/**
 * 거래처 등록/수정 컴포넌트
 *
 * ResponsiveFormTemplate 적용
 * - 데스크톱/태블릿/모바일 통합 폼 레이아웃
 * - 섹션 기반 정보 입력
 * - 유효성 검사 및 에러 표시
 */

"use client";

import { useState, useEffect } from "react";
import { Input } from "../ui/input";
import { Textarea } from "../ui/textarea";
import { RadioGroup, RadioGroupItem } from "../ui/radio-group";
import { Label } from "../ui/label";
import {
  Building2,
  UserCircle,
  Phone,
  FileText,
} from "lucide-react";
import { toast } from "sonner";
import {
  ResponsiveFormTemplate,
  FormSection,
  FormFieldGrid,
} from "../templates/ResponsiveFormTemplate";
import { FormField } from "../molecules/FormField";
import {
  ClientFormData,
  INITIAL_CLIENT_FORM,
  ClientType,
} from "../../hooks/useClientList";

interface ClientRegistrationProps {
  onBack: () => void;
  onSave: (client: ClientFormData) => Promise<void>;
  editingClient?: ClientFormData | null;
  isLoading?: boolean;
}

// 4자리 영문+숫자 조합 코드 생성 (중복 방지를 위해 타임스탬프 기반)
const generateClientCode = (): string => {
  const chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
  const timestamp = Date.now().toString(36).toUpperCase().slice(-2); // 타임스탬프 2자리
  let random = "";
  for (let i = 0; i < 2; i++) {
    random += chars.charAt(Math.floor(Math.random() * chars.length));
  }
  return timestamp + random;
};

export function ClientRegistration({
  onBack,
  onSave,
  editingClient,
  isLoading = false,
}: ClientRegistrationProps) {
  const [formData, setFormData] = useState<ClientFormData>(() => {
    if (editingClient) {
      return editingClient;
    }
    // 신규 등록 시 클라이언트 코드 자동 생성
    return {
      ...INITIAL_CLIENT_FORM,
      clientCode: generateClientCode(),
    };
  });
  const [errors, setErrors] = useState<Record<string, string>>({});
  const [isSaving, setIsSaving] = useState(false);

  // editingClient가 변경되면 formData 업데이트
  useEffect(() => {
    if (editingClient) {
      setFormData(editingClient);
    }
  }, [editingClient]);

  // 유효성 검사
  const validateForm = (): boolean => {
    const newErrors: Record<string, string> = {};

    if (!formData.name || formData.name.length < 2) {
      newErrors.name = "거래처명은 2자 이상 입력해주세요";
    }

    // 하이픈 제거 후 10자리 숫자 검증 (123-45-67890 또는 1234567890 허용)
    const businessNoDigits = formData.businessNo.replace(/-/g, "").trim();
    console.log("[ClientRegistration] businessNo 검증:", {
      원본: formData.businessNo,
      하이픈제거: businessNoDigits,
      길이: businessNoDigits.length,
      숫자만: /^\d{10}$/.test(businessNoDigits),
    });
    if (!formData.businessNo || !/^\d{10}$/.test(businessNoDigits)) {
      newErrors.businessNo = "사업자등록번호는 10자리 숫자여야 합니다";
    }

    if (!formData.representative || formData.representative.length < 2) {
      newErrors.representative = "대표자명은 2자 이상 입력해주세요";
    }

    // 전화번호 형식 검사 (선택적)
    const phonePattern = /^[0-9-]+$/;
    if (formData.phone && !phonePattern.test(formData.phone)) {
      newErrors.phone = "올바른 전화번호 형식이 아닙니다";
    }

    if (formData.email && !/^[^\s@]+@[^\s@]+\.[^\s@]+$/.test(formData.email)) {
      newErrors.email = "올바른 이메일 형식이 아닙니다";
    }

    setErrors(newErrors);
    return Object.keys(newErrors).length === 0;
  };

  const handleSubmit = async () => {
    if (!validateForm()) {
      toast.error("입력 내용을 확인해주세요.");
      return;
    }

