Resolve Concelier/Excititor merge conflicts

src/StellaOps.Policy/PolicyScoringConfigBinder.cs

@@ -0,0 +1,603 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.Globalization;
+using System.IO;
+using System.Linq;
+using System.Reflection;
+using System.Text;
+using System.Text.Json;
+using System.Text.Json.Nodes;
+using Json.Schema;
+using YamlDotNet.Serialization;
+using YamlDotNet.Serialization.NamingConventions;
+
+namespace StellaOps.Policy;
+
+public sealed record PolicyScoringBindingResult(
+    bool Success,
+    PolicyScoringConfig? Config,
+    ImmutableArray<PolicyIssue> Issues);
+
+public static class PolicyScoringConfigBinder
+{
+    private const string DefaultResourceName = "StellaOps.Policy.Schemas.policy-scoring-default.json";
+
+    private static readonly JsonSchema ScoringSchema = PolicyScoringSchema.Schema;
+
+    private static readonly ImmutableDictionary<string, double> DefaultReachabilityBuckets = CreateDefaultReachabilityBuckets();
+
+    private static readonly PolicyUnknownConfidenceConfig DefaultUnknownConfidence = CreateDefaultUnknownConfidence();
+
+    private static readonly IDeserializer YamlDeserializer = new DeserializerBuilder()
+        .WithNamingConvention(CamelCaseNamingConvention.Instance)
+        .IgnoreUnmatchedProperties()
+        .Build();
+
+    public static PolicyScoringConfig LoadDefault()
+    {
+        var assembly = Assembly.GetExecutingAssembly();
+        using var stream = assembly.GetManifestResourceStream(DefaultResourceName)
+            ?? throw new InvalidOperationException($"Embedded resource '{DefaultResourceName}' not found.");
+        using var reader = new StreamReader(stream, Encoding.UTF8, detectEncodingFromByteOrderMarks: true);
+        var json = reader.ReadToEnd();
+        var binding = Bind(json, PolicyDocumentFormat.Json);
+        if (!binding.Success || binding.Config is null)
+        {
+            throw new InvalidOperationException("Failed to load default policy scoring configuration.");
+        }
+
+        return binding.Config;
+    }
+
+    public static PolicyScoringBindingResult Bind(string content, PolicyDocumentFormat format)
+    {
+        if (string.IsNullOrWhiteSpace(content))
+        {
+            var issue = PolicyIssue.Error("scoring.empty", "Scoring configuration content is empty.", "$");
+            return new PolicyScoringBindingResult(false, null, ImmutableArray.Create(issue));
+        }
+
+        try
+        {
+            var root = Parse(content, format);
+            if (root is not JsonObject obj)
+            {
+                var issue = PolicyIssue.Error("scoring.invalid", "Scoring configuration must be a JSON object.", "$");
+                return new PolicyScoringBindingResult(false, null, ImmutableArray.Create(issue));
+            }
+
+            var issues = ImmutableArray.CreateBuilder<PolicyIssue>();
+            var schemaIssues = ValidateAgainstSchema(root);
+            issues.AddRange(schemaIssues);
+            if (schemaIssues.Any(static issue => issue.Severity == PolicyIssueSeverity.Error))
+            {
+                return new PolicyScoringBindingResult(false, null, issues.ToImmutable());
+            }
+
+            var config = BuildConfig(obj, issues);
+            var hasErrors = issues.Any(issue => issue.Severity == PolicyIssueSeverity.Error);
+            return new PolicyScoringBindingResult(!hasErrors, config, issues.ToImmutable());
+        }
+        catch (JsonException ex)
+        {
+            var issue = PolicyIssue.Error("scoring.parse.json", $"Failed to parse scoring JSON: {ex.Message}", "$");
+            return new PolicyScoringBindingResult(false, null, ImmutableArray.Create(issue));
+        }
+        catch (YamlDotNet.Core.YamlException ex)
+        {
+            var issue = PolicyIssue.Error("scoring.parse.yaml", $"Failed to parse scoring YAML: {ex.Message}", "$");
+            return new PolicyScoringBindingResult(false, null, ImmutableArray.Create(issue));
+        }
+    }
+
