package com.tcm.training.admin.app.auth.service;

import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.tcm.training.admin.app.auth.dto.AppPasswordLoginRequest;
import com.tcm.training.admin.app.auth.dto.AppPasswordResetRequest;
import com.tcm.training.admin.app.auth.dto.AppPasswordResetVerifyRequest;
import com.tcm.training.admin.app.auth.dto.AppAppleLoginRequest;
import com.tcm.training.admin.app.auth.dto.AppSmsCodeSendRequest;
import com.tcm.training.admin.app.auth.dto.AppSmsLoginRequest;
import com.tcm.training.admin.app.auth.dto.AppWechatLoginRequest;
import com.tcm.training.admin.app.auth.vo.AppLoginResponse;
import com.tcm.training.admin.app.auth.vo.AppLoginUserVO;
import com.tcm.training.admin.app.auth.vo.AppPasswordResetVerifyResponse;
import com.tcm.training.admin.app.auth.vo.AppSmsCodeSendResponse;
import com.tcm.training.admin.app.auth.exception.InviteCodeRequiredException;
import com.tcm.training.admin.app.share.service.AppShareService;
import com.tcm.training.admin.member.entity.AppUser;
import com.tcm.training.admin.member.mapper.UserMapper;
import cn.dev33.satoken.stp.SaTokenInfo;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;
import org.springframework.stereotype.Service;

import java.time.LocalDateTime;
import java.util.UUID;
import java.util.concurrent.TimeUnit;
import java.util.regex.Pattern;

/**
 * APP 登录认证服务，负责短信登录、密码登录、微信登录与忘记密码流程。
 */
@Service
public class AppAuthService {

    private static final Pattern PHONE_PATTERN = Pattern.compile("^1\\d{10}$");
    private static final Pattern PASSWORD_PATTERN = Pattern.compile("^(?![0-9]+$)(?![a-zA-Z]+$)(?![^0-9a-zA-Z]+$).{8,32}$");
    private static final String PASSWORD_RESET_TICKET_CACHE_PREFIX = "app:password-reset:ticket:";
    private static final long PASSWORD_RESET_TICKET_EXPIRE_MINUTES = 10L;

    private final UserMapper userMapper;
    private final AppSmsCodeService appSmsCodeService;
    private final BCryptPasswordEncoder passwordEncoder;
    private final AppAuthSessionService appAuthSessionService;
    private final AppWechatAuthClient appWechatAuthClient;
    private final AppAppleAuthClient appAppleAuthClient;
    private final AppShareService appShareService;
    private final StringRedisTemplate stringRedisTemplate;

    /**
     * 注入 APP 用户查询能力与短信验证码服务。
     */
    public AppAuthService(UserMapper userMapper,
                          AppSmsCodeService appSmsCodeService,
                          BCryptPasswordEncoder passwordEncoder,
                          AppAuthSessionService appAuthSessionService,
                          AppWechatAuthClient appWechatAuthClient,
                          AppAppleAuthClient appAppleAuthClient,
                          AppShareService appShareService,
                          StringRedisTemplate stringRedisTemplate) {
        this.userMapper = userMapper;
        this.appSmsCodeService = appSmsCodeService;
        this.passwordEncoder = passwordEncoder;
        this.appAuthSessionService = appAuthSessionService;
        this.appWechatAuthClient = appWechatAuthClient;
        this.appAppleAuthClient = appAppleAuthClient;
        this.appShareService = appShareService;
        this.stringRedisTemplate = stringRedisTemplate;
    }

    /**
     * 为已注册 APP 用户生成登录验证码。
     */
    public AppSmsCodeSendResponse sendLoginCode(AppSmsCodeSendRequest request) {
        String phone = normalizePhone(request.getPhone());
        requireEnabledUserByPhone(phone);
        return appSmsCodeService.createLoginCode(phone);
    }

    /**
     * 为已注册 APP 用户生成忘记密码验证码。
     */
    public AppSmsCodeSendResponse sendPasswordResetCode(AppSmsCodeSendRequest request) {
        String phone = normalizePhone(request.getPhone());
        requireEnabledUserByPhone(phone);
        return appSmsCodeService.createPasswordResetCode(phone);
    }

