import { useTranslation } from 'react-i18next';
import { PATHS } from '@/shared/constants/paths';
import { useNavigate } from '@/shared/lib/hooks/use-navigate';
import { HeaderType } from '@/entities/common/model/types';
import {
  useSetHeaderTitle,
  useSetHeaderType,
  useSetFooterMode,
  useSetOnBack
} from '@/widgets/sub-layout/use-sub-layout';
import { useState, useEffect, useRef } from 'react';
import { VerificationItem } from '@/entities/account/model/types';
import { useUserCreateMutation } from '@/entities/user/api/use-user-create-mutation';
import { useUserExistsUseridQuery } from '@/entities/user/api/use-user-exists-userid-query';
import { useLocation } from 'react-router';
import { snackBar } from '@/shared/lib/toast';

export const UserAddAccountPage = () => {
  const { t } = useTranslation();
  const { navigate } = useNavigate();
  const location = useLocation();
  const { mid } = location.state || {};

  const { mutateAsync: userCreate, isPending } = useUserCreateMutation({
    onSuccess: () => {
      snackBar(t('account.userAddedSuccessfully'));
    },
    onError: (error) => {
      snackBar(error?.response?.data?.message || t('account.userAddFailed'));
    }
  });

  // 폼 상태 관리
  const [formData, setFormData] = useState({
    usrid: '',
    password: '',
    loginRange: 'MID'
  });

  // 에러 상태 관리
  const [errors, setErrors] = useState({
    usrid: '',
    password: ''
  });

  // 사용자 ID 검증을 위한 상태
  const [shouldCheckUsrid, setShouldCheckUsrid] = useState(false);
  const [isCheckingUsrid, setIsCheckingUsrid] = useState(false);
  const debounceTimeout = useRef<NodeJS.Timeout | null>(null);

  // 이메일/전화번호 상태 관리 (기본 1개씩 빈 공란 배치)
  const [newEmails, setNewEmails] = useState<string[]>(['']);
  const [newPhones, setNewPhones] = useState<string[]>(['']);
  const [editableEmailIndex, setEditableEmailIndex] = useState<number>(0);
  const [editablePhoneIndex, setEditablePhoneIndex] = useState<number>(0);
  const [readOnlyEmails, setReadOnlyEmails] = useState<Set<number>>(new Set());
  const [readOnlyPhones, setReadOnlyPhones] = useState<Set<number>>(new Set());

  // 사용자 ID 존재 여부 확인 쿼리
  const { data: userExistsData, isLoading: isUserExistsLoading } = useUserExistsUseridQuery(
    shouldCheckUsrid && formData.usrid.trim().length > 0 ? formData.usrid : '',
    {
      enabled: shouldCheckUsrid && formData.usrid.trim().length > 0,
    }
  );

  // Handle user exists query result
  useEffect(() => {
    if (userExistsData && shouldCheckUsrid) {
      setIsCheckingUsrid(false);
      if (userExistsData.exists) {
        setErrors(prev => ({ ...prev, usrid: t('account.duplicateIdExists') }));
      } else {
        setErrors(prev => ({ ...prev, usrid: '' }));
      }
      setShouldCheckUsrid(false);
    }
  }, [userExistsData, shouldCheckUsrid, t]);

  // 이메일/전화번호 관리 함수들 (user-login-auth-info-wrap 방식)
  const handleAddEmail = () => {
    // 현재 편집 중인 항목을 읽기전용으로 고정
    if (editableEmailIndex >= 0) {
      setReadOnlyEmails(prev => new Set([...prev, editableEmailIndex]));
    }

    // 새로운 편집 가능한 항목 추가
    setEditableEmailIndex(newEmails.length);
    setNewEmails([...newEmails, '']);
  };

  const handleAddPhone = () => {
    // 현재 편집 중인 항목을 읽기전용으로 고정
    if (editablePhoneIndex >= 0) {
      setReadOnlyPhones(prev => new Set([...prev, editablePhoneIndex]));
    }

    // 새로운 편집 가능한 항목 추가
    setEditablePhoneIndex(newPhones.length);
    setNewPhones([...newPhones, '']);
  };

  const handleRemoveNewEmail = (index: number) => {
    const updatedEmails = newEmails.filter((_, i) => i !== index);
    setNewEmails(updatedEmails);

    // 읽기전용 인덱스들을 업데이트
    const updatedReadOnlyEmails = new Set<number>();
    readOnlyEmails.forEach(readOnlyIndex => {
      if (readOnlyIndex < index) {
        updatedReadOnlyEmails.add(readOnlyIndex);
      } else if (readOnlyIndex > index) {
        updatedReadOnlyEmails.add(readOnlyIndex - 1);
      }
    });
    setReadOnlyEmails(updatedReadOnlyEmails);

