import type { UIEventHandler } from 'react';
import type { Ref } from 'react';
import {
  useEffect,
  useImperativeHandle,
  useMemo,
  useRef,
  useState,
} from 'react';

import { AGENT_CHAT_SCROLL_BOTTOM_THRESHOLD } from '../../../app/constants';
import { claimInitialTurnForPage } from '../../../app/initialTurnClaims';
import type { PendingUiConfirmation } from '../../../app/types';
import { projectNameFromPath } from '../../../features/agent-runtime';
import { directCodexUserItemFromContent } from '../../../features/project-workspace/resourceReferences';
import { type ApprovalMode, approvalModeLabel } from '../approvalMode';
import { ApprovalModeDialog } from '../ApprovalModeDialog';
import { DirectProjectChatHeader } from './components/DirectProjectChatHeader/DirectProjectChatHeader';
import { DirectProjectComposer } from './components/DirectProjectComposer/DirectProjectComposer';
import { DirectProjectConversation } from './components/DirectProjectConversation/DirectProjectConversation';
import { DirectProjectSettingsDialog } from './components/DirectProjectSettingsDialog/DirectProjectSettingsDialog';
import {
  type DirectProjectConversationReadGate,
  type DirectProjectConversationWriteGate,
  useDirectProjectChatController,
} from './controller/useDirectProjectChatController';
import { useDirectProjectManifest } from './controller/useDirectProjectManifest';
import { useDirectProjectTurnStatus } from './controller/useDirectProjectTurnStatus';
import {
  createDirectProjectTurnId,
  directCodexConversationMessageId,
  type DirectProjectTurnInput,
} from './conversation/directCodexConversation';
import { buildDirectChatTurns } from './conversation/directTurnPresentation';
import type { DirectCodexUserContentPart } from './generated/DirectCodexUserContentPart';

/**
 * DirectProject 对外只有这一条命令式出口：工作台壳跑完运行/预览这类工作台级动作后，
 * 把结果告诉用户。聊天容器持有会话真相，壳不持有聊天消息，只把这句话交给聊天的本地
 * 消息流。
 */
export type DirectProjectChatHandle = {
  announce: (text: string) => void;
};

/**
 * 首页（或立项链路）带过来的首轮需求：项目打开后由聊天自己认领并发出。
 *
 * 认领记录按「项目路径 + claimScope」与 Design / Planning 入口共用一份
 * （见 `app/initialTurnClaims`），所以同一条首轮需求不会被两个入口各发一次。
 */
export type DirectProjectInitialTurn = {
  projectPath: string;
  /**
   * 入口首轮需求的 canonical 内容：文本、`@` 素材引用和附件引用都内联在这一份 content
   * 里，和 Composer 提交的回合保持同一种形状。
   */
  content: DirectCodexUserContentPart[];
  creationType?: DirectProjectTurnInput['creationType'];
  claimScope: string;
};

/**
 * DirectProject 的公开入参：只有项目身份、入口带进来的首轮需求和两条权限门。
 *
 * 项目清单（素材/版本/projectId）、订阅、首屏锚点与历史分页、发送与 FIFO 队列、附件、
 * 终止、草稿、本地消息、状态文案和错误提示都由这个组件自己持有；工作台壳不再传 Direct
 * 专属 state/ref/effect，也不再有 Design Agent / Planning V2 的运行态。
 */
export type DirectProjectChatViewProps = {
  /** 绑定的项目路径：项目身份、素材与版本都从这份项目清单读取。 */
  projectPath: string | null;
  /** 入口带进来的首轮需求；未提供时不自动发送任何回合。 */
  initialTurn?: DirectProjectInitialTurn | null;
  /**
   * 项目对话读权限门：策略要求确认时由工作台壳入队，聊天不重复判定权限。
   * 必填：这道门是聊天发起读取/回合的授权判据，缺省放行等于绕过工作台壳的权限判定。
   */
  ensureConversationReadAllowed: DirectProjectConversationReadGate;
  /** 项目对话写权限门：只在发起回合时检查；同样必填，缺省会让未传入的调用方静默跳过授权。 */
  ensureConversationWriteAllowed: DirectProjectConversationWriteGate;
  /** 发布入口：由工作台壳持有导出与发布面板，聊天只提供触发按钮。 */
  onRequestGamePublish?: () => void;
  /**
   * 工作台壳入队的项目权限确认：聊天只展示并转发确认/取消，
   * 策略读取、拒绝判定和确认后的动作仍由工作台壳持有。
   */
  pendingConfirmation?: PendingUiConfirmation | null;
  onConfirmConfirmation?: () => void;
  onCancelConfirmation?: () => void;
  /** 工作台壳把运行/预览这类动作结果交给聊天的出口。 */
  ref?: Ref<DirectProjectChatHandle>;
};

