feat(s7): resolve equipment-tag refs (read + write) via EquipmentTagRefResolver

2026-06-13 11:25:31 -04:00
parent 34a42486dc
commit b031a6ceef
3 changed files with 137 additions and 13 deletions
@@ -0,0 +1,59 @@
+using System.Text.Json;
+
+namespace ZB.MOM.WW.OtOpcUa.Driver.S7;
+
+/// <summary>Parses an equipment tag's <c>TagConfig</c> JSON (the shape authored by the AdminUI
+/// <c>S7TagConfigModel</c> — <c>address</c> / <c>dataType</c> / <c>stringLength</c>) into a transient
+/// <see cref="S7TagDefinition"/> whose <see cref="S7TagDefinition.Name"/> equals the reference string
+/// itself, so a value the driver publishes back keys the runtime's forward router correctly.</summary>
+public static class S7EquipmentTagParser
+{
+    /// <summary>S7 string max length (DBSTRING header reserves 2 bytes; 254 chars max).</summary>
+    private const int MaxStringLength = 254;
+
+    /// <summary>Attempts to parse an equipment-tag reference into a transient definition.</summary>
+    /// <param name="reference">The equipment tag's TagConfig JSON (also used as the def identity).</param>
+    /// <param name="def">The transient definition when parsing succeeds.</param>
+    /// <returns><see langword="true"/> when <paramref name="reference"/> is an S7 address object.</returns>
+    public static bool TryParse(string reference, out S7TagDefinition def)
+    {
+        def = null!;
+        // Authored tag names never start with '{' (AdminUI name validation), so a leading brace marks an equipment-tag TagConfig blob.
+        if (string.IsNullOrWhiteSpace(reference) || reference[0] != '{') return false;
+        try
+        {
+            using var doc = JsonDocument.Parse(reference);
+            var root = doc.RootElement;
+            if (root.ValueKind != JsonValueKind.Object
+                || !root.TryGetProperty("address", out var addrEl)
+                || addrEl.ValueKind != JsonValueKind.String
+                || !root.TryGetProperty("dataType", out _))
+                return false;
+            var address = addrEl.GetString();
+            if (string.IsNullOrWhiteSpace(address)) return false;
+            var dataType = ReadEnum(root, "dataType", S7DataType.Int16);
+            var stringLength = ReadInt(root, "stringLength");
+            // Range-guard rather than truncate: an S7 string can't exceed 254 chars, and a
+            // negative length is meaningless — reject so a malformed blob can't slip through.
+            if (stringLength < 0 || stringLength > MaxStringLength) return false;
+            def = new S7TagDefinition(
+                Name: reference,
+                Address: address,
+                DataType: dataType,
+                Writable: true, // node-level authz governs writes
+                StringLength: stringLength == 0 ? MaxStringLength : stringLength);
+            return true;
+        }
+        catch (JsonException) { return false; }
+        catch (FormatException) { return false; }
+        catch (InvalidOperationException) { return false; }
+    }
+
+    private static TEnum ReadEnum<TEnum>(JsonElement o, string name, TEnum fallback) where TEnum : struct, Enum
+        => o.TryGetProperty(name, out var e) && e.ValueKind == JsonValueKind.String
+           && Enum.TryParse<TEnum>(e.GetString(), ignoreCase: true, out var v) ? v : fallback;
+
+    private static int ReadInt(JsonElement o, string name)
+        => o.TryGetProperty(name, out var e) && e.ValueKind == JsonValueKind.Number
+           && e.TryGetInt32(out var v) ? v : 0;
+}