using System.Text.Json;
using System.Text.Json.Serialization;
using Shouldly;
using Xunit;
using ZB.MOM.WW.OtOpcUa.Core.Abstractions;

namespace ZB.MOM.WW.OtOpcUa.Driver.Modbus.Tests;

/// <summary>
///     Review 07 U1: <c>Family</c>, <c>MelsecSubFamily</c> and <c>DisableFC23</c> were authored in the
///     AdminUI and consumed by nothing. A tag's <c>addressString</c> now resolves through
///     <see cref="ModbusAddressParser"/> with the driver's family; <c>DisableFC23</c> gates the FC23
///     write-and-read-back path for multi-register writes. Also pins that the AdminUI form's own
///     (TimeSpan-shaped) config keys reach the driver.
/// </summary>
[Trait("Category", "Unit")]
public sealed class ModbusFamilyWiringTests
{
    // ---------------- addressString through the family-aware parser ----------------

    [Fact]
    public void A_MELSEC_D_register_resolves_only_under_the_MELSEC_family()
    {
        const string json = """{"addressString":"D100"}""";
        ModbusTagDefinitionFactory.FromTagConfig(json, "T", ModbusFamily.MELSEC, MelsecFamily.Q_L_iQR, out var def).ShouldBeTrue();
        def.Region.ShouldBe(ModbusRegion.HoldingRegisters);
        def.Address.ShouldBe((ushort)100);
        // Positive control: the same text means nothing to a Generic (Modicon) driver.
        ModbusTagDefinitionFactory.FromTagConfig(json, "T", ModbusFamily.Generic, MelsecFamily.Q_L_iQR, out _).ShouldBeFalse();
    }

    [Fact]
    public void A_DL205_V_memory_address_resolves_octal_under_DL205()
    {
        ModbusTagDefinitionFactory.FromTagConfig("""{"addressString":"V2000"}""", "T", ModbusFamily.DL205, MelsecFamily.Q_L_iQR, out var def)
            .ShouldBeTrue();
        def.Region.ShouldBe(ModbusRegion.HoldingRegisters);
        def.Address.ShouldBe((ushort)0x400); // V2000 octal = 1024
    }

    [Fact]
    public void A_string_only_blob_carries_type_order_and_count_and_keeps_the_other_keys()
    {
        ModbusTagDefinitionFactory.FromTagConfig(
            """{"addressString":"40011:F:CDAB:4","writable":false,"unitId":3}""",
            "T", ModbusFamily.Generic, MelsecFamily.Q_L_iQR, out var def).ShouldBeTrue();
        def.Region.ShouldBe(ModbusRegion.HoldingRegisters);
        def.Address.ShouldBe((ushort)10);
        def.DataType.ShouldBe(ModbusDataType.Float32);
        def.ByteOrder.ShouldBe(ModbusByteOrder.WordSwap);
        def.ArrayCount.ShouldBe(4);
        def.Writable.ShouldBeFalse();
        def.UnitId.ShouldBe((byte)3);
    }

    /// <summary>
    ///     Fix round 1 (review m2): persisted region/address are authoritative over an addressString, so a
    ///     later Family / MelsecSubFamily change can never silently remap a live tag the editor resolved. (Since
    ///     fix round 3 the keys win by PRESENCE; the marker in this blob is display state only.)
    /// </summary>
    [Fact]
    public void Persisted_resolved_keys_win_over_the_address_string_so_a_family_change_cannot_remap()
    {
        // The editor resolved D100 under MELSEC, persisted HR 100 and MARKED it; the driver is later switched.
        const string json = """{"addressString":"D100","addressResolved":true,"region":"HoldingRegisters","address":100,"dataType":"Int16"}""";
        foreach (var family in new[] { ModbusFamily.MELSEC, ModbusFamily.DL205, ModbusFamily.Generic })
        {
            ModbusTagDefinitionFactory.FromTagConfig(json, "T", family, MelsecFamily.Q_L_iQR, out var def).ShouldBeTrue();
            def.Address.ShouldBe((ushort)100, $"family {family}");
        }
    }

