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

import cn.hutool.core.codec.Base64;
import cn.hutool.core.img.ImgUtil;
import cn.hutool.extra.qrcode.QrCodeUtil;
import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.tcm.training.admin.app.auth.service.AppAuthSessionService;
import com.tcm.training.admin.app.share.config.AppShareProperties;
import com.tcm.training.admin.app.share.vo.AppInviteBindTicketVO;
import com.tcm.training.admin.app.share.vo.AppInviteBindTicketValidateVO;
import com.tcm.training.admin.app.share.vo.AppInviteLandingVO;
import com.tcm.training.admin.app.share.vo.AppShareBoundUserItemVO;
import com.tcm.training.admin.app.share.vo.AppShareQrcodeVO;
import com.tcm.training.admin.live.entity.Clinic;
import com.tcm.training.admin.live.mapper.ClinicMapper;
import com.tcm.training.admin.member.entity.AppUser;
import com.tcm.training.admin.member.mapper.UserMapper;
import com.tcm.training.admin.system.entity.AppVersionConfig;
import com.tcm.training.admin.system.service.AppVersionSettingsAppService;
import com.tcm.training.admin.system.vo.AppVersionCheckVO;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;
import org.springframework.util.StringUtils;

import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import java.util.ArrayList;
import java.util.List;
import java.util.UUID;
import java.util.concurrent.TimeUnit;

/**
 * APP 邀请分享服务。
 */
@Service
public class AppShareService {

    private static final int USER_TYPE_DOCTOR = 1;
    private static final int USER_TYPE_PERSONAL = 0;
    private static final int USER_STATUS_ENABLED = 1;
    private static final int DEFAULT_VERSION_CODE = 0;
    private static final String BIND_TICKET_CACHE_PREFIX = "app:invite:bind-ticket:";
    private static final long BIND_TICKET_EXPIRE_HOURS = 24L;
    private static final DateTimeFormatter DATE_TIME_FORMATTER = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");

    private final AppAuthSessionService appAuthSessionService;
    private final UserMapper userMapper;
    private final ClinicMapper clinicMapper;
    private final AppVersionSettingsAppService appVersionSettingsAppService;
    private final AppShareProperties appShareProperties;
    private final StringRedisTemplate stringRedisTemplate;
    private final ObjectMapper objectMapper;

    /**
     * 注入邀请分享相关依赖。
     */
    public AppShareService(AppAuthSessionService appAuthSessionService,
                           UserMapper userMapper,
                           ClinicMapper clinicMapper,
                           AppVersionSettingsAppService appVersionSettingsAppService,
                           AppShareProperties appShareProperties,
                           StringRedisTemplate stringRedisTemplate,
                           ObjectMapper objectMapper) {
        this.appAuthSessionService = appAuthSessionService;
        this.userMapper = userMapper;
        this.clinicMapper = clinicMapper;
        this.appVersionSettingsAppService = appVersionSettingsAppService;
        this.appShareProperties = appShareProperties;
        this.stringRedisTemplate = stringRedisTemplate;
        this.objectMapper = objectMapper;
    }

    /**
     * 获取当前医生的分享二维码页聚合数据。
     */
    public AppShareQrcodeVO getCurrentUserShareQrcode() {
        AppUser doctorUser = requireDoctorUser(appAuthSessionService.requireLoginUserId());
        Clinic clinic = requireClinic(doctorUser.getClinicId());
        String inviteCode = requireInviteCode(clinic);
        String shareLandingUrl = buildShareLandingUrl(inviteCode);

        AppShareQrcodeVO result = new AppShareQrcodeVO();
        result.setClinicName(trimToEmpty(clinic.getName()));
        result.setInviteCode(inviteCode);
        result.setShareLandingUrl(shareLandingUrl);
        result.setQrCodeImageUrl(buildQrCodeImageUrl(inviteCode));
        result.setQrCodeDataUrl(buildQrCodeDataUrl(shareLandingUrl));
        result.setBoundUsers(listBoundUsers(doctorUser));
        return result;
    }

