import { Bot, ExternalLink, History, Maximize2, Minus, SquarePen, X } from "lucide-react";
import { useEffect, useRef, useState } from "react";
import { Link, useLocation } from "react-router";
import { toast } from "sonner";
import { agentMockEnabled, isRunActive, useAgentRun, useCreateAgentRun } from "~/api/agent.ts";
import { useDownloadTask } from "~/api/downloads.ts";
import { useLibraryDetail } from "~/api/library.ts";
import { useRecord } from "~/api/records.ts";
import { useSite } from "~/api/sites.ts";
import { StreamingCursor } from "~/components/agentui/streaming-response.tsx";
import { Button } from "~/components/ui/button.tsx";
import { Popover, PopoverContent, PopoverTrigger } from "~/components/ui/popover.tsx";
import { Sheet, SheetClose, SheetContent, SheetDescription, SheetHeader, SheetTitle } from "~/components/ui/sheet.tsx";
import { errorMessage } from "~/lib/api.ts";
import { capabilityMeta, isDenied, RunStatusBadge } from "./agent-conversation.tsx";
import { DRAFT_DRAWER_GOAL, writeDraft } from "./agent-nav.ts";
import { AgentRunPanel, GoalComposer } from "./agent-run-panel.tsx";
import { AgentSessionList, drawerListMemory } from "./agent-session-list.tsx";
import {
  type AgentContext,
  agentShortcutLabel,
  clearAgentContext,
  contextPrefix,
  minimizeAgentDrawer,
  newAgentConversation,
  noteAgentReturnPath,
  restoreAgentDrawer,
  setAgentDrawerOpen,
  shortGoalTitle,
  showAgentRunInDrawer,
  syncAgentContextToPath,
  takeReturnFocus,
  toggleAgentDrawer,
  useAgentDrawer,
} from "./agent-store.ts";
import { AgentRunOpenContext } from "./agent-subagent-tree.tsx";
import { quickGoalsFor } from "./quick-goals.ts";
import { useAgentStream } from "./use-agent-stream.ts";

/** 悬浮按钮等"抽屉外但属于抽屉"的控件打这个属性:点它不算点外面(否则先被关掉又被重新打开) */
export const AGENT_LAUNCHER_ATTR = "data-agent-launcher";

/**
 * 上下文的显示名称:页面按钮给的 label(「作品：沙丘2」)去掉类别;按路由推断的只有 ID,按 ID 查名称。
 * 查不到时退回类别名(「这部作品」),不显示 ID。
 */
export function useContextName(ctx: AgentContext | null): string | null {
  const path = !!ctx?.fromPath;
  const entity = useLibraryDetail(path ? ctx?.entityId : undefined);
  const site = useSite(path ? ctx?.siteId : undefined);
  const task = useDownloadTask(path ? ctx?.downloadTaskId : undefined);
  const record = useRecord(path ? ctx?.recordId : undefined);
  if (!ctx) return null;
  if (!path) return ctx.label ? ctx.label.replace(/^(作品|资源|下载|整理记录|站点|任务|后台任务)[：:]\s*/, "") : null;
  if (ctx.entityId) return entity.data?.entity.title ?? "这部作品";
  if (ctx.siteId) return site.data?.name ?? ctx.siteId;
  if (ctx.downloadTaskId) return task.data?.name ?? "这个下载任务";
  if (ctx.recordId) return record.data?.media?.title ?? "这条整理记录";
  if (ctx.taskId) return "这个后台任务";
  return null;
}

/** 历史弹层:最近 20 条,等你处理置顶,子会话收在父会话下;点一条在抽屉里打开 */
function HistoryPopover({ activeId }: { activeId: string | null }) {
  const [open, setOpen] = useState(false);
  const mock = agentMockEnabled();
  return (
    <Popover open={open} onOpenChange={setOpen}>
      <PopoverTrigger asChild>
        <Button variant="ghost" size="sm" aria-label="历史会话" title="历史会话">
          <History />
          历史
        </Button>
      </PopoverTrigger>
      <PopoverContent align="end" className="flex h-[min(32rem,70dvh)] w-[min(22rem,calc(100vw-2rem))] flex-col p-2">
        <AgentSessionList
          memory={drawerListMemory}
          limit={20}
          activeId={activeId ?? undefined}
          onOpen={(id) => {
            setOpen(false);
            showAgentRunInDrawer(id);
          }}
          className="min-h-0 flex-1"
        />
        <Button asChild variant="ghost" size="sm" className="mt-1 shrink-0 text-muted-foreground">
          <Link to={`/console/agent${mock ? "?mock=1" : ""}`} onClick={() => setAgentDrawerOpen(false)}>
            全部会话
          </Link>
        </Button>
      </PopoverContent>
    </Popover>
  );
}

