using Shouldly;
using Xunit;

namespace ZB.MOM.WW.OtOpcUa.Core.Abstractions.Tests;

/// <summary>lmxopcua#815 — the shared credential-reference parser, resolver and per-driver policy table.</summary>
public sealed class CredentialReferencesTests
{
    private static readonly CredentialScope Galaxy = DriverCredentialPolicy.GalaxyScope;

    [Theory]
    [InlineData(null, CredentialReferenceKind.Blank)]
    [InlineData("", CredentialReferenceKind.Blank)]
    [InlineData("secret:galaxy/inst/apikey", CredentialReferenceKind.Secret)]
    [InlineData("${secret:galaxy/inst/apikey}", CredentialReferenceKind.Secret)]
    [InlineData("secret:otopcua/galaxy/ack-fallback", CredentialReferenceKind.Secret)]
    [InlineData("env:OTOPCUA_GALAXY_API_KEY", CredentialReferenceKind.Environment)]
    [InlineData("env:GALAXY_MXGW_API_KEY", CredentialReferenceKind.Environment)]
    [InlineData("plain-key", CredentialReferenceKind.Literal)]
    [InlineData("dev:k", CredentialReferenceKind.Literal)]
    [InlineData("secret:otopcua/historian/api-key", CredentialReferenceKind.OutOfScope)]
    [InlineData("secret:otopcua/apikeys/ab/galaxy-ack-password", CredentialReferenceKind.OutOfScope)]
    [InlineData("secret:OT-MESH-PSK-MAIN", CredentialReferenceKind.OutOfScope)]
    [InlineData("secret:galaxy/", CredentialReferenceKind.OutOfScope)]
    [InlineData("secret:galaxy/../otopcua/historian/api-key", CredentialReferenceKind.OutOfScope)]
    [InlineData("secret:galaxy//x", CredentialReferenceKind.OutOfScope)]
    [InlineData("secret:galaxyx/y", CredentialReferenceKind.OutOfScope)]
    [InlineData("${secret:galaxy/x", CredentialReferenceKind.OutOfScope)]
    [InlineData("SECRET:galaxy/x", CredentialReferenceKind.OutOfScope)]
    [InlineData("Env:OTOPCUA_GALAXY_X", CredentialReferenceKind.OutOfScope)]
    [InlineData("env:ConnectionStrings__ConfigDb", CredentialReferenceKind.OutOfScope)]
    [InlineData("env:ServerHistorian__ApiKey", CredentialReferenceKind.OutOfScope)]
    [InlineData("env:OTOPCUA_GALAXY_", CredentialReferenceKind.OutOfScope)]
    [InlineData("env:OTOPCUA_GALAXY_lower", CredentialReferenceKind.OutOfScope)]
    [InlineData("env:OTOPCUA_HEIDENHAIN_X", CredentialReferenceKind.OutOfScope)]
    [InlineData("file:appsettings.json", CredentialReferenceKind.OutOfScope)]
    [InlineData("FILE:x", CredentialReferenceKind.OutOfScope)]
    public void Parse_classifies_against_the_galaxy_scope(string? value, CredentialReferenceKind expected) =>
        CredentialReferences.Parse(value, Galaxy, out _).ShouldBe(expected);

    [Fact]
    public void Scopes_do_not_overlap_across_drivers()
    {
        CredentialReferences.Parse("secret:heidenhain/x", Galaxy, out _).ShouldBe(CredentialReferenceKind.OutOfScope);
        CredentialReferences.Parse("secret:galaxy/x", DriverCredentialPolicy.OpcUaClientScope, out _)
            .ShouldBe(CredentialReferenceKind.OutOfScope);
        CredentialReferences.Parse("env:OTOPCUA_GALAXY_X", DriverCredentialPolicy.HeidenhainScope, out _)
            .ShouldBe(CredentialReferenceKind.OutOfScope);
    }

    [Theory]
    [InlineData(CredentialLiteralPolicy.Allowed, "plain", true)]
    [InlineData(CredentialLiteralPolicy.Refused, "plain", false)]
    [InlineData(CredentialLiteralPolicy.Refused, "dev:x", false)]
    [InlineData(CredentialLiteralPolicy.DevPrefixOnly, "dev:x", true)]
    [InlineData(CredentialLiteralPolicy.DevPrefixOnly, "plain", false)]
    [InlineData(CredentialLiteralPolicy.Allowed, "env:ConnectionStrings__ConfigDb", false)]
    public void IsAcceptable_applies_the_literal_policy(CredentialLiteralPolicy policy, string value, bool expected) =>
        CredentialReferences.IsAcceptable(value, Galaxy, policy).ShouldBe(expected);

    /// <summary>The fail-closed core: an out-of-scope reference throws before either source is consulted.</summary>
    [Theory]
    [InlineData("env:ConnectionStrings__ConfigDb")]
    [InlineData("secret:otopcua/historian/api-key")]
    [InlineData("file:appsettings.json")]
    public async Task Resolve_never_reads_for_an_out_of_scope_reference(string value)
    {
        var reads = 0;
        var ex = await Should.ThrowAsync<CredentialReferenceException>(async () => await CredentialReferences.ResolveAsync(
            value, Galaxy, "F", CredentialLiteralPolicy.Allowed,
            (_, _) => { reads++; return ValueTask.FromResult<string?>("LEAKED"); },
            _ => { reads++; return "LEAKED"; },
            CancellationToken.None));
        reads.ShouldBe(0);
        ex.Message.ShouldContain("'secret:galaxy/<name>'");
        ex.Message.ShouldContain("'env:OTOPCUA_GALAXY_<NAME>'");
        ex.Message.ShouldNotContain("LEAKED");
    }