    /**
     * 使用短信验证码完成 APP 用户登录。
     */
    public AppLoginResponse smsLogin(AppSmsLoginRequest request) {
        String phone = normalizePhone(request.getPhone());
        AppUser user = requireEnabledUserByPhone(phone);
        appSmsCodeService.validateLoginCode(phone, normalizeCode(request.getCode()));
        return createLoginResponse(user);
    }

    /**
     * 使用手机号密码完成 APP 用户登录。
     */
    public AppLoginResponse passwordLogin(AppPasswordLoginRequest request) {
        String phone = normalizePhone(request.getPhone());
        String password = normalizeLoginPassword(request.getPassword());
        AppUser user = requireEnabledUserByPhone(phone);
        if (!passwordEncoder.matches(password, user.getPassword())) {
            throw new IllegalArgumentException("账号或密码错误");
        }
        return createLoginResponse(user);
    }

    /**
     * 使用微信授权结果完成 APP 登录，首次登录自动创建普通用户。
     */
    public AppLoginResponse wechatLogin(AppWechatLoginRequest request) {
        AppWechatUserProfile profile = appWechatAuthClient.resolveUserProfile(request);
        AppUser user = findUserByWechatOpenid(profile.getOpenid());
        if (user == null) {
            requireInviteCodeForThirdPartyRegister(request.getInviteCode());
            user = buildWechatUser(profile);
            bindInviteRelationIfAbsent(user, request.getInviteCode());
            userMapper.insert(user);
            return createLoginResponse(user);
        }

        requireEnabledUser(user);
        // 登录时同步微信专用资料，并仅在本地昵称头像为空时补齐展示字段。
        applyWechatProfile(user, profile, false);
        userMapper.updateById(user);
        return createLoginResponse(user);
    }

    /**
     * 使用苹果授权结果完成 APP 登录，首次登录自动创建普通用户。
     */
    public AppLoginResponse appleLogin(AppAppleLoginRequest request) {
        AppAppleUserProfile profile = appAppleAuthClient.resolveUserProfile(request);
        AppUser user = findUserByAppleSubject(profile.getSubject());
        if (user == null) {
            requireInviteCodeForThirdPartyRegister(request.getInviteCode());
            user = buildAppleUser(profile);
            bindInviteRelationIfAbsent(user, request.getInviteCode());
            userMapper.insert(user);
            return createLoginResponse(user);
        }

        requireEnabledUser(user);
        // 登录时同步苹果绑定标识，避免历史账号缺少最新 subject 或绑定时间。
        applyAppleProfile(user, profile, false);
        userMapper.updateById(user);
        return createLoginResponse(user);
    }

    /**
     * 校验忘记密码验证码并生成一次性重置凭证。
     */
    public AppPasswordResetVerifyResponse verifyPasswordResetCode(AppPasswordResetVerifyRequest request) {
        String phone = normalizePhone(request.getPhone());
        requireEnabledUserByPhone(phone);
        appSmsCodeService.validatePasswordResetCode(phone, normalizeCode(request.getCode()));

        String resetTicket = createResetTicket();
        cacheResetTicket(resetTicket, phone);
        return new AppPasswordResetVerifyResponse(resetTicket);
    }

    /**
     * 使用一次性重置凭证更新 APP 用户密码。
     */
    public void resetPassword(AppPasswordResetRequest request) {
        String resetTicket = normalizeResetTicket(request.getResetTicket());
        String password = normalizeNewPassword(request.getPassword());
        String confirmPassword = normalizeConfirmPassword(request.getConfirmPassword());
        validatePasswordConfirmation(password, confirmPassword);

        String phone = loadPhoneByResetTicket(resetTicket);
        AppUser user = requireEnabledUserByPhone(phone);
        user.setPassword(passwordEncoder.encode(password));
        userMapper.updateById(user);
        stringRedisTemplate.delete(buildResetTicketKey(resetTicket));
    }

