#!/usr/bin/env bash

set -euo pipefail

backup_path="${1:-}"

if [[ -z "$backup_path" ]] || [[ ! -f "$backup_path" ]]; then
    echo "Utilização: $0 <ficheiro.dump>" >&2
    exit 1
fi

database_user="$(docker compose exec -T postgres printenv POSTGRES_USER)"
restore_database="reserva_restore_$(date -u +%Y%m%d%H%M%S)_$$"

if [[ ! "$database_user" =~ ^[A-Za-z0-9_]+$ ]] || [[ ! "$restore_database" =~ ^reserva_restore_[0-9_]+$ ]]; then
    echo "Identificador de restauro inválido." >&2
    exit 1
fi

cleanup() {
    docker compose exec -T postgres dropdb \
        --username="$database_user" \
        --if-exists \
        "$restore_database" > /dev/null
}

trap cleanup EXIT

docker compose exec -T postgres createdb \
    --username="$database_user" \
    "$restore_database"

docker compose exec -T postgres pg_restore \
    --username="$database_user" \
    --dbname="$restore_database" \
    --no-owner \
    --no-privileges < "$backup_path"

migration_count="$(docker compose exec -T postgres psql \
    --username="$database_user" \
    --dbname="$restore_database" \
    --tuples-only \
    --no-align \
    --command='select count(*) from migrations')"

if [[ ! "$migration_count" =~ ^[1-9][0-9]*$ ]]; then
    echo "O restauro não contém o histórico de migrations esperado." >&2
    exit 1
fi

echo "Restauro validado em base temporária (${migration_count} migrations)."