"use client";

import * as React from "react";
import { Loader2, Users, Building2, AlertCircle } from "lucide-react";
import { Button } from "@/components/ui/button";
import {
  Dialog,
  DialogContent,
  DialogDescription,
  DialogFooter,
  DialogHeader,
  DialogTitle,
} from "@/components/ui/dialog";
import {
  Select,
  SelectContent,
  SelectItem,
  SelectTrigger,
  SelectValue,
} from "@/components/ui/select";
import { Textarea } from "@/components/ui/textarea";
import { Badge } from "@/components/ui/badge";
import { ScrollArea } from "@/components/ui/scroll-area";
import { Label } from "@/components/ui/label";
import { Separator } from "@/components/ui/separator";
import { 
  Table,
  TableBody,
  TableCell,
  TableHead,
  TableHeader,
  TableRow,
} from "@/components/ui/table";
import { 
  DepartmentNode
} from "@/lib/users/knox-service";
import { 
  getDepartmentDomainAssignmentsByDepartments,
  type UserDomain 
} from "@/lib/users/department-domain/service";
import { DOMAIN_OPTIONS, getDomainLabel } from "./domain-constants";

interface ExistingAssignment {
  id: number;
  companyCode: string;
  departmentCode: string;
  departmentName: string;
  assignedDomain: string;
  description?: string | null;
  createdAt: Date;
  updatedAt: Date;
}

interface DepartmentDomainAssignmentDialogProps {
  open: boolean;
  onOpenChange: (open: boolean) => void;
  selectedDepartments: string[];
  departments: DepartmentNode[];
  companyInfo: { code: string; name: string };
  onAssign: (assignments: {
    departmentCodes: string[];
    domain: string;
    description?: string;
  }) => Promise<void>;
  isLoading?: boolean;
}

export function DepartmentDomainAssignmentDialog({
  open,
  onOpenChange,
  selectedDepartments,
  departments,
  companyInfo,
  onAssign,
  isLoading = false,
}: DepartmentDomainAssignmentDialogProps) {
  const [selectedDomain, setSelectedDomain] = React.useState<string>("");
  const [description, setDescription] = React.useState<string>("");
  const [isSubmitting, setIsSubmitting] = React.useState(false);
  const [existingAssignments, setExistingAssignments] = React.useState<ExistingAssignment[]>([]);
  const [isLoadingAssignments, setIsLoadingAssignments] = React.useState(false);

  // 선택된 부서들의 정보 가져오기
  const getSelectedDepartmentInfo = React.useCallback(() => {
    const findDepartment = (nodes: DepartmentNode[], code: string): DepartmentNode | null => {
      for (const node of nodes) {
        if (node.departmentCode === code) {
          return node;
        }
        const found = findDepartment(node.children, code);
        if (found) return found;
      }
      return null;
    };

    return selectedDepartments
      .map(code => findDepartment(departments, code))
      .filter(Boolean) as DepartmentNode[];
  }, [departments, selectedDepartments]);

  // 회사별로 그룹화
  const selectedDepartmentsByCompany = React.useMemo(() => {
    const deptInfo = getSelectedDepartmentInfo();
    const grouped = new Map<string, DepartmentNode[]>();
    
    deptInfo.forEach(dept => {
      if (!grouped.has(dept.companyCode)) {
        grouped.set(dept.companyCode, []);
      }
      grouped.get(dept.companyCode)!.push(dept);
    });
    
    return grouped;
  }, [getSelectedDepartmentInfo]);

  // 기존 할당 정보 조회
  React.useEffect(() => {
    if (open && selectedDepartments.length > 0) {
      const loadExistingAssignments = async () => {
        setIsLoadingAssignments(true);
        try {
          const assignments = await getDepartmentDomainAssignmentsByDepartments(selectedDepartments);
          setExistingAssignments(assignments as ExistingAssignment[]);
        } catch (error) {
          console.error("기존 할당 정보 조회 실패:", error);
          setExistingAssignments([]);
        } finally {
          setIsLoadingAssignments(false);
        }
      };

      loadExistingAssignments();
    } else {
      setExistingAssignments([]);
    }
  }, [open, selectedDepartments]);

