using Microsoft.Extensions.Caching.Memory;
using NSubstitute;
using ScadaLink.CentralUI.ScriptAnalysis;

namespace ScadaLink.CentralUI.Tests.ScriptAnalysis;

public class ScriptAnalysisServiceTests
{
    private readonly ISharedScriptCatalog _catalog = Substitute.For<ISharedScriptCatalog>();
    private readonly IMemoryCache _cache = new MemoryCache(new MemoryCacheOptions { SizeLimit = 100 });
    private readonly ScriptAnalysisService _svc;

    private static ScriptShape Shape(string name, params ParameterShape[] ps) =>
        new(name, ps, null);

    private static ParameterShape Param(string name, string type = "String", bool required = true) =>
        new(name, type, required);

    public ScriptAnalysisServiceTests()
    {
        _catalog.GetShapesAsync().Returns(Array.Empty<ScriptShape>());
        _svc = new ScriptAnalysisService(_catalog, _cache);
    }

    // ── Diagnose ──────────────────────────────────────────────────────────

    [Fact]
    public void EmptyCode_NoMarkers()
    {
        var resp = _svc.Diagnose(new DiagnoseRequest(""));
        Assert.Empty(resp.Markers);
    }

    [Fact]
    public void CleanScript_NoMarkers()
    {
        var resp = _svc.Diagnose(new DiagnoseRequest("var x = 1 + 2; return x;"));
        Assert.Empty(resp.Markers);
    }

    [Fact]
    public void MissingSemicolon_ReportsRoslynDiagnostic()
    {
        var resp = _svc.Diagnose(new DiagnoseRequest("var x = 1\n"));
        Assert.Contains(resp.Markers, m => m.Code.StartsWith("CS"));
    }

    [Fact]
    public void ForbiddenUsingDirective_RaisesSCADA001()
    {
        var resp = _svc.Diagnose(new DiagnoseRequest("using System.IO;"));
        Assert.Contains(resp.Markers, m => m.Code == "SCADA001" && m.Message.Contains("System.IO"));
    }

    [Theory]
    [InlineData("System.Diagnostics")]
    [InlineData("System.Reflection")]
    [InlineData("System.Net")]
    public void ForbiddenUsing_AllBannedNamespaces(string ns)
    {
        var resp = _svc.Diagnose(new DiagnoseRequest($"using {ns};"));
        Assert.Contains(resp.Markers, m => m.Code == "SCADA001" && m.Message.Contains(ns));
    }

    [Fact]
    public void ForbiddenTypeUsage_ResolvesViaSemanticModel()
    {
        var resp = _svc.Diagnose(new DiagnoseRequest(
            "using System.IO; var s = File.ReadAllText(\"x\");"));
        Assert.Contains(resp.Markers, m => m.Code == "SCADA002" && m.Message.Contains("File"));
    }

    [Fact]
    public void UserIdentifierNamedFile_DoesNotFalsePositive()
    {
        var resp = _svc.Diagnose(new DiagnoseRequest(
            "var File = \"hello\"; return File.Length;"));
        Assert.DoesNotContain(resp.Markers, m => m.Code == "SCADA002");
    }

    [Fact]
    public void UserIdentifierNamedThread_DoesNotFalsePositive()
    {
        var resp = _svc.Diagnose(new DiagnoseRequest(
            "var Thread = 42; return Thread;"));
        Assert.DoesNotContain(resp.Markers, m => m.Code == "SCADA002");
    }

    [Fact]
    public void DiagnosticsAreCached_SecondCallSkipsRecompile()
    {
        var req = new DiagnoseRequest("using System.IO;");
        var first = _svc.Diagnose(req);
        var second = _svc.Diagnose(req);
        Assert.Same(first, second);
    }

    [Fact]
    public void DifferentCode_GetsDifferentCacheEntries()
    {
        var a = _svc.Diagnose(new DiagnoseRequest("var x = 1;"));
        var b = _svc.Diagnose(new DiagnoseRequest("var y = 2;"));
        Assert.NotSame(a, b);
    }

    [Fact]
    public void UnknownParameterKey_RaisesSCADA003()
    {
        var resp = _svc.Diagnose(new DiagnoseRequest(
            Code: "var x = Parameters[\"typo\"];",
            DeclaredParameters: new[] { "name", "temperature" }));
        Assert.Contains(resp.Markers, m => m.Code == "SCADA003" && m.Message.Contains("'typo'"));
    }

    [Fact]
    public void DeclaredParameterKey_NoMarker()
    {
        var resp = _svc.Diagnose(new DiagnoseRequest(
            Code: "var x = Parameters[\"name\"];",
            DeclaredParameters: new[] { "name", "temperature" }));
        Assert.DoesNotContain(resp.Markers, m => m.Code == "SCADA003");
    }

    [Fact]
    public void ArgumentCountTooFew_RaisesSCADA004()
    {
        var siblings = new[] { Shape("Calc", Param("x"), Param("y")) };
        var resp = _svc.Diagnose(new DiagnoseRequest(
            Code: "var r = CallScript(\"Calc\", 1);",
            SiblingScripts: siblings));
        Assert.Contains(resp.Markers, m => m.Code == "SCADA004" && m.Message.Contains("expects 2"));
    }

    [Fact]
    public void ArgumentCountTooMany_RaisesSCADA004()
    {
        var siblings = new[] { Shape("Ping") };
        var resp = _svc.Diagnose(new DiagnoseRequest(
            Code: "var r = CallScript(\"Ping\", 1, 2);",
            SiblingScripts: siblings));
        Assert.Contains(resp.Markers, m => m.Code == "SCADA004" && m.Message.Contains("got 2"));
    }