    setIsSaving(true);
    try {
      await onSave(formData);
      toast.success(
        editingClient ? "거래처가 수정되었습니다." : "거래처가 등록되었습니다."
      );
      onBack();
    } catch (error) {
      toast.error("저장 중 오류가 발생했습니다.");
    } finally {
      setIsSaving(false);
    }
  };

  const handleFieldChange = (
    field: keyof ClientFormData,
    value: string | boolean
  ) => {
    console.log("[ClientRegistration] handleFieldChange:", field, value);
    setFormData({ ...formData, [field]: value });
    if (errors[field]) {
      setErrors((prev) => {
        const newErrors = { ...prev };
        delete newErrors[field];
        return newErrors;
      });
    }
  };

  return (
    <ResponsiveFormTemplate
      title={editingClient ? "거래처 수정" : "거래처 등록"}
      description="거래처 정보를 입력하세요"
      icon={Building2}
      onSave={handleSubmit}
      onCancel={onBack}
      saveLabel={editingClient ? "수정" : "등록"}
      isEditMode={!!editingClient}
      saveLoading={isSaving || isLoading}
      saveDisabled={isSaving || isLoading}
      maxWidth="2xl"
    >
      {/* 1. 기본 정보 */}
      <FormSection
        title="기본 정보"
        description="거래처의 기본 정보를 입력하세요"
        icon={Building2}
      >
        <FormFieldGrid columns={2}>
          <FormField
            label="사업자등록번호"
            required
            error={errors.businessNo}
            htmlFor="businessNo"
            type="custom"
          >
            <Input
              id="businessNo"
              placeholder="10자리 숫자 (예: 123-45-67890)"
              value={formData.businessNo}
              onChange={(e) => handleFieldChange("businessNo", e.target.value)}
            />
          </FormField>

          <FormField
            label="거래처 코드"
            htmlFor="clientCode"
            helpText="자동 생성됩니다"
            type="custom"
          >
            <Input
              id="clientCode"
              placeholder="자동생성"
              value={formData.clientCode || ""}
              disabled
            />
          </FormField>
        </FormFieldGrid>

        <FormFieldGrid columns={2}>
          <FormField
            label="거래처명"
            required
            error={errors.name}
            htmlFor="name"
            type="custom"
          >
            <Input
              id="name"
              placeholder="거래처명 입력"
              value={formData.name}
              onChange={(e) => handleFieldChange("name", e.target.value)}
            />
          </FormField>

          <FormField
            label="대표자명"
            required
            error={errors.representative}
            htmlFor="representative"
            type="custom"
          >
            <Input
              id="representative"
              placeholder="대표자명 입력"
              value={formData.representative}
              onChange={(e) =>
                handleFieldChange("representative", e.target.value)
              }
            />
          </FormField>
        </FormFieldGrid>

        <FormField label="거래처 유형" required type="custom">
          <RadioGroup
            value={formData.clientType}
            onValueChange={(value) =>
              handleFieldChange("clientType", value as ClientType)
            }
            className="flex gap-4"
          >
            <div className="flex items-center space-x-2">
              <RadioGroupItem value="매입" id="type-purchase" />
              <Label htmlFor="type-purchase">매입</Label>
            </div>
            <div className="flex items-center space-x-2">
              <RadioGroupItem value="매출" id="type-sales" />
              <Label htmlFor="type-sales">매출</Label>
            </div>
            <div className="flex items-center space-x-2">
              <RadioGroupItem value="매입매출" id="type-both" />
              <Label htmlFor="type-both">매입매출</Label>
            </div>
          </RadioGroup>
        </FormField>

        <FormFieldGrid columns={2}>
          <FormField label="업태" htmlFor="businessType" type="custom">
            <Input
              id="businessType"
              placeholder="제조업, 도소매업 등"
              value={formData.businessType}
              onChange={(e) =>
                handleFieldChange("businessType", e.target.value)
              }
            />
          </FormField>

          <FormField label="종목" htmlFor="businessItem" type="custom">
            <Input
              id="businessItem"
              placeholder="철강, 건설 등"
              value={formData.businessItem}
              onChange={(e) =>
                handleFieldChange("businessItem", e.target.value)
              }
            />
          </FormField>
        </FormFieldGrid>
      </FormSection>

