// lib/auth/passwordUtils.ts

import bcrypt from 'bcryptjs';
import crypto from 'crypto';
import { eq, and, desc, count, sql, gte, inArray } from 'drizzle-orm';
import db from '@/db/db';
import { 
  users, 
  passwords, 
  passwordHistory, 
  securitySettings,
  mfaTokens 
} from '@/db/schema';

export interface PasswordStrength {
  score: number; // 1-5
  hasUppercase: boolean;
  hasLowercase: boolean;
  hasNumbers: boolean;
  hasSymbols: boolean;
  length: number;
  feedback: string[];
}

export interface PasswordPolicy {
  minLength: number;
  requireUppercase: boolean;
  requireLowercase: boolean;
  requireNumbers: boolean;
  requireSymbols: boolean;
  historyCount: number;
}

// 패스워드 강도 분석
export function analyzePasswordStrength(password: string): PasswordStrength {
  const hasUppercase = /[A-Z]/.test(password);
  const hasLowercase = /[a-z]/.test(password);
  const hasNumbers = /\d/.test(password);
  const hasSymbols = /[!@#$%^&*()_+\-=\[\]{};':"\\|,.<>\/?]/.test(password);
  const length = password.length;
  
  const feedback: string[] = [];
  let score = 1;
  
  // 길이 체크
  if (length >= 12) {
    score += 1;
  } else if (length < 8) {
    feedback.push('최소 8자 이상 사용하세요');
  }
  
  // 문자 종류 체크
  const typeCount = [hasUppercase, hasLowercase, hasNumbers, hasSymbols]
    .filter(Boolean).length;
  
  if (typeCount >= 4) {
    score += 2;
  } else if (typeCount >= 3) {
    score += 1;
  } else {
    if (!hasUppercase) feedback.push('대문자를 포함하세요');
    if (!hasLowercase) feedback.push('소문자를 포함하세요');
    if (!hasNumbers) feedback.push('숫자를 포함하세요');
    if (!hasSymbols) feedback.push('특수문자를 포함하세요');
  }
  
  // 일반적인 패턴 체크
  if (/(.)\1{2,}/.test(password)) {
    feedback.push('같은 문자가 3번 이상 반복되지 않도록 하세요');
    score = Math.max(1, score - 1);
  }
  
  if (/123|abc|qwe|password|admin/i.test(password)) {
    feedback.push('일반적인 패턴이나 단어는 피하세요');
    score = Math.max(1, score - 1);
  }
  
  return {
    score: Math.min(5, score),
    hasUppercase,
    hasLowercase,
    hasNumbers,
    hasSymbols,
    length,
    feedback,
  };
}

// 패스워드 정책 가져오기
export async function getPasswordPolicy(): Promise<PasswordPolicy> {
  const settings = await db.select().from(securitySettings).limit(1);
  const setting = settings[0];
  
  return {
    minLength: setting?.minPasswordLength || 8,
    requireUppercase: setting?.requireUppercase || true,
    requireLowercase: setting?.requireLowercase || true,
    requireNumbers: setting?.requireNumbers || true,
    requireSymbols: setting?.requireSymbols || true,
    historyCount: setting?.passwordHistoryCount || 5,
  };
}

// 패스워드 정책 검증
export async function validatePasswordPolicy(
  password: string,
  policy?: PasswordPolicy
): Promise<{ valid: boolean; errors: string[] }> {
  const passwordPolicy = policy || await getPasswordPolicy();
  const strength = analyzePasswordStrength(password);
  const errors: string[] = [];
  
  if (strength.length < passwordPolicy.minLength) {
    errors.push(`최소 ${passwordPolicy.minLength}자 이상이어야 합니다`);
  }
  
  if (passwordPolicy.requireUppercase && !strength.hasUppercase) {
    errors.push('대문자를 포함해야 합니다');
  }
  
  if (passwordPolicy.requireLowercase && !strength.hasLowercase) {
    errors.push('소문자를 포함해야 합니다');
  }
  
  if (passwordPolicy.requireNumbers && !strength.hasNumbers) {
    errors.push('숫자를 포함해야 합니다');
  }
  
  if (passwordPolicy.requireSymbols && !strength.hasSymbols) {
    errors.push('특수문자를 포함해야 합니다');
  }
  
  return {
    valid: errors.length === 0,
    errors,
  };
}

// 이전 패스워드와 중복 체크
export async function checkPasswordHistory(
  userId: number,
  newPassword: string,
  historyCount: number = 5
): Promise<boolean> {
  const histories = await db
    .select({
      passwordHash: passwordHistory.passwordHash,
      salt: passwordHistory.salt,
    })
    .from(passwordHistory)
    .where(eq(passwordHistory.userId, userId))
    .orderBy(desc(passwordHistory.createdAt))
    .limit(historyCount);
  
