import { useCallback, useRef, useState, type ReactNode, type Ref } from "react";
import { createPortal } from "react-dom";
import { motion, useReducedMotion } from "motion/react";
import { Maximize2, X } from "lucide-react";
import { Button } from "@/shared/ui/button";
import { Dialog, DialogClose, DialogContent, DialogTitle, DialogTrigger } from "@/shared/ui/dialog";
import { createReadingPreview } from "@/shared/ui/reading-preview";
import { cn } from "@/shared/ui/cn";

/** Report-specific progressive disclosure. The source stays mounted while reading. */
export function InvestigationExpandCard({
  title, label = title, preview, children, wide = false, onOpen, contentRef,
  triggerLabel = `展开${title}`, className, revision, disabled = false, reuseContent = false, headingAccessory
}: {
  title: string;
  label?: string;
  preview: ReactNode;
  children: ReactNode | ((close: (restoreFocus?: boolean) => void) => ReactNode);
  wide?: boolean;
  onOpen?: () => void;
  contentRef?: Ref<HTMLElement>;
  triggerLabel?: string;
  className?: string;
  /** Freeze versioned prose while reading; live controls must not use this. */
  revision?: string;
  disabled?: boolean;
  /** Move one live content host between slots, preserving expensive renderers. */
  reuseContent?: boolean;
  headingAccessory?: ReactNode;
}) {
  const triggerRef = useRef<HTMLButtonElement>(null);
  const restoreFocusRef = useRef(true);
  const [open, setOpen] = useState(false);
  const [keyboard, setKeyboard] = useState(false);
  const [reading, setReading] = useState<{ revision: string; content: typeof children } | null>(null);
  const [contentHost] = useState(() => reuseContent ? document.createElement("div") : null);
  const previewSlot = useRef<HTMLDivElement | null>(null);
  const snapshot = useRef<HTMLElement | null>(null);
  const attachPreview = useCallback((slot: HTMLDivElement | null) => {
    previewSlot.current = slot;
    if (slot && contentHost && !contentHost.isConnected) slot.appendChild(contentHost);
  }, [contentHost]);
  const attachDetail = useCallback((slot: HTMLDivElement | null) => {
    const preview = previewSlot.current;
    if (!preview || !contentHost) return;
    if (slot) {
      snapshot.current?.remove();
      snapshot.current = createReadingPreview(contentHost);
      preview.append(snapshot.current);
      slot.appendChild(contentHost);
    } else {
      snapshot.current?.remove();
      snapshot.current = null;
      preview.appendChild(contentHost);
    }
  }, [contentHost]);
  const reduced = useReducedMotion();
  const close = (restoreFocus = true) => { restoreFocusRef.current = restoreFocus; setOpen(false); };
  const content = reading?.content ?? children;

  return (
    <Dialog open={open} onOpenChange={(next) => {
      setOpen(next);
      if (next) {
        restoreFocusRef.current = true;
        setReading(revision === undefined ? null : { revision, content: children });
        onOpen?.();
      }
    }}>
      <section
        ref={contentRef}
        aria-label={label}
        className={cn("investigation-report-section investigation-expand-card", className)}
      >
        <div className="investigation-card-heading">
          <div className="flex min-w-0 flex-wrap items-center gap-2">
            <h3 className="text-sm font-semibold text-[var(--ink)]">{title}</h3>
            {headingAccessory}
          </div>
          <DialogTrigger asChild>
            <Button ref={triggerRef} variant="ghost" size="icon-sm" aria-label={triggerLabel} disabled={disabled}
              title={triggerLabel} onClick={(event) => setKeyboard(event.detail === 0)}>
              <Maximize2 size={15} aria-hidden />
            </Button>
          </DialogTrigger>
        </div>
        {/* Contain child margins so the occupied and vacated slots measure alike. */}
        {contentHost ? <div ref={attachPreview} className="flow-root" /> : preview}
      </section>
      {contentHost ? createPortal(typeof children === "function" ? children(close) : children, contentHost) : null}
      <DialogContent
        className={cn("investigation-detail-panel bg-card", wide && "investigation-detail-panel-wide", keyboard && "investigation-detail-no-motion")}
        overlayClassName={cn("investigation-detail-backdrop", keyboard && "investigation-detail-no-motion")}
        data-agent-theme="chat" aria-describedby={undefined} showCloseButton={false}
        onEscapeKeyDown={(event) => { event.stopPropagation(); setKeyboard(true); }}
        onCloseAutoFocus={(event) => { event.preventDefault(); if (restoreFocusRef.current) triggerRef.current?.focus({ preventScroll: true }); }}>
        <header className="investigation-detail-heading border-b border-border">
          <DialogTitle className="text-base leading-6 tracking-normal">{title}</DialogTitle>
          <DialogClose asChild>
            <Button variant="ghost" size="icon-sm" aria-label="关闭详情"><X size={17} aria-hidden /></Button>
          </DialogClose>
        </header>
        <div className="investigation-detail-scroll">
          <motion.div initial={reduced || keyboard ? false : { opacity: 0, y: 4 }} animate={{ opacity: 1, y: 0 }}
            transition={{ duration: 0.18, ease: [0.22, 1, 0.36, 1] }}>
            {contentHost ? <div ref={attachDetail} /> : typeof content === "function" ? content(close) : content}
          </motion.div>
        </div>
        {reading && revision !== undefined && reading.revision !== revision ? (
          <div className="investigation-report-update" role="status">
            <span>已有更新，当前保留正在阅读的版本。</span>
            <Button variant="outline" size="sm" onClick={() => setReading({ revision, content: children })}>查看最新内容</Button>
          </div>
        ) : null}
      </DialogContent>
    </Dialog>
  );
}