    /**
     * 注销当前 APP 登录态。
     */
    public void logout() {
        appAuthSessionService.logout();
    }

    /**
     * 为成功登录的 APP 用户建立登录态并拼装统一响应。
     */
    private AppLoginResponse createLoginResponse(AppUser user) {
        appAuthSessionService.login(user.getId());
        SaTokenInfo tokenInfo = appAuthSessionService.getTokenInfo();
        return new AppLoginResponse(
                tokenInfo.getTokenValue(),
                "Bearer",
                tokenInfo.getTokenTimeout(),
                buildLoginUser(user)
        );
    }

    /**
     * 将 APP 用户实体转换为登录响应中的用户摘要。
     */
    private AppLoginUserVO buildLoginUser(AppUser user) {
        AppLoginUserVO loginUser = new AppLoginUserVO();
        loginUser.setId(user.getId());
        loginUser.setNickname(resolveNickname(user));
        loginUser.setPhone(user.getPhone());
        loginUser.setAvatar(resolveAvatar(user));
        loginUser.setType(user.getType());
        loginUser.setStatus(user.getStatus());
        loginUser.setClinicId(user.getClinicId());
        loginUser.setMemberExpireAt(user.getMemberExpireAt());
        return loginUser;
    }

    /**
     * 按手机号查询 APP 用户，不存在时抛出统一业务异常。
     */
    private AppUser requireExistingUserByPhone(String phone) {
        AppUser user = userMapper.selectOne(new LambdaQueryWrapper<AppUser>()
                .eq(AppUser::getPhone, phone)
                .eq(AppUser::getDeleted, 0)
                .last("limit 1"));
        if (user == null) {
            throw new IllegalArgumentException("账号不存在，请先注册");
        }
        return user;
    }

    /**
     * 按手机号查询并校验 APP 用户状态。
     */
    private AppUser requireEnabledUserByPhone(String phone) {
        AppUser user = requireExistingUserByPhone(phone);
        requireEnabledUser(user);
        return user;
    }

    /**
     * 校验给定 APP 用户是否处于启用状态。
     */
    private void requireEnabledUser(AppUser user) {
        if (user.getStatus() == null || user.getStatus() != 1) {
            throw new IllegalArgumentException("账号已被禁用");
        }
    }

    /**
     * 按微信 openid 查询本地 APP 用户，重复脏数据场景优先返回启用且已绑定手机号的账号。
     */
    private AppUser findUserByWechatOpenid(String openid) {
        return userMapper.selectOne(new LambdaQueryWrapper<AppUser>()
                .eq(AppUser::getWechatOpenid, openid)
                .eq(AppUser::getDeleted, 0)
                .last("ORDER BY CASE WHEN status = 1 THEN 0 ELSE 1 END, "
                        + "CASE WHEN phone IS NOT NULL AND TRIM(phone) <> '' THEN 0 ELSE 1 END, "
                        + "updated_at DESC, id DESC LIMIT 1"));
    }

    /**
     * 按苹果 subject 查询本地 APP 用户，重复脏数据场景优先返回启用且已绑定手机号的账号。
     */
    private AppUser findUserByAppleSubject(String subject) {
        return userMapper.selectOne(new LambdaQueryWrapper<AppUser>()
                .eq(AppUser::getAppleIdentitySubject, subject)
                .eq(AppUser::getDeleted, 0)
                .last("ORDER BY CASE WHEN status = 1 THEN 0 ELSE 1 END, "
                        + "CASE WHEN phone IS NOT NULL AND TRIM(phone) <> '' THEN 0 ELSE 1 END, "
                        + "updated_at DESC, id DESC LIMIT 1"));
    }

    /**
     * 基于微信资料构造首次登录时的本地普通用户。
     */
    private AppUser buildWechatUser(AppWechatUserProfile profile) {
        AppUser user = new AppUser();
        user.setType(0);
        user.setStatus(1);
        applyWechatProfile(user, profile, true);
        return user;
    }