  // 현재 활성 패스워드도 체크
  const currentPassword = await db
    .select({
      passwordHash: passwords.passwordHash,
      salt: passwords.salt,
    })
    .from(passwords)
    .where(
      and(
        eq(passwords.userId, userId),
        eq(passwords.isActive, true)
      )
    )
    .limit(1);
  
  const allPasswords = [...histories];
  if (currentPassword[0]) {
    allPasswords.unshift(currentPassword[0]);
  }
  
  // 각 이전 패스워드와 비교
  for (const pwd of allPasswords) {
    const isMatch = await bcrypt.compare(
      newPassword + pwd.salt,
      pwd.passwordHash
    );
    if (isMatch) {
      return false; // 중복됨
    }
  }
  
  return true; // 중복 없음
}

// Salt 생성
function generateSalt(): string {
  return crypto.randomBytes(16).toString('hex');
}

// 패스워드 해싱
async function hashPassword(password: string, salt: string): Promise<string> {
  const saltRounds = 12;
  return bcrypt.hash(password + salt, saltRounds);
}

// 새 패스워드 설정
export async function setPassword(
  userId: number,
  newPassword: string
): Promise<{ success: boolean; errors: string[] }> {
  try {
    // 1. 정책 검증
    const policyResult = await validatePasswordPolicy(newPassword);
    if (!policyResult.valid) {
      return { success: false, errors: policyResult.errors };
    }
    
    // 2. 히스토리 검증
    const policy = await getPasswordPolicy();
    const isUnique = await checkPasswordHistory(userId, newPassword, policy.historyCount);
    if (!isUnique) {
      return { 
        success: false, 
        errors: [`최근 ${policy.historyCount}개 패스워드와 달라야 합니다`] 
      };
    }
    
    // 3. 현재 패스워드를 히스토리로 이동
    const currentPassword = await db
      .select()
      .from(passwords)
      .where(
        and(
          eq(passwords.userId, userId),
          eq(passwords.isActive, true)
        )
      )
      .limit(1);
    
    if (currentPassword[0]) {
      await db.insert(passwordHistory).values({
        userId,
        passwordHash: currentPassword[0].passwordHash,
        salt: currentPassword[0].salt,
        createdAt: currentPassword[0].createdAt,
        replacedAt: new Date(),
      });
      
      // 현재 패스워드 비활성화
      await db
        .update(passwords)
        .set({ isActive: false })
        .where(eq(passwords.id, currentPassword[0].id));
    }
    
    // 4. 새 패스워드 생성
    const salt = generateSalt();
    const hashedPassword = await hashPassword(newPassword, salt);
    const strength = analyzePasswordStrength(newPassword);
    
    // 패스워드 만료일 계산
    let expiresAt: Date | null = null;
    const settings = await db.select().from(securitySettings).limit(1);
    const expiryDays = settings[0]?.passwordExpiryDays;
    if (expiryDays) {
      expiresAt = new Date();
      expiresAt.setDate(expiresAt.getDate() + expiryDays);
    }
    
    await db.insert(passwords).values({
      userId,
      passwordHash: hashedPassword,
      salt,
      strength: strength.score,
      hasUppercase: strength.hasUppercase,
      hasLowercase: strength.hasLowercase,
      hasNumbers: strength.hasNumbers,
      hasSymbols: strength.hasSymbols,
      length: strength.length,
      expiresAt,
      isActive: true,
    });
    
    // 5. 패스워드 변경 필수 플래그 해제
    await db
      .update(users)
      .set({ passwordChangeRequired: false })
      .where(eq(users.id, userId));
    
    // 6. 오래된 히스토리 정리
    await cleanupPasswordHistory(userId, policy.historyCount);
    
    return { success: true, errors: [] };
    
  } catch (error) {
    console.error('Password setting error:', error);
    return { success: false, errors: ['패스워드 설정 중 오류가 발생했습니다'] };
  }
}

// 패스워드 히스토리 정리
async function cleanupPasswordHistory(userId: number, keepCount: number) {
  const histories = await db
    .select({ id: passwordHistory.id })
    .from(passwordHistory)
    .where(eq(passwordHistory.userId, userId))
    .orderBy(desc(passwordHistory.createdAt))
    .offset(keepCount);
  
  if (histories.length > 0) {
    const idsToDelete = histories.map(h => h.id);
    await db
      .delete(passwordHistory)
      .where(and(eq(passwordHistory.userId, userId), inArray(passwordHistory.id, idsToDelete)))
  }
}

