using Domain;

namespace Db;

/// <summary>Hand-written mappers between domain objects and persistence records; each method maps one direction and never mutates its input.</summary>
public static class DataMappers
{
    /// <summary>Map a <see cref="Client"/> to its persistence record <see cref="ClientData"/>.</summary>
    public static ClientData ToClientData(Client client)
    {
        ArgumentNullException.ThrowIfNull(client);
        return new ClientData { Id = client.Id, Name = client.Name };
    }

    /// <summary>Map an <see cref="Order"/> to its persistence record <see cref="OrderData"/>; the client back-reference becomes a foreign key.</summary>
    public static OrderData ToOrderData(Order order)
    {
        ArgumentNullException.ThrowIfNull(order);
        return new OrderData
        {
            Id = order.Id,
            Description = order.Description,
            TotalInCents = order.TotalInCents.Cents,   // value object → plain int for the row
            ClientId = order.Client?.Id ?? Guid.Empty,
        };
    }

    /// <summary>Map a <see cref="ClientData"/> record back to a <see cref="Client"/>.</summary>
    public static Client FromClientData(ClientData row)
    {
        ArgumentNullException.ThrowIfNull(row);
        return new Client { Id = row.Id, Name = row.Name };
    }

    /// <summary>Map an <see cref="OrderData"/> record back to an <see cref="Order"/>; the context reassembles the graph.</summary>
    public static Order FromOrderData(OrderData row)
    {
        ArgumentNullException.ThrowIfNull(row);
        return new Order
        {
            Id = row.Id,
            Description = row.Description,
            TotalInCents = OrderMoney.From(row.TotalInCents),   // plain int from the row → value object
        };
    }
}