    /**
     * 第三方授权首次创建账号时必须携带医生邀请码。
     */
    private void requireInviteCodeForThirdPartyRegister(String inviteCode) {
        if (normalizeInviteCode(inviteCode) == null) {
            throw new InviteCodeRequiredException();
        }
    }

    /**
     * 用户尚未绑定诊所关系时，根据医生邀请码补齐上下级关系。
     */
    private void bindInviteRelationIfAbsent(AppUser user, String inviteCode) {
        if (user.getClinicId() != null || user.getSuperiorClinicUserId() != null) {
            return;
        }
        String normalizedInviteCode = normalizeInviteCode(inviteCode);
        if (normalizedInviteCode == null) {
            return;
        }
        AppShareService.InviteBindingTarget bindingTarget = appShareService.resolveInviteBindingTarget(normalizedInviteCode);
        user.setClinicId(bindingTarget.getClinicId());
        user.setSuperiorClinicUserId(bindingTarget.getSuperiorClinicUserId());
    }

    /**
     * 基于苹果资料构造首次登录时的本地普通用户。
     */
    private AppUser buildAppleUser(AppAppleUserProfile profile) {
        AppUser user = new AppUser();
        user.setType(0);
        user.setStatus(1);
        applyAppleProfile(user, profile, true);
        return user;
    }

    /**
     * 将微信资料回填到本地用户，必要时补齐昵称头像展示字段。
     */
    private void applyWechatProfile(AppUser user, AppWechatUserProfile profile, boolean syncLocalProfile) {
        String nickname = trimToNull(profile.getNickname());
        String avatar = trimToNull(profile.getAvatar());

        user.setWechatOpenid(profile.getOpenid());
        user.setWechatNickname(nickname);
        user.setWechatAvatar(avatar);
        user.setWechatBoundAt(LocalDateTime.now());

        if (syncLocalProfile || trimToNull(user.getNickname()) == null) {
            user.setNickname(nickname == null ? profile.getOpenid() : nickname);
        }
        if (syncLocalProfile || trimToNull(user.getAvatar()) == null) {
            user.setAvatar(avatar);
        }
        if (syncLocalProfile || user.getGender() == null) {
            user.setGender(resolveWechatGender(profile.getSex()));
        }
    }

    /**
     * 将苹果资料回填到本地用户，并在首次自动建号时补齐基础展示昵称。
     */
    private void applyAppleProfile(AppUser user, AppAppleUserProfile profile, boolean syncLocalProfile) {
        user.setAppleUserIdentifier(trimToNull(profile.getUserIdentifier()));
        user.setAppleIdentitySubject(trimToNull(profile.getSubject()));
        user.setAppleBoundAt(LocalDateTime.now());

        if (syncLocalProfile || trimToNull(user.getNickname()) == null) {
            user.setNickname("苹果用户");
        }
    }

    /**
     * 将微信性别值转换为本地用户性别枚举。
     */
    private Integer resolveWechatGender(Integer sex) {
        if (sex == null) {
            return null;
        }
        if (sex == 1) {
            return 1;
        }
        if (sex == 2) {
            return 0;
        }
        return null;
    }

    /**
     * 归一化并校验手机号格式。
     */
    private String normalizePhone(String phone) {
        String normalized = trimToNull(phone);
        if (normalized == null || !PHONE_PATTERN.matcher(normalized).matches()) {
            throw new IllegalArgumentException("请输入正确的手机号");
        }
        return normalized;
    }

    /**
     * 归一化并校验验证码。
     */
    private String normalizeCode(String code) {
        String normalized = trimToNull(code);
        if (normalized == null) {
            throw new IllegalArgumentException("请输入验证码");
        }
        return normalized;
    }

    /**
     * 归一化密码登录场景下的密码输入，仅要求非空。
     */
    private String normalizeLoginPassword(String password) {
        String normalized = trimToNull(password);
        if (normalized == null) {
            throw new IllegalArgumentException("请输入密码");
        }
        return normalized;
    }

