#!/usr/bin/env bash
# =============================================================================
# restore-postgres.sh – Wiederherstellung einer PostgreSQL-Datenbank aus Borg
# Läuft auf dem Raspberry Pi
# =============================================================================

set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
CONFIG_FILE="${SCRIPT_DIR}/../config/backup.conf"
source "$CONFIG_FILE"

RED='\033[0;31m'; GREEN='\033[0;32m'; YELLOW='\033[1;33m'; BLUE='\033[0;34m'; NC='\033[0m'
log()     { echo -e "${BLUE}[RESTORE]${NC} $*"; }
log_ok()  { echo -e "${GREEN}[RESTORE] ✓${NC} $*"; }
log_warn(){ echo -e "${YELLOW}[RESTORE] ⚠${NC} $*"; }
log_err() { echo -e "${RED}[RESTORE] ✗${NC} $*" >&2; }

export BORG_PASSPHRASE
export BORG_REPO

usage() {
    echo ""
    echo "Verwendung: $0 [OPTIONEN]"
    echo ""
    echo "Optionen:"
    echo "  -l, --list               Verfügbare Archive auflisten"
    echo "  -a, --archive ARCHIVE    Archiv-Name (z.B. mydb-2025-01-15T02:30)"
    echo "  -d, --database DB        Ziel-Datenbank für Wiederherstellung"
    echo "  -t, --target-host HOST   Ziel-Host (Standard: ${PG_HOST})"
    echo "  -o, --output-dir DIR     Nur als Datei extrahieren (kein DB-Import)"
    echo "  -h, --help               Diese Hilfe anzeigen"
    echo ""
    echo "Beispiele:"
    echo "  $0 --list"
    echo "  $0 --archive mydb-2025-01-15T02:30 --database mydb_restored"
    echo "  $0 --archive mydb-2025-01-15T02:30 --output-dir /tmp/restore"
    echo ""
    exit 0
}

list_archives() {
    log "Verfügbare Archive in ${BORG_REPO}:"
    echo ""
    borg list --short "${BORG_REPO}" | sort -r | while read -r archive; do
        local info
        info=$(borg info "${BORG_REPO}::${archive}" 2>/dev/null | grep -E "Time|Duration|Deduplicated" || echo "")
        echo "  📦 ${archive}"
        echo "$info" | sed 's/^/     /'
        echo ""
    done
}

restore_to_db() {
    local archive="$1"
    local target_db="$2"
    local target_host="${3:-$PG_HOST}"

    log_warn "ACHTUNG: Datenbank '${target_db}' auf '${target_host}' wird überschrieben!"
    read -rp "Fortfahren? (ja/NEIN): " confirm
    [[ "$confirm" != "ja" ]] && { log "Abgebrochen."; exit 0; }

    log "Stelle '${archive}' → '${target_db}' auf '${target_host}' wieder her..."

    # Dump aus Borg extrahieren und direkt per SSH zu pg_restore pipen
    borg extract --stdout "${BORG_REPO}::${archive}" \
    | ssh -i "${SSH_KEY_PATH}" \
          -o StrictHostKeyChecking=accept-new \
          "${PG_SSH_USER}@${target_host}" \
          "sudo -u ${PG_DB_USER} pg_restore \
              --dbname=${target_db} \
              --no-owner \
              --no-privileges \
              --clean \
              --if-exists \
              --format=custom"

    log_ok "Wiederherstellung abgeschlossen!"
}

extract_to_dir() {
    local archive="$1"
    local output_dir="$2"

    mkdir -p "$output_dir"
    log "Extrahiere '${archive}' nach '${output_dir}'..."
    borg extract --destination "$output_dir" "${BORG_REPO}::${archive}"
    log_ok "Datei(en) in: ${output_dir}"
    ls -lh "$output_dir"
}

# --- Argumente parsen --------------------------------------------------------
LIST=false
ARCHIVE=""
DATABASE=""
TARGET_HOST="${PG_HOST}"
OUTPUT_DIR=""

while [[ $# -gt 0 ]]; do
    case "$1" in
        -l|--list)        LIST=true ;;
        -a|--archive)     ARCHIVE="$2";      shift ;;
        -d|--database)    DATABASE="$2";     shift ;;
        -t|--target-host) TARGET_HOST="$2";  shift ;;
        -o|--output-dir)  OUTPUT_DIR="$2";   shift ;;
        -h|--help)        usage ;;
        *) log_err "Unbekannte Option: $1"; usage ;;
    esac
    shift
done

# --- Hauptlogik --------------------------------------------------------------
if $LIST; then
    list_archives
elif [[ -n "$ARCHIVE" && -n "$OUTPUT_DIR" ]]; then
    extract_to_dir "$ARCHIVE" "$OUTPUT_DIR"
elif [[ -n "$ARCHIVE" && -n "$DATABASE" ]]; then
    restore_to_db "$ARCHIVE" "$DATABASE" "$TARGET_HOST"
else
    log_err "Keine gültige Aktion angegeben."
    usage
fi