using System.Text.Json;
using System.Text.Json.Serialization;
using Shouldly;
using Xunit;
using ZB.MOM.WW.OtOpcUa.AdminUI.Components.Shared.Drivers.Forms;
using ZB.MOM.WW.OtOpcUa.Driver.Sql;
using ZB.MOM.WW.OtOpcUa.Driver.Sql.Contracts;

namespace ZB.MOM.WW.OtOpcUa.AdminUI.Tests.Uns;

/// <summary>
/// Guards the AdminUI <c>SqlDriverForm</c>'s driver-config output against the runtime factory that consumes
/// it. The form is razor (no bUnit here), so these tests pin two things the live verify then confirms:
/// (1) the exact JSON bytes the form emits for a minimal + fuller config are accepted by the authoritative
/// reader, <see cref="SqlDriverFactoryExtensions.CreateInstance(string,string)"/>; and (2) the
/// serialization contract — <c>provider</c> as a NAME string (never an ordinal), camelCase keys, and no
/// composer-owned <c>rawTags</c> or an unrequested <c>allowWrites</c> leaking into the authored blob. A numeric enum
/// or a stray connection string is the "authors fine, never reads / leaks a secret" defect class this guards.
/// </summary>
public sealed class SqlDriverFormContractTests
{
    // The JsonSerializerOptions SqlDriverForm serializes with (camelCase + string enums + omit-nulls).
    private static readonly JsonSerializerOptions FormOptions = new()
    {
        PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
        UnmappedMemberHandling = JsonUnmappedMemberHandling.Skip,
        DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull,
        WriteIndented = false,
        Converters = { new JsonStringEnumConverter() },
    };

    // ---- LOAD-BEARING: the exact bytes SqlDriverForm emits must construct a driver through the factory ----

    [Theory]
    // Minimal valid config: provider + required connectionStringRef only (all timeouts left to the factory).
    [InlineData("""{"provider":"SqlServer","connectionStringRef":"AdminUiFormTest"}""")]
    // Fuller config with every optional the form authors (timeouts satisfy operationTimeout > commandTimeout).
    [InlineData("""{"provider":"SqlServer","connectionStringRef":"AdminUiFormTest","defaultPollInterval":"00:00:05","operationTimeout":"00:00:20","commandTimeout":"00:00:10","maxConcurrentGroups":8,"nullIsBad":true}""")]
    public void FormEmittedJson_constructs_a_driver_through_the_factory(string formEmittedJson)
    {
        var envVar = SqlConnectionStringResolver.EnvironmentVariableFor("AdminUiFormTest");
        var previous = Environment.GetEnvironmentVariable(envVar);
        Environment.SetEnvironmentVariable(envVar, "Server=localhost;Database=Test;Trusted_Connection=True;");
        try
        {
            var driver = SqlDriverFactoryExtensions.CreateInstance("adminui-form-test", formEmittedJson);
            driver.ShouldNotBeNull();
        }
        finally
        {
            Environment.SetEnvironmentVariable(envVar, previous);
        }
    }

    [Fact]
    public void Factory_rejects_a_blob_missing_connectionStringRef()
    {
        // The form marks connectionStringRef required; the factory is the authoritative enforcement.
        var ex = Should.Throw<InvalidOperationException>(
            () => SqlDriverFactoryExtensions.CreateInstance("adminui-form-test", """{"provider":"SqlServer"}"""));
        ex.Message.ShouldContain("connectionStringRef");
    }

    // ---- serialization contract: enum-by-name, camelCase, no rawTags / allowWrites / null optionals --------