    /**
     * 归一化医生邀请码，非法时忽略以保持第三方登录主流程可用。
     */
    private String normalizeInviteCode(String inviteCode) {
        String normalized = trimToNull(inviteCode);
        if (normalized == null) {
            return null;
        }
        String upperInviteCode = normalized.toUpperCase();
        return upperInviteCode.matches("^[A-Z0-9]{6}$") ? upperInviteCode : null;
    }

    /**
     * 归一化并校验忘记密码场景下的新密码格式。
     */
    private String normalizeNewPassword(String password) {
        String normalized = trimToNull(password);
        if (normalized == null) {
            throw new IllegalArgumentException("请输入新密码");
        }
        if (!PASSWORD_PATTERN.matcher(normalized).matches()) {
            throw new IllegalArgumentException("密码需为8-32位，且包含数字、字母、符号至少2种");
        }
        return normalized;
    }

    /**
     * 归一化并校验确认密码输入。
     */
    private String normalizeConfirmPassword(String confirmPassword) {
        String normalized = trimToNull(confirmPassword);
        if (normalized == null) {
            throw new IllegalArgumentException("请再次输入密码");
        }
        if (!PASSWORD_PATTERN.matcher(normalized).matches()) {
            throw new IllegalArgumentException("密码需为8-32位，且包含数字、字母、符号至少2种");
        }
        return normalized;
    }

    /**
     * 归一化并校验一次性重置凭证。
     */
    private String normalizeResetTicket(String resetTicket) {
        String normalized = trimToNull(resetTicket);
        if (normalized == null) {
            throw new IllegalArgumentException("重置凭证已失效，请重新验证");
        }
        return normalized;
    }

    /**
     * 校验两次输入的新密码保持一致。
     */
    private void validatePasswordConfirmation(String password, String confirmPassword) {
        if (!password.equals(confirmPassword)) {
            throw new IllegalArgumentException("两次密码输入不一致");
        }
    }

    /**
     * 生成忘记密码场景使用的一次性重置凭证。
     */
    private String createResetTicket() {
        return UUID.randomUUID().toString().replace("-", "");
    }

    /**
     * 将重置凭证与手机号绑定写入 Redis，供下一步更新密码使用。
     */
    private void cacheResetTicket(String resetTicket, String phone) {
        stringRedisTemplate.opsForValue().set(
                buildResetTicketKey(resetTicket),
                phone,
                PASSWORD_RESET_TICKET_EXPIRE_MINUTES,
                TimeUnit.MINUTES
        );
    }

    /**
     * 从 Redis 读取并校验一次性重置凭证对应的手机号。
     */
    private String loadPhoneByResetTicket(String resetTicket) {
        String phone = stringRedisTemplate.opsForValue().get(buildResetTicketKey(resetTicket));
        if (phone == null || phone.trim().isEmpty()) {
            throw new IllegalArgumentException("重置凭证已失效，请重新验证");
        }
        return phone;
    }

    /**
     * 构造忘记密码重置凭证的 Redis key。
     */
    private String buildResetTicketKey(String resetTicket) {
        return PASSWORD_RESET_TICKET_CACHE_PREFIX + resetTicket;
    }

    /**
     * 优先使用昵称，缺失时回退到手机号作为展示名称。
     */
    private String resolveNickname(AppUser user) {
        String nickname = trimToNull(user.getNickname());
        if (nickname != null) {
            return nickname;
        }
        String wechatNickname = trimToNull(user.getWechatNickname());
        if (wechatNickname != null) {
            return wechatNickname;
        }
        return user.getPhone();
    }

    /**
     * 优先使用本地头像，缺失时回退到微信头像。
     */
    private String resolveAvatar(AppUser user) {
        String avatar = trimToNull(user.getAvatar());
        if (avatar != null) {
            return avatar;
        }
        return trimToNull(user.getWechatAvatar());
    }

    /**
     * 将空白字符串归一化为 null。
     */
    private String trimToNull(String value) {
        if (value == null) {
            return null;
        }
        String trimmed = value.trim();
        return trimmed.isEmpty() ? null : trimmed;
    }
}