import { ArrowLeft, PlugZap } from "lucide-react";
import * as React from "react";
import { useCallback, useEffect, useMemo, useRef, useState, type ComponentType } from "react";

import { platformApiClient } from "../api/client";
import type { GamePluginResponse } from "../api/types";
import { PageFrame } from "../components/PageFrame";
import { EmptyState, ErrorState, LoadingState } from "../components/StateViews";
import type { PageComponentProps } from "../contracts/page";
import { pluginBridgeManifestContractFromResponse } from "../contracts/pluginBridge";
import type { PluginPageWorkspaceActions } from "../contracts/pluginPageHost";
import { createPluginBridgeDispatcher, createPluginBridgeHostContext } from "../utils/pluginBridgeHost";
import { loadPluginPageBundle, type PluginPageAvailability } from "../utils/pluginPageBundles";

type PluginPageState =
  | { status: "loading" }
  | { status: "error"; reason: string }
  | { status: "ready"; plugin: GamePluginResponse };

interface PluginPageHostPageProps extends PageComponentProps {
  initialPlugin?: GamePluginResponse;
  embedded?: boolean;
}

export function PluginPageHostPage({ params, onNavigate, initialPlugin, embedded = false }: PluginPageHostPageProps) {
  const pluginId = params.pluginId ?? "";
  const routeKey = params.routeKey ?? "";
  const serverId = params.serverId ?? "";
  const [state, setState] = useState<PluginPageState>(() => initialPlugin ? { status: "ready", plugin: initialPlugin } : { status: "loading" });
  const [bundle, setBundle] = useState<ComponentType<{ context: ReturnType<typeof createPluginBridgeHostContext>; workspaceActions?: PluginPageWorkspaceActions; availability: PluginPageAvailability }> | null>(null);
  const [bundleError, setBundleError] = useState("");
  const [availability, setAvailability] = useState<PluginPageAvailability>({ available: false, reason: "正在验证插件桥接可用性。" });
  const readyPluginRef = useRef<GamePluginResponse | undefined>(undefined);
  const hostContextRef = useRef<ReturnType<typeof createPluginBridgeHostContext> | undefined>(undefined);

  const load = useCallback(async () => {
    if (!pluginId || !routeKey) {
      setState({ status: "error", reason: "插件页面路由缺少 pluginId 或 routeKey。" });
      return;
    }
    setState({ status: "loading" });
    try {
      const response = await platformApiClient.listGamePlugins();
      const plugin = response.items.find((candidate) => candidate.id === pluginId);
      setState(plugin ? { status: "ready", plugin } : { status: "error", reason: "未找到已注册的插件声明。" });
    } catch (error) {
      setState({ status: "error", reason: error instanceof Error ? error.message : "插件页面声明加载失败。" });
    }
  }, [pluginId, routeKey]);

  useEffect(() => {
    if (!initialPlugin) {
      void load();
    }
  }, [initialPlugin, load]);

