {
    local uptime_check
    uptime_check=$(systemctl --user show photobooth-app --property=ActiveEnterTimestamp 2>/dev/null | cut -d= -f2 || true)
    if [ -n "$uptime_check" ]; then
        local now
        now=$(date +%s)
        local started
        started=$(date -d "$uptime_check" +%s 2>/dev/null || echo "$now")
        local diff=$((now - started))
        if [ "$diff" -gt 600 ]; then
            echo "0" > "$RESTART_COUNT_FILE"
        fi
    fi
}

# -------------------------------------------------------------------
# 1. VERIFIER LA MEMOIRE
# -------------------------------------------------------------------
check_memory() {
    local mem_available
    mem_available=$(awk '/MemAvailable/ {print $2}' /proc/meminfo)
    local mem_total
    mem_total=$(awk '/MemTotal/ {print $2}' /proc/meminfo)

    # Alerte si moins de 100 Mo disponibles
    if [ "$mem_available" -lt 102400 ]; then
        log_warn "Memoire faible: ${mem_available}kB disponible sur ${mem_total}kB total"

        # Liberer les caches
        sync
        echo 3 > /proc/sys/vm/drop_caches 2>/dev/null || true
        log_info "Caches memoire vides"

        # Re-verifier
        mem_available=$(awk '/MemAvailable/ {print $2}' /proc/meminfo)
        if [ "$mem_available" -lt 51200 ]; then
            log_error "Memoire critique: ${mem_available}kB - intervention necessaire"
            return 1
        fi
    fi
    log_info "Memoire OK: ${mem_available}kB disponible"
    return 0
}

# -------------------------------------------------------------------
# 2. VERIFIER LA TEMPERATURE CPU
# -------------------------------------------------------------------
check_temperature() {
    local temp_file="/sys/class/thermal/thermal_zone0/temp"
    if [ -f "$temp_file" ]; then
        local temp
        temp=$(cat "$temp_file")
        local temp_c=$((temp / 1000))

        if [ "$temp_c" -ge 80 ]; then
            log_error "Temperature CPU critique: ${temp_c}C - throttling probable!"
            return 1
        elif [ "$temp_c" -ge 70 ]; then
            log_warn "Temperature CPU elevee: ${temp_c}C"
        else
            log_info "Temperature CPU OK: ${temp_c}C"
        fi
    fi
    return 0
}

# -------------------------------------------------------------------
# 3. VERIFIER PHOTOBOOTH-APP
# -------------------------------------------------------------------
check_photobooth() {
    # Verifier si le service tourne
    if ! systemctl --user is-active photobooth-app &>/dev/null; then
        log_error "photobooth-app n'est pas actif!"
        restart_service "photobooth-app"
        return 1
    fi

    # Verifier si l'interface web repond
    local http_code
    http_code=$(curl -s -o /dev/null -w "%{http_code}" --max-time 10 "$PHOTOBOOTH_URL" 2>/dev/null || echo "000")

    if [ "$http_code" = "000" ] || [ "$http_code" = "502" ] || [ "$http_code" = "503" ]; then
        log_error "photobooth-app ne repond pas (HTTP $http_code)"
        restart_service "photobooth-app"
        return 1
    fi

    log_info "photobooth-app OK (HTTP $http_code)"
    reset_restart_counter
    return 0
}

# -------------------------------------------------------------------
# 4. VERIFIER CUPS / IMPRIMANTES
# -------------------------------------------------------------------
check_printers() {
    if ! systemctl is-active cups &>/dev/null; then
        log_error "CUPS n'est pas actif!"
        systemctl restart cups 2>/dev/null || true
        return 1
    fi

    # Verifier les imprimantes
    local disabled_printers
    disabled_printers=$(lpstat -p 2>/dev/null | grep -c "disabled" || echo "0")

    if [ "$disabled_printers" -gt 0 ]; then
        log_warn "$disabled_printers imprimante(s) desactivee(s), reactivation..."
        # Reactiver les imprimantes
        for printer in $(lpstat -p 2>/dev/null | grep "disabled" | awk '{print $2}'); do
            cupsenable "$printer" 2>/dev/null || true
            log_info "Imprimante reactivee: $printer"
        done
    fi

    # Nettoyer les jobs bloques (plus de 10 minutes)
    local stuck_jobs
    stuck_jobs=$(lpstat -o 2>/dev/null | wc -l || echo "0")
    if [ "$stuck_jobs" -gt 5 ]; then
        log_warn "$stuck_jobs jobs d'impression en attente, nettoyage..."
        cancel -a 2>/dev/null || true
    fi

    log_info "Imprimantes OK"
    return 0
}

# -------------------------------------------------------------------
# 5. VERIFIER L'ESPACE DISQUE
# -------------------------------------------------------------------
check_disk() {
    local usage
    usage=$(df / | awk 'NR==2 {print $5}' | tr -d '%')

    if [ "$usage" -ge 90 ]; then
        log_error "Espace disque critique: ${usage}% utilise"

        # Nettoyage d'urgence
        # Supprimer les anciens logs
        find /var/log -name "*.gz" -mtime +1 -delete 2>/dev/null || true
        find /var/log -name "*.[0-9]" -mtime +1 -delete 2>/dev/null || true
        # Vider le cache apt
        apt-get clean 2>/dev/null || true

        log_info "Nettoyage d'urgence effectue"
        return 1
    elif [ "$usage" -ge 80 ]; then
        log_warn "Espace disque: ${usage}% utilise"
    else
        log_info "Espace disque OK: ${usage}% utilise"
    fi
    return 0
}

# -------------------------------------------------------------------
# 6. VERIFIER LA CAMERA
# -------------------------------------------------------------------
check_camera() {
    # Verifier que la camera est detectee
    if command -v libcamera-hello &>/dev/null; then
        # Test rapide sans afficher d'image
        if ! libcamera-hello --list-cameras 2>/dev/null | grep -q "Available cameras"; then
            log_warn "Camera non detectee par libcamera"
            return 1
        fi
    elif [ -e /dev/video0 ]; then
        log_info "Camera detectee: /dev/video0"
    else
        log_warn "Aucun peripherique camera detecte"
        return 1
    fi

    log_info "Camera OK"
    return 0
}

# -------------------------------------------------------------------
# EXECUTION
# -------------------------------------------------------------------
echo "=== Health Check Photomaton - $(date) ==="

ERRORS=0

check_memory      || ((ERRORS++))
check_temperature || ((ERRORS++))
check_photobooth  || ((ERRORS++))
check_printers    || ((ERRORS++))
check_disk        || ((ERRORS++))
check_camera      || ((ERRORS++))

echo ""
if [ "$ERRORS" -eq 0 ]; then
    log_info "Tous les checks OK"
else
    log_warn "$ERRORS probleme(s) detecte(s)"
fi

exit "$ERRORS"