using ZB.MOM.WW.ScadaBridge.TemplateEngine.Validation;

namespace ZB.MOM.WW.ScadaBridge.TemplateEngine.Tests.Validation;

/// <summary>
/// M3.2: the design-time deploy gate now delegates to the shared
/// <c>ZB.MOM.WW.ScadaBridge.ScriptAnalysis</c> analyzer — a real Roslyn semantic
/// forbidden-API verdict plus a real CSharpScript compile against the
/// runtime-mirroring <c>ScriptCompileSurface</c>. These tests assert the
/// authoritative behavior: bypasses the old substring scan missed are now caught,
/// and undefined symbols (which a structural scan could never see) fail compile.
/// </summary>
public class ScriptCompilerTests
{
    private readonly ScriptCompiler _sut = new();

    [Fact]
    public void TryCompile_EmptyCode_ReturnsFailure()
    {
        var result = _sut.TryCompile("", "Test");
        Assert.True(result.IsFailure);
        Assert.Contains("empty", result.Error, StringComparison.OrdinalIgnoreCase);
    }

    [Fact]
    public void TryCompile_WhitespaceOnly_ReturnsFailure()
    {
        var result = _sut.TryCompile("   \n\t  ", "Test");
        Assert.True(result.IsFailure);
        Assert.Contains("empty", result.Error, StringComparison.OrdinalIgnoreCase);
    }

    // --- Forbidden-API gate (authoritative) ---

    [Fact]
    public void TryCompile_ForbiddenApi_ReturnsFailure()
    {
        var result = _sut.TryCompile("using System.IO; File.ReadAllText(\"x\");", "Test");
        Assert.True(result.IsFailure);
        Assert.Contains("forbidden", result.Error, StringComparison.OrdinalIgnoreCase);
    }

    [Theory]
    // Namespace alias — the old substring scan never saw "System.IO." spelled out.
    [InlineData("using IO = System.IO; IO.File.ReadAllText(\"x\");")]
    // using static — the call site is a bare ReadAllText(...) with no namespace text.
    [InlineData("using static System.IO.File; ReadAllText(\"x\");")]
    // global::-qualified reference.
    [InlineData("global::System.IO.File.ReadAllText(\"x\");")]
    // Reflection gateway — never spells a forbidden namespace at all.
    [InlineData("typeof(string).Assembly.GetType(\"System.IO.File\");")]
    public void TryCompile_AdversarialForbiddenApiBypass_StillRejected(string code)
    {
        var result = _sut.TryCompile(code, "Test");
        Assert.True(result.IsFailure);
        Assert.Contains("forbidden", result.Error, StringComparison.OrdinalIgnoreCase);
    }

    // --- Real-compile gate (the win over the old structural-only scan) ---

    [Fact]
    public void TryCompile_UndefinedSymbol_ReturnsFailure()
    {
        // A brace-balanced, forbidden-API-free script that references an undefined
        // symbol. The old substring + brace scan accepted this; the real compile
        // rejects it.
        var result = _sut.TryCompile("var x = NoSuchThing.Foo();", "Test");
        Assert.True(result.IsFailure);
        Assert.Contains("compile", result.Error, StringComparison.OrdinalIgnoreCase);
    }

    [Fact]
    public void TryCompile_SyntaxError_ReturnsFailure()
    {
        // Genuinely malformed — must fail the real compile.
        var result = _sut.TryCompile("if (true) { var x = 1;", "Test");
        Assert.True(result.IsFailure);
    }

    // --- Valid real script against the script API surface ---

    [Fact]
    public void TryCompile_ValidScriptUsingApiSurface_ReturnsSuccess()
    {
        const string code = """
            var t = Attributes["Temperature"];
            Attributes["Setpoint"] = 42;
            var r = await ExternalSystem.Call("erp", "sync");
            await Notify.To("ops").Send("s", "m");
            """;

        var result = _sut.TryCompile(code, "Test");
        Assert.True(result.IsSuccess, result.IsFailure ? result.Error : null);
    }

    // --- Trigger-expression gate via ValidationService.CheckExpressionSyntax ---

    [Fact]
    public void CheckExpressionSyntax_ValidExpression_ReturnsNull()
    {
        // A bare boolean expression binding against the trigger globals surface.
        var error = ValidationService.CheckExpressionSyntax("Attributes[\"Temp\"] != null");
        Assert.Null(error);
    }

    [Fact]
    public void CheckExpressionSyntax_ForbiddenApi_ReturnsMessage()
    {
        var error = ValidationService.CheckExpressionSyntax("System.IO.File.Exists(\"x\")");
        Assert.NotNull(error);
        Assert.Contains("forbidden", error, StringComparison.OrdinalIgnoreCase);
    }
}