    // 편집 가능한 인덱스 조정
    if (index === editableEmailIndex) {
      setEditableEmailIndex(-1);
    } else if (index < editableEmailIndex) {
      setEditableEmailIndex(editableEmailIndex - 1);
    }
  };

  const handleRemoveNewPhone = (index: number) => {
    const updatedPhones = newPhones.filter((_, i) => i !== index);
    setNewPhones(updatedPhones);

    // 읽기전용 인덱스들을 업데이트
    const updatedReadOnlyPhones = new Set<number>();
    readOnlyPhones.forEach(readOnlyIndex => {
      if (readOnlyIndex < index) {
        updatedReadOnlyPhones.add(readOnlyIndex);
      } else if (readOnlyIndex > index) {
        updatedReadOnlyPhones.add(readOnlyIndex - 1);
      }
    });
    setReadOnlyPhones(updatedReadOnlyPhones);

    // 편집 가능한 인덱스 조정
    if (index === editablePhoneIndex) {
      setEditablePhoneIndex(-1);
    } else if (index < editablePhoneIndex) {
      setEditablePhoneIndex(editablePhoneIndex - 1);
    }
  };

  const handleNewEmailChange = (index: number, value: string) => {
    const updated = [...newEmails];
    updated[index] = value;
    setNewEmails(updated);
  };

  const handleNewPhoneChange = (index: number, value: string) => {
    const updated = [...newPhones];
    updated[index] = value;
    setNewPhones(updated);
  };

  // 비밀번호 검증 함수
  const validatePassword = (password: string) => {
    if (!password.trim()) {
      return t('account.pleaseEnterPassword');
    } else if (password.length < 8) {
      return t('account.pleaseEnter8OrMoreCharacters');
    }
    return '';
  };

  // 폼 입력 핸들러
  const handleInputChange = (field: string, value: string) => {
    setFormData(prev => ({ ...prev, [field]: value }));

    // 사용자 ID의 경우 디바운스 적용하여 자동 검증
    if (field === 'usrid') {
      // 기존 타이머 클리어
      if (debounceTimeout.current) {
        clearTimeout(debounceTimeout.current);
      }

      // 에러 초기화
      setErrors(prev => ({ ...prev, usrid: '' }));

      // 값이 있으면 500ms 후 검증 실행
      if (value.trim().length > 0) {
        setIsCheckingUsrid(true);
        debounceTimeout.current = setTimeout(() => {
          setShouldCheckUsrid(true);
        }, 500);
      } else {
        setIsCheckingUsrid(false);
      }
    } else {
      // 다른 필드는 에러만 초기화
      if (errors[field as keyof typeof errors]) {
        setErrors(prev => ({ ...prev, [field]: '' }));
      }
    }
  };

  // 비밀번호 blur 핸들러
  const handlePasswordBlur = () => {
    const passwordError = validatePassword(formData.password);
    if (passwordError) {
      setErrors(prev => ({ ...prev, password: passwordError }));
    }
  };

  // 컴포넌트 언마운트 시 타이머 정리
  useEffect(() => {
    return () => {
      if (debounceTimeout.current) {
        clearTimeout(debounceTimeout.current);
      }
    };
  }, []);

  // 검증 함수들
  const isValidEmail = (email: string) => {
    const emailRegex = /^[^\s@]+@[^\s@]+\.[^\s@]+$/;
    return emailRegex.test(email);
  };

  const isValidPhone = (phone: string) => {
    const phoneRegex = /^010\d{8}$/;
    return phoneRegex.test(phone);
  };

  // 이메일 추가 버튼 활성화 조건
  const isEmailAddButtonEnabled = () => {
    if (newEmails.length === 0) return true;

    const lastEmailIndex = newEmails.length - 1;
    const lastEmail = newEmails[lastEmailIndex];

    return lastEmailIndex >= editableEmailIndex &&
           lastEmail &&
           lastEmail.trim() &&
           isValidEmail(lastEmail) &&
           !hasDuplicateEmail();
  };

  // 전화번호 추가 버튼 활성화 조건
  const isPhoneAddButtonEnabled = () => {
    if (newPhones.length === 0) return true;

    const lastPhoneIndex = newPhones.length - 1;
    const lastPhone = newPhones[lastPhoneIndex];

    return lastPhoneIndex >= editablePhoneIndex &&
           lastPhone &&
           lastPhone.trim() &&
           isValidPhone(lastPhone) &&
           !hasDuplicatePhone();
  };

  // 중복 검증
  const hasDuplicateEmail = () => {
    const validEmails = newEmails.filter(e => e.trim());
    const uniqueEmails = new Set(validEmails);
    return validEmails.length !== uniqueEmails.size;
  };

  const hasDuplicatePhone = () => {
    const validPhones = newPhones.filter(p => p.trim());
    const uniquePhones = new Set(validPhones);
    return validPhones.length !== uniquePhones.size;
  };