    /**
     * 获取公开邀请下载页数据。
     */
    public AppInviteLandingVO getInviteLanding(String inviteCode) {
        AppVersionCheckVO androidVersion = appVersionSettingsAppService.checkUpdate(AppVersionConfig.PLATFORM_ANDROID, DEFAULT_VERSION_CODE);
        AppVersionCheckVO iosVersion = appVersionSettingsAppService.checkUpdate(AppVersionConfig.PLATFORM_IOS, DEFAULT_VERSION_CODE);

        String androidDownloadUrl = trimToNull(androidVersion == null ? null : androidVersion.getDownloadUrl());
        String iosDownloadUrl = trimToNull(iosVersion == null ? null : iosVersion.getDownloadUrl());
        if (androidDownloadUrl == null && iosDownloadUrl == null) {
            throw new IllegalArgumentException("APP安装包暂未配置");
        }

        AppInviteLandingVO result = new AppInviteLandingVO();
        Clinic clinic = findClinicByInviteCode(inviteCode);
        result.setClinicName(clinic == null ? "" : trimToEmpty(clinic.getName()));
        result.setInviteCode(trimToEmpty(inviteCode));
        result.setAndroidDownloadUrl(androidDownloadUrl);
        result.setIosDownloadUrl(iosDownloadUrl);
        // 安卓与 iOS 版本配置共用同一条最新记录，这里优先回显安卓，再回退 iOS。
        result.setLatestVersionNo(resolveLatestVersionNo(androidVersion, iosVersion));
        result.setUpdateNotice(resolveUpdateNotice(androidVersion, iosVersion));
        result.setOpenAppBaseUrl(trimToEmpty(appShareProperties.getAndroidAppSchemeUrl()));
        return result;
    }

    /**
     * 为落地页生成一次性绑定票据。
     */
    public AppInviteBindTicketVO createBindTicket(String inviteCode) {
        InviteBindingTarget bindingTarget = resolveInviteBindingTarget(inviteCode);
        String bindTicket = UUID.randomUUID().toString().replace("-", "");
        LocalDateTime expireAt = LocalDateTime.now().plusHours(BIND_TICKET_EXPIRE_HOURS);
        InviteBindTicketCacheValue cacheValue = new InviteBindTicketCacheValue();
        cacheValue.setInviteCode(bindingTarget.getInviteCode());
        cacheValue.setClinicId(bindingTarget.getClinicId());
        cacheValue.setSuperiorClinicUserId(bindingTarget.getSuperiorClinicUserId());
        cacheValue.setCreatedAt(LocalDateTime.now().format(DATE_TIME_FORMATTER));
        try {
            stringRedisTemplate.opsForValue().set(
                    buildBindTicketKey(bindTicket),
                    objectMapper.writeValueAsString(cacheValue),
                    BIND_TICKET_EXPIRE_HOURS,
                    TimeUnit.HOURS
            );
        } catch (Exception ex) {
            throw new IllegalArgumentException("绑定凭证生成失败，请稍后重试");
        }
        AppInviteBindTicketVO result = new AppInviteBindTicketVO();
        result.setBindTicket(bindTicket);
        result.setInviteCode(bindingTarget.getInviteCode());
        result.setExpireAt(expireAt.format(DATE_TIME_FORMATTER));
        result.setOpenAppUrl(buildOpenAppUrl(bindTicket, bindingTarget.getInviteCode()));
        return result;
    }

    /**
     * 校验绑定票据是否仍然有效。
     */
    public AppInviteBindTicketValidateVO validateBindTicket(String bindTicket) {
        loadBindTicket(bindTicket, false);
        AppInviteBindTicketValidateVO result = new AppInviteBindTicketValidateVO();
        result.setValid(true);
        return result;
    }