// MFA SMS 토큰 생성 및 전송
// Bizppurio API 토큰 발급
async function getBizppurioToken(): Promise<string> {
  const account = process.env.BIZPPURIO_ACCOUNT;
  const password = process.env.BIZPPURIO_PASSWORD;
  
  if (!account || !password) {
    throw new Error('Bizppurio credentials not configured');
  }

  const credentials = Buffer.from(`${account}:${password}`).toString('base64');
  
  const response = await fetch('https://api.bizppurio.com/v1/token', {
    method: 'POST',
    headers: {
      'Authorization': `Basic ${credentials}`,
      'Content-Type': 'application/json; charset=utf-8'
    }
  });

  if (!response.ok) {
    throw new Error(`Token request failed: ${response.status}`);
  }

  const data = await response.json();
  return data.accesstoken;
}

// SMS 메시지 전송
async function sendSmsMessage(phoneNumber: string, message: string): Promise<boolean> {
  try {
    const accessToken = await getBizppurioToken();
    const account = process.env.BIZPPURIO_ACCOUNT;
    const fromNumber = process.env.BIZPPURIO_FROM_NUMBER;
    
    if (!account || !fromNumber) {
      throw new Error('Bizppurio configuration missing');
    }

    // phoneNumber에서 국가코드와 번호 분리
    let country = '';
    let to = phoneNumber;
    
    if (phoneNumber.startsWith('+82')) {
      country = '82';
      to = phoneNumber.substring(3);
      // 한국 번호는 0으로 시작하지 않는 경우 0 추가
      if (!to.startsWith('0')) {
        to = '0' + to;
      }
    } else if (phoneNumber.startsWith('+1')) {
      country = '1';
      to = phoneNumber.substring(2);
    } else if (phoneNumber.startsWith('+81')) {
      country = '81';
      to = phoneNumber.substring(3);
    } else if (phoneNumber.startsWith('+86')) {
      country = '86';
      to = phoneNumber.substring(3);
    }
    // 국가코드가 없는 경우 한국으로 가정
    else if (!phoneNumber.startsWith('+')) {
      country = '82';
      to = phoneNumber.replace(/-/g, ''); // 하이픈 제거
      if (!to.startsWith('0')) {
        to = '0' + to;
      }
    }

    const requestBody = {
      account: account,
      type: 'SMS',
      from: fromNumber,
      to: to,
      country: country,
      content: {
        sms: {
          message: message
        }
      },
      refkey: `sms_${Date.now()}_${Math.random().toString(36).substring(7)}` // 고객사에서 부여한 키
    };

    const response = await fetch('https://api.bizppurio.com/v3/message', {
      method: 'POST',
      headers: {
        'Authorization': `Bearer ${accessToken}`,
        'Content-Type': 'application/json; charset=utf-8'
      },
      body: JSON.stringify(requestBody)
    });

    if (!response.ok) {
      const errorText = await response.text();
      throw new Error(`SMS send failed: ${response.status} - ${errorText}`);
    }

    const result = await response.json();
    
    if (result.code === 1000) {
      console.log(`SMS sent successfully. MessageKey: ${result.messagekey}`);
      return true;
    } else {
      throw new Error(`SMS send failed: ${result.description} (Code: ${result.code})`);
    }
  } catch (error) {
    console.error('SMS send error:', error);
    return false;
  }
}


const SMS_TEMPLATES = {
  '82': '[인증번호] {token}',           // 한국
  '1': '[Verification Code] {token}',   // 미국
  '81': '[認証コード] {token}',         // 일본
  '86': '[验证码] {token}',             // 중국
  'default': '[Verification Code] {token}' // 기본값 (영어)
} as const;

function getSmsMessage(country: string, token: string): string {
  const template = SMS_TEMPLATES[country as keyof typeof SMS_TEMPLATES] || SMS_TEMPLATES.default;
  return template.replace('{token}', token);
}

// 업데이트된 메인 함수
export async function generateAndSendSmsToken(
  userId: number,
  phoneNumber: string
): Promise<{ success: boolean; error?: string }> {
  try {
    // 1. 일일 SMS 한도 체크
    const settings = await db.select().from(securitySettings).limit(1);
    const maxSmsPerDay = settings[0]?.maxSmsAttemptsPerDay || 10;
    
    const today = new Date();
    today.setHours(0, 0, 0, 0);
    const tomorrow = new Date(today);
    tomorrow.setDate(tomorrow.getDate() + 1);
    
    const todayCount = await db
      .select({ count: count() })
      .from(mfaTokens)
      .where(
        and(
          eq(mfaTokens.userId, userId),
          eq(mfaTokens.type, 'sms'),
          gte(mfaTokens.createdAt, today)
        )
      );
    
    if (todayCount[0]?.count >= maxSmsPerDay) {
      return { success: false, error: '일일 SMS 한도를 초과했습니다' };
    }
    
