"use client";

import { useState } from "react";
import { Card } from "@/components/ui/card";
import { Button } from "@/components/ui/button";
import { Input } from "@/components/ui/input";
import { ScrollArea } from "@/components/ui/scroll-area";
import { useReportDesigner } from "@/contexts/ReportDesignerContext";
import { Plus, Copy, Trash2, GripVertical, Edit2, Check, X } from "lucide-react";
import {
  DropdownMenu,
  DropdownMenuContent,
  DropdownMenuItem,
  DropdownMenuTrigger,
} from "@/components/ui/dropdown-menu";

export function PageListPanel() {
  const {
    layoutConfig,
    currentPageId,
    addPage,
    deletePage,
    duplicatePage,
    reorderPages,
    selectPage,
    updatePageSettings,
  } = useReportDesigner();

  const [editingPageId, setEditingPageId] = useState<string | null>(null);
  const [editingName, setEditingName] = useState("");
  const [draggedIndex, setDraggedIndex] = useState<number | null>(null);

  const handleStartEdit = (pageId: string, currentName: string) => {
    setEditingPageId(pageId);
    setEditingName(currentName);
  };

  const handleSaveEdit = () => {
    if (editingPageId && editingName.trim()) {
      updatePageSettings(editingPageId, { page_name: editingName.trim() });
    }
    setEditingPageId(null);
    setEditingName("");
  };

  const handleCancelEdit = () => {
    setEditingPageId(null);
    setEditingName("");
  };

  const handleDragStart = (index: number) => {
    setDraggedIndex(index);
  };

  const handleDragOver = (e: React.DragEvent, index: number) => {
    e.preventDefault();
    if (draggedIndex === null || draggedIndex === index) return;

    // 실시간으로 순서 변경하지 않고, drop 시에만 변경
  };

  const handleDrop = (e: React.DragEvent, targetIndex: number) => {
    e.preventDefault();
    if (draggedIndex === null) return;

    const sourceIndex = draggedIndex;
    if (sourceIndex !== targetIndex) {
      reorderPages(sourceIndex, targetIndex);
    }

    setDraggedIndex(null);
  };

  const handleDragEnd = () => {
    setDraggedIndex(null);
  };

  return (
    <div className="bg-background flex h-full w-64 flex-col border-r">
      {/* 헤더 */}
      <div className="flex items-center justify-between border-b p-3">
        <h3 className="text-sm font-semibold">페이지 목록</h3>
        <Button size="sm" variant="ghost" onClick={() => addPage()}>
          <Plus className="h-4 w-4" />
        </Button>
      </div>

      {/* 페이지 목록 */}
      <ScrollArea className="flex-1 p-2">
        <div className="space-y-2">
          {layoutConfig.pages
            .sort((a, b) => a.page_order - b.page_order)
            .map((page, index) => (
              <Card
                key={page.page_id}
                draggable
                onDragStart={() => handleDragStart(index)}
                onDragOver={(e) => handleDragOver(e, index)}
                onDrop={(e) => handleDrop(e, index)}
                onDragEnd={handleDragEnd}
                className={`group relative cursor-pointer transition-all hover:shadow-md ${
                  page.page_id === currentPageId
                    ? "border-primary bg-primary/5 ring-primary/20 ring-2"
                    : "border-border hover:border-primary/50"
                } ${draggedIndex === index ? "opacity-50" : ""}`}
                onClick={() => selectPage(page.page_id)}
              >
                <div className="p-3">
                  {/* 드래그 핸들 & 페이지 정보 */}
                  <div className="flex items-start gap-2">
                    <div className="text-muted-foreground cursor-grab pt-1 opacity-0 transition-opacity group-hover:opacity-100">
                      <GripVertical className="h-4 w-4" />
                    </div>

