// -----------------------------------------------------------------------------
// NodeCallGraphExtractorTests.cs
// Sprint: SPRINT_3610_0003_0001_nodejs_callgraph
// Description: Unit tests for Node.js/JavaScript call graph extraction.
// -----------------------------------------------------------------------------

using StellaOps.Scanner.CallGraph.Node;
using Xunit;

namespace StellaOps.Scanner.CallGraph.Tests;

public class NodeCallGraphExtractorTests
{
    [Fact]
    public void BabelResultParser_ParsesValidJson()
    {
        // Arrange
        var json = """
        {
            "module": "my-app",
            "version": "1.0.0",
            "nodes": [
                {
                    "id": "js:my-app/src/index.handleRequest",
                    "package": "my-app",
                    "name": "handleRequest",
                    "visibility": "public"
                }
            ],
            "edges": [
                {
                    "from": "js:my-app/src/index.handleRequest",
                    "to": "js:external/express.Router",
                    "kind": "direct"
                }
            ],
            "entrypoints": [
                {
                    "id": "js:my-app/src/index.handleRequest",
                    "type": "http_handler",
                    "route": "/api/users",
                    "method": "GET"
                }
            ]
        }
        """;

        // Act
        var result = BabelResultParser.Parse(json);

        // Assert
        Assert.Equal("my-app", result.Module);
        Assert.Equal("1.0.0", result.Version);
        Assert.Single(result.Nodes);
        Assert.Single(result.Edges);
        Assert.Single(result.Entrypoints);
    }

    [Fact]
    public void BabelResultParser_ParsesNodeWithPosition()
    {
        // Arrange
        var json = """
        {
            "module": "test",
            "nodes": [
                {
                    "id": "js:test/app.main",
                    "package": "test",
                    "name": "main",
                    "position": {
                        "file": "app.js",
                        "line": 10,
                        "column": 5
                    }
                }
            ],
            "edges": [],
            "entrypoints": []
        }
        """;

        // Act
        var result = BabelResultParser.Parse(json);

        // Assert
        Assert.Single(result.Nodes);
        var node = result.Nodes[0];
        Assert.NotNull(node.Position);
        Assert.Equal("app.js", node.Position.File);
        Assert.Equal(10, node.Position.Line);
        Assert.Equal(5, node.Position.Column);
    }

    [Fact]
    public void BabelResultParser_ParsesEdgeWithSite()
    {
        // Arrange
        var json = """
        {
            "module": "test",
            "nodes": [],
            "edges": [
                {
                    "from": "js:test/a.foo",
                    "to": "js:test/b.bar",
                    "kind": "callback",
                    "site": {
                        "file": "a.js",
                        "line": 25
                    }
                }
            ],
            "entrypoints": []
        }
        """;

        // Act
        var result = BabelResultParser.Parse(json);

        // Assert
        Assert.Single(result.Edges);
        var edge = result.Edges[0];
        Assert.Equal("callback", edge.Kind);
        Assert.NotNull(edge.Site);
        Assert.Equal("a.js", edge.Site.File);
        Assert.Equal(25, edge.Site.Line);
    }

    [Fact]
    public void BabelResultParser_ThrowsOnEmptyInput()
    {
        // Arrange & Act & Assert
        Assert.Throws<ArgumentException>(() => BabelResultParser.Parse(""));
        Assert.Throws<ArgumentNullException>(() => BabelResultParser.Parse(null!));
    }

    [Fact]
    public void BabelResultParser_ParsesNdjson()
    {
        // Arrange
        var ndjson = """
        {"type": "progress", "percent": 50}
        {"type": "progress", "percent": 100}
        {"module": "app", "nodes": [], "edges": [], "entrypoints": []}
        """;

        // Act
        var result = BabelResultParser.ParseNdjson(ndjson);

        // Assert
        Assert.Equal("app", result.Module);
    }

    [Fact]
    public void JsEntrypointInfo_HasCorrectProperties()
    {
        // Arrange
        var json = """
        {
            "module": "api",
            "nodes": [],
            "edges": [],
            "entrypoints": [
                {
                    "id": "js:api/routes.getUsers",
                    "type": "http_handler",
                    "route": "/users/:id",
                    "method": "GET"
                }
            ]
        }
        """;