    /**
     * 读取注册阶段绑定票据对应的目标关系。
     */
    public InviteBindingTarget consumeBindTicket(String bindTicket) {
        InviteBindTicketCacheValue cacheValue = loadBindTicket(bindTicket, true);
        InviteBindingTarget target = new InviteBindingTarget();
        target.setInviteCode(trimToNull(cacheValue.getInviteCode()));
        target.setClinicId(cacheValue.getClinicId());
        target.setSuperiorClinicUserId(cacheValue.getSuperiorClinicUserId());
        return target;
    }

    /**
     * 校验当前登录用户为有效医生。
     */
    private AppUser requireDoctorUser(Long userId) {
        AppUser user = userMapper.selectById(userId);
        if (user == null || user.getDeleted() == null || user.getDeleted().intValue() != 0) {
            throw new IllegalArgumentException("用户不存在");
        }
        if (user.getStatus() == null || user.getStatus().intValue() != USER_STATUS_ENABLED) {
            throw new IllegalArgumentException("用户已禁用");
        }
        if (user.getType() == null || user.getType().intValue() != USER_TYPE_DOCTOR) {
            throw new IllegalArgumentException("仅经营者可分享");
        }
        if (user.getClinicId() == null) {
            throw new IllegalArgumentException("当前账号未绑定诊所");
        }
        return user;
    }

    /**
     * 读取当前医生绑定的诊所，不存在时阻止分享。
     */
    private Clinic requireClinic(Long clinicId) {
        Clinic clinic = clinicMapper.selectById(clinicId);
        if (clinic == null || clinic.getDeleted() == null || clinic.getDeleted().intValue() != 0) {
            throw new IllegalArgumentException("当前账号未绑定有效诊所");
        }
        return clinic;
    }

    /**
     * 读取诊所邀请码，未配置时阻止分享。
     */
    private String requireInviteCode(Clinic clinic) {
        String inviteCode = trimToNull(clinic == null ? null : clinic.getInviteCode());
        if (inviteCode == null) {
            throw new IllegalArgumentException("当前诊所暂未生成邀请码");
        }
        return inviteCode;
    }

    /**
     * 根据邀请码查询诊所，未命中时返回空，供公开下载页做降级展示。
     */
    private Clinic findClinicByInviteCode(String inviteCode) {
        String normalizedInviteCode = trimToNull(inviteCode);
        if (normalizedInviteCode == null) {
            return null;
        }
        return clinicMapper.selectOne(new LambdaQueryWrapper<Clinic>()
                .eq(Clinic::getInviteCode, normalizedInviteCode)
                .eq(Clinic::getDeleted, 0)
                .last("limit 1"));
    }

    /**
     * 将邀请码解析为可绑定的诊所与经营者关系。
     */
    public InviteBindingTarget resolveInviteBindingTarget(String inviteCode) {
        String normalizedInviteCode = trimToNull(inviteCode);
        if (normalizedInviteCode == null) {
            throw new IllegalArgumentException("邀请码不能为空");
        }
        Clinic clinic = findClinicByInviteCode(normalizedInviteCode);
        if (clinic == null) {
            throw new IllegalArgumentException("邀请码无效");
        }
        AppUser clinicUser = userMapper.selectOne(new LambdaQueryWrapper<AppUser>()
                .eq(AppUser::getClinicId, clinic.getId())
                .eq(AppUser::getType, USER_TYPE_DOCTOR)
                .eq(AppUser::getDeleted, 0)
                .last("limit 1"));
        if (clinicUser == null) {
            throw new IllegalArgumentException("邀请码暂不可用，请联系诊所管理员");
        }
        InviteBindingTarget target = new InviteBindingTarget();
        target.setInviteCode(normalizedInviteCode);
        target.setClinicId(clinicUser.getClinicId());
        target.setSuperiorClinicUserId(clinicUser.getId());
        return target;
    }