      {/* 2. 연락처 정보 */}
      <FormSection
        title="연락처 정보"
        description="거래처의 연락처 정보를 입력하세요"
        icon={Phone}
      >
        <FormField label="주소" htmlFor="address" type="custom">
          <Input
            id="address"
            placeholder="주소 입력"
            value={formData.address}
            onChange={(e) => handleFieldChange("address", e.target.value)}
          />
        </FormField>

        <FormFieldGrid columns={3}>
          <FormField label="전화번호" error={errors.phone} htmlFor="phone" type="custom">
            <Input
              id="phone"
              placeholder="02-1234-5678"
              value={formData.phone}
              onChange={(e) => handleFieldChange("phone", e.target.value)}
            />
          </FormField>

          <FormField label="모바일" htmlFor="mobile" type="custom">
            <Input
              id="mobile"
              placeholder="010-1234-5678"
              value={formData.mobile}
              onChange={(e) => handleFieldChange("mobile", e.target.value)}
            />
          </FormField>

          <FormField label="팩스" htmlFor="fax" type="custom">
            <Input
              id="fax"
              placeholder="02-1234-5678"
              value={formData.fax}
              onChange={(e) => handleFieldChange("fax", e.target.value)}
            />
          </FormField>
        </FormFieldGrid>

        <FormField label="이메일" error={errors.email} htmlFor="email" type="custom">
          <Input
            id="email"
            type="email"
            placeholder="example@company.com"
            value={formData.email}
            onChange={(e) => handleFieldChange("email", e.target.value)}
          />
        </FormField>
      </FormSection>

      {/* 3. 담당자 정보 */}
      <FormSection
        title="담당자 정보"
        description="거래처 담당자 정보를 입력하세요"
        icon={UserCircle}
      >
        <FormFieldGrid columns={2}>
          <FormField label="담당자명" htmlFor="managerName" type="custom">
            <Input
              id="managerName"
              placeholder="담당자명 입력"
              value={formData.managerName}
              onChange={(e) => handleFieldChange("managerName", e.target.value)}
            />
          </FormField>

          <FormField label="담당자 전화" htmlFor="managerTel" type="custom">
            <Input
              id="managerTel"
              placeholder="010-1234-5678"
              value={formData.managerTel}
              onChange={(e) => handleFieldChange("managerTel", e.target.value)}
            />
          </FormField>
        </FormFieldGrid>

        <FormField label="시스템 관리자" htmlFor="systemManager" type="custom">
          <Input
            id="systemManager"
            placeholder="시스템 관리자명"
            value={formData.systemManager}
            onChange={(e) =>
              handleFieldChange("systemManager", e.target.value)
            }
          />
        </FormField>
      </FormSection>

      {/*
        TODO: 기획 확정 후 활성화 (2025-12-09)
        - 발주처 설정: 계정ID, 비밀번호, 매입/매출 결제일
        - 약정 세금: 약정 여부, 금액, 시작/종료일
        - 악성채권 정보: 악성채권 여부, 금액, 발생/만료일, 진행상태

        백엔드 API에서는 이미 지원됨 (nullable 필드)
      */}

      {/* 4. 기타 */}
      <FormSection
        title="기타 정보"
        description="추가 정보를 입력하세요"
        icon={FileText}
      >
        <FormField label="메모" htmlFor="memo" type="custom">
          <Textarea
            id="memo"
            placeholder="메모 입력"
            value={formData.memo}
            onChange={(e) => handleFieldChange("memo", e.target.value)}
            rows={4}
          />
        </FormField>

        <FormField label="상태" type="custom">
          <RadioGroup
            value={formData.isActive ? "활성" : "비활성"}
            onValueChange={(value) =>
              handleFieldChange("isActive", value === "활성")
            }
            className="flex gap-4"
          >
            <div className="flex items-center space-x-2">
              <RadioGroupItem value="활성" id="status-active" />
              <Label htmlFor="status-active">활성</Label>
            </div>
            <div className="flex items-center space-x-2">
              <RadioGroupItem value="비활성" id="status-inactive" />
              <Label htmlFor="status-inactive">비활성</Label>
            </div>
          </RadioGroup>
        </FormField>
      </FormSection>
    </ResponsiveFormTemplate>
  );
}
