up

src/StellaOps.Feedser.Source.Vndr.Cisco/Internal/CiscoCsafParser.cs

@@ -0,0 +1,123 @@
+using System.Collections.Generic;
+using System.Linq;
+using System.Text.Json;
+
+namespace StellaOps.Feedser.Source.Vndr.Cisco.Internal;
+
+internal static class CiscoCsafParser
+{
+    public static CiscoCsafData Parse(string content)
+    {
+        if (string.IsNullOrWhiteSpace(content))
+        {
+            return new CiscoCsafData(
+                Products: new Dictionary<string, CiscoCsafProduct>(0, StringComparer.OrdinalIgnoreCase),
+                ProductStatuses: new Dictionary<string, IReadOnlyCollection<string>>(0, StringComparer.OrdinalIgnoreCase));
+        }
+
+        using var document = JsonDocument.Parse(content);
+        var root = document.RootElement;
+
+        var products = ParseProducts(root);
+        var statuses = ParseStatuses(root);
+
+        return new CiscoCsafData(products, statuses);
+    }
+
+    private static IReadOnlyDictionary<string, CiscoCsafProduct> ParseProducts(JsonElement root)
+    {
+        var dictionary = new Dictionary<string, CiscoCsafProduct>(StringComparer.OrdinalIgnoreCase);
+        if (!root.TryGetProperty("product_tree", out var productTree))
+        {
+            return dictionary;
+        }
+
+        if (productTree.TryGetProperty("full_product_names", out var fullProductNames)
+            && fullProductNames.ValueKind == JsonValueKind.Array)
+        {
+            foreach (var entry in fullProductNames.EnumerateArray())
+            {
+                var productId = entry.TryGetProperty("product_id", out var idElement) && idElement.ValueKind == JsonValueKind.String
+                    ? idElement.GetString()
+                    : null;
+
+                if (string.IsNullOrWhiteSpace(productId))
+                {
+                    continue;
+                }
+
+                var name = entry.TryGetProperty("name", out var nameElement) && nameElement.ValueKind == JsonValueKind.String
+                    ? nameElement.GetString()
+                    : null;
+
+                if (string.IsNullOrWhiteSpace(name))
+                {
+                    name = productId;
+                }
+
+                dictionary[productId] = new CiscoCsafProduct(productId, name);
+            }
+        }
+
+        return dictionary;
+    }
+
+    private static IReadOnlyDictionary<string, IReadOnlyCollection<string>> ParseStatuses(JsonElement root)
+    {
+        var map = new Dictionary<string, HashSet<string>>(StringComparer.OrdinalIgnoreCase);
+
+        if (!root.TryGetProperty("vulnerabilities", out var vulnerabilities)
+            || vulnerabilities.ValueKind != JsonValueKind.Array)
+        {
+            return map.ToDictionary(
+                static kvp => kvp.Key,
+                static kvp => (IReadOnlyCollection<string>)kvp.Value.ToArray(),
+                StringComparer.OrdinalIgnoreCase);
+        }
+
+        foreach (var vulnerability in vulnerabilities.EnumerateArray())
+        {
+            if (!vulnerability.TryGetProperty("product_status", out var productStatus)
+                || productStatus.ValueKind != JsonValueKind.Object)
+            {
+                continue;
+            }
+
+            foreach (var property in productStatus.EnumerateObject())
+            {
+                var statusLabel = property.Name;
+                if (property.Value.ValueKind != JsonValueKind.Array)
+                {
+                    continue;
+                }
+
+                foreach (var productIdElement in property.Value.EnumerateArray())
+                {
+                    if (productIdElement.ValueKind != JsonValueKind.String)
+                    {
+                        continue;
+                    }
+
+                    var productId = productIdElement.GetString();
+                    if (string.IsNullOrWhiteSpace(productId))
+                    {
+                        continue;
+                    }
+
+                    if (!map.TryGetValue(productId, out var set))
+                    {
+                        set = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
+                        map[productId] = set;
+                    }
+
+                    set.Add(statusLabel);
+                }
+            }
+        }
+
+        return map.ToDictionary(
+            static kvp => kvp.Key,
+            static kvp => (IReadOnlyCollection<string>)kvp.Value.ToArray(),
+            StringComparer.OrdinalIgnoreCase);
+    }
+}