+    private static JsonNode? Parse(string content, PolicyDocumentFormat format)
+    {
+        return format switch
+        {
+            PolicyDocumentFormat.Json => JsonNode.Parse(content, new JsonNodeOptions { PropertyNameCaseInsensitive = true }),
+            PolicyDocumentFormat.Yaml => ConvertYamlToJsonNode(content),
+            _ => throw new ArgumentOutOfRangeException(nameof(format), format, "Unsupported scoring configuration format."),
+        };
+    }
+
+    private static JsonNode? ConvertYamlToJsonNode(string content)
+    {
+        var yamlObject = YamlDeserializer.Deserialize<object?>(content);
+        return PolicyBinderUtilities.ConvertYamlObject(yamlObject);
+    }
+
+    private static ImmutableArray<PolicyIssue> ValidateAgainstSchema(JsonNode root)
+    {
+        try
+        {
+            using var document = JsonDocument.Parse(root.ToJsonString(new JsonSerializerOptions
+            {
+                WriteIndented = false,
+            }));
+
+            var result = ScoringSchema.Evaluate(document.RootElement, new EvaluationOptions
+            {
+                OutputFormat = OutputFormat.List,
+                RequireFormatValidation = true,
+            });
+
+            if (result.IsValid)
+            {
+                return ImmutableArray<PolicyIssue>.Empty;
+            }
+
+            var issues = ImmutableArray.CreateBuilder<PolicyIssue>();
+            var seen = new HashSet<string>(StringComparer.Ordinal);
+            CollectSchemaIssues(result, issues, seen);
+            return issues.ToImmutable();
+        }
+        catch (JsonException ex)
+        {
+            return ImmutableArray.Create(PolicyIssue.Error("scoring.schema.normalize", $"Failed to normalize scoring configuration for schema validation: {ex.Message}", "$"));
+        }
+    }
+
+    private static void CollectSchemaIssues(EvaluationResults result, ImmutableArray<PolicyIssue>.Builder issues, HashSet<string> seen)
+    {
+        if (result.Errors is { Count: > 0 })
+        {
+            foreach (var pair in result.Errors)
+            {
+                var keyword = SanitizeKeyword(pair.Key);
+                var path = ConvertPointerToPath(result.InstanceLocation?.ToString() ?? "#");
+                var message = pair.Value ?? "Schema violation.";
+                var key = $"{path}|{keyword}|{message}";
+                if (seen.Add(key))
+                {
+                    issues.Add(PolicyIssue.Error($"scoring.schema.{keyword}", message, path));
+                }
+            }
+        }
+
+        if (result.Details is null)
+        {
+            return;
+        }
+
+        foreach (var detail in result.Details)
+        {
+            CollectSchemaIssues(detail, issues, seen);
+        }
+    }
+
+    private static string ConvertPointerToPath(string pointer)
+    {
+        if (string.IsNullOrEmpty(pointer) || pointer == "#")
+        {
+            return "$";
+        }
+
+        if (pointer[0] == '#')
+        {
+            pointer = pointer.Length > 1 ? pointer[1..] : string.Empty;
+        }
+
+        if (string.IsNullOrEmpty(pointer))
+        {
+            return "$";
+        }
+
+        var segments = pointer.Split('/', StringSplitOptions.RemoveEmptyEntries);
+        var builder = new StringBuilder("$");
+        foreach (var segment in segments)
+        {
+            var unescaped = segment.Replace("~1", "/").Replace("~0", "~");
+            if (int.TryParse(unescaped, out var index))
+            {
+                builder.Append('[').Append(index).Append(']');
+            }
+            else
+            {
+                builder.Append('.').Append(unescaped);
+            }
+        }
+
+        return builder.ToString();
+    }
+
+    private static string SanitizeKeyword(string keyword)
+    {
+        if (string.IsNullOrWhiteSpace(keyword))
+        {
+            return "unknown";
+        }
+
+        var builder = new StringBuilder(keyword.Length);
+        foreach (var ch in keyword)