    /// <summary>
    ///     Fix round 3 (review r2 N2): the persisted-shape matrix. Every shape that carries region + address loads
    ///     from them under every family — including the pre-#741 "keys + addressString, no marker" row, which the
    ///     old driver served from its keys and must keep serving so. Only a string-only blob (no keys) resolves
    ///     the string.
    /// </summary>
    [Theory]
    [InlineData("keys only", """{"region":"InputRegisters","address":5}""", ModbusRegion.InputRegisters, 5)]
    [InlineData("pre-lane keys + string", """{"region":"InputRegisters","address":5,"dataType":"Int16","addressString":"40011:F"}""", ModbusRegion.InputRegisters, 5)]
    [InlineData("pre-lane stamped HR/0 + string", """{"region":"HoldingRegisters","address":0,"dataType":"Int16","addressString":"D100"}""", ModbusRegion.HoldingRegisters, 0)]
    [InlineData("string only", """{"addressString":"40011:F"}""", ModbusRegion.HoldingRegisters, 10)]
    [InlineData("string + marker + keys (editor-pinned)", """{"addressString":"D100","addressResolved":true,"region":"HoldingRegisters","address":100}""", ModbusRegion.HoldingRegisters, 100)]
    [InlineData("string + marker, no keys", """{"addressString":"40011:F","addressResolved":true}""", ModbusRegion.HoldingRegisters, 10)]
    public void Every_persisted_shape_resolves_to_its_address_under_every_family(
        string shape, string json, ModbusRegion region, int address)
    {
        foreach (var (family, sub) in new[]
                 {
                     (ModbusFamily.Generic, MelsecFamily.Q_L_iQR), (ModbusFamily.DL205, MelsecFamily.Q_L_iQR),
                     (ModbusFamily.MELSEC, MelsecFamily.Q_L_iQR), (ModbusFamily.MELSEC, MelsecFamily.F_iQF),
                 })
        {
            ModbusTagDefinitionFactory.FromTagConfig(json, "T", family, sub, out var def).ShouldBeTrue($"{shape} / {family}");
            def.Region.ShouldBe(region, $"{shape} / {family}");
            def.Address.ShouldBe((ushort)address, $"{shape} / {family}");
        }
    }

    [Fact]
    public void A_string_only_blob_no_family_parses_is_refused_not_served_as_HR0()
    {
        ModbusTagDefinitionFactory.FromTagConfig("""{"addressString":"D100"}""", "T", ModbusFamily.Generic, MelsecFamily.Q_L_iQR, out _)
            .ShouldBeFalse();
    }

    [Fact]
    public void An_unparseable_address_string_rejects_the_tag_and_the_deploy_gate_says_why()
    {
        const string json = """{"addressString":"ZZ9"}""";
        ModbusTagDefinitionFactory.FromTagConfig(json, "T", out _).ShouldBeFalse();
        ModbusTagDefinitionFactory.Inspect(json).ShouldContain(w => w.Contains("addressString"));
        // The family-unaware gate accepts what SOME family resolves (it must never be stricter than the driver).
        ModbusTagDefinitionFactory.Inspect("""{"addressString":"D100"}""").ShouldBeEmpty();
    }

    [Fact]
    public async Task The_driver_resolves_address_strings_with_its_configured_family()
    {
        var fake = new ScriptedTransport();
        fake.Bank.HoldingRegisters[100] = 1234;
        var opts = new ModbusDriverOptions
        {
            Host = "f", Family = ModbusFamily.MELSEC, Probe = new ModbusProbeOptions { Enabled = false },
            RawTags = [new RawTagEntry("D100", """{"addressString":"D100"}""", false)],
        };
        await using var drv = new ModbusDriver(opts, "m1", _ => fake);
        await drv.InitializeAsync("{}", TestContext.Current.CancellationToken);
        var r = await drv.ReadAsync(["D100"], TestContext.Current.CancellationToken);
        r[0].StatusCode.ShouldBe(0u);
        r[0].Value.ShouldBe((short)1234);
    }

    [Fact]
    public void Family_and_MelsecSubFamily_parse_from_the_driver_config()
    {
        var o = ModbusDriverFactoryExtensions.ParseOptions("m1",
            """{"host":"h","family":"MELSEC","melsecSubFamily":"F_iQF","disableFC23":true,"useFC23ForMultiRegisterWrites":true}""");
        o.Family.ShouldBe(ModbusFamily.MELSEC);
        o.MelsecSubFamily.ShouldBe(MelsecFamily.F_iQF);
        o.DisableFC23.ShouldBeTrue();
        o.UseFC23ForMultiRegisterWrites.ShouldBeTrue();
    }

    // ---------------- FC23 is OPT-IN; DisableFC23 is the kill-switch ----------------

    private static async Task<(ModbusDriver, ScriptedTransport)> StartWriteAsync(string driverConfigJson)
    {
        var t = new ScriptedTransport();
        var opts = ModbusDriverFactoryExtensions.ParseOptions("m1", driverConfigJson) is var parsed
            ? new ModbusDriverOptions
            {
                Host = "f", DisableFC23 = parsed.DisableFC23,
                UseFC23ForMultiRegisterWrites = parsed.UseFC23ForMultiRegisterWrites,
                Probe = new ModbusProbeOptions { Enabled = false },
                RawTags = ModbusRawTags.Entries([new ModbusTagDefinition("F", ModbusRegion.HoldingRegisters, 20, ModbusDataType.Float32)]),
            }
            : null!;
        var drv = new ModbusDriver(opts, "m1", _ => t);
        await drv.InitializeAsync("{}", TestContext.Current.CancellationToken);
        return (drv, t);
    }

    /// <summary>
    ///     Fix round 1 (coordinator ruling 1): a config without the opt-in key keeps the FC16 wire — including the
    ///     legacy shape every form-saved config carries ("disableFC23": false).
    /// </summary>
    [Theory]
    [InlineData("""{"host":"h"}""")]
    [InlineData("""{"host":"h","disableFC23":false,"maxReadGap":0,"useFC15ForSingleCoilWrites":false}""")]
    public async Task Without_the_opt_in_multi_register_writes_stay_on_FC16(string legacyConfig)
    {
        var (drv, t) = await StartWriteAsync(legacyConfig);
        await using var _ = drv;
        (await drv.WriteAsync([new WriteRequest("F", 1.5f)], TestContext.Current.CancellationToken))[0].StatusCode.ShouldBe(0u);
        t.Sent.Select(s => s.Pdu[0]).ShouldBe([(byte)0x10]);
    }

