using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;
using System.Reflection;

namespace MicroORM;

public class OrmMetadata
{
    public static string GetTableName<T>()
    {
        var table = typeof(T).GetCustomAttribute<TableAttribute>();
        if (table == null)
            throw new InvalidOperationException("La entidad no tiene [Table]");

        return string.IsNullOrEmpty(table.Schema)
            ? table.Name
            : $"{table.Schema}.{table.Name}";
    }

    public static PropertyInfo GetKeyProperty<T>()
    {
        var key = typeof(T)
            .GetProperties()
            .FirstOrDefault(p => p.GetCustomAttribute<KeyAttribute>() != null);

        if (key == null)
            throw new InvalidOperationException("La entidad no tiene [Key]");

        return key;
    }

    public static string GetColumnName(PropertyInfo prop)
    {
        var columnAttr = prop.GetCustomAttribute<ColumnAttribute>();
        return columnAttr?.Name ?? prop.Name;
    }

    public static bool IsIdentity(PropertyInfo prop)
    {
        var key = prop.GetCustomAttribute<KeyAttribute>() != null;
        var dbGenerated = prop.GetCustomAttribute<DatabaseGeneratedAttribute>();

        return key &&
               dbGenerated?.DatabaseGeneratedOption == DatabaseGeneratedOption.Identity;
    }

    public static IEnumerable<PropertyInfo> GetScaffoldProperties<T>()
    {
        var type = typeof(T);
        var key = GetKeyProperty<T>();

        return type.GetProperties(BindingFlags.Public | BindingFlags.Instance)
            .Where(p =>
                p.CanWrite &&                                  // tiene setter
                p.GetCustomAttribute<NotMappedAttribute>() == null &&
                (
                    p.GetCustomAttribute<ColumnAttribute>() != null ||
                    p == key
                )
            );
    }

}