#!/bin/bash
# scripts/backup.sh - Backup complet Nextcloud

set -euo pipefail

# Variables globales
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
PROJECT_ROOT="$(cd "$SCRIPT_DIR/.." && pwd)"
cd "$PROJECT_ROOT"

LOCK_FILE="/tmp/nextcloud_backup.lock"
LOG_DIR="./logs"
LOG_FILE="$LOG_DIR/backup_$(date +%Y%m%d_%H%M%S).log"
MAINTENANCE_ENABLED=false

# Créer le dossier de logs
mkdir -p "$LOG_DIR"

# Fonction de logging
log() {
  local level="$1"
  shift
  local message="$*"
  local timestamp
  timestamp=$(date '+%Y-%m-%d %H:%M:%S')
  echo "[$timestamp] [$level] $message" | tee -a "$LOG_FILE"
}

# Charger les variables d'environnement
if [ ! -f .env ]; then
  log "ERROR" "Fichier .env introuvable"
  exit 1
fi

# Charger .env de manière sécurisée
set -a
# shellcheck disable=SC1091
source .env
set +a

# Vérifier les variables requises
: "${MYSQL_USER:?Variable MYSQL_USER non définie}"
: "${MYSQL_PASSWORD:?Variable MYSQL_PASSWORD non définie}"
: "${MYSQL_DATABASE:?Variable MYSQL_DATABASE non définie}"

BACKUP_DIR="${BACKUP_DESTINATION:-./backups}"
BACKUP_RETENTION_DAYS="${BACKUP_RETENTION_DAYS:-7}"
DATE=$(date +%Y%m%d_%H%M%S)
BACKUP_NAME="nextcloud_backup_$DATE"
BACKUP_PATH="$BACKUP_DIR/$BACKUP_NAME"

# Fonction de nettoyage en cas d'erreur
cleanup() {
  local exit_code=$?

  if [ "$exit_code" -ne 0 ]; then
    log "ERROR" "Erreur détectée (code: $exit_code), nettoyage..."
  fi

  # Désactiver le mode maintenance si activé
  if [ "$MAINTENANCE_ENABLED" = true ]; then
    log "INFO" "Désactivation du mode maintenance..."
    docker-compose exec -T -u www-data nextcloud php occ maintenance:mode --off 2>>"$LOG_FILE" || true
  fi

  # Nettoyer le backup partiel
  if [ -d "$BACKUP_PATH" ]; then
    log "INFO" "Nettoyage du backup partiel..."
    rm -rf "${BACKUP_PATH:?}"
  fi

  # Supprimer le lock
  rm -f "$LOCK_FILE"

  if [ "$exit_code" -eq 0 ]; then
    log "SUCCESS" "Backup terminé avec succès"
  else
    log "ERROR" "Backup échoué avec code: $exit_code"
  fi

  exit "$exit_code"
}

trap cleanup EXIT INT TERM

# Vérifier qu'un backup n'est pas déjà en cours
if [ -f "$LOCK_FILE" ]; then
  log "ERROR" "Un backup est déjà en cours (lock file: $LOCK_FILE)"
  exit 1
fi

# Créer le lock file
echo $$ > "$LOCK_FILE"

log "INFO" "=== Démarrage du backup: $BACKUP_NAME ==="
log "INFO" "Log file: $LOG_FILE"

# Vérifier l'espace disque disponible
log "INFO" "Vérification de l'espace disque..."
REQUIRED_SPACE=$(du -sb ./data ./db 2>/dev/null | awk '{sum+=$1} END {print int(sum*1.2)}' || echo "0")
AVAILABLE_SPACE=$(df -B1 "$BACKUP_DIR" | awk 'NR==2 {print $4}')

log "INFO" "Espace requis (estimé): $(numfmt --to=iec-i --suffix=B "$REQUIRED_SPACE" 2>/dev/null || echo "$REQUIRED_SPACE bytes")"
log "INFO" "Espace disponible: $(numfmt --to=iec-i --suffix=B "$AVAILABLE_SPACE" 2>/dev/null || echo "$AVAILABLE_SPACE bytes")"

if [ "$AVAILABLE_SPACE" -lt "$REQUIRED_SPACE" ]; then
  log "ERROR" "Espace disque insuffisant"
  exit 1
fi

# Créer le dossier de backup
mkdir -p "$BACKUP_PATH"

# 1. Activer le mode maintenance
log "INFO" "Activation du mode maintenance..."
if docker-compose exec -T -u www-data nextcloud php occ maintenance:mode --on 2>>"$LOG_FILE"; then
  MAINTENANCE_ENABLED=true
  log "INFO" "Mode maintenance activé"
else
  log "ERROR" "Impossible d'activer le mode maintenance"
  exit 1
fi

# 2. Backup de la base de données
log "INFO" "Backup de la base de données..."
START_TIME=$(date +%s)
if ! docker-compose exec -T db sh -c "MYSQL_PWD=\"\$MYSQL_PASSWORD\" mysqldump \
  -u\"\$MYSQL_USER\" \
  \"\$MYSQL_DATABASE\" \
  --single-transaction \
  --quick \
  --lock-tables=false" >"$BACKUP_PATH/database.sql" 2>>"$LOG_FILE"; then
  log "ERROR" "Erreur lors du backup de la base de données"
  exit 1
fi
END_TIME=$(date +%s)
DB_SIZE=$(du -h "$BACKUP_PATH/database.sql" | cut -f1)
log "INFO" "Base de données sauvegardée: $DB_SIZE ($(( END_TIME - START_TIME ))s)"