    [Fact]
    public async Task Resolve_reads_scoped_references_and_fails_closed_when_absent()
    {
        (await CredentialReferences.ResolveAsync("secret:galaxy/a", Galaxy, "F", CredentialLiteralPolicy.Refused,
            (n, _) => ValueTask.FromResult<string?>(n == "galaxy/a" ? "v" : null), _ => null, CancellationToken.None))
            .ShouldBe("v");
        (await CredentialReferences.ResolveAsync("env:OTOPCUA_GALAXY_A", Galaxy, "F", CredentialLiteralPolicy.Refused,
            null, n => n == "OTOPCUA_GALAXY_A" ? "e" : null, CancellationToken.None)).ShouldBe("e");
        (await Should.ThrowAsync<CredentialReferenceException>(async () => await CredentialReferences.ResolveAsync(
            "secret:galaxy/missing", Galaxy, "F", CredentialLiteralPolicy.Refused,
            (_, _) => ValueTask.FromResult<string?>(null), null, CancellationToken.None))).Message.ShouldContain("absent");
        (await Should.ThrowAsync<CredentialReferenceException>(async () => await CredentialReferences.ResolveAsync(
            "env:OTOPCUA_GALAXY_UNSET", Galaxy, "F", CredentialLiteralPolicy.Refused,
            null, _ => null, CancellationToken.None))).Message.ShouldContain("not set");
        (await Should.ThrowAsync<CredentialReferenceException>(async () => await CredentialReferences.ResolveAsync(
            "secret:galaxy/a", Galaxy, "F", CredentialLiteralPolicy.Refused,
            null, null, CancellationToken.None))).Message.ShouldContain("no secret store");
    }

    [Fact]
    public void DescribeProblems_scans_every_depth_case_insensitively_and_never_echoes_the_value()
    {
        const string json = """
            {
              "gateway": { "endpoint": "http://evil:5001", "apiKeySecretRef": "env:ConnectionStrings__ConfigDb" },
              "Devices": [ { "AlarmAck": { "FallbackPasswordSecretRef": "hunter2" } } ]
            }
            """;
        var problems = DriverCredentialPolicy.DescribeProblems(DriverTypeNames.Galaxy, json);
        problems.Count.ShouldBe(2);
        problems.ShouldContain(p => p.StartsWith("gateway.apiKeySecretRef", StringComparison.Ordinal));
        problems.ShouldContain(p => p.StartsWith("Devices[0].AlarmAck.FallbackPasswordSecretRef", StringComparison.Ordinal));
        problems.ShouldAllBe(p => !p.Contains("hunter2") && !p.Contains("ConnectionStrings__ConfigDb"));
    }

    [Theory]
    [InlineData(DriverTypeNames.Galaxy, """{"Gateway":{"ApiKeySecretRef":"secret:galaxy/main/apikey"},"AlarmAck":{"FallbackPasswordSecretRef":"dev:x"}}""")]
    [InlineData(DriverTypeNames.Galaxy, """{"Gateway":{"ApiKeySecretRef":"literal-key"}}""")]
    [InlineData(DriverTypeNames.OpcUaClient, """{"Password":"plain","UserCertificatePassword":"secret:opcuaclient/plant/cert"}""")]
    [InlineData(DriverTypeNames.Heidenhain, """{"Access":{"InspectPassword":"env:OTOPCUA_HEIDENHAIN_INSPECT"}}""")]
    [InlineData(DriverTypeNames.Modbus, """{"Password":"env:ConnectionStrings__ConfigDb"}""")]
    [InlineData(DriverTypeNames.Galaxy, "")]
    public void DescribeProblems_accepts_namespaced_and_unrelated_configs(string driverType, string json) =>
        DriverCredentialPolicy.DescribeProblems(driverType, json).ShouldBeEmpty();

    [Theory]
    [InlineData(DriverTypeNames.OpcUaClient, """{"Password":"secret:galaxy/main/apikey"}""")]
    [InlineData(DriverTypeNames.OpcUaClient, """{"UserCertificatePassword":"env:ServerHistorian__ApiKey"}""")]
    [InlineData(DriverTypeNames.Galaxy, """{"Gateway":{"ApiKeySecretRef":"file:C:\\ProgramData\\x.txt"}}""")]
    [InlineData(DriverTypeNames.Galaxy, """{"Gateway":{"ApiKeySecretRef":42}}""")]
    [InlineData(DriverTypeNames.Heidenhain, """{"InspectPassword":"plain"}""")]
    [InlineData(DriverTypeNames.Galaxy, "{not json")]
    public void DescribeProblems_refuses_out_of_namespace_configs(string driverType, string json) =>
        DriverCredentialPolicy.DescribeProblems(driverType, json).ShouldNotBeEmpty();
}