"use client";

import React, { useState, useEffect, useCallback } from "react";
import { Button } from "@/components/ui/button";
import { Input } from "@/components/ui/input";
import { Label } from "@/components/ui/label";
import { Badge } from "@/components/ui/badge";
import {
  Select,
  SelectContent,
  SelectItem,
  SelectTrigger,
  SelectValue,
} from "@/components/ui/select";
import {
  Dialog,
  DialogContent,
  DialogDescription,
  DialogFooter,
  DialogHeader,
  DialogTitle,
} from "@/components/ui/dialog";
import {
  Card,
  CardContent,
  CardDescription,
  CardHeader,
  CardTitle,
} from "@/components/ui/card";
import { Plus, Pencil, Trash2, Database, RefreshCw, Layers } from "lucide-react";
import { toast } from "sonner";
import { LoadingSpinner } from "@/components/common/LoadingSpinner";
import {
  hierarchyColumnApi,
  HierarchyColumnGroup,
  CreateHierarchyGroupRequest,
} from "@/lib/api/hierarchyColumn";
import { commonCodeApi } from "@/lib/api/commonCode";
import apiClient from "@/lib/api/client";

interface TableInfo {
  tableName: string;
  displayName?: string;
}

interface ColumnInfo {
  columnName: string;
  displayName?: string;
  dataType?: string;
}

interface CategoryInfo {
  categoryCode: string;
  categoryName: string;
}

export default function HierarchyColumnTab() {
  // 상태
  const [groups, setGroups] = useState<HierarchyColumnGroup[]>([]);
  const [loading, setLoading] = useState(true);
  const [modalOpen, setModalOpen] = useState(false);
  const [deleteDialogOpen, setDeleteDialogOpen] = useState(false);
  const [selectedGroup, setSelectedGroup] = useState<HierarchyColumnGroup | null>(null);
  const [isEditing, setIsEditing] = useState(false);

  // 폼 상태
  const [formData, setFormData] = useState({
    groupCode: "",
    groupName: "",
    description: "",
    codeCategory: "",
    tableName: "",
    maxDepth: 3,
    mappings: [
      { depth: 1, levelLabel: "대분류", columnName: "", placeholder: "대분류 선택", isRequired: true },
      { depth: 2, levelLabel: "중분류", columnName: "", placeholder: "중분류 선택", isRequired: false },
      { depth: 3, levelLabel: "소분류", columnName: "", placeholder: "소분류 선택", isRequired: false },
    ],
  });

  // 참조 데이터
  const [tables, setTables] = useState<TableInfo[]>([]);
  const [columns, setColumns] = useState<ColumnInfo[]>([]);
  const [categories, setCategories] = useState<CategoryInfo[]>([]);
  const [loadingTables, setLoadingTables] = useState(false);
  const [loadingColumns, setLoadingColumns] = useState(false);
  const [loadingCategories, setLoadingCategories] = useState(false);

  // 그룹 목록 로드
  const loadGroups = useCallback(async () => {
    setLoading(true);
    try {
      const response = await hierarchyColumnApi.getAll();
      if (response.success && response.data) {
        setGroups(response.data);
      } else {
        toast.error(response.error || "계층구조 그룹 로드 실패");
      }
    } catch (error) {
      console.error("계층구조 그룹 로드 에러:", error);
      toast.error("계층구조 그룹을 로드하는 중 오류가 발생했습니다.");
    } finally {
      setLoading(false);
    }
  }, []);

  // 테이블 목록 로드
  const loadTables = useCallback(async () => {
    setLoadingTables(true);
    try {
      const response = await apiClient.get("/table-management/tables");
      if (response.data?.success && response.data?.data) {
        setTables(response.data.data);
      }
    } catch (error) {
      console.error("테이블 로드 에러:", error);
    } finally {
      setLoadingTables(false);
    }
  }, []);

  // 카테고리 목록 로드
  const loadCategories = useCallback(async () => {
    setLoadingCategories(true);
    try {
      const response = await commonCodeApi.categories.getList();
      if (response.success && response.data) {
        setCategories(
          response.data.map((cat: any) => ({
            categoryCode: cat.categoryCode || cat.category_code,
            categoryName: cat.categoryName || cat.category_name,
          }))
        );
      }
    } catch (error) {
      console.error("카테고리 로드 에러:", error);
    } finally {
      setLoadingCategories(false);
    }
  }, []);