    /**
     * 查询当前医生直接邀请绑定的普通用户。
     */
    private List<AppShareBoundUserItemVO> listBoundUsers(AppUser doctorUser) {
        List<AppUser> users = userMapper.selectList(new LambdaQueryWrapper<AppUser>()
                .eq(AppUser::getClinicId, doctorUser.getClinicId())
                .eq(AppUser::getSuperiorClinicUserId, doctorUser.getId())
                .eq(AppUser::getType, USER_TYPE_PERSONAL)
                .eq(AppUser::getDeleted, 0)
                .orderByDesc(AppUser::getCreatedAt)
                .orderByDesc(AppUser::getId));
        List<AppShareBoundUserItemVO> result = new ArrayList<AppShareBoundUserItemVO>();
        for (AppUser user : users) {
            result.add(toBoundUserItem(user));
        }
        return result;
    }

    /**
     * 组装邀请下载页完整地址。
     */
    private String buildShareLandingUrl(String inviteCode) {
        String landingBaseUrl = trimToNull(appShareProperties.getLandingBaseUrl());
        if (landingBaseUrl == null) {
            throw new IllegalArgumentException("邀请下载页地址暂未配置");
        }
        String queryJoiner = landingBaseUrl.contains("?") ? "&" : "?";
        return landingBaseUrl + queryJoiner + "inviteCode=" + inviteCode;
    }

    /**
     * 将邀请下载地址编码为二维码 base64 图片，便于 APP 直接展示与保存。
     */
    private String buildQrCodeDataUrl(String shareLandingUrl) {
        try {
            BufferedImage image = QrCodeUtil.generate(shareLandingUrl, 400, 400);
            ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
            ImgUtil.write(image, "png", outputStream);
            return "data:image/png;base64," + Base64.encode(outputStream.toByteArray());
        } catch (Exception ex) {
            throw new IllegalArgumentException("生成分享二维码失败");
        }
    }

    /**
     * 构建二维码图片公开访问地址。
     */
    private String buildQrCodeImageUrl(String inviteCode) {
        String qrcodeImageBaseUrl = trimToNull(appShareProperties.getQrcodeImageBaseUrl());
        if (qrcodeImageBaseUrl == null) {
            throw new IllegalArgumentException("分享二维码图片地址暂未配置");
        }
        String normalizedInviteCode = trimToNull(inviteCode);
        if (!StringUtils.hasText(normalizedInviteCode)) {
            throw new IllegalArgumentException("邀请码不能为空");
        }
        String queryJoiner = qrcodeImageBaseUrl.contains("?") ? "&" : "?";
        return qrcodeImageBaseUrl + queryJoiner + "inviteCode=" + normalizedInviteCode;
    }

    /**
     * 生成二维码 PNG 图片字节流。
     */
    public byte[] generateQrcodeImage(String inviteCode) {
        Clinic clinic = findClinicByInviteCode(inviteCode);
        if (clinic == null) {
            throw new IllegalArgumentException("邀请码无效");
        }
        String shareLandingUrl = buildShareLandingUrl(requireInviteCode(clinic));
        try {
            BufferedImage image = QrCodeUtil.generate(shareLandingUrl, 400, 400);
            ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
            ImgUtil.write(image, "png", outputStream);
            return outputStream.toByteArray();
        } catch (Exception ex) {
            throw new IllegalArgumentException("生成分享二维码失败");
        }
    }

    /**
     * 构建绑定用户展示项。
     */
    private AppShareBoundUserItemVO toBoundUserItem(AppUser user) {
        AppShareBoundUserItemVO item = new AppShareBoundUserItemVO();
        item.setId(user.getId());
        item.setNickname(resolveBoundUserPhone(user));
        item.setAvatar(resolveAvatar(user));
        item.setRegisteredAt(resolveRegisteredAt(user));
        return item;
    }

    /**
     * 解析下载页需要展示的最新版本号。
     */
    private String resolveLatestVersionNo(AppVersionCheckVO androidVersion, AppVersionCheckVO iosVersion) {
        String androidVersionNo = trimToNull(androidVersion == null ? null : androidVersion.getLatestVersionNo());
        if (androidVersionNo != null) {
            return androidVersionNo;
        }
        return trimToEmpty(iosVersion == null ? null : iosVersion.getLatestVersionNo());
    }