  // 폼 초기화
  React.useEffect(() => {
    if (open) {
      setSelectedDomain("");
      setDescription("");
      setIsSubmitting(false);
    }
  }, [open]);

  // 할당 처리
  const handleAssign = async () => {
    if (!selectedDomain || selectedDepartments.length === 0) {
      return;
    }

    setIsSubmitting(true);
    
    try {
      await onAssign({
        departmentCodes: selectedDepartments,
        domain: selectedDomain,
        description: description.trim() || undefined,
      });
      
      // 성공 시 다이얼로그 닫기
      onOpenChange(false);
    } catch (error) {
      console.error("도메인 할당 실패:", error);
    } finally {
      setIsSubmitting(false);
    }
  };

  const canSubmit = selectedDomain && selectedDepartments.length > 0 && !isSubmitting && !isLoading;
  const selectedDomainInfo = DOMAIN_OPTIONS.find(opt => opt.value === selectedDomain);
  const hasConflicts = existingAssignments.some(a => a.assignedDomain !== selectedDomain && selectedDomain);

  return (
    <Dialog open={open} onOpenChange={onOpenChange}>
      <DialogContent className="max-w-4xl max-h-[90vh] overflow-hidden flex flex-col">
        <DialogHeader>
          <DialogTitle className="flex items-center gap-2">
            <Building2 className="h-5 w-5" />
            부서별 도메인 할당
          </DialogTitle>
          <DialogDescription>
            선택된 {selectedDepartments.length}개 부서에 도메인을 할당합니다.
            상위 부서를 선택한 경우 하위 부서들도 자동으로 포함됩니다.
          </DialogDescription>
        </DialogHeader>

        <div className="flex-1 overflow-hidden">
          <ScrollArea className="h-full pr-4">
            <div className="space-y-6">
              {/* 선택된 부서들 표시 */}
              <div className="space-y-3">
                <Label className="text-sm font-medium flex items-center gap-2">
                  <Users className="h-4 w-4" />
                  선택된 부서 ({selectedDepartments.length}개)
                </Label>
                
                <div className="border rounded-md p-3 max-h-32 overflow-y-auto">
                  {Array.from(selectedDepartmentsByCompany.entries()).map(([companyCode, depts]) => (
                    <div key={companyCode} className="mb-3 last:mb-0">
                      <div className="text-sm font-medium text-muted-foreground mb-2">
                        {companyCode} - {companyInfo.name}
                      </div>
                      <div className="flex flex-wrap gap-2">
                        {depts.map((dept) => (
                          <Badge
                            key={dept.departmentCode}
                            variant="outline"
                            className="text-xs"
                          >
                            {dept.departmentName || dept.departmentCode}
                          </Badge>
                        ))}
                      </div>
                    </div>
                  ))}
                </div>
              </div>

              {/* 기존 할당 현황 */}
              {(existingAssignments.length > 0 || isLoadingAssignments) && (
                <>
                  <Separator />
                  <div className="space-y-3">
                    <Label className="text-sm font-medium flex items-center gap-2">
                      <AlertCircle className="h-4 w-4" />
                      현재 할당 현황
                    </Label>
                    
                    {isLoadingAssignments ? (
                      <div className="flex items-center justify-center py-4">
                        <Loader2 className="h-4 w-4 animate-spin mr-2" />
                        기존 할당 정보를 조회하는 중...
                      </div>
                    ) : (
                      <div className="border rounded-md">
                        <Table>
                          <TableHeader>
                            <TableRow>
                              <TableHead>부서</TableHead>
                              <TableHead>현재 도메인</TableHead>
                              <TableHead>할당일</TableHead>
                              <TableHead>설명</TableHead>
                            </TableRow>
                          </TableHeader>
                          <TableBody>
                            {existingAssignments.map((assignment) => (
                              <TableRow key={assignment.id}>
                                <TableCell className="font-medium">
                                  {assignment.departmentName}
                                </TableCell>
                                <TableCell>
                                                                  <Badge 
                                  variant={assignment.assignedDomain === 'evcp' ? 'default' : 'secondary'}
                                >
                                  {getDomainLabel(assignment.assignedDomain)}
                                </Badge>
                                </TableCell>
                                <TableCell className="text-sm text-muted-foreground">
                                  {new Date(assignment.createdAt).toLocaleDateString('ko-KR')}
                                </TableCell>
                                <TableCell className="max-w-xs truncate text-sm">
                                  {assignment.description || '-'}
                                </TableCell>
                              </TableRow>
                            ))}
                          </TableBody>
                        </Table>
                      </div>
                    )}
                    