  // 테이블 선택 시 컬럼 로드
  const loadColumns = useCallback(async (tableName: string) => {
    if (!tableName) {
      setColumns([]);
      return;
    }
    setLoadingColumns(true);
    try {
      const response = await apiClient.get(`/table-management/tables/${tableName}/columns`);
      if (response.data?.success && response.data?.data) {
        setColumns(response.data.data);
      }
    } catch (error) {
      console.error("컬럼 로드 에러:", error);
    } finally {
      setLoadingColumns(false);
    }
  }, []);

  // 초기 로드
  useEffect(() => {
    loadGroups();
    loadTables();
    loadCategories();
  }, [loadGroups, loadTables, loadCategories]);

  // 테이블 선택 변경 시 컬럼 로드
  useEffect(() => {
    if (formData.tableName) {
      loadColumns(formData.tableName);
    }
  }, [formData.tableName, loadColumns]);

  // 폼 초기화
  const resetForm = () => {
    setFormData({
      groupCode: "",
      groupName: "",
      description: "",
      codeCategory: "",
      tableName: "",
      maxDepth: 3,
      mappings: [
        { depth: 1, levelLabel: "대분류", columnName: "", placeholder: "대분류 선택", isRequired: true },
        { depth: 2, levelLabel: "중분류", columnName: "", placeholder: "중분류 선택", isRequired: false },
        { depth: 3, levelLabel: "소분류", columnName: "", placeholder: "소분류 선택", isRequired: false },
      ],
    });
    setSelectedGroup(null);
    setIsEditing(false);
  };

  // 모달 열기 (신규)
  const openCreateModal = () => {
    resetForm();
    setModalOpen(true);
  };

  // 모달 열기 (수정)
  const openEditModal = (group: HierarchyColumnGroup) => {
    setSelectedGroup(group);
    setIsEditing(true);

    // 매핑 데이터 변환
    const mappings = [1, 2, 3].map((depth) => {
      const existing = group.mappings?.find((m) => m.depth === depth);
      return {
        depth,
        levelLabel: existing?.level_label || (depth === 1 ? "대분류" : depth === 2 ? "중분류" : "소분류"),
        columnName: existing?.column_name || "",
        placeholder: existing?.placeholder || `${depth === 1 ? "대분류" : depth === 2 ? "중분류" : "소분류"} 선택`,
        isRequired: existing?.is_required === "Y",
      };
    });

    setFormData({
      groupCode: group.group_code,
      groupName: group.group_name,
      description: group.description || "",
      codeCategory: group.code_category,
      tableName: group.table_name,
      maxDepth: group.max_depth,
      mappings,
    });

    // 컬럼 로드
    loadColumns(group.table_name);
    setModalOpen(true);
  };

  // 삭제 확인 열기
  const openDeleteDialog = (group: HierarchyColumnGroup) => {
    setSelectedGroup(group);
    setDeleteDialogOpen(true);
  };

  // 저장
  const handleSave = async () => {
    // 필수 필드 검증
    if (!formData.groupCode || !formData.groupName || !formData.codeCategory || !formData.tableName) {
      toast.error("필수 필드를 모두 입력해주세요.");
      return;
    }

    // 최소 1개 컬럼 매핑 검증
    const validMappings = formData.mappings
      .filter((m) => m.depth <= formData.maxDepth && m.columnName)
      .map((m) => ({
        depth: m.depth,
        levelLabel: m.levelLabel,
        columnName: m.columnName,
        placeholder: m.placeholder,
        isRequired: m.isRequired,
      }));

    if (validMappings.length === 0) {
      toast.error("최소 하나의 컬럼 매핑이 필요합니다.");
      return;
    }

    try {
      if (isEditing && selectedGroup) {
        // 수정
        const response = await hierarchyColumnApi.update(selectedGroup.group_id, {
          groupName: formData.groupName,
          description: formData.description,
          maxDepth: formData.maxDepth,
          mappings: validMappings,
        });

