Create new unused Filter library

SabreTools.Filter/FilterParser.cs

@@ -0,0 +1,141 @@
+using System;
+using System.Linq;
+using System.Reflection;
+using SabreTools.Models.Internal;
+
+namespace SabreTools.Filter
+{
+    public static class FilterParser
+    {
+        /// <summary>
+        /// Parse a filter ID string into the item name and field name, if possible
+        /// </summary>
+        /// <remarks>TODO: Have validation of fields done automatically</remarks>
+        public static (string?, string?) ParseFilterId(string filterId)
+        {
+            // If we don't have a filter ID, we can't do anything
+            if (string.IsNullOrWhiteSpace(filterId))
+                return (null, null);
+
+            // If we only have one part, we can't do anything
+            string[] splitFilter = filterId.Split('.');
+            if (splitFilter.Length != 2)
+                return (null, null);
+
+            // Return santized values based on the split ID
+            return splitFilter[0].ToLowerInvariant() switch
+            {
+                // Header
+                "header" => ParseHeaderFilterId(splitFilter),
+
+                // Machine
+                "game" => ParseMachineFilterId(splitFilter),
+                "machine" => ParseMachineFilterId(splitFilter),
+                "resource" => ParseMachineFilterId(splitFilter),
+                "set" => ParseMachineFilterId(splitFilter),
+
+                // DatItem
+                // TODO: Implement parsers for all item types
+                _ => (null, null),
+            };
+        }
+
+        /// <summary>
+        /// Parse and validate header fields
+        /// </summary>
+        private static (string?, string?) ParseHeaderFilterId(string[] filterId)
+        {
+            // Get the set of constants
+            var constants = GetConstants(typeof(Header));
+            if (constants == null)
+                return (null, null);
+
+            // Get if there's a match to the constant
+            string? constantMatch = constants.FirstOrDefault(c => string.Equals(c, filterId[1], StringComparison.OrdinalIgnoreCase));
+            if (constantMatch == null)
+                return (null, null);
+
+            // Filter out fields that can't be matched on
+            return constantMatch switch
+            {
+                Header.CanOpenKey => (null, null),
+                Header.ImagesKey => (null, null),
+                Header.InfosKey => (null, null),
+                Header.NewDatKey => (null, null),
+                Header.SearchKey => (null, null),
+                _ => (MetadataFile.HeaderKey, constantMatch),
+            };
+        }
+
+        /// <summary>
+        /// Parse and validate machine/game fields
+        /// </summary>
+        private static (string?, string?) ParseMachineFilterId(string[] filterId)
+        {
+            // Get the set of constants
+            var constants = GetConstants(typeof(Header));
+            if (constants == null)
+                return (null, null);
+
+            // Get if there's a match to the constant
+            string? constantMatch = constants.FirstOrDefault(c => string.Equals(c, filterId[1], StringComparison.OrdinalIgnoreCase));
+            if (constantMatch == null)
+                return (null, null);
+
+            // Filter out fields that can't be matched on
+            return constantMatch switch
+            {
+                Machine.AdjusterKey => (null, null),
+                Machine.ArchiveKey => (null, null),
+                Machine.BiosSetKey => (null, null),
+                Machine.ChipKey => (null, null),
+                Machine.ConfigurationKey => (null, null),
+                Machine.ControlKey => (null, null),
+                Machine.DeviceKey => (null, null),
+                Machine.DeviceRefKey => (null, null),
+                Machine.DipSwitchKey => (null, null),
+                Machine.DiskKey => (null, null),
+                Machine.DisplayKey => (null, null),
+                Machine.DriverKey => (null, null),
+                Machine.DumpKey => (null, null),
+                Machine.FeatureKey => (null, null),
+                Machine.InfoKey => (null, null),
+                Machine.InputKey => (null, null),
+                Machine.MediaKey => (null, null),
+                Machine.PartKey => (null, null),
+                Machine.PortKey => (null, null),
+                Machine.RamOptionKey => (null, null),
+                Machine.ReleaseKey => (null, null),
+                Machine.RomKey => (null, null),
+                Machine.SampleKey => (null, null),
+                Machine.SharedFeatKey => (null, null),
+                Machine.SlotKey => (null, null),
+                Machine.SoftwareListKey => (null, null),
+                Machine.SoundKey => (null, null),
+                Machine.TruripKey => (null, null),
+                Machine.VideoKey => (null, null),
+                _ => (MetadataFile.MachineKey, constantMatch),
+            };
+        }
+
+        /// <summary>
+        /// Get constant values for the given type, if possible
+        /// </summary>
+        /// <remarks>TODO: Create a NoFilter attribute for non-mappable filter IDs</remarks>
+        private static string[]? GetConstants(Type? type)
+        {
+            if (type == null)
+                return null;
+
+            var fields = type.GetFields(BindingFlags.Static | BindingFlags.Public | BindingFlags.FlattenHierarchy);
+            if (fields == null)
+                return null;
+
+            return fields
+                .Where(f => f.IsLiteral && !f.IsInitOnly)
+                .Select(f => f.GetRawConstantValue() as string)
+                .Where(v => v != null)
+                .ToArray()!;
+        }
+    }
+}