refactor(reactions): share reaction level resolver

src/utils/reaction-level.ts

@@ -0,0 +1,74 @@
+export type ReactionLevel = "off" | "ack" | "minimal" | "extensive";
+
+export type ResolvedReactionLevel = {
+  level: ReactionLevel;
+  /** Whether ACK reactions (e.g., 👀 when processing) are enabled. */
+  ackEnabled: boolean;
+  /** Whether agent-controlled reactions are enabled. */
+  agentReactionsEnabled: boolean;
+  /** Guidance level for agent reactions (minimal = sparse, extensive = liberal). */
+  agentReactionGuidance?: "minimal" | "extensive";
+};
+
+const LEVELS = new Set<ReactionLevel>(["off", "ack", "minimal", "extensive"]);
+
+function parseLevel(
+  value: unknown,
+): { kind: "missing" } | { kind: "invalid" } | { kind: "ok"; value: ReactionLevel } {
+  if (value === undefined || value === null) {
+    return { kind: "missing" };
+  }
+  if (typeof value !== "string") {
+    return { kind: "invalid" };
+  }
+  const trimmed = value.trim();
+  if (!trimmed) {
+    return { kind: "missing" };
+  }
+  if (LEVELS.has(trimmed as ReactionLevel)) {
+    return { kind: "ok", value: trimmed as ReactionLevel };
+  }
+  return { kind: "invalid" };
+}
+
+export function resolveReactionLevel(params: {
+  value: unknown;
+  defaultLevel: ReactionLevel;
+  invalidFallback: "ack" | "minimal";
+}): ResolvedReactionLevel {
+  const parsed = parseLevel(params.value);
+  const effective =
+    parsed.kind === "ok"
+      ? parsed.value
+      : parsed.kind === "missing"
+        ? params.defaultLevel
+        : params.invalidFallback;
+
+  switch (effective) {
+    case "off":
+      return { level: "off", ackEnabled: false, agentReactionsEnabled: false };
+    case "ack":
+      return { level: "ack", ackEnabled: true, agentReactionsEnabled: false };
+    case "minimal":
+      return {
+        level: "minimal",
+        ackEnabled: false,
+        agentReactionsEnabled: true,
+        agentReactionGuidance: "minimal",
+      };
+    case "extensive":
+      return {
+        level: "extensive",
+        ackEnabled: false,
+        agentReactionsEnabled: true,
+        agentReactionGuidance: "extensive",
+      };
+    default:
+      return {
+        level: "minimal",
+        ackEnabled: false,
+        agentReactionsEnabled: true,
+        agentReactionGuidance: "minimal",
+      };
+  }
+}