"use client";

import { useState, useEffect, useCallback } from "react";
import { useSearchParams } from "next/navigation";
import { Button } from "@/components/ui/button";
import { Input } from "@/components/ui/input";
import { ArrowLeft, Plus, RefreshCw, Search, LayoutGrid, LayoutList } from "lucide-react";
import ScreenList from "@/components/screen/ScreenList";
import ScreenDesigner from "@/components/screen/ScreenDesigner";
import TemplateManager from "@/components/screen/TemplateManager";
import { ScreenGroupTreeView } from "@/components/screen/ScreenGroupTreeView";
import { ScreenRelationFlow } from "@/components/screen/ScreenRelationFlow";
import { ScrollToTop } from "@/components/common/ScrollToTop";
import { ScreenDefinition } from "@/types/screen";
import { screenApi } from "@/lib/api/screen";
import { Tabs, TabsList, TabsTrigger } from "@/components/ui/tabs";
import CreateScreenModal from "@/components/screen/CreateScreenModal";

// 단계별 진행을 위한 타입 정의
type Step = "list" | "design" | "template";
type ViewMode = "tree" | "table";

export default function ScreenManagementPage() {
  const searchParams = useSearchParams();
  const [currentStep, setCurrentStep] = useState<Step>("list");
  const [selectedScreen, setSelectedScreen] = useState<ScreenDefinition | null>(null);
  const [selectedGroup, setSelectedGroup] = useState<{ id: number; name: string; company_code?: string } | null>(null);
  const [focusedScreenIdInGroup, setFocusedScreenIdInGroup] = useState<number | null>(null);
  const [stepHistory, setStepHistory] = useState<Step[]>(["list"]);
  const [viewMode, setViewMode] = useState<ViewMode>("tree");
  const [screens, setScreens] = useState<ScreenDefinition[]>([]);
  const [loading, setLoading] = useState(true);
  const [searchTerm, setSearchTerm] = useState("");
  const [isCreateOpen, setIsCreateOpen] = useState(false);

  // 화면 목록 로드
  const loadScreens = useCallback(async () => {
    try {
      setLoading(true);
      const result = await screenApi.getScreens({ page: 1, size: 1000, searchTerm: "" });
      // screenApi.getScreens는 { data: ScreenDefinition[], total, page, size, totalPages } 형태 반환
      if (result.data && result.data.length > 0) {
        setScreens(result.data);
      }
    } catch (error) {
      console.error("화면 목록 로드 실패:", error);
    } finally {
      setLoading(false);
    }
  }, []);

  useEffect(() => {
    loadScreens();
  }, [loadScreens]);

  // URL 쿼리 파라미터로 화면 디자이너 자동 열기
  useEffect(() => {
    const openDesignerId = searchParams.get("openDesigner");
    if (openDesignerId && screens.length > 0) {
      const screenId = parseInt(openDesignerId, 10);
      const targetScreen = screens.find((s) => s.screenId === screenId);
      if (targetScreen) {
        setSelectedScreen(targetScreen);
        setCurrentStep("design");
        setStepHistory(["list", "design"]);
      }
    }
  }, [searchParams, screens]);

  // 화면 설계 모드일 때는 전체 화면 사용
  const isDesignMode = currentStep === "design";

  // 다음 단계로 이동
  const goToNextStep = (nextStep: Step) => {
    setStepHistory((prev) => [...prev, nextStep]);
    setCurrentStep(nextStep);
  };

  // 특정 단계로 이동
  const goToStep = (step: Step) => {
    setCurrentStep(step);
    const stepIndex = stepHistory.findIndex((s) => s === step);
    if (stepIndex !== -1) {
      setStepHistory(stepHistory.slice(0, stepIndex + 1));
    }
  };

  // 화면 선택 핸들러 (개별 화면 선택 시 그룹 선택 해제)
  const handleScreenSelect = (screen: ScreenDefinition) => {
    setSelectedScreen(screen);
    setSelectedGroup(null); // 그룹 선택 해제
  };

  // 화면 디자인 핸들러
  const handleDesignScreen = (screen: ScreenDefinition) => {
    setSelectedScreen(screen);
    goToNextStep("design");
  };

  // 검색어로 필터링된 화면
  const filteredScreens = screens.filter((screen) =>
    screen.screenName.toLowerCase().includes(searchTerm.toLowerCase()) ||
    screen.screenCode.toLowerCase().includes(searchTerm.toLowerCase())
  );

