/**
 * 任务深链（rwfx / 任务FX）的「任务工作区」：一个任务挂多个对话（1:N）。
 *
 *   左侧 = 该任务下的对话列表（按 metadata.taskId 过滤）+「新建对话」；
 *   右下角 = 常驻浮层红色按钮（编辑 / 下一步 / 清除任务记录），absolute 定位，时刻可见、不被内容挤走；
 *   右侧 = <Outlet/> 渲染选中的对话（AgentChatPage，新建对话顶部带目的树闸门面板）。
 *
 *   - 进入 chats 索引：有历史 → 跳最新；无历史 → 跳 new（=新建，走闸门）。
 *   - 新建对话 = 直接跳入：navigate 到 chats/new；切换/新建时 AgentChatPage 会停掉老对话的服务端 run。
 *   - 清除任务记录：仅调 delete 接口（聊天对话保留）。
 *   - 编辑 / 下一步：window.open 配置里的 B 系统地址（?id=taskId）。
 * 见 [[task-purpose]] / [[task-deeplink-config]]。
 */

import { useEffect, useMemo, useState } from "react";
import { Outlet, useLocation, useNavigate, useParams } from "react-router-dom";
import { ArrowRight, ExternalLink, Loader2, MessageSquare, PlusSquare, Trash2 } from "lucide-react";
import { toast } from "sonner";

import { Button } from "@/components/ui/button";
import {
  Dialog,
  DialogContent,
  DialogDescription,
  DialogFooter,
  DialogHeader,
  DialogTitle,
} from "@/components/ui/dialog";
import {
  buildTreemapEditUrl,
  buildTreemapNextUrl,
  deleteTaskPurpose,
  readTaskContext,
} from "@/core/auth/task-purpose";
import { fetchTaskDeeplinkConfig } from "@/core/auth/task-deeplink-config";
import { useTaskThreads } from "@/core/threads/use-task-threads";
import { titleOfThread } from "@/core/threads/utils";
import { desensitize } from "@/lib/desensitize";
import { cn } from "@/lib/utils";
import AgentChatPage from "@/pages/AgentChatPage";
import { ChatRuntime } from "@/pages/WorkspaceRoutes";

function useChatsBase(taskBase: string): { taskId: string; chatsBase: string } {
  const { agent_id } = useParams<{ agent_id: string }>();
  const taskId = readTaskContext()?.taskId ?? "";
  return { taskId, chatsBase: `${taskBase}/agent/${agent_id}/chats` };
}

/** 从路由路径里解析当前打开的会话 id（布局组件读不到子路由的 :thread_id，故从 path 取）。 */
function parseThreadId(pathname: string, chatsBase: string): string | null {
  if (!pathname.startsWith(chatsBase)) return null;
  const seg = pathname.slice(chatsBase.length).replace(/^\/+/, "").split("/")[0];
  return seg && seg !== "new" ? seg : null;
}

/** 左侧任务对话列表 +「新建对话」。 */
function TaskConversationsList({ taskId, chatsBase }: { taskId: string; chatsBase: string }) {
  const { pathname } = useLocation();
  const navigate = useNavigate();
  const { threads, isLoading } = useTaskThreads(taskId);
  const currentThreadId = useMemo(() => parseThreadId(pathname, chatsBase), [pathname, chatsBase]);

  return (
    <div className="border-border/70 bg-card/40 flex w-60 shrink-0 flex-col border-r">
      <div className="border-border/70 border-b p-2">
        <Button size="sm" className="w-full" onClick={() => navigate(`${chatsBase}/new`)}>
          <PlusSquare className="h-4 w-4" /> 新建对话
        </Button>
      </div>

      <div className="min-h-0 flex-1 overflow-y-auto p-1.5">
        {isLoading ? (
          <div className="text-muted-foreground p-2 text-sm">加载中…</div>
        ) : threads.length === 0 ? (
          <div className="text-muted-foreground p-2 text-sm">暂无对话</div>
        ) : (
          threads.map((thread) => (
            <button
              key={thread.thread_id}
              onClick={() => navigate(`${chatsBase}/${thread.thread_id}`)}
              className={cn(
                "hover:bg-accent flex w-full items-center gap-2 rounded px-2 py-1.5 text-left text-sm",
                thread.thread_id === currentThreadId && "bg-accent font-medium",
              )}
              title={desensitize(titleOfThread(thread, "新对话"))}
            >
              <MessageSquare className="h-3.5 w-3.5 shrink-0" />
              <span className="truncate">{desensitize(titleOfThread(thread, "新对话"))}</span>
            </button>
          ))
        )}
      </div>
    </div>
  );
}

