using SSPCTester.Devices.Config;
using SSPCTester.Devices.Protocol;

namespace SSPCTester.Tests;

public sealed class ModbusProfileTests
{
    [Fact]
    public void FieldProfile_IsValidAndCoversPhysicalSlots1To24()
    {
        string path = FindRepoFile("Docs", "Modbus接口规范", "device-profile.json");

        var profile = ModbusDeviceProfileLoader.Load(path);

        Assert.Equal(Enumerable.Range(1, 24), profile.Channels.OrderBy(x => x.PhysicalSlot).Select(x => x.PhysicalSlot));
        Assert.Equal((byte)1, profile.Channels.Single(x => x.PhysicalSlot == 1).Relay.Slave);
        Assert.Equal((ushort)7, profile.Channels.Single(x => x.PhysicalSlot == 1).Relay.Coil);
        Assert.Equal(12, profile.Channels.Single(x => x.PhysicalSlot == 24).Current.RegisterOffset);
    }

    [Fact]
    public void Crc16_UsesModbusLowByteFirst()
    {
        byte[] request = ModbusRtuProtocol.BuildRequest(4, 3, 0, 24);

        Assert.Equal(new byte[] { 0x04, 0x03, 0x00, 0x00, 0x00, 0x18 }, request[..6]);
        Assert.Equal((byte)(ModbusRtuProtocol.ComputeCrc(request.AsSpan(0, 6)) & 0xFF), request[6]);
        ModbusRtuProtocol.ValidateCrc(request);
    }

    [Fact]
    public void SignedCurrent_UsesInt16TwosComplementAndFormulaA()
    {
        ushort rawBits = unchecked((ushort)(short)-1000);

        double amps = ModbusValueConverter.ConvertRaw(rawBits, true, "A", 60.0);

        Assert.Equal(-6.0, amps, 6);
    }

    [Fact]
    public void InvalidDuplicateRegisterMapping_IsRejected()
    {
        var profile = ModbusDeviceProfileLoader.Load(ProfilePath());
        profile.Current.ChannelsForTestDuplicate(profile.Channels);

        var error = Assert.Throws<InvalidDataException>(() => ModbusDeviceProfileLoader.Validate(profile));
        Assert.Contains("current.registerOffset 存在重复", error.Message);
    }

    private static string ProfilePath() => FindRepoFile("Docs", "Modbus接口规范", "device-profile.json");

    private static string FindRepoFile(params string[] parts)
    {
        var directory = new DirectoryInfo(AppContext.BaseDirectory);
        while (directory != null)
        {
            string candidate = Path.Combine(new[] { directory.FullName }.Concat(parts).ToArray());
            if (File.Exists(candidate)) return candidate;
            directory = directory.Parent;
        }
        throw new FileNotFoundException($"找不到仓库文件：{Path.Combine(parts)}");
    }
}

internal static class ProfileTestExtensions
{
    public static void ChannelsForTestDuplicate(
        this MeasurementProtocol _, IReadOnlyList<ChannelMapping> channels)
    {
        channels[1].Current.RegisterOffset = channels[0].Current.RegisterOffset;
    }
}