                    {hasConflicts && (
                      <div className="bg-yellow-50 border-yellow-200 border rounded-md p-3">
                        <div className="flex items-start gap-2">
                          <AlertCircle className="h-4 w-4 text-yellow-600 mt-0.5" />
                          <div className="text-sm">
                            <div className="font-medium text-yellow-800">도메인 변경 주의</div>
                            <div className="text-yellow-700">
                              일부 부서의 기존 도메인과 다른 도메인을 할당하려고 합니다. 
                              기존 할당은 자동으로 비활성화됩니다.
                            </div>
                          </div>
                        </div>
                      </div>
                    )}
                  </div>
                </>
              )}

              <Separator />

              {/* 도메인 선택 */}
              <div className="space-y-2">
                <Label htmlFor="domain-select" className="text-sm font-medium">
                  할당할 도메인 *
                </Label>
                <Select value={selectedDomain} onValueChange={setSelectedDomain}>
                  <SelectTrigger id="domain-select">
                    <SelectValue placeholder="도메인을 선택하세요" />
                  </SelectTrigger>
                  <SelectContent>
                    {DOMAIN_OPTIONS.map((option) => (
                      <SelectItem key={option.value} value={option.value}>
                        <div className="flex flex-col">
                          <span className="font-medium">{option.label}</span>
                          <span className="text-xs text-muted-foreground">
                            {option.description}
                          </span>
                        </div>
                      </SelectItem>
                    ))}
                  </SelectContent>
                </Select>
                
                {selectedDomainInfo && (
                  <div className="text-sm text-muted-foreground">
                    <Badge variant="secondary" className="mr-2">
                      {selectedDomainInfo.label}
                    </Badge>
                    {selectedDomainInfo.description}
                  </div>
                )}
              </div>

              {/* 할당 사유/설명 */}
              <div className="space-y-2">
                <Label htmlFor="description" className="text-sm font-medium">
                  할당 사유 또는 설명 (선택사항)
                </Label>
                <Textarea
                  id="description"
                  placeholder="예: 구매 업무 담당자들에게 procurement 도메인 할당"
                  value={description}
                  onChange={(e) => setDescription(e.target.value)}
                  rows={3}
                  maxLength={500}
                />
                <div className="text-xs text-muted-foreground text-right">
                  {description.length}/500
                </div>
              </div>

              {/* 주의사항 */}
              <div className="bg-muted/50 p-3 rounded-md">
                <div className="text-sm text-muted-foreground">
                  <div className="font-medium mb-1">⚠️ 주의사항</div>
                  <ul className="list-disc list-inside space-y-1 text-xs">
                    <li>도메인 할당은 해당 부서 소속 사용자들의 메뉴 접근 권한에 영향을 줍니다.</li>
                    <li>기존에 다른 도메인이 할당된 부서는 새로운 도메인으로 덮어씌워집니다.</li>
                    <li>Knox 조직도 변경으로 인해 부서가 삭제된 경우, 해당 할당은 고립된 레코드가 됩니다.</li>
                  </ul>
                </div>
              </div>
            </div>
          </ScrollArea>
        </div>

        <DialogFooter className="border-t pt-4">
          <Button
            variant="outline"
            onClick={() => onOpenChange(false)}
            disabled={isSubmitting || isLoading}
          >
            취소
          </Button>
          <Button
            onClick={handleAssign}
            disabled={!canSubmit}
          >
            {isSubmitting || isLoading ? (
              <>
                <Loader2 className="mr-2 h-4 w-4 animate-spin" />
                할당 중...
              </>
            ) : (
              `도메인 할당 (${selectedDepartments.length}개 부서)`
            )}
          </Button>
        </DialogFooter>
      </DialogContent>
    </Dialog>
  );
}