  // 화면 설계 모드일 때는 레이아웃 없이 전체 화면 사용
  if (isDesignMode) {
    return (
      <div className="fixed inset-0 z-50 bg-background">
        <ScreenDesigner selectedScreen={selectedScreen} onBackToList={() => goToStep("list")} />
      </div>
    );
  }

  return (
    <div className="flex h-screen flex-col bg-background overflow-hidden">
      {/* 페이지 헤더 */}
      <div className="flex-shrink-0 border-b bg-background px-6 py-4">
        <div className="flex items-center justify-between">
          <div>
            <h1 className="text-2xl font-bold tracking-tight">화면 관리</h1>
            <p className="text-sm text-muted-foreground">화면을 그룹별로 관리하고 데이터 관계를 확인합니다</p>
          </div>
          <div className="flex items-center gap-2">
            {/* 뷰 모드 전환 */}
            <Tabs value={viewMode} onValueChange={(v) => setViewMode(v as ViewMode)}>
              <TabsList className="h-9">
                <TabsTrigger value="tree" className="gap-1.5 px-3">
                  <LayoutGrid className="h-4 w-4" />
                  트리
                </TabsTrigger>
                <TabsTrigger value="table" className="gap-1.5 px-3">
                  <LayoutList className="h-4 w-4" />
                  테이블
                </TabsTrigger>
              </TabsList>
            </Tabs>
            <Button variant="outline" size="icon" onClick={loadScreens}>
              <RefreshCw className="h-4 w-4" />
            </Button>
            <Button onClick={() => setIsCreateOpen(true)} className="gap-2">
              <Plus className="h-4 w-4" />
              새 화면
            </Button>
          </div>
        </div>
      </div>

      {/* 메인 콘텐츠 */}
      {viewMode === "tree" ? (
        <div className="flex-1 overflow-hidden flex">
          {/* 왼쪽: 트리 구조 */}
          <div className="w-[350px] min-w-[280px] max-w-[450px] flex flex-col border-r bg-background">
            {/* 검색 */}
            <div className="flex-shrink-0 p-3 border-b">
              <div className="relative">
                <Search className="absolute left-3 top-1/2 -translate-y-1/2 h-4 w-4 text-muted-foreground" />
                <Input
                  placeholder="화면 검색..."
                  value={searchTerm}
                  onChange={(e) => setSearchTerm(e.target.value)}
                  className="pl-9 h-9"
                />
              </div>
            </div>
            {/* 트리 뷰 */}
            <div className="flex-1 overflow-hidden">
              <ScreenGroupTreeView
                screens={filteredScreens}
                selectedScreen={selectedScreen}
                onScreenSelect={handleScreenSelect}
                onScreenDesign={handleDesignScreen}
                onGroupSelect={(group) => {
                  setSelectedGroup(group);
                  setSelectedScreen(null); // 화면 선택 해제
                  setFocusedScreenIdInGroup(null); // 포커스 초기화
                }}
                onScreenSelectInGroup={(group, screenId) => {
                  // 그룹 내 화면 클릭 시
                  const isNewGroup = selectedGroup?.id !== group.id;
                  
                  if (isNewGroup) {
                    // 새 그룹 진입: 포커싱 없이 시작 (첫 진입 시 망가지는 문제 방지)
                    setSelectedGroup(group);
                    setFocusedScreenIdInGroup(null);
                  } else {
                    // 같은 그룹 내에서 다른 화면 클릭: 포커싱 유지
                    setFocusedScreenIdInGroup(screenId);
                  }
                  setSelectedScreen(null);
                }}
              />
            </div>
          </div>

          {/* 오른쪽: 관계 시각화 (React Flow) */}
          <div className="flex-1 overflow-hidden">
            <ScreenRelationFlow 
              screen={selectedScreen} 
              selectedGroup={selectedGroup}
              initialFocusedScreenId={focusedScreenIdInGroup}
            />
          </div>
        </div>
      ) : (
        // 테이블 뷰 (기존 ScreenList 사용)
        <div className="flex-1 overflow-auto p-6">
          <ScreenList
            onScreenSelect={handleScreenSelect}
            selectedScreen={selectedScreen}
            onDesignScreen={handleDesignScreen}
          />
        </div>
      )}

      {/* 화면 생성 모달 */}
      <CreateScreenModal
        isOpen={isCreateOpen}
        onClose={() => setIsCreateOpen(false)}
        onSuccess={() => {
          setIsCreateOpen(false);
          loadScreens();
        }}
      />

      {/* Scroll to Top 버튼 */}
      <ScrollToTop />
    </div>
  );
}


