using Shouldly;
using Xunit;

namespace ZB.MOM.WW.OtOpcUa.Driver.S7.Tests;

/// <summary>
///     Gitea #551 item 2: <see cref="S7TagDefinitionFactory.Inspect"/> is <b>accept-gate-first</b> — it asks
///     <see cref="S7TagDefinitionFactory.FromTagConfig"/> for the verdict and only explains a refusal. See
///     <c>ModbusInspectAcceptGateTests</c>'s remarks for why both directions (never stricter, never silent)
///     are pinned.
///     <para>
///         S7 carries the fleet's one unique rule: the reader REQUIRES the <c>dataType</c> key to be
///         present. A blob with only an <c>address</c> therefore deploys green and reads
///         <c>BadNodeIdUnknown</c> forever — and neither this gate nor the AdminUI model said a word about
///         it until #551.
///     </para>
/// </summary>
public sealed class S7InspectAcceptGateTests
{
    private const string RawPath = "cell/s7/dev1/T1";

    /// <summary>Blobs the mapper ACCEPTS — the gate must say nothing about any of them.</summary>
    public static TheoryData<string> Accepted() =>
    [
        """{"address":"DB1.DBW0","dataType":"Int16"}""",
        """{"address":"M0.0","dataType":"Bool"}""",
        """{"address":"DB1.DBB0","dataType":"String","stringLength":254}""",
        // stringLength is irrelevant to a non-String tag, so an out-of-range remnant is ACCEPTED.
        """{"address":"DB1.DBW0","dataType":"Int16","stringLength":9999}""",
        // A non-string dataType token satisfies the PRESENCE rule and then reads as absent ⇒ Int16.
        """{"address":"DB1.DBW0","dataType":7}""",
    ];

    /// <summary>Blobs the mapper REJECTS — the gate must produce at least one warning for each.</summary>
    public static TheoryData<string> Rejected() =>
    [
        """{"dataType":"Int16"}""",                                        // no address
        """{"address":"","dataType":"Int16"}""",                           // blank address
        """{"address":123,"dataType":"Int16"}""",                          // address not a string
        """{"address":"DB1.DBW0"}""",                                      // no dataType key at all (#551)
        """{"address":"DB1.DBW0","dataType":"Intt16"}""",                  // typo'd dataType
        """{"address":"DB1.DBB0","dataType":"String","stringLength":255}""", // over the 254 S7 limit
        """{"address":"DB1.DBB0","dataType":"String","stringLength":-1}""",  // negative length
    ];

    [Theory]
    [MemberData(nameof(Accepted))]
    public void A_config_the_mapper_accepts_draws_no_warning(string tagConfig)
    {
        S7TagDefinitionFactory.FromTagConfig(tagConfig, RawPath, out _).ShouldBeTrue("fixture must be accepted");
        S7TagDefinitionFactory.Inspect(tagConfig).ShouldBeEmpty();
    }

    [Theory]
    [MemberData(nameof(Rejected))]
    public void A_config_the_mapper_rejects_is_never_passed_over_in_silence(string tagConfig)
    {
        S7TagDefinitionFactory.FromTagConfig(tagConfig, RawPath, out _).ShouldBeFalse("fixture must be rejected");
        S7TagDefinitionFactory.Inspect(tagConfig).ShouldNotBeEmpty();
    }

    /// <summary>The headline case: present-and-typo'd was reported; ABSENT was not (Gitea #551 item 2).</summary>
    [Fact]
    public void An_absent_dataType_is_named()
        => S7TagDefinitionFactory.Inspect("""{"address":"DB1.DBW0"}""")
            .ShouldContain(w => w.Contains("no 'dataType'"));

    [Fact]
    public void An_absent_address_is_named()
        => S7TagDefinitionFactory.Inspect("""{"dataType":"Int16"}""")
            .ShouldContain(w => w.Contains("'address'"));

    [Fact]
    public void An_out_of_range_string_length_is_named()
        => S7TagDefinitionFactory.Inspect("""{"address":"DB1.DBB0","dataType":"String","stringLength":255}""")
            .ShouldContain(w => w.Contains("stringLength"));

    // ---- DeclaresDataType is the shared authority the AdminUI model asks (one rule, two doors) ----

    [Theory]
    [InlineData("""{"dataType":"Int16"}""", true)]
    [InlineData("""{"dataType":7}""", true)]          // presence is judged on the KEY, not the value
    [InlineData("""{"dataType":null}""", true)]
    [InlineData("""{"address":"DB1.DBW0"}""", false)]
    public void DeclaresDataType_judges_the_key_not_the_value(string tagConfig, bool expected)
    {
        using var doc = System.Text.Json.JsonDocument.Parse(tagConfig);
        S7TagDefinitionFactory.DeclaresDataType(doc.RootElement).ShouldBe(expected);
    }

    [Fact]
    public void A_blank_reference_draws_nothing()
        => S7TagDefinitionFactory.Inspect("   ").ShouldBeEmpty();

    [Fact]
    public void Unparseable_json_names_the_json()
        => S7TagDefinitionFactory.Inspect("{oops").ShouldContain(w => w.Contains("not valid JSON"));
}