#!/usr/bin/env bash
# ==============================================================================
# Metatron Student ERP - Production Backup & Recovery Script
# Usage:
#   ./backup_restore.sh backup [DEST_DIR]
#   ./backup_restore.sh restore <DB_DUMP_FILE> <FILESTORE_ARCHIVE> <TARGET_DB>
#   ./backup_restore.sh verify <DB_DUMP_FILE> <FILESTORE_ARCHIVE>
# ==============================================================================

set -euo pipefail

DB_CONTAINER="${DB_CONTAINER:-metatron_academic_db}"
ODOO_CONTAINER="${ODOO_CONTAINER:-metatron_academic}"
DB_USER="${POSTGRES_USER:-odoo}"
DB_NAME="${POSTGRES_DB:-metatron_aca_erp}"
TIMESTAMP=$(date +%Y%m%d_%H%M%S)

ACTION="${1:-help}"

case "$ACTION" in
    backup)
        BACKUP_DIR="${2:-./backups}"
        mkdir -p "$BACKUP_DIR"

        DB_FILE="$BACKUP_DIR/${DB_NAME}_${TIMESTAMP}.dump"
        FS_FILE="$BACKUP_DIR/filestore_${DB_NAME}_${TIMESTAMP}.tar.gz"

        echo "[+] Starting PostgreSQL database backup for '$DB_NAME'..."
        docker exec -t "$DB_CONTAINER" pg_dump -U "$DB_USER" -Fc "$DB_NAME" > "$DB_FILE"
        echo "[✓] Database backup created: $DB_FILE ($(du -h "$DB_FILE" | cut -f1))"

        echo "[+] Starting Odoo filestore archive for '$DB_NAME'..."
        docker exec "$ODOO_CONTAINER" tar -czf - -C /var/lib/odoo/filestore "$DB_NAME" > "$FS_FILE"
        echo "[✓] Filestore archive created: $FS_FILE ($(du -h "$FS_FILE" | cut -f1))"

        echo "[+] Calculating SHA256 checksums..."
        if command -v shasum >/dev/null 2>&1; then
            shasum -a 256 "$DB_FILE" "$FS_FILE" > "$BACKUP_DIR/checksums_${TIMESTAMP}.sha256"
        elif command -v sha256sum >/dev/null 2>&1; then
            sha256sum "$DB_FILE" "$FS_FILE" > "$BACKUP_DIR/checksums_${TIMESTAMP}.sha256"
        fi

        echo "=================================================================="
        echo "BACKUP SUCCESSFUL: $TIMESTAMP"
        echo "Database:  $DB_FILE"
        echo "Filestore: $FS_FILE"
        echo "=================================================================="
        ;;

    verify)
        DB_FILE="${2:-}"
        FS_FILE="${3:-}"

        if [[ -z "$DB_FILE" || -z "$FS_FILE" ]]; then
            echo "[-] Error: Provide both database dump and filestore archive to verify."
            echo "    Usage: $0 verify <DB_DUMP_FILE> <FILESTORE_ARCHIVE>"
            exit 1
        fi

        echo "[+] Verifying database archive integrity..."
        # pg_restore -l lists table of contents without restoring
        docker exec -i "$DB_CONTAINER" pg_restore -l < "$DB_FILE" > /dev/null
        echo "[✓] Database dump archive is valid."

        echo "[+] Verifying filestore tar.gz integrity..."
        tar -tzf "$FS_FILE" > /dev/null
        echo "[✓] Filestore tar.gz archive is valid."
        echo "All backup archives verified intact."
        ;;

    restore)
        DB_FILE="${2:-}"
        FS_FILE="${3:-}"
        TARGET_DB="${4:-${DB_NAME}_restored}"

        if [[ -z "$DB_FILE" || -z "$FS_FILE" ]]; then
            echo "[-] Error: Provide DB dump file, filestore archive, and target database name."
            echo "    Usage: $0 restore <DB_DUMP_FILE> <FILESTORE_ARCHIVE> [TARGET_DB]"
            exit 1
        fi

        echo "[!] WARNING: You are about to restore to database '$TARGET_DB'."
        read -p "Are you sure you want to continue? (y/N): " CONFIRM
        if [[ "$CONFIRM" != "y" && "$CONFIRM" != "Y" ]]; then
            echo "Restore aborted by user."
            exit 0
        fi

        echo "[+] Creating database '$TARGET_DB' if not exists..."
        docker exec -i "$DB_CONTAINER" psql -U "$DB_USER" -c "CREATE DATABASE \"$TARGET_DB\" OWNER \"$DB_USER\";" 2>/dev/null || true

        echo "[+] Restoring PostgreSQL database from $DB_FILE..."
        docker exec -i "$DB_CONTAINER" pg_restore -U "$DB_USER" -d "$TARGET_DB" --clean --if-exists < "$DB_FILE" || true
        echo "[✓] Database restore completed."

        echo "[+] Restoring filestore to container..."
        docker exec -i "$ODOO_CONTAINER" mkdir -p /var/lib/odoo/filestore/"$TARGET_DB"
        docker exec -i "$ODOO_CONTAINER" tar -xzf - -C /var/lib/odoo/filestore/"$TARGET_DB" --strip-components=1 < "$FS_FILE"
        echo "[✓] Filestore restored to /var/lib/odoo/filestore/$TARGET_DB."
        ;;

    *)
        echo "Metatron Student ERP Backup & Recovery Utility"
        echo "Usage:"
        echo "  $0 backup [DEST_DIR]                               - Take full DB and filestore backup"
        echo "  $0 verify <DB_DUMP_FILE> <FILESTORE_ARCHIVE>       - Test backup archive integrity"
        echo "  $0 restore <DB_DUMP_FILE> <FS_ARCHIVE> <TARGET_DB> - Restore to target database"
        exit 1
        ;;
esac