                    <div className="min-w-0 flex-1">
                      {/* 페이지 이름 편집 */}
                      {editingPageId === page.page_id ? (
                        <div className="flex items-center gap-1" onClick={(e) => e.stopPropagation()}>
                          <Input
                            value={editingName}
                            onChange={(e) => setEditingName(e.target.value)}
                            onKeyDown={(e) => {
                              if (e.key === "Enter") handleSaveEdit();
                              if (e.key === "Escape") handleCancelEdit();
                            }}
                            className="h-6 text-sm"
                            autoFocus
                          />
                          <Button size="sm" variant="ghost" className="h-6 w-6 p-0" onClick={handleSaveEdit}>
                            <Check className="h-3 w-3" />
                          </Button>
                          <Button size="sm" variant="ghost" className="h-6 w-6 p-0" onClick={handleCancelEdit}>
                            <X className="h-3 w-3" />
                          </Button>
                        </div>
                      ) : (
                        <div className="flex items-center gap-2">
                          <span className="truncate text-sm font-medium">{page.page_name}</span>
                          <Button
                            size="sm"
                            variant="ghost"
                            className="h-5 w-5 p-0 opacity-0 transition-opacity group-hover:opacity-100"
                            onClick={(e) => {
                              e.stopPropagation();
                              handleStartEdit(page.page_id, page.page_name);
                            }}
                          >
                            <Edit2 className="h-3 w-3" />
                          </Button>
                        </div>
                      )}

                      {/* 페이지 정보 */}
                      <div className="text-muted-foreground mt-1 flex items-center gap-2 text-xs">
                        <span>
                          {page.width} x {page.height}mm
                        </span>
                        <span>•</span>
                        <span>{page.components.length}개 컴포넌트</span>
                      </div>
                    </div>

                    {/* 액션 메뉴 */}
                    <DropdownMenu>
                      <DropdownMenuTrigger asChild onClick={(e) => e.stopPropagation()}>
                        <Button
                          size="sm"
                          variant="ghost"
                          className="h-6 w-6 p-0 opacity-0 transition-opacity group-hover:opacity-100"
                        >
                          <span className="sr-only">메뉴</span>
                          <span className="text-xl leading-none">⋮</span>
                        </Button>
                      </DropdownMenuTrigger>
                      <DropdownMenuContent align="end">
                        <DropdownMenuItem
                          onClick={(e) => {
                            e.stopPropagation();
                            duplicatePage(page.page_id);
                          }}
                        >
                          <Copy className="mr-2 h-4 w-4" />
                          복제
                        </DropdownMenuItem>
                        <DropdownMenuItem
                          onClick={(e) => {
                            e.stopPropagation();
                            deletePage(page.page_id);
                          }}
                          disabled={layoutConfig.pages.length <= 1}
                          className="text-destructive focus:text-destructive"
                        >
                          <Trash2 className="mr-2 h-4 w-4" />
                          삭제
                        </DropdownMenuItem>
                      </DropdownMenuContent>
                    </DropdownMenu>
                  </div>

                  {/* 썸네일 (간단한 미리보기) */}
                  <div className="mt-2 aspect-[210/297] overflow-hidden rounded border bg-white">
                    <div className="relative h-full w-full origin-top-left scale-[0.15]">
                      <div
                        className="absolute inset-0 bg-white"
                        style={{
                          width: `${page.width * 3.7795}px`,
                          height: `${page.height * 3.7795}px`,
                        }}
                      >
                        {/* 간단한 컴포넌트 표시 */}
                        {page.components.slice(0, 10).map((comp) => (
                          <div
                            key={comp.id}
                            className="border-primary/20 bg-primary/5 absolute border"
                            style={{
                              left: `${comp.x}px`,
                              top: `${comp.y}px`,
                              width: `${comp.width}px`,
                              height: `${comp.height}px`,
                            }}
                          />
                        ))}
                      </div>
                    </div>
                  </div>
                </div>
              </Card>
            ))}
        </div>
      </ScrollArea>

      {/* 푸터 */}
      <div className="border-t p-2">
        <Button size="sm" variant="outline" className="w-full" onClick={() => addPage()}>
          <Plus className="mr-2 h-4 w-4" />새 페이지 추가
        </Button>
      </div>
    </div>
  );
}