        if (response.success) {
          toast.success("계층구조 그룹이 수정되었습니다.");
          setModalOpen(false);
          loadGroups();
        } else {
          toast.error(response.error || "수정 실패");
        }
      } else {
        // 생성
        const request: CreateHierarchyGroupRequest = {
          groupCode: formData.groupCode,
          groupName: formData.groupName,
          description: formData.description,
          codeCategory: formData.codeCategory,
          tableName: formData.tableName,
          maxDepth: formData.maxDepth,
          mappings: validMappings,
        };

        const response = await hierarchyColumnApi.create(request);

        if (response.success) {
          toast.success("계층구조 그룹이 생성되었습니다.");
          setModalOpen(false);
          loadGroups();
        } else {
          toast.error(response.error || "생성 실패");
        }
      }
    } catch (error) {
      console.error("저장 에러:", error);
      toast.error("저장 중 오류가 발생했습니다.");
    }
  };

  // 삭제
  const handleDelete = async () => {
    if (!selectedGroup) return;

    try {
      const response = await hierarchyColumnApi.delete(selectedGroup.group_id);
      if (response.success) {
        toast.success("계층구조 그룹이 삭제되었습니다.");
        setDeleteDialogOpen(false);
        loadGroups();
      } else {
        toast.error(response.error || "삭제 실패");
      }
    } catch (error) {
      console.error("삭제 에러:", error);
      toast.error("삭제 중 오류가 발생했습니다.");
    }
  };

  // 매핑 컬럼 변경
  const handleMappingChange = (depth: number, field: string, value: any) => {
    setFormData((prev) => ({
      ...prev,
      mappings: prev.mappings.map((m) =>
        m.depth === depth ? { ...m, [field]: value } : m
      ),
    }));
  };

  return (
    <div className="space-y-6">
      {/* 헤더 */}
      <div className="flex items-center justify-between">
        <div>
          <h2 className="text-xl font-semibold">계층구조 컬럼 그룹</h2>
          <p className="text-sm text-muted-foreground">
            공통코드 계층구조를 테이블 컬럼에 매핑하여 대분류/중분류/소분류를 각각 별도 컬럼에 저장합니다.
          </p>
        </div>
        <div className="flex gap-2">
          <Button variant="outline" size="sm" onClick={loadGroups} disabled={loading}>
            <RefreshCw className={`mr-2 h-4 w-4 ${loading ? "animate-spin" : ""}`} />
            새로고침
          </Button>
          <Button size="sm" onClick={openCreateModal}>
            <Plus className="mr-2 h-4 w-4" />
            새 그룹 추가
          </Button>
        </div>
      </div>

      {/* 그룹 목록 */}
      {loading ? (
        <div className="flex items-center justify-center py-12">
          <LoadingSpinner />
          <span className="ml-2 text-muted-foreground">로딩 중...</span>
        </div>
      ) : groups.length === 0 ? (
        <Card>
          <CardContent className="flex flex-col items-center justify-center py-12">
            <Layers className="h-12 w-12 text-muted-foreground" />
            <p className="mt-4 text-muted-foreground">계층구조 컬럼 그룹이 없습니다.</p>
            <Button className="mt-4" onClick={openCreateModal}>
              <Plus className="mr-2 h-4 w-4" />
              첫 번째 그룹 만들기
            </Button>
          </CardContent>
        </Card>
      ) : (
        <div className="grid gap-4 md:grid-cols-2 lg:grid-cols-3">
          {groups.map((group) => (
            <Card key={group.group_id} className="hover:shadow-md transition-shadow">
              <CardHeader className="pb-3">
                <div className="flex items-start justify-between">
                  <div>
                    <CardTitle className="text-base">{group.group_name}</CardTitle>
                    <CardDescription className="text-xs">{group.group_code}</CardDescription>
                  </div>
                  <div className="flex gap-1">
                    <Button variant="ghost" size="icon" className="h-8 w-8" onClick={() => openEditModal(group)}>
                      <Pencil className="h-4 w-4" />
                    </Button>
                    <Button variant="ghost" size="icon" className="h-8 w-8 text-destructive" onClick={() => openDeleteDialog(group)}>
                      <Trash2 className="h-4 w-4" />
                    </Button>
                  </div>
                </div>
              </CardHeader>
              <CardContent className="space-y-3">
                <div className="flex items-center gap-2 text-sm">
                  <Database className="h-4 w-4 text-muted-foreground" />
                  <span className="font-medium">{group.table_name}</span>
                </div>
                <div className="flex items-center gap-2">
                  <Badge variant="outline">{group.code_category}</Badge>
                  <Badge variant="secondary">{group.max_depth}단계</Badge>
                </div>
                {group.mappings && group.mappings.length > 0 && (
                  <div className="space-y-1">
                    {group.mappings.map((mapping) => (
                      <div key={mapping.depth} className="flex items-center gap-2 text-xs">
                        <Badge variant="outline" className="w-14 justify-center">
                          {mapping.level_label}
                        </Badge>
                        <span className="font-mono text-muted-foreground">{mapping.column_name}</span>
                      </div>
                    ))}
                  </div>
                )}
              </CardContent>
            </Card>
          ))}
        </div>
      )}