    // 2. 이전 SMS 토큰 비활성화
    await db
      .update(mfaTokens)
      .set({ isActive: false })
      .where(
        and(
          eq(mfaTokens.userId, userId),
          eq(mfaTokens.type, 'sms'),
          eq(mfaTokens.isActive, true)
        )
      );
    
    // 3. 새 토큰 생성
    const token = Math.random().toString().slice(2, 8).padStart(6, '0');
    const expiryMinutes = settings[0]?.smsTokenExpiryMinutes || 5;
    const expiresAt = new Date();
    expiresAt.setMinutes(expiresAt.getMinutes() + expiryMinutes);
    
    await db.insert(mfaTokens).values({
      userId,
      token,
      type: 'sms',
      phoneNumber,
      expiresAt,
      isActive: true,
    });

    let country = '';
    
    if (phoneNumber.startsWith('+82')) {
      country = '82';
    } else if (phoneNumber.startsWith('+1')) {
      country = '1';
    } else if (phoneNumber.startsWith('+81')) {
      country = '81';
    } else if (phoneNumber.startsWith('+86')) {
      country = '86';
    }
    // 국가코드가 없는 경우 한국으로 가정
    else if (!phoneNumber.startsWith('+')) {
      country = '82';
    }
    
    // 4. SMS 전송 (Bizppurio API 사용)
    const message = getSmsMessage(country, token);
    const smsResult = await sendSmsMessage(phoneNumber, message);
    
    if (!smsResult) {
      // SMS 전송 실패 시 토큰 비활성화
      await db
        .update(mfaTokens)
        .set({ isActive: false })
        .where(
          and(
            eq(mfaTokens.userId, userId),
            eq(mfaTokens.token, token)
          )
        );
      
      return { success: false, error: 'SMS 전송에 실패했습니다' };
    }
    
    console.log(`SMS 토큰 ${token}을 ${phoneNumber}로 전송했습니다`);
    return { success: true };
    
  } catch (error) {
    console.error('SMS token generation error:', error);
    return { success: false, error: 'SMS 전송 중 오류가 발생했습니다' };
  }
}
// SMS 토큰 검증
export async function verifySmsToken(
  userId: number,
  token: string
): Promise<{ success: boolean; error?: string }> {
  try {
    const mfaToken = await db
      .select()
      .from(mfaTokens)
      .where(
        and(
          eq(mfaTokens.userId, userId),
          eq(mfaTokens.token, token),
          eq(mfaTokens.type, 'sms'),
          eq(mfaTokens.isActive, true)
        )
      )
      .limit(1);
    
    if (!mfaToken[0]) {
      return { success: false, error: '잘못된 인증번호입니다' };
    }
    
    // 만료 체크
    if (mfaToken[0].expiresAt < new Date()) {
      await db
        .update(mfaTokens)
        .set({ isActive: false })
        .where(eq(mfaTokens.id, mfaToken[0].id));
      
      return { success: false, error: '인증번호가 만료되었습니다' };
    }
    
    // 시도 횟수 증가
    const newAttempts = mfaToken[0].attempts + 1;
    if (newAttempts > 3) {
      await db
        .update(mfaTokens)
        .set({ isActive: false })
        .where(eq(mfaTokens.id, mfaToken[0].id));
      
      return { success: false, error: '시도 횟수를 초과했습니다' };
    }
    
    // 토큰 사용 처리
    await db
      .update(mfaTokens)
      .set({
        usedAt: new Date(),
        isActive: false,
        attempts: newAttempts,
      })
      .where(eq(mfaTokens.id, mfaToken[0].id));
    
    return { success: true };
    
  } catch (error) {
    console.error('SMS token verification error:', error);
    return { success: false, error: '인증 중 오류가 발생했습니다' };
  }
}

// 패스워드 강제 변경 필요 체크
export async function checkPasswordChangeRequired(userId: number): Promise<boolean> {
  const user = await db
    .select({ passwordChangeRequired: users.passwordChangeRequired })
    .from(users)
    .where(eq(users.id, userId))
    .limit(1);
  
  return user[0]?.passwordChangeRequired || false;
}