  // 삭제 버튼 활성화 조건
  const isDeleteButtonEnabled = () => {
    const totalCount = newEmails.length + newPhones.length;
    return totalCount > 1;
  };

  // 저장 버튼 활성화 조건 체크
  const isSaveButtonEnabled = () => {
    // 1. 사용자 ID가 입력되고 중복되지 않아야 함
    if (!formData.usrid.trim()) return false;
    if (errors.usrid) return false;
    if (isCheckingUsrid || isUserExistsLoading) return false;

    // 2. 비밀번호가 8자리 이상
    if (!formData.password.trim() || formData.password.length < 8) return false;

    // 3. 입력된 모든 이메일과 휴대폰 번호가 유효한 형식이어야 함
    const nonEmptyEmails = newEmails.filter(email => email.trim());
    const nonEmptyPhones = newPhones.filter(phone => phone.trim());

    // 입력된 이메일이 있으면 모두 유효한 형식이어야 함
    if (nonEmptyEmails.length > 0) {
      const invalidEmails = nonEmptyEmails.filter(email => !isValidEmail(email));
      if (invalidEmails.length > 0) return false;
    }

    // 입력된 휴대폰 번호가 있으면 모두 유효한 형식이어야 함
    if (nonEmptyPhones.length > 0) {
      const invalidPhones = nonEmptyPhones.filter(phone => !isValidPhone(phone));
      if (invalidPhones.length > 0) return false;
    }

    // 4. 유효한 이메일 또는 휴대폰 번호가 최소 1개 이상
    const validEmails = nonEmptyEmails.filter(email => isValidEmail(email));
    const validPhones = nonEmptyPhones.filter(phone => isValidPhone(phone));

    if (validEmails.length === 0 && validPhones.length === 0) return false;

    // 5. 중복이 없어야 함
    if (hasDuplicateEmail() || hasDuplicatePhone()) return false;

    return true;
  };

  // 폼 검증
  const validateForm = () => {
    const newErrors = { usrid: '', password: '' };
    let isValid = true;

    // 사용자 ID 검증
    if (!formData.usrid.trim()) {
      newErrors.usrid = t('account.pleaseEnterId');
      isValid = false;
    }

    // 비밀번호 검증
    if (!formData.password.trim()) {
      newErrors.password = t('account.pleaseEnterPassword');
      isValid = false;
    } else if (formData.password.length < 8) {
      newErrors.password = t('account.pleaseEnter8OrMoreCharacters');
      isValid = false;
    }

    // 이메일/전화번호 중 하나는 필수
    const validEmails = newEmails.filter(email => email.trim() && isValidEmail(email));
    const validPhones = newPhones.filter(phone => phone.trim() && isValidPhone(phone));

    if (validEmails.length === 0 && validPhones.length === 0) {
      // 최소 하나의 유효한 연락처가 필요
      isValid = false;
    }

    // 중복이 있으면 비활성화
    if (hasDuplicateEmail() || hasDuplicatePhone()) {
      isValid = false;
    }

    setErrors(newErrors);
    return isValid;
  };

  // 저장 핸들러
  const handleSave = async () => {
    if (!validateForm()) {
      return;
    }

    try {
      // verifications 배열 생성
      const verifications: VerificationItem[] = [];

      newEmails.forEach(email => {
        if (email.trim() && isValidEmail(email)) {
          verifications.push({ type: 'EMAIL', contact: email });
        }
      });

      newPhones.forEach(phone => {
        if (phone.trim() && isValidPhone(phone)) {
          verifications.push({ type: 'PHONE', contact: phone });
        }
      });

      const request = {
        mid: mid,
        usrid: formData.usrid,
        password: formData.password,
        loginRange: formData.loginRange,
        verifications: verifications
      };

      const response = await userCreate(request);

      if (response.status) {
        // 성공 시 사용자 관리 페이지로 이동
        snackBar(t('account.userAddedSuccessfully'));
        navigate(PATHS.account.user.manage);
      } else if (response.error) {
        // 에러 처리
        if (response.error.errKey === 'USER_DUPLICATE') {
          setErrors(prev => ({ ...prev, usrid: t('account.duplicateIdExists') }));
        } else {
          // 기타 에러 처리
          console.error('User creation failed:', response.error.message);
        }
      }
    } catch (error) {
      console.error('User creation error:', error);
    }
  };

  useSetHeaderTitle(t('account.addUser'));
  useSetHeaderType(HeaderType.LeftArrow);
  useSetFooterMode(false);
  useSetOnBack(() => {
    navigate(PATHS.account.user.manage);
  });

