using System.Reflection;
using Microsoft.Data.SqlClient;

namespace ZB.MOM.WW.ScadaBridge.AuditLog.Tests.TestSupport;

/// <summary>
/// Fabricates a <see cref="SqlException"/> with a given error number via the driver's internal
/// <c>CreateException</c> factory (the type has no public constructor) — same technique as
/// ExternalSystemGateway.Tests' <c>FabricateSqlException</c>.
/// </summary>
internal static class SqlExceptionFactory
{
    /// <summary>Creates a <see cref="SqlException"/> carrying one error with <paramref name="number"/>.</summary>
    /// <param name="number">The SQL Server error number.</param>
    /// <param name="message">The error message.</param>
    /// <returns>The fabricated exception.</returns>
    public static SqlException Create(int number, string message = "simulated")
    {
        var errorCtor = typeof(SqlError).GetConstructors(BindingFlags.Instance | BindingFlags.NonPublic)
            .First(c => c.GetParameters().Length == 8 && c.GetParameters()[7].ParameterType == typeof(Exception));
        var sqlError = (SqlError)errorCtor.Invoke(
            new object?[] { number, (byte)0, (byte)0, "server", message, "procedure", 0, null });

        var collection = (SqlErrorCollection)typeof(SqlErrorCollection)
            .GetConstructors(BindingFlags.Instance | BindingFlags.NonPublic).First()
            .Invoke(Array.Empty<object?>());
        typeof(SqlErrorCollection).GetMethod("Add", BindingFlags.Instance | BindingFlags.NonPublic)!
            .Invoke(collection, new object?[] { sqlError });

        var create = typeof(SqlException).GetMethod("CreateException",
            BindingFlags.Static | BindingFlags.NonPublic,
            new[] { typeof(SqlErrorCollection), typeof(string) })!;
        return (SqlException)create.Invoke(null, new object?[] { collection, "6.0.0" })!;
    }
}