// -----------------------------------------------------------------------------
// FindingEvidenceContractsTests.cs
// Sprint: SPRINT_4300_0001_0002_findings_evidence_api
// Description: Unit tests for JSON serialization of evidence API contracts.
// -----------------------------------------------------------------------------

using System;
using System.Collections.Generic;
using System.Text.Json;
using StellaOps.Scanner.WebService.Contracts;
using Xunit;

namespace StellaOps.Scanner.WebService.Tests;

public class FindingEvidenceContractsTests
{
    private static readonly JsonSerializerOptions SerializerOptions = new()
    {
        PropertyNamingPolicy = JsonNamingPolicy.SnakeCaseLower,
        WriteIndented = false
    };

    [Fact]
    public void FindingEvidenceResponse_SerializesToSnakeCase()
    {
        var response = new FindingEvidenceResponse
        {
            FindingId = "finding-123",
            Cve = "CVE-2021-44228",
            Component = new ComponentInfo
            {
                Name = "log4j-core",
                Version = "2.14.1",
                Purl = "pkg:maven/org.apache.logging.log4j/log4j-core@2.14.1",
                Ecosystem = "maven"
            },
            ReachablePath = new[] { "com.example.App.main", "org.apache.log4j.Logger.log" },
            LastSeen = new DateTimeOffset(2025, 12, 18, 12, 0, 0, TimeSpan.Zero),
            AttestationRefs = new[] { "dsse:sha256:abc123" },
            Freshness = new FreshnessInfo { IsStale = false }
        };

        var json = JsonSerializer.Serialize(response, SerializerOptions);

        Assert.Contains("\"finding_id\":\"finding-123\"", json);
        Assert.Contains("\"cve\":\"CVE-2021-44228\"", json);
        Assert.Contains("\"component\":", json);
        Assert.Contains("\"reachable_path\":", json);
        Assert.Contains("\"freshness\":", json);
    }

    [Fact]
    public void FindingEvidenceResponse_RoundTripsCorrectly()
    {
        var original = new FindingEvidenceResponse
        {
            FindingId = "finding-456",
            Cve = "CVE-2023-12345",
            Component = new ComponentInfo
            {
                Name = "lodash",
                Version = "4.17.20",
                Purl = "pkg:npm/lodash@4.17.20",
                Ecosystem = "npm"
            },
            Entrypoint = new EntrypointInfo
            {
                Type = "http",
                Route = "/api/v1/users",
                Method = "POST",
                Auth = "jwt:write"
            },
            Score = new ScoreInfo
            {
                RiskScore = 75,
                Contributions = new[]
                {
                    new ScoreContribution
                    {
                        Factor = "reachability",
                        Value = 25,
                        Reason = "Reachable from entrypoint"
                    }
                }
            },
            LastSeen = DateTimeOffset.UtcNow,
            Freshness = new FreshnessInfo { IsStale = false }
        };

        var json = JsonSerializer.Serialize(original, SerializerOptions);
        var deserialized = JsonSerializer.Deserialize<FindingEvidenceResponse>(json, SerializerOptions);

        Assert.NotNull(deserialized);
        Assert.Equal(original.FindingId, deserialized.FindingId);
        Assert.Equal(original.Cve, deserialized.Cve);
        Assert.Equal(original.Component.Purl, deserialized.Component.Purl);
        Assert.Equal(original.Entrypoint?.Type, deserialized.Entrypoint?.Type);
        Assert.Equal(original.Score?.RiskScore, deserialized.Score?.RiskScore);
    }

    [Fact]
    public void ComponentInfo_SerializesAllFields()
    {
        var component = new ComponentInfo
        {
            Name = "Newtonsoft.Json",
            Version = "13.0.1",
            Purl = "pkg:nuget/Newtonsoft.Json@13.0.1",
            Ecosystem = "nuget"
        };

        var json = JsonSerializer.Serialize(component, SerializerOptions);

        Assert.Contains("\"name\":\"Newtonsoft.Json\"", json);
        Assert.Contains("\"version\":\"13.0.1\"", json);
        Assert.Contains("\"purl\":\"pkg:nuget/Newtonsoft.Json@13.0.1\"", json);
        Assert.Contains("\"ecosystem\":\"nuget\"", json);
    }

