#!/bin/sh
# GerbilManager Backup-Skript (Container-Welt)
# Laeuft als Cron-Job im backup-Sidecar-Container.
# Volumes: /data/photos (read-only), /backups (read-write)
# Umgebungsvariablen: PGPASSWORD, POSTGRES_HOST, POSTGRES_USER, POSTGRES_DB, BACKUP_KEEP_DAYS
set -e

TIMESTAMP=$(date +%Y-%m-%d_%H-%M)
BACKUP_DIR="/backups/$TIMESTAMP"
DB_DUMP="$BACKUP_DIR/gerbilmanager_${TIMESTAMP}.sql"
PHOTO_ARCHIVE="$BACKUP_DIR/photos_${TIMESTAMP}.tar.gz"
KEEP_DAYS="${BACKUP_KEEP_DAYS:-7}"
HOST="${POSTGRES_HOST:-db}"
USER="${POSTGRES_USER:-postgres}"
DB="${POSTGRES_DB:-gerbilmanager}"

log() { echo "[$(date +'%Y-%m-%d %H:%M:%S')] $1"; }

log "=== Backup gestartet ($TIMESTAMP) ==="
mkdir -p "$BACKUP_DIR"

# --- Datenbank-Dump ---
log "Erstelle pg_dump fuer $DB@$HOST..."
if ! pg_dump -h "$HOST" -U "$USER" -d "$DB" --clean --if-exists --format=plain \
        > "$DB_DUMP" 2>/tmp/pg_err; then
    log "FEHLER bei pg_dump: $(cat /tmp/pg_err)"
    exit 1
fi
DUMP_SIZE=$(du -k "$DB_DUMP" | cut -f1)
log "Dump erstellt: $DB_DUMP (${DUMP_SIZE} KB)"

# Validierung: mindestens CREATE TABLE muss vorhanden sein
if ! grep -q "CREATE TABLE" "$DB_DUMP" 2>/dev/null; then
    log "WARNUNG: Dump sieht ungueltig aus -- bitte $DB_DUMP pruefen"
fi

# --- Fotos archivieren ---
if [ -d /data/photos ] && [ "$(ls -A /data/photos 2>/dev/null)" ]; then
    PHOTO_COUNT=$(find /data/photos -type f | wc -l)
    log "Archiviere $PHOTO_COUNT Fotos..."
    tar czf "$PHOTO_ARCHIVE" -C /data photos/ 2>/tmp/tar_err || {
        log "WARNUNG: Foto-Archiv fehlgeschlagen: $(cat /tmp/tar_err)"
    }
    PHOTO_SIZE=$(du -k "$PHOTO_ARCHIVE" 2>/dev/null | cut -f1)
    log "Foto-Archiv erstellt: $PHOTO_ARCHIVE (${PHOTO_SIZE} KB)"
else
    log "Keine Fotos gefunden -- Foto-Backup uebersprungen"
fi

# --- Rotation: alte Backups loeschen ---
log "Rotiere Backups (behalte $KEEP_DAYS Tage)..."
find /backups -maxdepth 1 -type d -name '????-??-??_??-??' \
    -mtime "+$KEEP_DAYS" -exec rm -rf {} + 2>/dev/null || true
REMAINING=$(find /backups -maxdepth 1 -type d -name '????-??-??_??-??' | wc -l)
log "Backup abgeschlossen. Vorhandene Sicherungen: $REMAINING"
log "=== Ende ==="