import { useEffect, useRef, useState } from "react";
import { LoaderCircle, MoreHorizontal, Pencil, X } from "lucide-react";
import { Button } from "@/shared/ui/button";
import { cn } from "@/shared/ui/cn";
import {
  DropdownMenu,
  DropdownMenuContent,
  DropdownMenuItem,
  DropdownMenuLabel,
  DropdownMenuRadioGroup,
  DropdownMenuRadioItem,
  DropdownMenuSeparator,
  DropdownMenuTrigger
} from "@/shared/ui/dropdown-menu";
import type { AgentInputDelivery, AgentResponseInput } from "../api/client";
import type { AgentCommandPanelPresentation } from "./agent-command-panel";

type AgentPendingInputsProps = {
  presentation: AgentCommandPanelPresentation;
  inputs: AgentResponseInput[];
  onDeliveryChange?: (id: string, delivery: AgentInputDelivery) => Promise<void> | void;
  onEdit?: (id: string) => Promise<void> | void;
  onCancel?: (id: string) => Promise<void> | void;
};

const menuItemClassName = "min-h-10 rounded-lg border border-transparent px-2.5 py-2 text-xs focus:border-[var(--action-border-hover)] focus:bg-[var(--action-selection-soft-hover)] data-[highlighted]:border-[var(--action-border-hover)] data-[highlighted]:bg-[var(--action-selection-soft-hover)]";

export function AgentPendingInputs({ presentation, inputs, onDeliveryChange, onEdit, onCancel }: AgentPendingInputsProps) {
  const [busyId, setBusyId] = useState<string | null>(null);
  const listRef = useRef<HTMLUListElement | null>(null);
  const latestId = inputs.at(-1)?.id;

  useEffect(() => {
    const list = listRef.current;
    if (list) list.scrollTop = list.scrollHeight;
  }, [latestId]);

  const performAction = (id: string, action: () => Promise<void> | void) => {
    setBusyId(id);
    void Promise.resolve().then(action).catch(() => {}).finally(() => setBusyId(null));
  };

  if (!inputs.length) return null;

  return (
    <section aria-label="待处理消息队列" className="order-first w-full min-w-0 border-b border-[var(--surface-divider)] bg-[var(--surface-reading)]">
      <p className="px-3 pt-2 text-[11px] leading-5 text-muted-foreground" aria-live="polite">
        等待处理 <span className="ml-1 tabular-nums">{inputs.length}</span>
      </p>
      <ul ref={listRef} aria-label="待处理消息" className="max-h-[min(12rem,28dvh)] divide-y divide-[var(--surface-divider)] overflow-y-auto overscroll-contain px-2 pb-1">
        {inputs.map((input) => (
          <li key={input.id} aria-busy={busyId === input.id} className="flex min-w-0 items-start gap-1 py-1">
            <PendingInputText text={input.text} />
            <span className="shrink-0 py-2 text-[11px] leading-6 text-muted-foreground" title={input.delivery === "queue" ? "当前任务结束后处理" : "在下一步补充当前任务"}>
              {input.delivery === "queue" ? "排队" : "引导"}
            </span>
            <DropdownMenu>
              <DropdownMenuTrigger asChild>
                <Button type="button" variant="ghost" size="icon" aria-label={`消息操作：${input.text}`}
                  disabled={Boolean(busyId)} className="agent-panel-icon-button size-10 shrink-0 active:scale-95 motion-reduce:transform-none">
                  {busyId === input.id
                    ? <LoaderCircle size={16} className="motion-safe:animate-spin" aria-hidden />
                    : <MoreHorizontal size={16} aria-hidden />}
                </Button>
              </DropdownMenuTrigger>
              <DropdownMenuContent data-agent-presentation={presentation} side="top" align="end" sideOffset={6} collisionPadding={12}
                className="agent-panel-overlay w-48 rounded-xl p-1.5">
                <DropdownMenuItem disabled={!onEdit} className={menuItemClassName}
                  onSelect={() => performAction(input.id, () => onEdit?.(input.id))}>
                  <Pencil size={14} aria-hidden />编辑消息
                </DropdownMenuItem>
                <DropdownMenuSeparator />
                <DropdownMenuLabel className="px-2 py-1 text-[11px] font-normal text-muted-foreground">处理方式</DropdownMenuLabel>
                <DropdownMenuRadioGroup aria-label="消息处理方式" value={input.delivery} onValueChange={(delivery) => {
                  if (onDeliveryChange && (delivery === "steer" || delivery === "queue")) {
                    void Promise.resolve().then(() => onDeliveryChange(input.id, delivery)).catch(() => {});
                  }
                }}>
                  <DropdownMenuRadioItem value="steer" disabled={!onDeliveryChange} className={`${menuItemClassName} pl-8`}>引导当前任务</DropdownMenuRadioItem>
                  <DropdownMenuRadioItem value="queue" disabled={!onDeliveryChange} className={`${menuItemClassName} pl-8`}>排队处理</DropdownMenuRadioItem>
                </DropdownMenuRadioGroup>
                <DropdownMenuSeparator />
                <DropdownMenuItem disabled={!onCancel} className={menuItemClassName}
                  onSelect={() => performAction(input.id, () => onCancel?.(input.id))}>
                  <X size={14} aria-hidden />关闭排队
                </DropdownMenuItem>
              </DropdownMenuContent>
            </DropdownMenu>
          </li>
        ))}
      </ul>
    </section>
  );
}

function PendingInputText({ text }: { text: string }) {
  const [expanded, setExpanded] = useState(false);
  const [overflows, setOverflows] = useState(false);
  const textRef = useRef<HTMLParagraphElement | null>(null);

  useEffect(() => {
    const node = textRef.current;
    if (!node) return;
    const measure = () => {
      setOverflows(node.scrollHeight > Number.parseFloat(getComputedStyle(node).lineHeight) * 2 + 1);
    };
    const observer = new ResizeObserver(measure);
    observer.observe(node);
    measure();
    return () => observer.disconnect();
  }, [text]);

  useEffect(() => {
    if (expanded) textRef.current?.parentElement?.scrollIntoView({ block: "nearest" });
  }, [expanded]);

  return (
    <div className="min-w-0 flex-1 px-1 py-2">
      <p ref={textRef} className={cn("text-sm leading-6 text-foreground [overflow-wrap:anywhere]", expanded ? "whitespace-pre-wrap" : "whitespace-normal line-clamp-2")}>
        {text}
      </p>
      {overflows ? <button type="button" aria-expanded={expanded} onClick={() => setExpanded((current) => !current)}
        className="relative mt-1 rounded-sm text-[11px] leading-5 text-muted-foreground underline underline-offset-4 after:absolute after:-inset-y-2.5 after:inset-x-0 hover:text-foreground focus-visible:outline-2 focus-visible:outline-offset-2 focus-visible:outline-ring active:opacity-70">
        {expanded ? "收起全文" : "展开全文"}
      </button> : null}
    </div>
  );
}