#!/bin/bash
set -x

# ==========================================================
# CONFIGURATION
# ==========================================================
CONTAINER_NAME="MongoDB"
MONGO_HOST="localhost"
MONGO_PORT="27017"

# Cesta k záloze kterou chceš obnovit
# Např: /mnt/user/Backup/Critical/MongoDBBackup/tower
BACKUP_BASE_PATH="$1"

# ==========================================================
# VALIDATION
# ==========================================================
if [ -z "$BACKUP_BASE_PATH" ]; then
    echo "Usage: $0 <backup_base_path>"
    echo "Example: $0 /mnt/user/Backup/Critical/MongoDBBackup/tower"
    exit 1
fi

if [ ! -d "$BACKUP_BASE_PATH" ]; then
    echo "ERROR: Backup path does not exist: $BACKUP_BASE_PATH"
    exit 1
fi

echo "Starting MongoDB restore from: $BACKUP_BASE_PATH"
START_TS=$(date '+%Y-%m-%d %H:%M:%S')

# ==========================================================
# RESTORE PROCESS
# ==========================================================

# Najdi nejnovější backupy pro každou DB
# Struktura: $BACKUP_BASE_PATH/DB_NAME/YYYY-MM-DD_HHMM/DB_NAME.archive.gz

for DB_DIR in "$BACKUP_BASE_PATH"/*; do
    if [ ! -d "$DB_DIR" ]; then
        continue
    fi

    DB_NAME=$(basename "$DB_DIR")
    echo "------------------------------------------"
    echo "Processing database: $DB_NAME"

    # Najdi nejnovější backup pro tuto DB
    LATEST_BACKUP=$(ls -td "$DB_DIR"/*/ 2>/dev/null | head -1)

    if [ -z "$LATEST_BACKUP" ]; then
        echo "WARNING: No backup found for $DB_NAME"
        continue
    fi

    BACKUP_FILE="$LATEST_BACKUP/${DB_NAME}.archive.gz"
    ERR_FILE="$LATEST_BACKUP/${DB_NAME}.restore.err"

    if [ ! -f "$BACKUP_FILE" ]; then
        echo "ERROR: Backup archive not found: $BACKUP_FILE"
        continue
    fi

    echo "Found backup: $BACKUP_FILE"
    echo "Backup date: $(stat -c %y "$BACKUP_FILE" | cut -d' ' -f1-2)"
    echo "Backup size: $(du -h "$BACKUP_FILE" | cut -f1)"

    # ======================================================
    # RESTORE TO MONGODB (streamuje přes stdin z hosta)
    # Restores: indexy, metadata, validators, all collections
    # ======================================================
    echo "Restoring $DB_NAME to MongoDB..."
    docker exec -i "$CONTAINER_NAME" mongorestore \
        --host="$MONGO_HOST" \
        --port="$MONGO_PORT" \
        --archive \
        --gzip \
        --drop \
        --numParallelCollections=4 \
        < "$BACKUP_FILE" \
        2> "$ERR_FILE"

    RESTORE_EXIT=$?

    # ======================================================
    # VALIDATION
    # ======================================================
    if [ $RESTORE_EXIT -eq 0 ]; then
        echo "SUCCESS: $DB_NAME restored successfully"
        rm -f "$ERR_FILE"
    else
        echo "ERROR: Restore failed for database: $DB_NAME"
        echo "Exit code: $RESTORE_EXIT"
        echo "Error output:"
        [ -s "$ERR_FILE" ] && cat "$ERR_FILE" || echo "  (no stderr output)"
    fi

done

echo "------------------------------------------"
echo "All restore tasks completed at $(date)"
echo "Started at: $START_TS"
set +x