    [Fact]
    public void Minimal_config_serializes_provider_as_a_name_and_omits_owned_and_null_fields()
    {
        // Mirrors SqlDriverForm.FormModel.ToDto() for a minimal config (only the required ref set).
        var dto = new SqlDriverConfigDto { Provider = SqlProvider.SqlServer, ConnectionStringRef = "MesStaging" };

        var json = JsonSerializer.Serialize(dto, FormOptions);

        json.ShouldBe("""{"provider":"SqlServer","connectionStringRef":"MesStaging"}""");
        json.ShouldNotContain("\"provider\":0");   // never an ordinal — that faults the string-typed factory read
        json.ShouldNotContain("rawTags");           // composer-owned; never authored by the form
        json.ShouldNotContain("allowWrites");       // off ⇒ omitted ⇒ read-only
        json.ShouldNotContain("defaultPollInterval"); // null optional omitted ⇒ factory default applies
    }

    [Fact]
    public void Provider_round_trips_as_the_SqlServer_name()
    {
        var json = JsonSerializer.Serialize(
            new SqlDriverConfigDto { Provider = SqlProvider.SqlServer, ConnectionStringRef = "R" }, FormOptions);

        json.ShouldContain("\"SqlServer\"");
        JsonSerializer.Deserialize<SqlDriverConfigDto>(json, FormOptions)!.Provider.ShouldBe(SqlProvider.SqlServer);
    }

    // ---- the multi-provider dropdown: every offered option survives the form model's own round-trip ----

    /// <summary>
    ///     The dropdown offers SqlServer + Postgres + Oracle, so each must survive
    ///     <c>FormModel.ToDto()</c> → JSON → <c>FormModel.FromDto()</c> as a NAME string. The razor markup
    ///     itself is not reachable (no bUnit), so this pins the model half of the change: a provider the
    ///     dropdown can select but the form model cannot carry back would silently reset to SqlServer on
    ///     the next modal open.
    /// </summary>
    [Theory]
    [InlineData(SqlProvider.SqlServer, "SqlServer")]
    [InlineData(SqlProvider.Postgres, "Postgres")]
    [InlineData(SqlProvider.Oracle, "Oracle")]
    [InlineData(SqlProvider.MySql, "MySql")]
    [InlineData(SqlProvider.Odbc, "Odbc")]
    public void Every_dropdown_provider_round_trips_through_the_form_model(SqlProvider provider, string name)
    {
        var form = new SqlDriverForm.FormModel { Provider = provider, ConnectionStringRef = "MesStaging" };

        var json = JsonSerializer.Serialize(form.ToDto(), FormOptions);

        json.ShouldContain($"\"provider\":\"{name}\"");
        json.ShouldNotContain($"\"provider\":{(int)provider}");   // never an ordinal — that faults the factory read
        var reloaded = SqlDriverForm.FormModel.FromDto(
            JsonSerializer.Deserialize<SqlDriverConfigDto>(json, FormOptions)!);
        reloaded.Provider.ShouldBe(provider);
        reloaded.ConnectionStringRef.ShouldBe("MesStaging");
    }

    /// <summary>
    ///     The dropdown offers every provider the build constructs (lmxopcua#753 made all five enum members real),
    ///     so the form-model theory above must cover exactly <see cref="SqlDialects.Supported"/> — a provider added
    ///     to the map without a dropdown option (or the reverse) has to argue with this test.
    /// </summary>
    [Fact]
    public void Every_constructed_provider_is_covered_by_the_dropdown_theory()
        => SqlDialects.Supported.ShouldBe(
            [SqlProvider.SqlServer, SqlProvider.Postgres, SqlProvider.MySql, SqlProvider.Odbc, SqlProvider.Oracle],
            ignoreOrder: true);

    // ---- named queries (lmxopcua#753): the form refuses exactly what the factory refuses ----