    [Fact]
    public async Task Opted_in_multi_register_writes_use_FC23_write_and_read_back()
    {
        var (drv, t) = await StartWriteAsync("""{"host":"h","useFC23ForMultiRegisterWrites":true}""");
        await using var _ = drv;
        var w = await drv.WriteAsync([new WriteRequest("F", 1.5f)], TestContext.Current.CancellationToken);
        w[0].StatusCode.ShouldBe(0u);
        t.Sent.Select(s => s.Pdu[0]).ShouldBe([(byte)0x17]);
        (await drv.ReadAsync(["F"], TestContext.Current.CancellationToken))[0].Value.ShouldBe(1.5f);
    }

    [Fact]
    public async Task DisableFC23_overrides_the_opt_in()
    {
        var (drv, t) = await StartWriteAsync("""{"host":"h","useFC23ForMultiRegisterWrites":true,"disableFC23":true}""");
        await using var _ = drv;
        (await drv.WriteAsync([new WriteRequest("F", 1.5f)], TestContext.Current.CancellationToken))[0].StatusCode.ShouldBe(0u);
        t.Sent.Select(s => s.Pdu[0]).ShouldBe([(byte)0x10]);
    }

    [Fact]
    public async Task An_opted_in_device_without_FC23_falls_back_to_FC16_once_and_stays_on_it()
    {
        var (drv, t) = await StartWriteAsync("""{"host":"h","useFC23ForMultiRegisterWrites":true}""");
        await using var _ = drv;
        t.Handler = (_, pdu, _) => pdu[0] == 0x17
            ? Task.FromException<byte[]>(new ModbusException(0x17, 0x01, "illegal function"))
            : null;

        (await drv.WriteAsync([new WriteRequest("F", 1.5f)], TestContext.Current.CancellationToken))[0].StatusCode.ShouldBe(0u);
        (await drv.WriteAsync([new WriteRequest("F", 2.5f)], TestContext.Current.CancellationToken))[0].StatusCode.ShouldBe(0u);

        t.Sent.Select(s => s.Pdu[0]).ShouldBe([(byte)0x17, (byte)0x10, (byte)0x10]);
        drv.GetHealth().State.ShouldBe(DriverState.Healthy);
    }

    // ---------------- the AdminUI form's own keys reach the driver ----------------

    [Fact]
    public void The_AdminUI_form_shape_of_the_timing_keys_is_honoured()
    {
        // The form serialises ModbusDriverOptions itself (camelCase, TimeSpan strings), not the *Ms DTO keys.
        var formShape = JsonSerializer.Serialize(new ModbusDriverOptions
        {
            Host = "h",
            Timeout = TimeSpan.FromSeconds(7),
            IdleDisconnectTimeout = TimeSpan.FromSeconds(90),
            AutoProhibitReprobeInterval = TimeSpan.FromSeconds(45),
            Probe = new ModbusProbeOptions { Interval = TimeSpan.FromSeconds(11), Timeout = TimeSpan.FromSeconds(3) },
            KeepAlive = new ModbusKeepAliveOptions { Time = TimeSpan.FromSeconds(60), Interval = TimeSpan.FromSeconds(20) },
            Reconnect = new ModbusReconnectOptions { InitialDelay = TimeSpan.FromSeconds(2), MaxDelay = TimeSpan.FromSeconds(40) },
        }, new JsonSerializerOptions { PropertyNamingPolicy = JsonNamingPolicy.CamelCase, Converters = { new JsonStringEnumConverter() } });

        var o = ModbusDriverFactoryExtensions.ParseOptions("m1", formShape);

        o.Timeout.ShouldBe(TimeSpan.FromSeconds(7));
        o.IdleDisconnectTimeout.ShouldBe(TimeSpan.FromSeconds(90));
        o.AutoProhibitReprobeInterval.ShouldBe(TimeSpan.FromSeconds(45));
        o.Probe.Interval.ShouldBe(TimeSpan.FromSeconds(11));
        o.Probe.Timeout.ShouldBe(TimeSpan.FromSeconds(3));
        o.KeepAlive.Time.ShouldBe(TimeSpan.FromSeconds(60));
        o.KeepAlive.Interval.ShouldBe(TimeSpan.FromSeconds(20));
        o.Reconnect.InitialDelay.ShouldBe(TimeSpan.FromSeconds(2));
        o.Reconnect.MaxDelay.ShouldBe(TimeSpan.FromSeconds(40));
    }

    [Fact]
    public void The_millisecond_keys_still_win_when_both_are_present()
    {
        var o = ModbusDriverFactoryExtensions.ParseOptions("m1", """{"host":"h","timeoutMs":1500,"timeout":"00:00:07"}""");
        o.Timeout.ShouldBe(TimeSpan.FromMilliseconds(1500));
    }
}