/**
 * 智能体抽屉(AGUI-3):任意页面可打开,带当前页面上下文(作品 / 站点 / 下载任务等)。
 * 头部只有「历史」弹层和「新对话」;没有 Tab。运行中可最小化到右下角小窗,流式输出继续。
 * 挂载:在 console layout 里渲染一次 <AgentDrawer />。页面内打开:openAgentDrawer({ entityId, label, ... })。
 */
export function AgentDrawer() {
  const { open, minimized, context, runId } = useAgentDrawer();
  const create = useCreateAgentRun();
  const { pathname, search } = useLocation();
  const content = useRef<HTMLDivElement>(null);
  // 记下最近的非智能体页面:会话页「在侧边打开」回到这里
  useEffect(() => noteAgentReturnPath(pathname, search), [pathname, search]);
  useEffect(() => syncAgentContextToPath(pathname), [pathname]);
  const name = useContextName(context);
  const mock = agentMockEnabled();
  // 目标前缀带名称和 ID:名称给人看,ID 给模型用
  const prefix = contextPrefix(context && name ? { ...context, label: name } : context);

  return (
    <>
      <Sheet open={open} onOpenChange={setAgentDrawerOpen}>
        <SheetContent
          ref={content}
          side="right"
          showCloseButton={false}
          className="w-full gap-0 p-0 sm:max-w-xl"
          // 打开即可输入:焦点直接给输入框,没有输入框时退回抽屉本身
          onOpenAutoFocus={(e) => {
            const ta = content.current?.querySelector<HTMLTextAreaElement>("textarea:not([disabled])");
            if (!ta) return;
            e.preventDefault();
            ta.focus();
            ta.setSelectionRange(ta.value.length, ta.value.length);
          }}
          // 关闭后焦点回到打开前的位置(快捷键打开没有触发元素,缺省会落到 body)
          onCloseAutoFocus={(e) => {
            const el = takeReturnFocus();
            if (!el) return;
            e.preventDefault();
            el.focus();
          }}
          onInteractOutside={(e) => {
            if ((e.target as Element | null)?.closest?.(`[${AGENT_LAUNCHER_ATTR}]`)) e.preventDefault();
          }}
        >
          <SheetHeader className="flex-row items-center gap-1 border-b border-[var(--shell-border)] py-2.5 pr-3 pl-5">
            <SheetTitle className="mr-auto flex items-center gap-2 text-lead">
              <Bot className="h-4 w-4" />
              智能体
            </SheetTitle>
            <SheetDescription className="sr-only">{`${agentShortcutLabel()} 打开或收起`}</SheetDescription>
            <HistoryPopover activeId={runId} />
            <Button variant="ghost" size="sm" onClick={newAgentConversation} disabled={!runId}>
              <SquarePen />
              新对话
            </Button>
            {runId ? (
              <>
                <Button asChild variant="ghost" size="icon-sm" aria-label="在页面打开" title="在页面打开">
                  <Link
                    to={`/console/agent/${runId}${mock ? "?mock=1" : ""}`}
                    onClick={() => setAgentDrawerOpen(false)}
                  >
                    <ExternalLink />
                  </Link>
                </Button>
                <Button
                  variant="ghost"
                  size="icon-sm"
                  aria-label="最小化，会话继续运行"
                  title="最小化，会话继续运行"
                  onClick={minimizeAgentDrawer}
                >
                  <Minus />
                </Button>
              </>
            ) : null}
            {/* 关闭钮放进标题栏这一行,与其它按钮对齐(Sheet 自带的是绝对定位,偏下 5px) */}
            <SheetClose asChild>
              <Button variant="ghost" size="icon-sm" aria-label="关闭" title="关闭（Esc）">
                <X />
              </Button>
            </SheetClose>
          </SheetHeader>
          <div className="flex min-h-0 flex-1 flex-col px-4 py-3">
            {runId ? (
              <AgentRunOpenContext.Provider value={showAgentRunInDrawer}>
                <AgentRunPanel key={runId} runId={runId} compact className="flex-1" onCreated={showAgentRunInDrawer} />
              </AgentRunOpenContext.Provider>
            ) : (
              <div className="flex min-h-0 flex-1 flex-col justify-end">
                <GoalComposer
                  key={`${context?.entityId ?? ""}${context?.releaseId ?? ""}${context?.goal ?? ""}`}
                  suggestions={context?.goal ? undefined : quickGoalsFor(pathname)}
                  context={name}
                  onClearContext={clearAgentContext}
                  defaultGoal={context?.goal ?? ""}
                  draftKey={DRAFT_DRAWER_GOAL}
                  pending={create.isPending}
                  onSubmit={(goal, opts) =>
                    create.mutate(
                      { goal: `${prefix}${goal}`, ...opts },
                      {
                        onSuccess: (run) => {
                          writeDraft(DRAFT_DRAWER_GOAL, "");
                          showAgentRunInDrawer(run.id);
                        },
                        onError: (e) => toast.error(errorMessage(e)),
                      },
                    )
                  }
                />
              </div>
            )}
          </div>
        </SheetContent>
      </Sheet>
      {minimized && runId ? <AgentMiniDock runId={runId} /> : null}
    </>
  );
}

