"use client";

import { useState } from "react";
import { SmilePlus, MessageSquare, Download, Loader2 } from "lucide-react";
import { cn } from "@/lib/utils";
import { UserAvatar } from "./UserAvatar";
import { AuthImage } from "./AuthImage";
import type { Message } from "@/hooks/useMessenger";
import { useAddReaction } from "@/hooks/useMessenger";
import { toast } from "sonner";

const QUICK_EMOJIS = ["\u{1F44D}", "\u{2764}\u{FE0F}", "\u{1F602}", "\u{1F44F}", "\u{1F64F}", "\u{1F525}"];

interface MessageItemProps {
  message: Message;
  isOwn: boolean;
  showAvatar: boolean;
  isLastInGroup: boolean;
}

export function MessageItem({ message, isOwn, showAvatar, isLastInGroup }: MessageItemProps) {
  const [showActions, setShowActions] = useState(false);
  const [showEmojiPicker, setShowEmojiPicker] = useState(false);
  const [hovering, setHovering] = useState(false);
  const [downloading, setDownloading] = useState(false);
  const addReaction = useAddReaction();

  if (message.isDeleted) {
    return (
      <div className={cn("flex gap-2 px-3 py-1", isOwn && "flex-row-reverse")}>
        {showAvatar && !isOwn ? (
          <UserAvatar photo={message.senderPhoto} name={message.senderName} size="sm" />
        ) : (
          <div className="w-7" />
        )}
        <div className="text-xs text-muted-foreground italic">삭제된 메시지입니다</div>
      </div>
    );
  }

  const time = new Date(message.createdAt).toLocaleTimeString("ko-KR", {
    hour: "2-digit",
    minute: "2-digit",
  });

  // Time element — sibling of bubble column in the outer flex row
  // isOwn: appears left of bubble (flex-row-reverse puts it visually left)
  // !isOwn: appears right of bubble
  const timeEl = (
    <span
      className={cn(
        "messenger-time text-muted-foreground shrink-0 self-end mt-auto pb-0.5 whitespace-nowrap transition-opacity",
        isLastInGroup || hovering ? "opacity-100" : "opacity-0"
      )}
    >
      {time}
    </span>
  );

  return (
    // DOM order: [avatar, bubble column, timeEl]
    // isOwn flex-row-reverse → visual: [timeEl, bubble column, avatar]
    // !isOwn normal → visual: [avatar, bubble column, timeEl]
    <div className={cn("flex items-start gap-2 px-3 py-0.5", isOwn && "flex-row-reverse")}>
      {/* avatar */}
      {!isOwn ? (
        showAvatar ? (
          <div className="mt-0.5 shrink-0">
            <UserAvatar photo={message.senderPhoto} name={message.senderName} size="sm" />
          </div>
        ) : (
          <div className="w-7 shrink-0" />
        )
      ) : (
        <div className="w-1 shrink-0" />
      )}

      {/* bubble column — direct flex child: max-w-[65%] resolves against full chat panel width */}
      <div
        className={cn("max-w-[65%]", isOwn ? "text-right" : "text-left")}
        onMouseEnter={() => { setShowActions(true); setHovering(true); }}
        onMouseLeave={() => { setShowActions(false); setShowEmojiPicker(false); setHovering(false); }}
      >
        {showAvatar && !isOwn && (
          <span className="block text-xs font-medium text-muted-foreground mb-0.5">
            {message.senderName}
          </span>
        )}

        {/* inline-block: sizes to content but constrained by parent max-w-[65%] */}
        <div className="relative inline-block max-w-full text-left">
          {message.type === "file" && message.fileMimeType?.startsWith("image/") && message.fileUrl ? (
            <AuthImage
              src={message.fileUrl}
              alt={message.fileName || "이미지"}
              className="max-w-[240px] max-h-[240px] rounded-lg object-contain block"
            />
          ) : (
          <div
            className={cn(
              "rounded-lg px-3 py-1.5 text-sm [overflow-wrap:anywhere]",
              isOwn ? "bg-primary text-primary-foreground" : "bg-muted"
            )}
          >
            {message.type === "file" && message.fileUrl ? (
              <button
                disabled={downloading}
                onClick={async () => {
                  setDownloading(true);
                  try {
                    const { apiClient } = await import("@/lib/api/client");
                    const path = message.fileUrl!.replace(apiClient.defaults.baseURL ?? "", "");
                    const res = await apiClient.get(path, { responseType: "blob" });
                    const url = URL.createObjectURL(res.data);
                    const a = document.createElement("a");
                    a.href = url;
                    a.download = message.fileName || "파일";
                    document.body.appendChild(a);
                    a.click();
                    document.body.removeChild(a);
                    URL.revokeObjectURL(url);
                  } catch {
                    toast.error("파일 다운로드에 실패했습니다.");
                  } finally {
                    setDownloading(false);
                  }
                }}
                className="flex items-center gap-1.5 underline text-left disabled:opacity-60"
              >
                {downloading
                  ? <Loader2 className="h-3.5 w-3.5 shrink-0 animate-spin" />
                  : <Download className="h-3.5 w-3.5 shrink-0" />
                }
                {message.fileName || "파일 다운로드"}
              </button>
            ) : (
              <span className="whitespace-pre-wrap">{message.content}</span>
            )}
          </div>
          )}

          {showActions && (
            <div
              className={cn(
                "absolute top-0 flex items-center gap-0.5 bg-background border rounded-md shadow-sm px-1 py-0.5 -translate-y-1/2",
                isOwn ? "left-0 -translate-x-full mr-1" : "right-0 translate-x-full ml-1"
              )}
            >
              <button
                onClick={() => setShowEmojiPicker((p) => !p)}
                className="p-0.5 hover:bg-muted rounded"
              >
                <SmilePlus className="h-3.5 w-3.5 text-muted-foreground" />
              </button>
              <button
                className="p-0.5 hover:bg-muted rounded opacity-50 cursor-not-allowed"
                title="준비 중"
                onClick={() => toast("답장 기능은 준비 중입니다.", { icon: "🚧" })}
              >
                <MessageSquare className="h-3.5 w-3.5 text-muted-foreground" />
              </button>
            </div>
          )}

          {showEmojiPicker && (
            <div
              className={cn(
                "absolute top-0 -translate-y-full bg-background border rounded-md shadow-md p-1 flex gap-0.5 z-10",
                isOwn ? "right-0" : "left-0"
              )}
            >
              {QUICK_EMOJIS.map((emoji) => (
                <button
                  key={emoji}
                  onClick={() => {
                    addReaction.mutate({ messageId: message.id, roomId: message.roomId, emoji });
                    setShowEmojiPicker(false);
                  }}
                  className="hover:bg-muted rounded p-0.5 text-base"
                >
                  {emoji}
                </button>
              ))}
            </div>
          )}
        </div>

        {message.reactions.length > 0 && (
          <div className={cn("flex flex-wrap gap-1 mt-0.5", isOwn ? "justify-end" : "justify-start")}>
            {message.reactions.map((r) => (
              <button
                key={r.emoji}
                onClick={() =>
                  addReaction.mutate({ messageId: message.id, roomId: message.roomId, emoji: r.emoji })
                }
                className="flex items-center gap-0.5 rounded-full bg-muted px-1.5 py-0.5 text-xs hover:bg-muted/80"
              >
                <span>{r.emoji}</span>
                <span className="text-muted-foreground">{r.users.length}</span>
              </button>
            ))}
          </div>
        )}
      </div>

      {/* time — direct flex child, sibling of bubble column */}
      {timeEl}
    </div>
  );
}