# 3. Backup des fichiers de config
log "INFO" "Backup de la configuration..."
START_TIME=$(date +%s)
if ! docker-compose exec -T -u www-data nextcloud tar -czf - -C /var/www/html/config . > "$BACKUP_PATH/config.tar.gz" 2>>"$LOG_FILE"; then
  log "ERROR" "Erreur lors du backup de la configuration"
  exit 1
fi
END_TIME=$(date +%s)
CONFIG_SIZE=$(du -h "$BACKUP_PATH/config.tar.gz" | cut -f1)
log "INFO" "Configuration sauvegardée: $CONFIG_SIZE ($(( END_TIME - START_TIME ))s)"

# 4. Backup des données utilisateurs
log "INFO" "Backup des données utilisateurs..."
START_TIME=$(date +%s)
if ! docker-compose exec -T -u www-data nextcloud tar -czf - \
  -C /var/www/html/data \
  --exclude='appdata_*/preview' \
  --exclude='*/cache' \
  --exclude='*/thumbnails' \
  . > "$BACKUP_PATH/data.tar.gz" 2>>"$LOG_FILE"; then
  log "ERROR" "Erreur lors du backup des données"
  exit 1
fi
END_TIME=$(date +%s)
DATA_SIZE=$(du -h "$BACKUP_PATH/data.tar.gz" | cut -f1)
log "INFO" "Données sauvegardées: $DATA_SIZE ($(( END_TIME - START_TIME ))s)"

# 5. Backup des apps personnalisées
log "INFO" "Backup des apps personnalisées..."
if docker-compose exec -T nextcloud [ -d /var/www/html/custom_apps ] 2>>"$LOG_FILE"; then
  if docker-compose exec -T -u www-data nextcloud tar -czf - \
    -C /var/www/html/custom_apps . > "$BACKUP_PATH/apps.tar.gz" 2>>"$LOG_FILE"; then
    APPS_SIZE=$(du -h "$BACKUP_PATH/apps.tar.gz" | cut -f1)
    log "INFO" "Apps sauvegardées: $APPS_SIZE"
  else
    log "WARN" "Erreur lors du backup des apps personnalisées"
  fi
else
  log "INFO" "Pas d'apps personnalisées à sauvegarder"
fi

# 6. Désactiver le mode maintenance
log "INFO" "Désactivation du mode maintenance..."
if docker-compose exec -T -u www-data nextcloud php occ maintenance:mode --off 2>>"$LOG_FILE"; then
  MAINTENANCE_ENABLED=false
  log "INFO" "Mode maintenance désactivé"
else
  log "WARN" "Impossible de désactiver le mode maintenance"
fi

# 7. Créer une archive complète
log "INFO" "Compression finale..."
START_TIME=$(date +%s)
if ! tar -czf "$BACKUP_DIR/$BACKUP_NAME.tar.gz" -C "$BACKUP_DIR" "$BACKUP_NAME/" 2>>"$LOG_FILE"; then
  log "ERROR" "Erreur lors de la compression"
  exit 1
fi
END_TIME=$(date +%s)
ARCHIVE_SIZE=$(du -h "$BACKUP_DIR/$BACKUP_NAME.tar.gz" | cut -f1)
log "INFO" "Archive créée: $ARCHIVE_SIZE ($(( END_TIME - START_TIME ))s)"

# 8. Générer le checksum SHA256
log "INFO" "Génération du checksum SHA256..."
if cd "$BACKUP_DIR" && sha256sum "$BACKUP_NAME.tar.gz" > "$BACKUP_NAME.tar.gz.sha256"; then
  cd "$PROJECT_ROOT"
  CHECKSUM=$(cut -d' ' -f1 "$BACKUP_DIR/$BACKUP_NAME.tar.gz.sha256")
  log "INFO" "Checksum: $CHECKSUM"
else
  cd "$PROJECT_ROOT"
  log "WARN" "Impossible de générer le checksum"
fi

# Supprimer le dossier temporaire après compression réussie
rm -rf "${BACKUP_PATH:?}"

# 9. Nettoyer les vieux backups
log "INFO" "Nettoyage des backups > $BACKUP_RETENTION_DAYS jours..."
DELETED_COUNT=0
while IFS= read -r -d '' file; do
  CHECKSUM_FILE="${file}.sha256"
  log "INFO" "Suppression: $(basename "$file")"
  rm -f "$file" "$CHECKSUM_FILE" 2>>"$LOG_FILE" || true
  DELETED_COUNT=$((DELETED_COUNT + 1))
done < <(find "$BACKUP_DIR" -name "nextcloud_backup_*.tar.gz" -type f -mtime +"$BACKUP_RETENTION_DAYS" -print0 2>/dev/null || true)

if [ "$DELETED_COUNT" -gt 0 ]; then
  log "INFO" "$DELETED_COUNT ancien(s) backup(s) supprimé(s)"
else
  log "INFO" "Aucun ancien backup à supprimer"
fi

# 10. Statistiques finales
log "INFO" "=== Statistiques du backup ==="
log "INFO" "Archive: $BACKUP_DIR/$BACKUP_NAME.tar.gz"
log "INFO" "Taille: $ARCHIVE_SIZE"
log "INFO" "Checksum: ${CHECKSUM:-N/A}"
log "INFO" "Rétention: $BACKUP_RETENTION_DAYS jours"
log "INFO" "Backups disponibles: $(find "$BACKUP_DIR" -name "nextcloud_backup_*.tar.gz" -type f 2>/dev/null | wc -l)"