    /// <summary>
    ///     The driver form's queries editor consults the runtime's own rules
    ///     (<see cref="SqlNamedQueryRules.Describe"/>), so what the form keeps is what the factory constructs and
    ///     what it refuses the factory refuses too. Driven through the real factory entry point, so a rule added
    ///     on one side only breaks this test.
    /// </summary>
    [Theory]
    [InlineData("""{"q":{"sql":"SELECT a FROM t WHERE x = @x","params":{"x":1}}}""", true)]
    [InlineData("""{"q":{"sql":"WITH l AS (SELECT a FROM t) SELECT a FROM l;","maxRows":10}}""", true)]
    [InlineData("""{"q":{"sql":"UPDATE t SET a = 1"}}""", false)]
    [InlineData("""{"q":{"sql":"SELECT a INTO t2 FROM t"}}""", false)]
    [InlineData("""{"q":{"sql":"SELECT 1; SELECT 2"}}""", false)]
    [InlineData("""{"q":{"sql":"SELECT a FROM t","maxRows":0}}""", false)]
    [InlineData("""{"q":{"sql":"SELECT a FROM t WHERE x = @x","params":{"x":{"nested":1}}}}""", false)]
    [InlineData("""{"q":{"sql":""}}""", false)]
    public void Form_queries_editor_and_factory_agree(string queriesJson, bool accepted)
    {
        var formError = SqlDriverForm.FormModel.TryParseQueries(queriesJson, out _);
        (formError is null).ShouldBe(accepted, formError);

        var envVar = SqlConnectionStringResolver.EnvironmentVariableFor("AdminUiFormTest");
        var previous = Environment.GetEnvironmentVariable(envVar);
        Environment.SetEnvironmentVariable(envVar, "Server=localhost;Database=Test;Trusted_Connection=True;");
        try
        {
            var blob = $$"""{"provider":"SqlServer","connectionStringRef":"AdminUiFormTest","queries":{{queriesJson}}}""";
            if (accepted) { SqlDriverFactoryExtensions.CreateInstance("adminui-form-test", blob).ShouldNotBeNull(); }
            else
            {
                Should.Throw<InvalidOperationException>(
                    () => SqlDriverFactoryExtensions.CreateInstance("adminui-form-test", blob));
            }
        }
        finally
        {
            Environment.SetEnvironmentVariable(envVar, previous);
        }
    }

    [Fact]
    public void AllowWrites_is_emitted_only_when_switched_on_and_the_factory_honours_it()
    {
        var off = JsonSerializer.Serialize(new SqlDriverForm.FormModel { ConnectionStringRef = "R" }.ToDto(), FormOptions);
        off.ShouldNotContain("allowWrites");

        var form = new SqlDriverForm.FormModel { ConnectionStringRef = "AdminUiFormTest", AllowWrites = true };
        var on = JsonSerializer.Serialize(form.ToDto(), FormOptions);
        on.ShouldContain("\"allowWrites\":true");
        SqlDriverForm.FormModel.FromDto(JsonSerializer.Deserialize<SqlDriverConfigDto>(on, FormOptions)!)
            .AllowWrites.ShouldBeTrue();

        var envVar = SqlConnectionStringResolver.EnvironmentVariableFor("AdminUiFormTest");
        var previous = Environment.GetEnvironmentVariable(envVar);
        Environment.SetEnvironmentVariable(envVar, "Server=localhost;Database=Test;Trusted_Connection=True;");
        try
        {
            SqlDriverFactoryExtensions.CreateInstance("adminui-form-test", on)
                .ShouldBeAssignableTo<ZB.MOM.WW.OtOpcUa.Core.Abstractions.IWritable>();
        }
        finally
        {
            Environment.SetEnvironmentVariable(envVar, previous);
        }
    }

    [Fact]
    public void Queries_survive_the_form_model_round_trip_and_a_typo_keeps_the_last_valid_set()
    {
        var dto = JsonSerializer.Deserialize<SqlDriverConfigDto>(
            """{"provider":"SqlServer","connectionStringRef":"R","queries":{"q":{"sql":"SELECT a FROM t"}}}""", FormOptions)!;
        var form = SqlDriverForm.FormModel.FromDto(dto);

        form.SetQueriesJson("{ not json");
        form.QueriesError.ShouldNotBeNull();

        var json = JsonSerializer.Serialize(form.ToDto(), FormOptions);
        json.ShouldContain("\"queries\":{\"q\":{\"sql\":\"SELECT a FROM t\"}}");
    }
}