#!/usr/bin/env bash

set -euo pipefail

umask 077

backup_directory="${1:-storage/app/backups}"
mkdir -p "$backup_directory"

database_name="$(docker compose exec -T postgres printenv POSTGRES_DB)"
database_user="$(docker compose exec -T postgres printenv POSTGRES_USER)"

if [[ ! "$database_name" =~ ^[A-Za-z0-9_]+$ ]] || [[ ! "$database_user" =~ ^[A-Za-z0-9_]+$ ]]; then
    echo "Nome de base de dados ou utilizador inválido." >&2
    exit 1
fi

timestamp="$(date -u +%Y%m%dT%H%M%SZ)"
backup_path="${backup_directory%/}/reserva-${timestamp}.dump"
temporary_path="${backup_path}.partial"

docker compose exec -T postgres pg_dump \
    --username="$database_user" \
    --dbname="$database_name" \
    --format=custom \
    --no-owner \
    --no-privileges > "$temporary_path"

docker compose exec -T postgres pg_restore --list < "$temporary_path" > /dev/null
mv "$temporary_path" "$backup_path"
shasum -a 256 "$backup_path" > "${backup_path}.sha256"

echo "$backup_path"