/** 最小化后的小窗:保持事件流订阅,显示状态与最新一句输出 */
function AgentMiniDock({ runId }: { runId: string }) {
  const run = useAgentRun(runId);
  const active = isRunActive(run.data?.run.status);
  const live = useAgentStream(runId, active || !run.data);
  const last = live.items[live.items.length - 1];
  const streaming = active && !live.finished;
  const line =
    last?.kind === "text"
      ? last.text.trim().split("\n").pop()
      : last?.kind === "tool"
        ? `${isDenied(last.call) ? "被拒绝" : last.call.status === "running" ? "调用" : "完成"} · ${capabilityMeta(last.call.capabilityId)?.title ?? last.call.capabilityId}`
        : last?.kind === "thinking"
          ? "思考中…"
          : last?.kind === "end"
            ? last.ok
              ? "已完成，展开查看结果"
              : last.message
            : "等待输出…";
  const status = run.data
    ? live.finished && isRunActive(run.data.run.status)
      ? "running"
      : run.data.run.status
    : null;
  return (
    <section
      aria-label="智能体小窗"
      className="pg-float fixed right-4 bottom-4 z-40 w-80 max-w-[calc(100vw-2rem)] rounded-2xl p-3 animate-in fade-in-0 slide-in-from-bottom-2 duration-base ease-pop motion-reduce:animate-none"
    >
      <div className="flex items-center gap-2">
        <Bot aria-hidden className="size-4 shrink-0 text-muted-foreground" />
        {status ? <RunStatusBadge status={status} /> : null}
        <span className="min-w-0 flex-1 truncate text-meta text-muted-foreground">
          {run.data ? shortGoalTitle(run.data.run.goal) : ""}
        </span>
        <Button variant="ghost" size="icon-xs" aria-label="展开智能体" title="展开" onClick={restoreAgentDrawer}>
          <Maximize2 />
        </Button>
        <Button
          variant="ghost"
          size="icon-xs"
          aria-label="关闭小窗，会话在后台继续"
          title="关闭小窗，会话在后台继续"
          onClick={() => setAgentDrawerOpen(false)}
        >
          <X />
        </Button>
      </div>
      <button
        type="button"
        onClick={restoreAgentDrawer}
        className="mt-2 block w-full cursor-pointer rounded-lg px-1 text-left text-caption leading-5 text-foreground/90 outline-none focus-visible:ring-2 focus-visible:ring-ring"
      >
        <span className="line-clamp-2 break-words">
          {line}
          {streaming && last?.kind === "text" ? <StreamingCursor /> : null}
        </span>
      </button>
    </section>
  );
}

/** 顶栏按钮(窄屏):与快捷键、悬浮按钮同一套切换(页面内按钮用 openAgentDrawer 传更完整的上下文) */
export function AgentDrawerTrigger({ className }: { className?: string }) {
  const { pathname } = useLocation();
  return (
    <Button
      variant="ghost"
      size="icon-sm"
      aria-label="打开智能体"
      title={`智能体(${agentShortcutLabel()})`}
      className={className}
      {...{ [AGENT_LAUNCHER_ATTR]: "" }}
      onClick={() => toggleAgentDrawer(pathname)}
    >
      <Bot />
    </Button>
  );
}