using System.Text.Json;
using StellaOps.Aoc;

namespace StellaOps.Aoc.Tests;

public sealed class AocWriteGuardTests
{
    private static readonly AocWriteGuard Guard = new();

    [Fact]
    public void Validate_ReturnsSuccess_ForMinimalValidDocument()
    {
        using var document = JsonDocument.Parse("""
        {
          "tenant": "default",
          "source": {"vendor": "osv"},
          "upstream": {
            "upstream_id": "GHSA-xxxx",
            "content_hash": "sha256:abc",
            "signature": { "present": false }
          },
          "content": {
            "format": "OSV",
            "raw": {"id": "GHSA-xxxx"}
          },
          "linkset": {}
        }
        """);

        var result = Guard.Validate(document.RootElement);

        Assert.True(result.IsValid);
        Assert.Empty(result.Violations);
    }

    [Fact]
    public void Validate_AllowsLinksAndAdvisoryKey_ByDefault()
    {
        using var document = JsonDocument.Parse("""
        {
          "tenant": "default",
          "source": {"vendor": "osv"},
          "upstream": {
            "upstream_id": "GHSA-xxxx",
            "content_hash": "sha256:abc",
            "signature": { "present": false }
          },
          "content": {
            "format": "OSV",
            "raw": {"id": "GHSA-xxxx"}
          },
          "linkset": {},
          "links": [
            { "scheme": "cve", "value": "CVE-2025-0001" }
          ],
          "advisory_key": "ghsa-xxxx"
        }
        """);

        var result = Guard.Validate(document.RootElement);

        Assert.True(result.IsValid);
        Assert.Empty(result.Violations);
    }

    [Fact]
    public void Validate_FlagsMissingTenant()
    {
        using var document = JsonDocument.Parse("""
        {
          "source": {"vendor": "osv"},
          "upstream": {
            "upstream_id": "GHSA-xxxx",
            "content_hash": "sha256:abc",
            "signature": { "present": false }
          },
          "content": {
            "format": "OSV",
            "raw": {"id": "GHSA-xxxx"}
          },
          "linkset": {}
        }
        """);

        var result = Guard.Validate(document.RootElement);

        Assert.False(result.IsValid);
        Assert.Contains(result.Violations, v => v.ErrorCode == "ERR_AOC_004" && v.Path == "/tenant");
    }

    [Fact]
    public void Validate_FlagsForbiddenField()
    {
        using var document = JsonDocument.Parse("""
        {
          "tenant": "default",
          "identifiers": {},
          "severity": "high",
          "source": {"vendor": "osv"},
          "upstream": {
            "upstream_id": "GHSA-xxxx",
            "content_hash": "sha256:abc",
            "signature": { "present": false }
          },
          "content": {
            "format": "OSV",
            "raw": {"id": "GHSA-xxxx"}
          },
          "linkset": {}
        }
        """);

        var result = Guard.Validate(document.RootElement);

        Assert.False(result.IsValid);
        Assert.Contains(result.Violations, v => v.ErrorCode == "ERR_AOC_001" && v.Path == "/severity");
    }

    [Fact]
    public void Validate_FlagsUnknownField()
    {
        using var document = JsonDocument.Parse("""
        {
          "tenant": "default",
          "source": {"vendor": "osv"},
          "upstream": {
            "upstream_id": "GHSA-xxxx",
            "content_hash": "sha256:abc",
            "signature": { "present": false }
          },
          "content": {
            "format": "OSV",
            "raw": {"id": "GHSA-xxxx"}
          },
          "linkset": {},
          "custom_field": {"extra": true}
        }
        """);

        var result = Guard.Validate(document.RootElement);

        Assert.False(result.IsValid);
        Assert.Contains(result.Violations, v => v.ErrorCode == "ERR_AOC_007" && v.Path == "/custom_field");
    }

    [Fact]
    public void Validate_AllowsCustomField_WhenConfigured()
    {
        using var document = JsonDocument.Parse("""
        {
          "tenant": "default",
          "source": {"vendor": "osv"},
          "upstream": {
            "upstream_id": "GHSA-xxxx",
            "content_hash": "sha256:abc",
            "signature": { "present": false }
          },
          "content": {
            "format": "OSV",
            "raw": {"id": "GHSA-xxxx"}
          },
          "linkset": {},
          "custom_field": {"extra": true}
        }
        """);

        var options = new AocGuardOptions
        {
            AllowedTopLevelFields = AocGuardOptions.Default.AllowedTopLevelFields.Add("custom_field")
        };

        var result = Guard.Validate(document.RootElement, options);

        Assert.True(result.IsValid);
    }

    [Fact]
    public void Validate_FlagsInvalidSignatureMetadata()
    {
        using var document = JsonDocument.Parse("""
        {
          "tenant": "default",
          "source": {"vendor": "osv"},
          "upstream": {
            "upstream_id": "GHSA-xxxx",
            "content_hash": "sha256:abc",
            "signature": { "present": true, "format": "dsse" }
          },
          "content": {
            "format": "OSV",
            "raw": {"id": "GHSA-xxxx"}
          },
          "linkset": {}
        }
        """);

        var result = Guard.Validate(document.RootElement);

        Assert.False(result.IsValid);
        Assert.Contains(result.Violations, v => v.ErrorCode == "ERR_AOC_005" && v.Path.Contains("/sig"));
    }
}