        // Act
        var result = BabelResultParser.Parse(json);

        // Assert
        Assert.Single(result.Entrypoints);
        var ep = result.Entrypoints[0];
        Assert.Equal("js:api/routes.getUsers", ep.Id);
        Assert.Equal("http_handler", ep.Type);
        Assert.Equal("/users/:id", ep.Route);
        Assert.Equal("GET", ep.Method);
    }

    [Fact]
    public void BabelResultParser_ParsesSinks()
    {
        // Arrange
        var json = """
        {
            "module": "test",
            "nodes": [
                {
                    "id": "js:test/handler.processRequest",
                    "package": "test",
                    "name": "processRequest"
                }
            ],
            "edges": [],
            "entrypoints": [],
            "sinks": [
                {
                    "caller": "js:test/handler.processRequest",
                    "category": "command_injection",
                    "method": "child_process.exec",
                    "site": {
                        "file": "handler.js",
                        "line": 42,
                        "column": 8
                    }
                }
            ]
        }
        """;

        // Act
        var result = BabelResultParser.Parse(json);

        // Assert
        Assert.Single(result.Sinks);
        var sink = result.Sinks[0];
        Assert.Equal("js:test/handler.processRequest", sink.Caller);
        Assert.Equal("command_injection", sink.Category);
        Assert.Equal("child_process.exec", sink.Method);
        Assert.NotNull(sink.Site);
        Assert.Equal("handler.js", sink.Site.File);
        Assert.Equal(42, sink.Site.Line);
    }

    [Fact]
    public void BabelResultParser_ParsesMultipleSinkCategories()
    {
        // Arrange
        var json = """
        {
            "module": "vulnerable-app",
            "nodes": [],
            "edges": [],
            "entrypoints": [],
            "sinks": [
                {
                    "caller": "js:vulnerable-app/db.query",
                    "category": "sql_injection",
                    "method": "connection.query"
                },
                {
                    "caller": "js:vulnerable-app/api.fetch",
                    "category": "ssrf",
                    "method": "fetch"
                },
                {
                    "caller": "js:vulnerable-app/file.write",
                    "category": "file_write",
                    "method": "fs.writeFileSync"
                }
            ]
        }
        """;

        // Act
        var result = BabelResultParser.Parse(json);

        // Assert
        Assert.Equal(3, result.Sinks.Count);
        Assert.Contains(result.Sinks, s => s.Category == "sql_injection");
        Assert.Contains(result.Sinks, s => s.Category == "ssrf");
        Assert.Contains(result.Sinks, s => s.Category == "file_write");
    }

    [Fact]
    public void BabelResultParser_ParsesEmptySinks()
    {
        // Arrange
        var json = """
        {
            "module": "safe-app",
            "nodes": [],
            "edges": [],
            "entrypoints": [],
            "sinks": []
        }
        """;

        // Act
        var result = BabelResultParser.Parse(json);

        // Assert
        Assert.Empty(result.Sinks);
    }

    [Fact]
    public void BabelResultParser_ParsesMissingSinks()
    {
        // Arrange - sinks field omitted entirely
        var json = """
        {
            "module": "legacy-app",
            "nodes": [],
            "edges": [],
            "entrypoints": []
        }
        """;

        // Act
        var result = BabelResultParser.Parse(json);

        // Assert - should default to empty list
        Assert.Empty(result.Sinks);
    }

    [Fact]
    public void BabelResultParser_ParsesSinkWithoutSite()
    {
        // Arrange
        var json = """
        {
            "module": "test",
            "nodes": [],
            "edges": [],
            "entrypoints": [],
            "sinks": [
                {
                    "caller": "js:test/func",
                    "category": "deserialization",
                    "method": "eval"
                }
            ]
        }
        """;

        // Act
        var result = BabelResultParser.Parse(json);

        // Assert
        Assert.Single(result.Sinks);
        Assert.Null(result.Sinks[0].Site);
    }
}