    [Fact]
    public void ArgumentCountCorrect_NoMarker()
    {
        var siblings = new[] { Shape("Calc", Param("x"), Param("y")) };
        var resp = _svc.Diagnose(new DiagnoseRequest(
            Code: "var r = CallScript(\"Calc\", 1, 2);",
            SiblingScripts: siblings));
        Assert.DoesNotContain(resp.Markers, m => m.Code == "SCADA004");
    }

    [Fact]
    public void OptionalParameter_AcceptsBothOmittedAndPresent()
    {
        var siblings = new[]
        {
            Shape("Calc", Param("x"), Param("y", required: false))
        };
        // Required only (1) — OK.
        var with1 = _svc.Diagnose(new DiagnoseRequest(
            Code: "var r = CallScript(\"Calc\", 1);",
            SiblingScripts: siblings));
        Assert.DoesNotContain(with1.Markers, m => m.Code == "SCADA004");
        // Both passed (2) — OK.
        var with2 = _svc.Diagnose(new DiagnoseRequest(
            Code: "var r = CallScript(\"Calc\", 1, 2);",
            SiblingScripts: siblings));
        Assert.DoesNotContain(with2.Markers, m => m.Code == "SCADA004");
    }

    // ── Completions ───────────────────────────────────────────────────────

    [Fact]
    public async Task ParametersStringLiteral_ReturnsDeclaredParameterNames()
    {
        var req = new CompletionsRequest(
            CodeText: "var x = Parameters[\"",
            Line: 1,
            Column: 21,
            DeclaredParameters: new[] { "name", "temperature" });

        var resp = await _svc.CompleteAsync(req);

        Assert.Contains(resp.Items, i => i.Label == "name" && i.Detail == "declared parameter");
        Assert.Contains(resp.Items, i => i.Label == "temperature");
    }

    [Fact]
    public async Task CallScriptStringLiteral_ReturnsSiblingNamesWithSnippet()
    {
        var siblings = new[] { Shape("SiblingA", Param("x")) };
        var req = new CompletionsRequest(
            CodeText: "var x = CallScript(\"",
            Line: 1,
            Column: 21,
            SiblingScripts: siblings);

        var resp = await _svc.CompleteAsync(req);

        var item = Assert.Single(resp.Items, i => i.Label == "SiblingA");
        Assert.Equal(4, item.InsertTextRules);
        Assert.Contains("${1:x}", item.InsertText);
        Assert.Contains("sibling script", item.Detail);
    }

    [Fact]
    public async Task CallSharedStringLiteral_ResolvesViaCatalogWithShapes()
    {
        _catalog.GetShapesAsync().Returns(new[]
        {
            Shape("GetWeather"),
            Shape("Greet", Param("name"))
        });

        var req = new CompletionsRequest(
            CodeText: "var x = CallShared(\"",
            Line: 1,
            Column: 21);

        var resp = await _svc.CompleteAsync(req);

        Assert.Contains(resp.Items, i => i.Label == "GetWeather");
        var greet = Assert.Single(resp.Items, i => i.Label == "Greet");
        Assert.Contains("${1:name}", greet.InsertText);
    }

    [Fact]
    public async Task GeneralCompletion_ReturnsInScopeSymbols()
    {
        var req = new CompletionsRequest("var x = ", 1, 9);
        var resp = await _svc.CompleteAsync(req);
        Assert.Contains(resp.Items, i => i.Label == "Parameters");
        Assert.Contains(resp.Items, i => i.Label == "CallShared");
    }

    // ── Hover ─────────────────────────────────────────────────────────────

    [Fact]
    public void Hover_OnSiblingName_ReturnsSignature()
    {
        var siblings = new[] { Shape("Calc", Param("x", "Integer"), Param("y", "Float")) };
        var resp = _svc.Hover(new HoverRequest(
            CodeText: "var r = CallScript(\"Calc\", 1, 2);",
            Line: 1,
            Column: 23,
            SiblingScripts: siblings));
        Assert.NotNull(resp.Markdown);
        Assert.Contains("Calc", resp.Markdown);
        Assert.Contains("x: Integer", resp.Markdown);
        Assert.Contains("y: Float", resp.Markdown);
    }

    [Fact]
    public void Hover_OnUnrelatedToken_ReturnsNull()
    {
        var resp = _svc.Hover(new HoverRequest(
            CodeText: "var r = 1 + 2;",
            Line: 1,
            Column: 5));
        Assert.Null(resp.Markdown);
    }

    // ── Signature help ────────────────────────────────────────────────────

    [Fact]
    public void SignatureHelp_InsideCallScript_ReturnsParameterStrip()
    {
        var siblings = new[] { Shape("Calc", Param("x", "Integer"), Param("y", "Float")) };
        var resp = _svc.SignatureHelp(new SignatureHelpRequest(
            CodeText: "var r = CallScript(\"Calc\", 1, ",
            Line: 1,
            Column: 31,
            SiblingScripts: siblings));
        Assert.NotNull(resp.Label);
        Assert.Equal(2, resp.Parameters!.Count);
        Assert.Equal("x: Integer", resp.Parameters[0].Label);
        Assert.Equal("y: Float", resp.Parameters[1].Label);
        Assert.Equal(1, resp.ActiveParameter);
    }

    [Fact]
    public void SignatureHelp_OutsideCall_ReturnsNull()
    {
        var resp = _svc.SignatureHelp(new SignatureHelpRequest(
            CodeText: "var r = 1 + 2;",
            Line: 1,
            Column: 5));
        Assert.Null(resp.Label);
    }
}