added encounter system

Packages/com.jovian.encounter-system/Runtime/DialogLineLibrary.cs

@@ -0,0 +1,55 @@
+using System;
+using System.Collections.Generic;
+using UnityEngine;
+
+namespace Jovian.EncounterSystem {
+    [Serializable]
+    public class DialogLine {
+        public string id;
+        [TextArea(2, 6)] public string text;
+    }
+
+    /// <summary>Flat registry of reusable dialog lines. Referenced via <see cref="DialogLineRef"/>.</summary>
+    [CreateAssetMenu(fileName = "DialogLineLibrary", menuName = "Jovian/Encounter System/Dialog Line Library", order = 4)]
+    public class DialogLineLibrary : ScriptableObject {
+        public List<DialogLine> lines = new();
+
+        private Dictionary<string, string> cache;
+
+        public string Resolve(string id) {
+            if(string.IsNullOrEmpty(id)) {
+                return null;
+            }
+
+            EnsureCache();
+            return cache.TryGetValue(id, out var text) ? text : null;
+        }
+
+        public void InvalidateCache() {
+            cache = null;
+        }
+
+        private void EnsureCache() {
+            if(cache != null) {
+                return;
+            }
+
+            cache = new Dictionary<string, string>();
+            if(lines == null) {
+                return;
+            }
+
+            foreach(var line in lines) {
+                if(line != null && !string.IsNullOrEmpty(line.id)) {
+                    cache[line.id] = line.text;
+                }
+            }
+        }
+
+#if UNITY_EDITOR
+        private void OnValidate() {
+            InvalidateCache();
+        }
+#endif
+    }
+}