+        {
+            if (char.IsLetterOrDigit(ch))
+            {
+                builder.Append(char.ToLowerInvariant(ch));
+            }
+            else if (ch is '.' or '_' or '-')
+            {
+                builder.Append(ch);
+            }
+            else
+            {
+                builder.Append('_');
+            }
+        }
+
+        return builder.Length == 0 ? "unknown" : builder.ToString();
+    }
+
+    private static PolicyScoringConfig BuildConfig(JsonObject obj, ImmutableArray<PolicyIssue>.Builder issues)
+    {
+        var version = ReadString(obj, "version", issues, required: true) ?? PolicyScoringConfig.BaselineVersion;
+
+        var severityWeights = ReadSeverityWeights(obj, issues);
+        var quietPenalty = ReadDouble(obj, "quietPenalty", issues, defaultValue: 45);
+        var warnPenalty = ReadDouble(obj, "warnPenalty", issues, defaultValue: 15);
+        var ignorePenalty = ReadDouble(obj, "ignorePenalty", issues, defaultValue: 35);
+        var trustOverrides = ReadTrustOverrides(obj, issues);
+        var reachabilityBuckets = ReadReachabilityBuckets(obj, issues);
+        var unknownConfidence = ReadUnknownConfidence(obj, issues);
+
+        return new PolicyScoringConfig(
+            version,
+            severityWeights,
+            quietPenalty,
+            warnPenalty,
+            ignorePenalty,
+            trustOverrides,
+            reachabilityBuckets,
+            unknownConfidence);
+    }
+
+    private static ImmutableDictionary<string, double> CreateDefaultReachabilityBuckets()
+    {
+        var builder = ImmutableDictionary.CreateBuilder<string, double>(StringComparer.OrdinalIgnoreCase);
+        builder["entrypoint"] = 1.0;
+        builder["direct"] = 0.85;
+        builder["indirect"] = 0.6;
+        builder["runtime"] = 0.45;
+        builder["unreachable"] = 0.25;
+        builder["unknown"] = 0.5;
+        return builder.ToImmutable();
+    }
+
+    private static PolicyUnknownConfidenceConfig CreateDefaultUnknownConfidence()
+    {
+        var bands = ImmutableArray.Create(
+            new PolicyUnknownConfidenceBand("high", 0.65, "Fresh unknowns with recent telemetry."),
+            new PolicyUnknownConfidenceBand("medium", 0.35, "Unknowns aging toward action required."),
+            new PolicyUnknownConfidenceBand("low", 0.0, "Stale unknowns that must be triaged."));
+        return new PolicyUnknownConfidenceConfig(0.8, 0.05, 0.2, bands);
+    }
+
+    private static ImmutableDictionary<string, double> ReadReachabilityBuckets(JsonObject obj, ImmutableArray<PolicyIssue>.Builder issues)
+    {
+        if (!obj.TryGetPropertyValue("reachabilityBuckets", out var node))
+        {
+            issues.Add(PolicyIssue.Warning("scoring.reachability.default", "reachabilityBuckets not specified; defaulting to baseline weights.", "$.reachabilityBuckets"));
+            return DefaultReachabilityBuckets;
+        }
+
+        if (node is not JsonObject bucketsObj)
+        {
+            issues.Add(PolicyIssue.Error("scoring.reachability.type", "reachabilityBuckets must be an object.", "$.reachabilityBuckets"));
+            return DefaultReachabilityBuckets;
+        }
+
+        var builder = ImmutableDictionary.CreateBuilder<string, double>(StringComparer.OrdinalIgnoreCase);
+        foreach (var pair in bucketsObj)
+        {
+            if (pair.Value is null)
+            {
+                issues.Add(PolicyIssue.Warning("scoring.reachability.null", $"Bucket '{pair.Key}' is null; defaulting to 0.", $"$.reachabilityBuckets.{pair.Key}"));
+                builder[pair.Key] = 0;
+                continue;
+            }
+
+            var value = ExtractDouble(pair.Value, issues, $"$.reachabilityBuckets.{pair.Key}");
+            builder[pair.Key] = value;
+        }
+
+        if (builder.Count == 0)
+        {
+            issues.Add(PolicyIssue.Warning("scoring.reachability.empty", "No reachability buckets defined; using defaults.", "$.reachabilityBuckets"));
