feat(coding-runtime): add managed Pi extension host

electron/coding-runtime/pi/extension-ui-projector.ts

@@ -0,0 +1,162 @@
+import type { PiRpcEvent } from './rpc-client';
+
+const MAX_MESSAGE_LENGTH = 2_000;
+const MAX_TITLE_LENGTH = 256;
+const MAX_EDITOR_TEXT_LENGTH = 64 * 1024;
+const MAX_WIDGET_LINES = 32;
+const MAX_WIDGET_LINE_LENGTH = 512;
+
+export type PiExtensionUiProjection =
+  | { kind: 'notify'; conversationId: string; message: string; level: 'info' | 'warning' | 'error' }
+  | { kind: 'status'; conversationId: string; key: string; text?: string }
+  | {
+    kind: 'widget';
+    conversationId: string;
+    key: string;
+    lines?: string[];
+    placement?: 'aboveEditor' | 'belowEditor';
+  }
+  | { kind: 'title'; conversationId: string; title: string }
+  | { kind: 'editor-text'; conversationId: string; text: string; draftRevision: number };
+
+export interface PiExtensionUiDiagnostic {
+  method: string;
+  reason: 'unsupported-ui-method' | 'invalid-ui-payload' | 'stale-draft-revision';
+}
+
+export interface PiExtensionUiProjectorOptions {
+  getDraftRevision(conversationId: string): number;
+  knownStatusKeys?: readonly string[];
+  knownWidgetKeys?: readonly string[];
+}
+
+interface RunProjectionState {
+  runId: string;
+  generation: number;
+  draftRevision: number;
+}
+
+function bounded(value: string, length: number): string {
+  return value.length <= length ? value : `${value.slice(0, length - 1)}…`;
+}
+
+export class PiExtensionUiProjector {
+  private readonly getDraftRevision: (conversationId: string) => number;
+  private readonly knownStatusKeys: Set<string>;
+  private readonly knownWidgetKeys: Set<string>;
+  private readonly runs = new Map<string, RunProjectionState>();
+  private readonly diagnostics: PiExtensionUiDiagnostic[] = [];
+
+  constructor(options: PiExtensionUiProjectorOptions) {
+    this.getDraftRevision = options.getDraftRevision;
+    this.knownStatusKeys = new Set(options.knownStatusKeys ?? ['makelore.write-lease']);
+    this.knownWidgetKeys = new Set(options.knownWidgetKeys ?? []);
+  }
+
+  beginRun(conversationId: string, generation: number, runId: string): void {
+    this.runs.set(conversationId, {
+      generation,
+      runId,
+      draftRevision: this.getDraftRevision(conversationId),
+    });
+  }
+
+  replaceGeneration(conversationId: string, generation: number, runId: string): void {
+    const current = this.runs.get(conversationId);
+    if (current?.runId === runId) current.generation = generation;
+  }
+
+  endRun(conversationId: string, runId: string): void {
+    if (this.runs.get(conversationId)?.runId === runId) this.runs.delete(conversationId);
+  }
+
+  getDiagnostics(): PiExtensionUiDiagnostic[] {
+    return structuredClone(this.diagnostics);
+  }
+
+  project(
+    conversationId: string,
+    generation: number,
+    runId: string,
+    event: PiRpcEvent,
+  ): PiExtensionUiProjection | null {
+    if (event.type !== 'extension_ui_request' || typeof event.method !== 'string') return null;
+    const run = this.runs.get(conversationId);
+    if (!run || run.runId !== runId || run.generation !== generation) return null;
+    if (event.method === 'notify'
+      && typeof event.message === 'string'
+      && ['info', 'warning', 'error', undefined].includes(event.notifyType as string | undefined)) {
+      return {
+        kind: 'notify',
+        conversationId,
+        message: bounded(event.message, MAX_MESSAGE_LENGTH),
+        level: event.notifyType === 'warning' || event.notifyType === 'error'
+          ? event.notifyType
+          : 'info',
+      };
+    }
+    if (event.method === 'setStatus'
+      && typeof event.statusKey === 'string'
+      && (event.statusText === undefined || typeof event.statusText === 'string')) {
+      if (!this.knownStatusKeys.has(event.statusKey)) return this.unsupported(event.method);
+      return {
+        kind: 'status',
+        conversationId,
+        key: event.statusKey,
+        ...(typeof event.statusText === 'string'
+          ? { text: bounded(event.statusText, MAX_MESSAGE_LENGTH) }
+          : {}),
+      };
+    }
+    if (event.method === 'setWidget'
+      && typeof event.widgetKey === 'string'
+      && (event.widgetLines === undefined || Array.isArray(event.widgetLines))) {
+      if (!this.knownWidgetKeys.has(event.widgetKey)) return this.unsupported(event.method);
+      if (Array.isArray(event.widgetLines)
+        && !event.widgetLines.every((line) => typeof line === 'string')) {
+        return this.invalid(event.method);
+      }
+      return {
+        kind: 'widget',
+        conversationId,
+        key: event.widgetKey,
+        ...(Array.isArray(event.widgetLines)
+          ? {
+            lines: event.widgetLines.slice(0, MAX_WIDGET_LINES)
+              .map((line) => bounded(line as string, MAX_WIDGET_LINE_LENGTH)),
+          }
+          : {}),
+        ...(event.widgetPlacement === 'aboveEditor' || event.widgetPlacement === 'belowEditor'
+          ? { placement: event.widgetPlacement }
+          : {}),
+      };
+    }
+    if (event.method === 'setTitle' && typeof event.title === 'string') {
+      return { kind: 'title', conversationId, title: bounded(event.title, MAX_TITLE_LENGTH) };
+    }
+    if (event.method === 'set_editor_text' && typeof event.text === 'string') {
+      if (this.getDraftRevision(conversationId) !== run.draftRevision) {
+        this.diagnostics.push({ method: event.method, reason: 'stale-draft-revision' });
+        return null;
+      }
+      return {
+        kind: 'editor-text',
+        conversationId,
+        text: bounded(event.text, MAX_EDITOR_TEXT_LENGTH),
+        draftRevision: run.draftRevision,
+      };
+    }
+    if (['select', 'confirm', 'input', 'editor'].includes(event.method)) return null;
+    return this.invalid(event.method);
+  }
+
+  private unsupported(method: string): null {
+    this.diagnostics.push({ method: bounded(method, 128), reason: 'unsupported-ui-method' });
+    return null;
+  }
+
+  private invalid(method: string): null {
+    this.diagnostics.push({ method: bounded(method, 128), reason: 'invalid-ui-payload' });
+    return null;
+  }
+}