  return (
    <>
      <main>
        <div className="tab-content">
          <div className="tab-pane sub active">
            <div className="ing-list pb-86">
              <div className="user-add">
                <div className="ua-row">
                  <div className="ua-label">{t('account.userId')} <span className="red">*</span></div>
                  <div style={{ position: 'relative' }}>
                    <input
                      className={`wid-100 ${errors.usrid ? 'error' : ''}`}
                      type="text"
                      placeholder={t('account.pleaseEnterId')}
                      value={formData.usrid}
                      onChange={(e) => handleInputChange('usrid', e.target.value)}
                    />
                    {isCheckingUsrid && (
                      <div style={{
                        position: 'absolute',
                        right: '10px',
                        top: '50%',
                        transform: 'translateY(-50%)',
                        fontSize: '12px',
                        color: '#666'
                      }}>
                        {t('account.checking')}
                      </div>
                    )}
                  </div>
                </div>
                {errors.usrid && <div className="ua-help error pt-10">{errors.usrid}</div>}
                {!errors.usrid && formData.usrid && userExistsData && !userExistsData.exists && (
                  <div className="ua-help" style={{ color: '#78D197' }}>{t('account.availableId')}</div>
                )}

                <div className="ua-row">
                  <div className="ua-label">{t('account.password')} <span className="red">*</span></div>
                  <input
                    className={`wid-100 ${errors.password ? 'error' : ''}`}
                    type="password"
                    placeholder={t('account.pleaseEnter8OrMoreCharacters')}
                    value={formData.password}
                    onChange={(e) => handleInputChange('password', e.target.value)}
                    onBlur={handlePasswordBlur}
                  />
                </div>
                {errors.password && <div className="ua-help error pt-10">{errors.password}</div>}

                <div className="ua-row">
                  <div className="ua-label">{t('account.loginRange')}</div>
                  <select
                    className="wid-100"
                    value={formData.loginRange}
                    onChange={(e) => handleInputChange('loginRange', e.target.value)}
                  >
                    <option value="MID">MID</option>
                    <option value="GID">MID + GID</option>
                  </select>
                </div>
              </div>
              <div className="info-divider"></div>
              <div className="user-add info">
                <div className="ua-desc">
                  <div className="ua-title">{t('account.identityVerificationInfo')}</div>
                  <p className="ua-note">{t('account.identityVerificationNotice')}</p>
                </div>

                <div className="ua-group">
                  <div className="ua-group-header">
                    <div className="ua-group-title">{t('account.emailAddress')}</div>
                    <button
                      className="ic20 plus"
                      type="button"
                      aria-label={t('account.addEmail')}
                      onClick={handleAddEmail}
                      disabled={!isEmailAddButtonEnabled()}
                    ></button>
                  </div>
                  {newEmails.map((email, index) => (
                    <div className="ua-input-row" key={index}>
                      <input
                        className="wid-100"
                        type="text"
                        placeholder="example@domain.com"
                        value={email}
                        onChange={(e) => handleNewEmailChange(index, e.target.value)}
                        readOnly={readOnlyEmails.has(index) || index !== editableEmailIndex}
                      />
                      <button
                        className="icon-btn minus"
                        type="button"
                        aria-label={t('common.delete')}
                        onClick={() => handleRemoveNewEmail(index)}
                        disabled={!isDeleteButtonEnabled()}
                      ></button>
                    </div>
                  ))}
                </div>

                <div className="ua-group">
                  <div className="ua-group-header">
                    <div className="ua-group-title">{t('account.phoneNumber')}</div>
                    <button
                      className="ic20 plus"
                      type="button"
                      aria-label={t('account.addPhone')}
                      onClick={handleAddPhone}
                      disabled={!isPhoneAddButtonEnabled()}
                    ></button>
                  </div>
                  {newPhones.map((phone, index) => (
                    <div className="ua-input-row" key={index}>
                      <input
                        className="wid-100"
                        type="tel"
                        placeholder="01012345678"
                        value={phone}
                        onChange={(e) => handleNewPhoneChange(index, e.target.value)}
                        readOnly={readOnlyPhones.has(index) || index !== editablePhoneIndex}
                      />
                      <button
                        className="icon-btn minus"
                        type="button"
                        aria-label={t('common.delete')}
                        onClick={() => handleRemoveNewPhone(index)}
                        disabled={!isDeleteButtonEnabled()}
                      ></button>
                    </div>
                  ))}
                </div>
              </div>

              <div className="apply-row">
                <button
                  className="btn-50 btn-blue flex-1"
                  type="button"
                  onClick={handleSave}
                  disabled={!isSaveButtonEnabled() || isPending}
                >
                  {isPending ? t('common.saving') : t('common.save')}
                </button>
              </div>
            </div>
          </div>
        </div>
      </main>
    </>
  );
};