"use client";

import { useState, useEffect } from "react";
import { cn } from "@/lib/utils";
import { Smartphone, Tablet, Loader2, ExternalLink, RefreshCw } from "lucide-react";
import { Button } from "@/components/ui/button";
import { Tabs, TabsList, TabsTrigger } from "@/components/ui/tabs";
import { ScreenDefinition } from "@/types/screen";
import { screenApi } from "@/lib/api/screen";

// ============================================================
// 타입 정의
// ============================================================

type DeviceType = "mobile" | "tablet";

interface PopScreenPreviewProps {
  screen: ScreenDefinition | null;
  className?: string;
}

// 디바이스 프레임 크기
// 모바일: 세로(portrait), 태블릿: 가로(landscape) 디폴트
const DEVICE_SIZES = {
  mobile: { width: 375, height: 667 }, // iPhone SE 기준 (세로)
  tablet: { width: 1024, height: 768 }, // iPad 기준 (가로)
};

// ============================================================
// 메인 컴포넌트
// ============================================================

export function PopScreenPreview({ screen, className }: PopScreenPreviewProps) {
  const [deviceType, setDeviceType] = useState<DeviceType>("tablet");
  const [loading, setLoading] = useState(false);
  const [hasLayout, setHasLayout] = useState(false);
  const [key, setKey] = useState(0); // iframe 새로고침용

  // 레이아웃 존재 여부 확인
  useEffect(() => {
    if (!screen) {
      setHasLayout(false);
      return;
    }

    const checkLayout = async () => {
      try {
        setLoading(true);
        const layout = await screenApi.getLayoutPop(screen.screenId);
        
        // v2 레이아웃: sections는 객체 (Record<string, PopSectionDefinition>)
        // v1 레이아웃: sections는 배열
        if (layout) {
          const isV2 = layout.version === "pop-2.0";
          const hasSections = isV2 
            ? layout.sections && Object.keys(layout.sections).length > 0
            : layout.sections && Array.isArray(layout.sections) && layout.sections.length > 0;
          
          setHasLayout(hasSections);
        } else {
          setHasLayout(false);
        }
      } catch {
        setHasLayout(false);
      } finally {
        setLoading(false);
      }
    };

    checkLayout();
  }, [screen]);

  // 미리보기 URL
  const previewUrl = screen ? `/pop/screens/${screen.screenId}?preview=true&device=${deviceType}` : null;

  // 새 탭에서 열기
  const openInNewTab = () => {
    if (previewUrl) {
      const size = DEVICE_SIZES[deviceType];
      window.open(previewUrl, "_blank", `width=${size.width + 40},height=${size.height + 80}`);
    }
  };

  // iframe 새로고침
  const refreshPreview = () => {
    setKey((prev) => prev + 1);
  };

  const deviceSize = DEVICE_SIZES[deviceType];
  // 미리보기 컨테이너에 맞게 스케일 조정
  const scale = deviceType === "tablet" ? 0.5 : 0.6;

  return (
    <div className={cn("flex flex-col h-full bg-muted/30", className)}>
      {/* 헤더 */}
      <div className="shrink-0 p-3 border-b bg-background flex items-center justify-between">
        <div className="flex items-center gap-2">
          <h3 className="text-sm font-medium">미리보기</h3>
          {screen && (
            <span className="text-xs text-muted-foreground truncate max-w-[150px]">
              {screen.screenName}
            </span>
          )}
        </div>

        <div className="flex items-center gap-2">
          {/* 디바이스 선택 */}
          <Tabs value={deviceType} onValueChange={(v) => setDeviceType(v as DeviceType)}>
            <TabsList className="h-8">
              <TabsTrigger value="mobile" className="h-7 px-3 gap-1.5" title="모바일 (375x667)">
                <Smartphone className="h-3.5 w-3.5" />
                <span className="text-xs">모바일</span>
              </TabsTrigger>
              <TabsTrigger value="tablet" className="h-7 px-3 gap-1.5" title="태블릿 (1024x768 가로)">
                <Tablet className="h-3.5 w-3.5" />
                <span className="text-xs">태블릿</span>
              </TabsTrigger>
            </TabsList>
          </Tabs>

          {screen && hasLayout && (
            <>
              <Button variant="ghost" size="icon" className="h-7 w-7" onClick={refreshPreview}>
                <RefreshCw className="h-3.5 w-3.5" />
              </Button>
              <Button variant="ghost" size="icon" className="h-7 w-7" onClick={openInNewTab}>
                <ExternalLink className="h-3.5 w-3.5" />
              </Button>
            </>
          )}
        </div>
      </div>

      {/* 미리보기 영역 */}
      <div className="flex-1 flex items-center justify-center p-4 overflow-auto">
        {!screen ? (
          // 화면 미선택
          <div className="text-center text-muted-foreground">
            <div className="w-16 h-16 rounded-full bg-muted flex items-center justify-center mx-auto mb-3">
              {deviceType === "mobile" ? (
                <Smartphone className="h-8 w-8" />
              ) : (
                <Tablet className="h-8 w-8" />
              )}
            </div>
            <p className="text-sm">화면을 선택하면 미리보기가 표시됩니다.</p>
          </div>
        ) : loading ? (
          // 로딩 중
          <div className="text-center text-muted-foreground">
            <Loader2 className="h-8 w-8 animate-spin mx-auto mb-3" />
            <p className="text-sm">레이아웃 확인 중...</p>
          </div>
        ) : !hasLayout ? (
          // 레이아웃 없음
          <div className="text-center text-muted-foreground">
            <div className="w-16 h-16 rounded-full bg-muted flex items-center justify-center mx-auto mb-3">
              {deviceType === "mobile" ? (
                <Smartphone className="h-8 w-8" />
              ) : (
                <Tablet className="h-8 w-8" />
              )}
            </div>
            <p className="text-sm mb-2">POP 레이아웃이 없습니다.</p>
            <p className="text-xs text-muted-foreground">
              화면을 더블클릭하여 설계 모드로 이동하세요.
            </p>
          </div>
        ) : (
          // 디바이스 프레임 + iframe (심플한 테두리)
          <div
            className="relative border-2 border-gray-300 rounded-lg shadow-lg overflow-hidden"
            style={{
              width: deviceSize.width * scale,
              height: deviceSize.height * scale,
            }}
          >
            <iframe
              key={key}
              src={previewUrl || ""}
              className="w-full h-full border-0"
              style={{
                width: deviceSize.width,
                height: deviceSize.height,
                transform: `scale(${scale})`,
                transformOrigin: "top left",
              }}
              title="POP Screen Preview"
            />
          </div>
        )}
      </div>
    </div>
  );
}