+            return DefaultReachabilityBuckets;
+        }
+
+        return builder.ToImmutable();
+    }
+
+    private static PolicyUnknownConfidenceConfig ReadUnknownConfidence(JsonObject obj, ImmutableArray<PolicyIssue>.Builder issues)
+    {
+        if (!obj.TryGetPropertyValue("unknownConfidence", out var node))
+        {
+            issues.Add(PolicyIssue.Warning("scoring.unknown.default", "unknownConfidence not specified; defaulting to baseline decay settings.", "$.unknownConfidence"));
+            return DefaultUnknownConfidence;
+        }
+
+        if (node is not JsonObject configObj)
+        {
+            issues.Add(PolicyIssue.Error("scoring.unknown.type", "unknownConfidence must be an object.", "$.unknownConfidence"));
+            return DefaultUnknownConfidence;
+        }
+
+        var initial = DefaultUnknownConfidence.Initial;
+        if (configObj.TryGetPropertyValue("initial", out var initialNode))
+        {
+            initial = ExtractDouble(initialNode, issues, "$.unknownConfidence.initial");
+        }
+        else
+        {
+            issues.Add(PolicyIssue.Warning("scoring.unknown.initial.default", "initial not specified; using baseline value.", "$.unknownConfidence.initial"));
+        }
+
+        var decay = DefaultUnknownConfidence.DecayPerDay;
+        if (configObj.TryGetPropertyValue("decayPerDay", out var decayNode))
+        {
+            decay = ExtractDouble(decayNode, issues, "$.unknownConfidence.decayPerDay");
+        }
+        else
+        {
+            issues.Add(PolicyIssue.Warning("scoring.unknown.decay.default", "decayPerDay not specified; using baseline value.", "$.unknownConfidence.decayPerDay"));
+        }
+
+        var floor = DefaultUnknownConfidence.Floor;
+        if (configObj.TryGetPropertyValue("floor", out var floorNode))
+        {
+            floor = ExtractDouble(floorNode, issues, "$.unknownConfidence.floor");
+        }
+        else
+        {
+            issues.Add(PolicyIssue.Warning("scoring.unknown.floor.default", "floor not specified; using baseline value.", "$.unknownConfidence.floor"));
+        }
+
+        var bands = ReadConfidenceBands(configObj, issues);
+        if (bands.IsDefaultOrEmpty)
+        {
+            bands = DefaultUnknownConfidence.Bands;
+        }
+
+        if (initial < 0 || initial > 1)
+        {
+            issues.Add(PolicyIssue.Warning("scoring.unknown.initial.range", "initial confidence should be between 0 and 1. Clamping to valid range.", "$.unknownConfidence.initial"));
+            initial = Math.Clamp(initial, 0, 1);
+        }
+
+        if (decay < 0 || decay > 1)
+        {
+            issues.Add(PolicyIssue.Warning("scoring.unknown.decay.range", "decayPerDay should be between 0 and 1. Clamping to valid range.", "$.unknownConfidence.decayPerDay"));
+            decay = Math.Clamp(decay, 0, 1);
+        }
+
+        if (floor < 0 || floor > 1)
+        {
+            issues.Add(PolicyIssue.Warning("scoring.unknown.floor.range", "floor should be between 0 and 1. Clamping to valid range.", "$.unknownConfidence.floor"));
+            floor = Math.Clamp(floor, 0, 1);
+        }
+
+        return new PolicyUnknownConfidenceConfig(initial, decay, floor, bands);
+    }
+
+    private static ImmutableArray<PolicyUnknownConfidenceBand> ReadConfidenceBands(JsonObject configObj, ImmutableArray<PolicyIssue>.Builder issues)
+    {
+        if (!configObj.TryGetPropertyValue("bands", out var node))
+        {
+            return ImmutableArray<PolicyUnknownConfidenceBand>.Empty;
+        }
+
+        if (node is not JsonArray array)
+        {
+            issues.Add(PolicyIssue.Error("scoring.unknown.bands.type", "unknownConfidence.bands must be an array.", "$.unknownConfidence.bands"));
+            return ImmutableArray<PolicyUnknownConfidenceBand>.Empty;
+        }
+
+        var builder = ImmutableArray.CreateBuilder<PolicyUnknownConfidenceBand>();
+        var seen = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