/** 首轮那条本地用户消息展示入口原话：附件与引用仍按 canonical content 进入回合。 */
function directInitialTurnText(content: readonly DirectCodexUserContentPart[]) {
  return content
    .filter((part) => part.type === 'input_text')
    .map((part) => part.text)
    .join('')
    .trim();
}

export function DirectProjectChatView({
  onRequestGamePublish,
  onConfirmConfirmation,
  onCancelConfirmation,
  pendingConfirmation = null,
  projectPath,
  initialTurn = null,
  ensureConversationReadAllowed,
  ensureConversationWriteAllowed,
  ref,
}: DirectProjectChatViewProps) {
  const { assets, projectId, refresh, versions } =
    useDirectProjectManifest(projectPath);
  const messagesRef = useRef<HTMLDivElement | null>(null);
  const shouldFollowLatestRef = useRef(true);
  const [runtimeNotice, setRuntimeNotice] = useState('');
  const [settingsOpen, setSettingsOpen] = useState(false);
  const [approvalOpen, setApprovalOpen] = useState(false);
  const [approvalMode, setApprovalMode] = useState<ApprovalMode>('strict');
  const [approvalNotice, setApprovalNotice] = useState('');
  const chat = useDirectProjectChatController({
    assets,
    enabled: Boolean(projectPath),
    ensureConversationReadAllowed,
    ensureConversationWriteAllowed,
    onRuntimeError: setRuntimeNotice,
    projectId,
    projectPath,
    refreshManifest: refresh,
  });
  const {
    appendLocalMessage,
    attachmentNotice,
    attachmentsImporting,
    cancelQueuedTurn,
    cancelTurn,
    composerNotice,
    directEntries,
    directTurnRunning,
    historyHasMore,
    loadEarlierHistory,
    localMessages,
    pendingUserItemId,
    queuedTurns,
    startInitialTurn,
    statusNotice,
    submit,
    turnBusy,
    turnCancelling,
    uploadFiles,
  } = chat;
  // 这份投影要参与下游 memo 的判据，必须自己先缓存：不缓存的话每次渲染都是一份新数组，
  // `useDirectProjectTurnStatus` 里以 `turns` 为判据的 `useMemo` 永远命中不了，那层 memo
  // 就成了死代码，读代码的人还会误以为 `turnStatus` 是引用稳定的。
  const directTurns = useMemo(
    () =>
      buildDirectChatTurns({
        entries: directEntries,
        localMessages,
        turnRunning: directTurnRunning,
        pendingUserItemId,
      }),
    [directEntries, localMessages, directTurnRunning, pendingUserItemId],
  );
  // 「这一轮在跑吗」只从这一个派生入口读：原生真相 / 本地命令在飞 / 最新一轮三态。
  const turnStatus = useDirectProjectTurnStatus({
    turnRunning: directTurnRunning,
    turnBusy,
    turns: directTurns,
  });
  // 状态条的起点只认**未结束**的最新一轮：`awaiting-start`（本地已发出、宿主还没确认）
  // 也有用户发送时间，只读 `running` 会让卡片在模型首 token 之前根本不出现。
  // 只可能是最后一轮：原生 `turnRunning` 只赋给最新一轮，`awaiting-start` 也只判最新一轮。
  const latestTurn = directTurns.at(-1) ?? null;
  const activeTurnStartedAt =
    latestTurn && latestTurn.state !== 'finished' ? latestTurn.startedAt : 0;
  const statusText =
    runtimeNotice ||
    statusNotice ||
    (projectPath
      ? `已打开：${projectNameFromPath(projectPath)}`
      : '请选择工作区');