/**
 * 右下角常驻红色操作浮层：编辑 / 下一步 / 清除任务记录。
 * absolute 定位在工作区右侧面板内，z-40，时刻可见、不被聊天内容挤走。
 */
function TaskFloatingActions({ taskId }: { taskId: string }) {
  const [clearOpen, setClearOpen] = useState(false);
  const [clearing, setClearing] = useState(false);

  const openExternal = (url: string, label: string) => {
    if (url) window.open(url, "_blank", "noopener,noreferrer");
    else toast.error(`未配置${label}地址`);
  };

  const handleClear = async () => {
    setClearing(true);
    try {
      const r = await deleteTaskPurpose(taskId);
      if (r.success) toast.success("已清除任务记录");
      else toast.error(r.message || "清除失败");
    } catch {
      toast.error("清除失败，请稍后再试");
    } finally {
      setClearing(false);
      setClearOpen(false);
    }
  };

  return (
    <>
      <div className="pointer-events-none absolute bottom-4 right-4 z-40 flex flex-col items-end gap-2">
        <Button
          size="sm"
          variant="destructive"
          className="pointer-events-auto shadow-lg"
          onClick={() => openExternal(buildTreemapEditUrl(taskId), "编辑")}
        >
          <ExternalLink className="h-3.5 w-3.5" /> 编辑
        </Button>
        <Button
          size="sm"
          variant="destructive"
          className="pointer-events-auto shadow-lg"
          onClick={() => openExternal(buildTreemapNextUrl(taskId), "下一步")}
        >
          <ArrowRight className="h-3.5 w-3.5" /> 下一步
        </Button>
        <Button
          size="sm"
          variant="destructive"
          className="pointer-events-auto shadow-lg"
          onClick={() => setClearOpen(true)}
          disabled={!taskId}
        >
          <Trash2 className="h-3.5 w-3.5" /> 清除任务记录
        </Button>
      </div>

      <Dialog open={clearOpen} onOpenChange={(o) => !clearing && setClearOpen(o)}>
        <DialogContent>
          <DialogHeader>
            <DialogTitle>清除任务记录</DialogTitle>
            <DialogDescription>
              将清除该任务在 B 系统中的目的策划数据（聊天对话保留），是否确认？
            </DialogDescription>
          </DialogHeader>
          <DialogFooter>
            <Button variant="outline" onClick={() => setClearOpen(false)} disabled={clearing}>
              取消
            </Button>
            <Button variant="destructive" onClick={handleClear} disabled={clearing}>
              {clearing ? <Loader2 className="h-4 w-4 animate-spin" /> : "确认清除"}
            </Button>
          </DialogFooter>
        </DialogContent>
      </Dialog>
    </>
  );
}

/** 任务工作区布局：左列表 + 右 Outlet + 右下角常驻红色操作浮层。 */
export function TaskFxWorkspace({ taskBase }: { taskBase: string }) {
  const { taskId, chatsBase } = useChatsBase(taskBase);
  // 预拉配置，保证「编辑/下一步」的同步 URL 构造能读到缓存。
  useEffect(() => {
    void fetchTaskDeeplinkConfig();
  }, []);
  return (
    <div className="flex size-full min-h-0 overflow-hidden">
      <TaskConversationsList taskId={taskId} chatsBase={chatsBase} />
      <div className="relative min-h-0 min-w-0 flex-1">
        <Outlet />
        <TaskFloatingActions taskId={taskId} />
      </div>
    </div>
  );
}

/** chats 索引：有历史对话 → 跳最新；否则 → 跳 new（走闸门）。 */
export function TaskFxIndexResolver({ taskBase }: { taskBase: string }) {
  const { taskId, chatsBase } = useChatsBase(taskBase);
  const navigate = useNavigate();
  const { isLoading, hasThreads, latestThreadId } = useTaskThreads(taskId);

  useEffect(() => {
    if (isLoading) return;
    if (hasThreads && latestThreadId) {
      navigate(`${chatsBase}/${latestThreadId}`, { replace: true });
    } else {
      navigate(`${chatsBase}/new`, { replace: true });
    }
  }, [isLoading, hasThreads, latestThreadId, chatsBase, navigate]);

  return (
    <div className="text-muted-foreground flex size-full items-center justify-center">
      <Loader2 className="h-5 w-5 animate-spin" />
    </div>
  );
}

/** 右侧对话宿主：AgentChatPage（taskGate 开启 → 新建对话顶部展示目的树闸门面板 + 老对话停止）。 */
export function TaskFxChat({ taskBase }: { taskBase: string }) {
  const { agent_id } = useParams<{ agent_id: string }>();
  return (
    <ChatRuntime>
      <AgentChatPage chatBasePath={`${taskBase}/agent/${agent_id}/chats`} taskGate />
    </ChatRuntime>
  );
}