  const readyPlugin = state.status === "ready" ? state.plugin : undefined;
  const declaredPage = readyPlugin?.pages.find((candidate) => candidate.key === routeKey);
  const manifestContract = useMemo(() => (readyPlugin ? pluginBridgeManifestContractFromResponse(readyPlugin) : undefined), [readyPlugin]);
  const declaredBundlePage = manifestContract?.pages.find((candidate) => candidate.key === routeKey);
  const hostContext = useMemo(() => manifestContract ? createPluginBridgeHostContext({
    plugin: manifestContract,
    routeKey,
    serverInstanceId: serverId || undefined,
    themeTokens: { colorScheme: "dark", accentColor: "#7dd3fc" }
  }) : undefined, [manifestContract, routeKey, serverId]);
  readyPluginRef.current = readyPlugin;
  hostContextRef.current = hostContext;
  const workspaceActions = useMemo<PluginPageWorkspaceActions | undefined>(() => {
    if (!pluginId) return undefined;
    return {
      pluginData: {
        list: (collection, key) => platformApiClient.listPluginData(serverId, collection, key),
        put: (collection, key, value) => platformApiClient.putPluginData(serverId, collection, key, value),
        delete: (collection, key) => platformApiClient.deletePluginData(serverId, collection, key),
        transact: (collection, mutations) => platformApiClient.transactPluginData(serverId, collection, mutations)
      },
      gameClient: {
        queue: (request) => platformApiClient.queueGameClientBridgeCommand(serverId, request),
        get: (commandId) => platformApiClient.getGameClientBridgeCommand(serverId, commandId),
        list: (filter) => platformApiClient.listGameClientBridgeCommands(serverId, filter),
        snapshots: (query) => platformApiClient.listGameClientBridgeSnapshots(serverId, query)
      },
      dispatch: (envelope, signal) => {
        const context = hostContextRef.current;
        if (!context) return Promise.resolve({ requestId: envelope.requestId, action: envelope.action, status: "error", error: { code: "host_unavailable", message: "plugin bridge host is unavailable" } });
        return createPluginBridgeDispatcher(context, platformApiClient)(envelope, signal);
      }
    };
  }, [pluginId, serverId]);
  const bundleLoadKey = declaredBundlePage ? [declaredBundlePage.bundleKey, declaredBundlePage.bundleVersion, declaredBundlePage.bundleIntegritySha256, declaredBundlePage.path].join(":") : "";
  const loadableBundlePage = useMemo(() => declaredBundlePage, [bundleLoadKey]);
  useEffect(() => {
    let active = true;
    if (!loadableBundlePage) return () => { active = false; };
    globalThis.__PLUGIN_PAGE_REACT__ = React;
    setBundle(null); setBundleError("");
    void loadPluginPageBundle(loadableBundlePage).then((loaded) => { if (active) setBundle(() => loaded); }).catch((error) => { if (active) setBundleError(error instanceof Error ? error.message : "插件页面 bundle 加载失败。"); });
    if (!serverId) { setAvailability({ available: false, reason: "插件页面没有绑定服务器。" }); return () => { active = false; }; }
    void platformApiClient.getGameClientBridgeStatus(serverId).then((status) => {
      if (active) setAvailability({ available: status.available, reason: status.reason, features: status.features });
    }).catch((error) => { if (active) setAvailability({ available: false, reason: error instanceof Error ? error.message : "无法验证插件桥接可用性。" }); });
    return () => { active = false; };
  }, [bundleLoadKey, loadableBundlePage, serverId]);

  if (state.status === "loading") {
    return <LoadingState label="正在加载插件页面声明…" />;
  }
  if (state.status === "error") {
    return <ErrorState title="插件页面不可用" reason={state.reason} onRetry={() => void load()} />;
  }

  const page = declaredPage;
  if (!page) {
    return <ErrorState title="插件页面不可用" reason="当前插件没有声明该 routeKey。" />;
  }
  if (!hostContext) {
    return <ErrorState title="插件页面不可用" reason="插件页面上下文初始化失败。" />;
  }
  if (embedded) {
    return (
      <>
        {bundleError && <ErrorState title="插件页面不可用" reason={bundleError} />}
        {!bundle && !bundleError && <LoadingState label="正在校验并加载插件页面 bundle…" compact />}
        {bundle && React.createElement(bundle, { context: hostContext, workspaceActions, availability })}
      </>
    );
  }
  return (
    <div className="console-page">
      <PageFrame
        kicker={`${state.plugin.name} / PLUGIN PAGE`}
        title={page.title}
        status={serverId ? `服务器 ${serverId}` : "未绑定服务器"}
        metrics={[
          { label: "有效权限", value: String(hostContext.permissions.length), tone: hostContext.permissions.length > 0 ? "success" : "warning" },
          { label: "桥接动作", value: String(hostContext.bridgeActions.length), tone: hostContext.bridgeActions.length > 0 ? "success" : "warning" },
          { label: "页面路由", value: routeKey, tone: "neutral" }
        ]}
      />

      <section className="console-panel" aria-label="plugin page host context">
        <div className="panel-header">
          <h2><PlugZap size={16} aria-hidden="true" /> 平台托管上下文</h2>
          <button type="button" className="icon-command" onClick={() => onNavigate(serverId ? "serverDetail" : "plugins", serverId ? { serverId } : {})}>
            <ArrowLeft size={14} aria-hidden="true" />
            <span>{serverId ? "返回服务器" : "返回插件市场"}</span>
          </button>
        </div>

        <div className="action-list" aria-label="plugin page declarations"><span><strong>Bundle</strong> {page.bundleKey ? `${page.bundleKey}@${page.bundleVersion}` : "未声明"}</span><span><strong>完整性</strong> {page.bundleIntegritySha256 ? `${page.bundleIntegritySha256.slice(0, 18)}…` : "未声明"}</span><span><strong>插件桥接</strong> {availability.available ? "可用" : "不可用"}</span></div>
      </section>
      {bundleError && <ErrorState title="插件页面不可用" reason={bundleError} />}
      {!bundle && !bundleError && <LoadingState label="正在校验并加载插件页面 bundle…" />}
      {bundle && React.createElement(bundle, { context: hostContext, workspaceActions, availability })}
    </div>
  );
}