using FrameworkBLL.Engine;
using Xunit;

namespace FrameworkTests;

/// <summary>
/// Covers TypeNormalizer's documented SQL Server ↔ PostgreSQL value mappings
/// (docs/Platform-Architecture-Integration-Reference.md §9.6/§5) — the only piece of the
/// DataSync engine that is pure, public, and needs no database connection to verify.
/// </summary>
public class TypeNormalizerTests
{
    [Fact]
    public void NormalizeCLR_NullValue_ReturnsNull()
    {
        Assert.Null(TypeNormalizer.NormalizeCLR(null, DatabaseType.SqlServer, DatabaseType.PostgreSQL));
    }

    [Fact]
    public void NormalizeCLR_SameSourceAndTarget_ReturnsValueUnchanged()
    {
        var result = TypeNormalizer.NormalizeCLR(true, DatabaseType.SqlServer, DatabaseType.SqlServer);
        Assert.Equal(true, result);
    }

    [Fact]
    public void NormalizeCLR_SqlServerBitToPostgresBool_ConvertsToBoolean()
    {
        var result = TypeNormalizer.NormalizeCLR(true, DatabaseType.SqlServer, DatabaseType.PostgreSQL);
        Assert.IsType<bool>(result);
        Assert.True((bool)result!);
    }

    [Fact]
    public void NormalizeCLR_PostgresBoolToSqlServerBit_ConvertsToByte()
    {
        var result = TypeNormalizer.NormalizeCLR(true, DatabaseType.PostgreSQL, DatabaseType.SqlServer);
        Assert.Equal((byte)1, result);
    }

    [Fact]
    public void NormalizeCLR_SqlServerGuidToPostgresUuid_ConvertsToStringRepresentation()
    {
        var guid = Guid.NewGuid();
        var result = TypeNormalizer.NormalizeCLR(guid, DatabaseType.SqlServer, DatabaseType.PostgreSQL);
        Assert.Equal(guid.ToString(), result);
    }

    [Fact]
    public void NormalizeCLR_PostgresUuidStringToSqlServerGuid_ParsesBackToGuid()
    {
        var guid = Guid.NewGuid();
        var result = TypeNormalizer.Normalize(guid.ToString(), "uuid", DatabaseType.SqlServer);
        Assert.Equal(guid, result);
    }

    [Fact]
    public void NormalizeCLR_DateTimeOffset_MapsToUtcDateTimeForSqlServerTarget()
    {
        var dto = new DateTimeOffset(2026, 1, 1, 12, 0, 0, TimeSpan.FromHours(5));
        var result = TypeNormalizer.NormalizeCLR(dto, DatabaseType.PostgreSQL, DatabaseType.SqlServer);
        Assert.Equal(dto.UtcDateTime, result);
    }

    [Fact]
    public void Normalize_SqlServerMoneyToDecimal_ConvertsCorrectly()
    {
        var result = TypeNormalizer.Normalize(123.45m, "money", DatabaseType.PostgreSQL);
        Assert.Equal(123.45m, result);
    }

    [Fact]
    public void Normalize_PostgresNumericToDecimal_ConvertsCorrectly()
    {
        var result = TypeNormalizer.Normalize(99.99m, "numeric", DatabaseType.SqlServer);
        Assert.Equal(99.99m, result);
    }

    [Fact]
    public void Normalize_UnmappedSourceDataType_ReturnsValueUnchanged()
    {
        var result = TypeNormalizer.Normalize("hello", "nvarchar", DatabaseType.PostgreSQL);
        Assert.Equal("hello", result);
    }

    [Fact]
    public void Normalize_TargetNotSqlServerOrPostgres_ReturnsValueUnchanged()
    {
        // MySQL/Oracle target: Normalize() has no branch for them yet (Phase 4) — must pass through as-is.
        var result = TypeNormalizer.Normalize(42, "int", DatabaseType.MySQL);
        Assert.Equal(42, result);
    }
}