      {/* 생성/수정 모달 */}
      <Dialog open={modalOpen} onOpenChange={setModalOpen}>
        <DialogContent className="max-w-[600px]">
          <DialogHeader>
            <DialogTitle>{isEditing ? "계층구조 그룹 수정" : "계층구조 그룹 생성"}</DialogTitle>
            <DialogDescription>
              공통코드 계층구조를 테이블 컬럼에 매핑합니다.
            </DialogDescription>
          </DialogHeader>

          <div className="space-y-4 py-4">
            {/* 기본 정보 */}
            <div className="grid grid-cols-2 gap-4">
              <div className="space-y-2">
                <Label>그룹 코드 *</Label>
                <Input
                  value={formData.groupCode}
                  onChange={(e) => setFormData({ ...formData, groupCode: e.target.value.toUpperCase() })}
                  placeholder="예: ITEM_CAT_HIERARCHY"
                  disabled={isEditing}
                />
              </div>
              <div className="space-y-2">
                <Label>그룹명 *</Label>
                <Input
                  value={formData.groupName}
                  onChange={(e) => setFormData({ ...formData, groupName: e.target.value })}
                  placeholder="예: 품목분류 계층"
                />
              </div>
            </div>

            <div className="space-y-2">
              <Label>설명</Label>
              <Input
                value={formData.description}
                onChange={(e) => setFormData({ ...formData, description: e.target.value })}
                placeholder="계층구조에 대한 설명"
              />
            </div>

            <div className="grid grid-cols-2 gap-4">
              <div className="space-y-2">
                <Label>공통코드 카테고리 *</Label>
                <Select
                  value={formData.codeCategory}
                  onValueChange={(value) => setFormData({ ...formData, codeCategory: value })}
                  disabled={isEditing}
                >
                  <SelectTrigger>
                    <SelectValue placeholder="카테고리 선택" />
                  </SelectTrigger>
                  <SelectContent>
                    {loadingCategories ? (
                      <SelectItem value="_loading" disabled>로딩 중...</SelectItem>
                    ) : (
                      categories.map((cat) => (
                        <SelectItem key={cat.categoryCode} value={cat.categoryCode}>
                          {cat.categoryName} ({cat.categoryCode})
                        </SelectItem>
                      ))
                    )}
                  </SelectContent>
                </Select>
              </div>
              <div className="space-y-2">
                <Label>적용 테이블 *</Label>
                <Select
                  value={formData.tableName}
                  onValueChange={(value) => setFormData({ ...formData, tableName: value })}
                  disabled={isEditing}
                >
                  <SelectTrigger>
                    <SelectValue placeholder="테이블 선택" />
                  </SelectTrigger>
                  <SelectContent>
                    {loadingTables ? (
                      <SelectItem value="_loading" disabled>로딩 중...</SelectItem>
                    ) : (
                      tables.map((table) => (
                        <SelectItem key={table.tableName} value={table.tableName}>
                          {table.displayName || table.tableName}
                        </SelectItem>
                      ))
                    )}
                  </SelectContent>
                </Select>
              </div>
            </div>