+        for (var index = 0; index < array.Count; index++)
+        {
+            var element = array[index];
+            if (element is not JsonObject bandObj)
+            {
+                issues.Add(PolicyIssue.Warning("scoring.unknown.band.type", "Band entry must be an object.", $"$.unknownConfidence.bands[{index}]"));
+                continue;
+            }
+
+            string? name = null;
+            if (bandObj.TryGetPropertyValue("name", out var nameNode) && nameNode is JsonValue nameValue && nameValue.TryGetValue(out string? text))
+            {
+                name = text?.Trim();
+            }
+
+            if (string.IsNullOrWhiteSpace(name))
+            {
+                issues.Add(PolicyIssue.Error("scoring.unknown.band.name", "Band entry requires a non-empty 'name'.", $"$.unknownConfidence.bands[{index}].name"));
+                continue;
+            }
+
+            if (!seen.Add(name))
+            {
+                issues.Add(PolicyIssue.Warning("scoring.unknown.band.duplicate", $"Duplicate band '{name}' encountered.", $"$.unknownConfidence.bands[{index}].name"));
+                continue;
+            }
+
+            if (!bandObj.TryGetPropertyValue("min", out var minNode))
+            {
+                issues.Add(PolicyIssue.Error("scoring.unknown.band.min", $"Band '{name}' is missing 'min'.", $"$.unknownConfidence.bands[{index}].min"));
+                continue;
+            }
+
+            var min = ExtractDouble(minNode, issues, $"$.unknownConfidence.bands[{index}].min");
+            if (min < 0 || min > 1)
+            {
+                issues.Add(PolicyIssue.Warning("scoring.unknown.band.range", $"Band '{name}' min should be between 0 and 1. Clamping to valid range.", $"$.unknownConfidence.bands[{index}].min"));
+                min = Math.Clamp(min, 0, 1);
+            }
+
+            string? description = null;
+            if (bandObj.TryGetPropertyValue("description", out var descriptionNode) && descriptionNode is JsonValue descriptionValue && descriptionValue.TryGetValue(out string? descriptionText))
+            {
+                description = descriptionText?.Trim();
+            }
+
+            builder.Add(new PolicyUnknownConfidenceBand(name, min, description));
+        }
+
+        if (builder.Count == 0)
+        {
+            return ImmutableArray<PolicyUnknownConfidenceBand>.Empty;
+        }
+
+        return builder.ToImmutable()
+            .OrderByDescending(static band => band.Min)
+            .ToImmutableArray();
+    }
+
+    private static ImmutableDictionary<PolicySeverity, double> ReadSeverityWeights(JsonObject obj, ImmutableArray<PolicyIssue>.Builder issues)
+    {
+        if (!obj.TryGetPropertyValue("severityWeights", out var node) || node is not JsonObject severityObj)
+        {
+            issues.Add(PolicyIssue.Error("scoring.severityWeights.missing", "severityWeights section is required.", "$.severityWeights"));
+            return ImmutableDictionary<PolicySeverity, double>.Empty;
+        }
+
+        var builder = ImmutableDictionary.CreateBuilder<PolicySeverity, double>();
+        foreach (var severity in Enum.GetValues<PolicySeverity>())
+        {
+            var key = severity.ToString();
+            if (!severityObj.TryGetPropertyValue(key, out var valueNode))
+            {
+                issues.Add(PolicyIssue.Warning("scoring.severityWeights.default", $"Severity '{key}' not specified; defaulting to 0.", $"$.severityWeights.{key}"));
+                builder[severity] = 0;
+                continue;
+            }
+
+            var value = ExtractDouble(valueNode, issues, $"$.severityWeights.{key}");
+            builder[severity] = value;
+        }
+
+        return builder.ToImmutable();
+    }
+
+    private static double ReadDouble(JsonObject obj, string property, ImmutableArray<PolicyIssue>.Builder issues, double defaultValue)
+    {
+        if (!obj.TryGetPropertyValue(property, out var node))
+        {