  useEffect(() => {
    if (!initialTurn || initialTurn.content.length === 0 || !projectPath)
      return;
    if (projectPath !== initialTurn.projectPath) return;
    // projectId 来自项目清单：清单还没到位时不能先认领，否则首轮需求会被空项目吃掉。
    if (!projectId || turnStatus.displayBusy) return;
    if (
      !claimInitialTurnForPage(initialTurn.projectPath, initialTurn.claimScope)
    ) {
      return;
    }
    const clientTurnId = createDirectProjectTurnId();
    const userItem = directCodexUserItemFromContent(
      initialTurn.content,
      directCodexConversationMessageId(clientTurnId, 'user'),
    );
    shouldFollowLatestRef.current = true;
    startInitialTurn({
      // 首轮那条用户消息按入口原话展示，引用/附件仍按 canonical content 发给运行时。
      messageText: directInitialTurnText(initialTurn.content),
      clientTurnId,
      ...(initialTurn.creationType
        ? { creationType: initialTurn.creationType }
        : {}),
      userItem,
    });
    // 首轮需求只由入口 payload、项目身份、清单就绪和回合忙态驱动。
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [turnStatus.displayBusy, initialTurn, projectId, projectPath]);

  useEffect(() => {
    if (!shouldFollowLatestRef.current) return;
    const list = messagesRef.current;
    if (list) list.scrollTop = list.scrollHeight;
  }, [directEntries, localMessages]);

  useImperativeHandle(ref, () => ({
    announce: (text: string) => {
      appendLocalMessage({ role: 'assistant', text, updatedAt: Date.now() });
    },
  }));

  const handleScroll: UIEventHandler<HTMLDivElement> = (event) => {
    const list = event.currentTarget;
    shouldFollowLatestRef.current =
      list.scrollHeight - list.scrollTop - list.clientHeight <=
      AGENT_CHAT_SCROLL_BOTTOM_THRESHOLD;
    if (historyHasMore && list.scrollTop <= 24) {
      void loadEarlierHistory();
    }
  };

  return (
    <section
      className="project-chat-surface is-direct-codex"
      aria-label="陶泥儿项目对话"
    >
      <div className="project-chat-conversation">
        <DirectProjectChatHeader
          busy={turnStatus.displayBusy}
          statusText={statusText}
          onOpenSettings={() => setSettingsOpen(true)}
          onRequestGamePublish={onRequestGamePublish}
        />
        <DirectProjectConversation
          turns={directTurns}
          messagesRef={messagesRef}
          historyHasMore={historyHasMore}
          turnInFlight={turnStatus.displayBusy}
          activeTurnStartedAt={activeTurnStartedAt}
          onLoadEarlierHistory={() => void loadEarlierHistory()}
          onScroll={handleScroll}
        />
        {pendingConfirmation &&
        onConfirmConfirmation &&
        onCancelConfirmation ? (
          <div className="pending-command">
            <span>
              {pendingConfirmation.commandId}
              <small>{pendingConfirmation.detail}</small>
            </span>
            <button type="button" onClick={onCancelConfirmation}>
              取消
            </button>
            <button type="button" onClick={onConfirmConfirmation}>
              确认
            </button>
          </div>
        ) : null}
        <DirectProjectComposer
          assets={assets}
          {...(versions ? { versions } : {})}
          projectPath={projectPath}
          attachmentNotice={attachmentNotice}
          attachmentsImporting={attachmentsImporting}
          queuedTurns={queuedTurns}
          composerNotice={composerNotice}
          busy={turnStatus.displayBusy}
          turnCancelling={turnCancelling}
          onCancelQueuedTurn={cancelQueuedTurn}
          onCancelTurn={() => void cancelTurn()}
          onReferencePickerOpen={() => {
            // 素材标签、改名、删除这些写入发生在资源画布，聊天侧收不到失效事件：
            // 打开 `@` 选择器时按需重读聊天自己那份清单，别把旧标签当现状。
            if (projectPath) void refresh(projectPath);
          }}
          onSubmit={submit}
          onUploadFiles={uploadFiles}
        />
      </div>
      {settingsOpen ? (
        <DirectProjectSettingsDialog
          projectPath={projectPath ?? ''}
          currentApprovalLabel={approvalModeLabel(approvalMode)}
          onOpenApproval={() => setApprovalOpen(true)}
          onClose={() => setSettingsOpen(false)}
        />
      ) : null}
      {settingsOpen && approvalOpen ? (
        <ApprovalModeDialog
          approvalMode={approvalMode}
          notice={approvalNotice}
          onSelect={setApprovalMode}
          onNotice={setApprovalNotice}
          onClose={() => setApprovalOpen(false)}
          closeOnEscape={false}
        />
      ) : null}
    </section>
  );
}