            <div className="space-y-2">
              <Label>최대 깊이</Label>
              <Select
                value={String(formData.maxDepth)}
                onValueChange={(value) => setFormData({ ...formData, maxDepth: Number(value) })}
              >
                <SelectTrigger className="w-40">
                  <SelectValue />
                </SelectTrigger>
                <SelectContent>
                  <SelectItem value="1">1단계 (대분류만)</SelectItem>
                  <SelectItem value="2">2단계 (대/중분류)</SelectItem>
                  <SelectItem value="3">3단계 (대/중/소분류)</SelectItem>
                </SelectContent>
              </Select>
            </div>

            {/* 컬럼 매핑 */}
            <div className="space-y-3 border-t pt-4">
              <Label className="text-base font-medium">컬럼 매핑</Label>
              <p className="text-xs text-muted-foreground">
                각 계층 레벨에 저장할 컬럼을 선택합니다.
              </p>

              {formData.mappings
                .filter((m) => m.depth <= formData.maxDepth)
                .map((mapping) => (
                  <div key={mapping.depth} className="grid grid-cols-4 gap-2 items-center">
                    <div className="flex items-center gap-2">
                      <Badge variant={mapping.depth === 1 ? "default" : "outline"}>
                        {mapping.depth}단계
                      </Badge>
                      <Input
                        value={mapping.levelLabel}
                        onChange={(e) => handleMappingChange(mapping.depth, "levelLabel", e.target.value)}
                        className="h-8 text-xs"
                        placeholder="라벨"
                      />
                    </div>
                    <Select
                      value={mapping.columnName || "_none"}
                      onValueChange={(value) => handleMappingChange(mapping.depth, "columnName", value === "_none" ? "" : value)}
                    >
                      <SelectTrigger className="h-8 text-xs">
                        <SelectValue placeholder="컬럼 선택" />
                      </SelectTrigger>
                      <SelectContent>
                        <SelectItem value="_none">컬럼 선택</SelectItem>
                        {loadingColumns ? (
                          <SelectItem value="_loading" disabled>로딩 중...</SelectItem>
                        ) : (
                          columns.map((col) => (
                            <SelectItem key={col.columnName} value={col.columnName}>
                              {col.displayName || col.columnName}
                            </SelectItem>
                          ))
                        )}
                      </SelectContent>
                    </Select>
                    <Input
                      value={mapping.placeholder}
                      onChange={(e) => handleMappingChange(mapping.depth, "placeholder", e.target.value)}
                      className="h-8 text-xs"
                      placeholder="플레이스홀더"
                    />
                    <div className="flex items-center gap-2">
                      <input
                        type="checkbox"
                        checked={mapping.isRequired}
                        onChange={(e) => handleMappingChange(mapping.depth, "isRequired", e.target.checked)}
                        className="h-4 w-4"
                      />
                      <span className="text-xs text-muted-foreground">필수</span>
                    </div>
                  </div>
                ))}
            </div>
          </div>

          <DialogFooter>
            <Button variant="outline" onClick={() => setModalOpen(false)}>
              취소
            </Button>
            <Button onClick={handleSave}>
              {isEditing ? "수정" : "생성"}
            </Button>
          </DialogFooter>
        </DialogContent>
      </Dialog>

      {/* 삭제 확인 다이얼로그 */}
      <Dialog open={deleteDialogOpen} onOpenChange={setDeleteDialogOpen}>
        <DialogContent className="max-w-md">
          <DialogHeader>
            <DialogTitle>계층구조 그룹 삭제</DialogTitle>
            <DialogDescription>
              "{selectedGroup?.group_name}" 그룹을 삭제하시겠습니까?
              <br />
              이 작업은 되돌릴 수 없습니다.
            </DialogDescription>
          </DialogHeader>
          <DialogFooter>
            <Button variant="outline" onClick={() => setDeleteDialogOpen(false)}>
              취소
            </Button>
            <Button variant="destructive" onClick={handleDelete}>
              삭제
            </Button>
          </DialogFooter>
        </DialogContent>
      </Dialog>
    </div>
  );
}