+            issues.Add(PolicyIssue.Warning("scoring.numeric.default", $"{property} not specified; defaulting to {defaultValue:0.##}.", $"$.{property}"));
+            return defaultValue;
+        }
+
+        return ExtractDouble(node, issues, $"$.{property}");
+    }
+
+    private static double ExtractDouble(JsonNode? node, ImmutableArray<PolicyIssue>.Builder issues, string path)
+    {
+        if (node is null)
+        {
+            issues.Add(PolicyIssue.Warning("scoring.numeric.null", $"Value at {path} missing; defaulting to 0.", path));
+            return 0;
+        }
+
+        if (node is JsonValue value)
+        {
+            if (value.TryGetValue(out double number))
+            {
+                return number;
+            }
+
+            if (value.TryGetValue(out string? text) && double.TryParse(text, NumberStyles.Float, CultureInfo.InvariantCulture, out number))
+            {
+                return number;
+            }
+        }
+
+        issues.Add(PolicyIssue.Error("scoring.numeric.invalid", $"Value at {path} is not numeric.", path));
+        return 0;
+    }
+
+    private static ImmutableDictionary<string, double> ReadTrustOverrides(JsonObject obj, ImmutableArray<PolicyIssue>.Builder issues)
+    {
+        if (!obj.TryGetPropertyValue("trustOverrides", out var node) || node is not JsonObject trustObj)
+        {
+            return ImmutableDictionary<string, double>.Empty;
+        }
+
+        var builder = ImmutableDictionary.CreateBuilder<string, double>(StringComparer.OrdinalIgnoreCase);
+        foreach (var pair in trustObj)
+        {
+            var value = ExtractDouble(pair.Value, issues, $"$.trustOverrides.{pair.Key}");
+            builder[pair.Key] = value;
+        }
+
+        return builder.ToImmutable();
+    }
+
+    private static string? ReadString(JsonObject obj, string property, ImmutableArray<PolicyIssue>.Builder issues, bool required)
+    {
+        if (!obj.TryGetPropertyValue(property, out var node) || node is null)
+        {
+            if (required)
+            {
+                issues.Add(PolicyIssue.Error("scoring.string.missing", $"{property} is required.", $"$.{property}"));
+            }
+            return null;
+        }
+
+        if (node is JsonValue value && value.TryGetValue(out string? text))
+        {
+            return text?.Trim();
+        }
+
+        issues.Add(PolicyIssue.Error("scoring.string.invalid", $"{property} must be a string.", $"$.{property}"));
+        return null;
+    }
+}
+
+internal static class PolicyBinderUtilities
+{
+    public static JsonNode? ConvertYamlObject(object? value)
+    {
+        switch (value)
+        {
+            case null:
+                return null;
+            case string s when bool.TryParse(s, out var boolValue):
+                return JsonValue.Create(boolValue);
+            case string s:
+                return JsonValue.Create(s);
+            case bool b:
+                return JsonValue.Create(b);
+            case sbyte or byte or short or ushort or int or uint or long or ulong or float or double or decimal:
+                return JsonValue.Create(Convert.ToDouble(value, CultureInfo.InvariantCulture));
+            case IDictionary dictionary:
+            {
+                var obj = new JsonObject();
+                foreach (DictionaryEntry entry in dictionary)
+                {
+                    if (entry.Key is null)
+                    {
+                        continue;
+                    }
+
+                    obj[entry.Key.ToString()!] = ConvertYamlObject(entry.Value);
+                }
+
+                return obj;
+            }
+            case IEnumerable enumerable:
+            {
+                var array = new JsonArray();
+                foreach (var item in enumerable)
+                {
+                    array.Add(ConvertYamlObject(item));
+                }
+
+                return array;
+            }
+            default:
+                return JsonValue.Create(value.ToString());
+        }
+    }
+}