    [Fact]
    public void EntrypointInfo_SerializesAllFields()
    {
        var entrypoint = new EntrypointInfo
        {
            Type = "grpc",
            Route = "grpc.UserService.GetUser",
            Method = "CALL",
            Auth = "mtls"
        };

        var json = JsonSerializer.Serialize(entrypoint, SerializerOptions);

        Assert.Contains("\"type\":\"grpc\"", json);
        Assert.Contains("\"route\":\"grpc.UserService.GetUser\"", json);
        Assert.Contains("\"method\":\"CALL\"", json);
        Assert.Contains("\"auth\":\"mtls\"", json);
    }

    [Fact]
    public void BoundaryInfo_SerializesWithControls()
    {
        var boundary = new BoundaryInfo
        {
            Surface = "api",
            Exposure = "internet",
            Controls = new[] { "waf", "rate_limit" }
        };

        var json = JsonSerializer.Serialize(boundary, SerializerOptions);

        Assert.Contains("\"surface\":\"api\"", json);
        Assert.Contains("\"exposure\":\"internet\"", json);
        Assert.Contains("\"controls\":[\"waf\",\"rate_limit\"]", json);
    }

    [Fact]
    public void VexStatusInfo_SerializesCorrectly()
    {
        var vex = new VexStatusInfo
        {
            Status = "not_affected",
            Justification = "vulnerable_code_not_in_execute_path",
            Timestamp = new DateTimeOffset(2025, 12, 1, 0, 0, 0, TimeSpan.Zero),
            Issuer = "vendor"
        };

        var json = JsonSerializer.Serialize(vex, SerializerOptions);

        Assert.Contains("\"status\":\"not_affected\"", json);
        Assert.Contains("\"justification\":\"vulnerable_code_not_in_execute_path\"", json);
        Assert.Contains("\"issuer\":\"vendor\"", json);
    }

    [Fact]
    public void ScoreInfo_SerializesContributions()
    {
        var score = new ScoreInfo
        {
            RiskScore = 62,
            Contributions = new[]
            {
                new ScoreContribution
                {
                    Factor = "cvss_base",
                    Value = 40,
                    Reason = "Critical CVSS base score"
                },
                new ScoreContribution
                {
                    Factor = "reachability",
                    Value = 22,
                    Reason = "Reachable from HTTP entrypoint"
                }
            }
        };

        var json = JsonSerializer.Serialize(score, SerializerOptions);

        Assert.Contains("\"risk_score\":62", json);
        Assert.Contains("\"factor\":\"cvss_base\"", json);
        Assert.Contains("\"factor\":\"reachability\"", json);
    }

    [Fact]
    public void FreshnessInfo_SerializesCorrectly()
    {
        var freshness = new FreshnessInfo
        {
            IsStale = true,
            ExpiresAt = new DateTimeOffset(2025, 12, 31, 0, 0, 0, TimeSpan.Zero),
            TtlRemainingHours = 0
        };

        var json = JsonSerializer.Serialize(freshness, SerializerOptions);

        Assert.Contains("\"is_stale\":true", json);
        Assert.Contains("\"expires_at\":", json);
        Assert.Contains("\"ttl_remaining_hours\":0", json);
    }

    [Fact]
    public void NullOptionalFields_AreOmittedOrNullInJson()
    {
        var response = new FindingEvidenceResponse
        {
            FindingId = "finding-minimal",
            Cve = "CVE-2025-0001",
            Component = new ComponentInfo
            {
                Name = "unknown",
                Version = "unknown"
            },
            LastSeen = DateTimeOffset.UtcNow,
            Freshness = new FreshnessInfo { IsStale = false }
        };

        var json = JsonSerializer.Serialize(response, SerializerOptions);
        var deserialized = JsonSerializer.Deserialize<FindingEvidenceResponse>(json, SerializerOptions);

        Assert.NotNull(deserialized);
        Assert.Null(deserialized.Entrypoint);
        Assert.Null(deserialized.Vex);
        Assert.Null(deserialized.Score);
        Assert.Null(deserialized.Boundary);
    }
}