/**
 * Chat Core App 的 Host 装配器。
 *
 * Chat 的样式、Shell、Renderer 和 DOM 上下文都属于 Chat 自己；Runtime Host
 * 只负责根据 app_scope 选择这个装配器，main.ts 不再直接依赖 Chat 的内部模块。
 */
import "@/core-apps/chat/styles/app.css";
import "@/core-apps/chat/styles/capability-card.css";
import "@/core-apps/chat/styles/execution-progress.css";
import { LineUpRuntime } from "@/runtime/coordination/lineup-runtime";
import type { ChatRuntimeSDK } from "@/runtime/app-management/app-sdk";
import { mountChatShell } from "@/core-apps/chat/chat-shell";
import { RendererRegistry } from "@/core-apps/chat/renderer-registry";
import {
  TrustedDOMRendererContext,
  type CapabilityInteractionHandlers,
  type TaskInteractionHandlers,
  type ToolInteractionHandlers,
} from "@/core-apps/chat/trusted-dom-renderers";

export type ChatAppHostOptions = {
  toolInteractions?: ToolInteractionHandlers;
  taskInteractions?: TaskInteractionHandlers;
  capabilityInteractions?: CapabilityInteractionHandlers;
};

export type MountedChatApp = {
  app_scope: "chat";
  sdk: ChatRuntimeSDK;
  messages: HTMLElement;
  loginView: HTMLElement;
  chatView: HTMLElement;
  presence: HTMLElement;
  rendererContext: TrustedDOMRendererContext;
  rendererRegistry: RendererRegistry<TrustedDOMRendererContext>;
};

function query<T extends Element>(root: ParentNode, selector: string): T {
  const found = root.querySelector<T>(selector);
  if (!found) throw new Error(`Missing Chat element: ${selector}`);
  return found;
}

/** Mounts the trusted Chat implementation selected by the Runtime App Host. */
export function mountChatApp(
  runtime: LineUpRuntime,
  root: HTMLElement,
  options: ChatAppHostOptions,
): MountedChatApp {
  mountChatShell(root);
  const messages = query<HTMLElement>(root, "#messages");
  const loginView = query<HTMLElement>(root, "#login-view");
  const chatView = query<HTMLElement>(root, "#chat-view");
  const presence = query<HTMLElement>(root, "#presence");
  const rendererContext = new TrustedDOMRendererContext(
    messages,
    presence,
    options.toolInteractions,
    options.taskInteractions,
    options.capabilityInteractions,
  );
  const rendererRegistry = new RendererRegistry<TrustedDOMRendererContext>();
  registerChatRenderers(rendererRegistry);

  return {
    app_scope: "chat",
    sdk: runtime.openApp("chat"),
    messages,
    loginView,
    chatView,
    presence,
    rendererContext,
    rendererRegistry,
  };
}

function registerChatRenderers(registry: RendererRegistry<TrustedDOMRendererContext>): void {
  registry.register("user-message", (item, context) => context.renderUserMessage(item));
  registry.register("markdown", (item, context) => context.renderMarkdown(item));
  registry.register("agent-status", (item, context) => context.renderAgentStatus(item));
  registry.register("execution-summary", (item, context) => context.renderExecutionTrace(item));
  registry.register("progress", (item, context) => context.renderProgress(item));
  registry.register("error", (item, context) => context.renderError(item));
  registry.register("tool-call", (item, context) => context.renderToolCall(item));
  registry.register("tool-result", (item, context) => context.renderToolResult(item));
  registry.register("tool-cancel", (item, context) => context.renderToolCancel(item));
  registry.register("surface", (item, context) => context.renderSurface(item));
  registry.register("app-call", (item, context) => context.renderAppCall(item));
  registry.register("fallback", (item, context) => context.renderFallback(item));
}