// Adapted from agentui (https://github.com/ashish200729/agentui), components/agents/streaming-response.tsx
// Copyright (c) 2026 Saurabh Chauhan. MIT License, see ./LICENSE-agentui.md
// 改造:上游是"整段替换"模型,这里由调用方把 text_delta 累积成全文再传入;新增流式光标(animate-pulse,
// reduced motion 下静止);去掉点赞/点踩(本项目不收集反馈)与 motion 按压动画;来源列表接 Citations;
// error 态用 destructive 语义色。
import { Check, Copy, RotateCcw } from "lucide-react";
import { type ReactNode, useCallback, useEffect, useRef, useState } from "react";
import { cn } from "~/lib/utils.ts";
import { type CitationItem, CitationList } from "./citations.tsx";

export type StreamingResponseStatus = "streaming" | "complete" | "error";

export interface StreamingResponseProps {
  children: ReactNode;
  status?: StreamingResponseStatus;
  /** 复制按钮复制的纯文本 */
  copyText?: string;
  onRetry?: () => void;
  sources?: CitationItem[];
  /** 外层已有 aria-live(MessageScroller 的 log)时设 false,避免重复播报 */
  announce?: boolean;
  showActions?: boolean;
  className?: string;
  contentClassName?: string;
}

/** 复制成功提示的停留时长(交互停留,非动效) */
const COPIED_HOLD_MS = 1600;

function ActionButton({ label, onClick, children }: { label: string; onClick: () => void; children: ReactNode }) {
  return (
    <button
      type="button"
      aria-label={label}
      title={label}
      onClick={onClick}
      className="grid size-7 cursor-pointer place-items-center rounded-md text-muted-foreground outline-none transition-[background-color,color,transform] duration-micro hover:bg-foreground/[0.06] hover:text-foreground focus-visible:ring-2 focus-visible:ring-ring active:scale-[0.95]"
    >
      {children}
    </button>
  );
}

/** 流式光标:只在 streaming 时出现 */
export function StreamingCursor({ className }: { className?: string }) {
  return (
    <span
      aria-hidden
      data-slot="streaming-cursor"
      className={cn(
        "ml-0.5 inline-block h-4 w-0.5 translate-y-0.5 rounded-full bg-foreground/70 animate-pulse motion-reduce:animate-none",
        className,
      )}
    />
  );
}

export function StreamingResponse({
  children,
  status = "streaming",
  copyText,
  onRetry,
  sources = [],
  announce = true,
  showActions = true,
  className,
  contentClassName,
}: StreamingResponseProps) {
  const [copied, setCopied] = useState(false);
  const t = useRef<number | undefined>(undefined);
  const streaming = status === "streaming";
  useEffect(
    () => () => {
      if (t.current) window.clearTimeout(t.current);
    },
    [],
  );
  const copy = useCallback(async () => {
    if (!copyText) return;
    try {
      await navigator.clipboard?.writeText(copyText);
      setCopied(true);
      if (t.current) window.clearTimeout(t.current);
      t.current = window.setTimeout(() => setCopied(false), COPIED_HOLD_MS);
    } catch {
      // 剪贴板不可用(非安全上下文)时静默
    }
  }, [copyText]);
  const actions = showActions && !streaming && (copyText || onRetry);

  return (
    <div data-state={status} aria-busy={streaming} className={cn("w-full min-w-0", className)}>
      <div
        aria-live={announce ? "polite" : "off"}
        className={cn(
          "text-sm leading-6 break-words whitespace-pre-wrap text-foreground/90",
          status === "error" && "text-destructive",
          contentClassName,
        )}
      >
        {children}
        {streaming ? <StreamingCursor /> : null}
      </div>
      {actions ? (
        <div className="mt-1 flex items-center gap-0.5 animate-in fade-in-0 duration-base motion-reduce:animate-none">
          {copyText ? (
            <ActionButton label={copied ? "已复制" : "复制回复"} onClick={copy}>
              {copied ? <Check className="size-3.5" /> : <Copy className="size-3.5" />}
            </ActionButton>
          ) : null}
          {onRetry ? (
            <ActionButton label="重试" onClick={onRetry}>
              <RotateCcw className="size-3.5" />
            </ActionButton>
          ) : null}
          <span className="sr-only" aria-live="polite">
            {copied ? "已复制" : ""}
          </span>
        </div>
      ) : null}
      {sources.length && !streaming ? <CitationList citations={sources} className="mt-2" /> : null}
    </div>
  );
}