feat(acp): add experimental ACP support

Co-authored-by: Jonathan Taylor <visionik@pobox.com>

src/acp/event-mapper.ts

@@ -0,0 +1,73 @@
+import type { ContentBlock, ImageContent, ToolKind } from "@agentclientprotocol/sdk";
+
+export type GatewayAttachment = {
+  type: string;
+  mimeType: string;
+  content: string;
+};
+
+export function extractTextFromPrompt(prompt: ContentBlock[]): string {
+  const parts: string[] = [];
+  for (const block of prompt) {
+    if (block.type === "text") {
+      parts.push(block.text);
+      continue;
+    }
+    if (block.type === "resource") {
+      const resource = block.resource as { text?: string } | undefined;
+      if (resource?.text) parts.push(resource.text);
+      continue;
+    }
+    if (block.type === "resource_link") {
+      const title = block.title ? ` (${block.title})` : "";
+      const uri = block.uri ?? "";
+      const line = uri ? `[Resource link${title}] ${uri}` : `[Resource link${title}]`;
+      parts.push(line);
+    }
+  }
+  return parts.join("\n");
+}
+
+export function extractAttachmentsFromPrompt(prompt: ContentBlock[]): GatewayAttachment[] {
+  const attachments: GatewayAttachment[] = [];
+  for (const block of prompt) {
+    if (block.type !== "image") continue;
+    const image = block as ImageContent;
+    if (!image.data || !image.mimeType) continue;
+    attachments.push({
+      type: "image",
+      mimeType: image.mimeType,
+      content: image.data,
+    });
+  }
+  return attachments;
+}
+
+export function formatToolTitle(
+  name: string | undefined,
+  args: Record<string, unknown> | undefined,
+): string {
+  const base = name ?? "tool";
+  if (!args || Object.keys(args).length === 0) return base;
+  const parts = Object.entries(args).map(([key, value]) => {
+    const raw = typeof value === "string" ? value : JSON.stringify(value);
+    const safe = raw.length > 100 ? `${raw.slice(0, 100)}...` : raw;
+    return `${key}: ${safe}`;
+  });
+  return `${base}: ${parts.join(", ")}`;
+}
+
+export function inferToolKind(name?: string): ToolKind | undefined {
+  if (!name) return "other";
+  const normalized = name.toLowerCase();
+  if (normalized.includes("read")) return "read";
+  if (normalized.includes("write") || normalized.includes("edit")) return "edit";
+  if (normalized.includes("delete") || normalized.includes("remove")) return "delete";
+  if (normalized.includes("move") || normalized.includes("rename")) return "move";
+  if (normalized.includes("search") || normalized.includes("find")) return "search";
+  if (normalized.includes("exec") || normalized.includes("run") || normalized.includes("bash")) {
+    return "execute";
+  }
+  if (normalized.includes("fetch") || normalized.includes("http")) return "fetch";
+  return "other";
+}