    /**
     * 解析下载页需要展示的更新说明。
     */
    private String resolveUpdateNotice(AppVersionCheckVO androidVersion, AppVersionCheckVO iosVersion) {
        String androidUpdateNotice = trimToNull(androidVersion == null ? null : androidVersion.getUpdateNotice());
        if (androidUpdateNotice != null) {
            return androidUpdateNotice;
        }
        return trimToEmpty(iosVersion == null ? null : iosVersion.getUpdateNotice());
    }

    /**
     * 构造安卓 App 打开注册页的深链地址。
     */
    private String buildOpenAppUrl(String bindTicket, String inviteCode) {
        String schemeUrl = trimToNull(appShareProperties.getAndroidAppSchemeUrl());
        if (schemeUrl == null) {
            throw new IllegalArgumentException("App 打开地址暂未配置");
        }
        String queryJoiner = schemeUrl.contains("?") ? "&" : "?";
        return schemeUrl + queryJoiner + "bindTicket=" + bindTicket + "&inviteCode=" + inviteCode;
    }

    /**
     * 绑定用户列表按业务要求直接在昵称字段展示完整手机号。
     */
    private String resolveBoundUserPhone(AppUser user) {
        return trimToEmpty(user == null ? null : user.getPhone());
    }

    /**
     * 优先使用头像，没有时回退微信头像。
     */
    private String resolveAvatar(AppUser user) {
        String avatar = trimToNull(user == null ? null : user.getAvatar());
        if (avatar != null) {
            return avatar;
        }
        return trimToEmpty(user == null ? null : user.getWechatAvatar());
    }

    /**
     * 读取用户注册时间，缺失时回退当前时间避免前端空白。
     */
    private LocalDateTime resolveRegisteredAt(AppUser user) {
        return user == null || user.getCreatedAt() == null ? LocalDateTime.now() : user.getCreatedAt();
    }

    /**
     * 按需读取并消费绑定票据。
     */
    private InviteBindTicketCacheValue loadBindTicket(String bindTicket, boolean consume) {
        String normalizedBindTicket = trimToNull(bindTicket);
        if (normalizedBindTicket == null) {
            throw new IllegalArgumentException("绑定凭证已失效，请重新扫码");
        }
        String cacheValue = stringRedisTemplate.opsForValue().get(buildBindTicketKey(normalizedBindTicket));
        if (cacheValue == null || cacheValue.trim().isEmpty()) {
            throw new IllegalArgumentException("绑定凭证已失效，请重新扫码");
        }
        try {
            InviteBindTicketCacheValue parsedValue = objectMapper.readValue(cacheValue, InviteBindTicketCacheValue.class);
            if (consume) {
                stringRedisTemplate.delete(buildBindTicketKey(normalizedBindTicket));
            }
            return parsedValue;
        } catch (Exception ex) {
            throw new IllegalArgumentException("绑定凭证已失效，请重新扫码");
        }
    }

    /**
     * 构造绑定票据缓存 key。
     */
    private String buildBindTicketKey(String bindTicket) {
        return BIND_TICKET_CACHE_PREFIX + bindTicket;
    }

    /**
     * 将可空文本归一化为空字符串。
     */
    private String trimToEmpty(String value) {
        if (value == null) {
            return "";
        }
        return value.trim();
    }

    /**
     * 将可空文本归一化为空值。
     */
    private String trimToNull(String value) {
        if (value == null) {
            return null;
        }
        String trimmed = value.trim();
        return trimmed.isEmpty() ? null : trimmed;
    }

    /**
     * 邀请绑定目标关系。
     */
    @lombok.Getter
    @lombok.Setter
    @lombok.NoArgsConstructor
    public static class InviteBindingTarget {

        private String inviteCode;

        private Long clinicId;

        private Long superiorClinicUserId;
    }

    /**
     * 绑定票据缓存结构。
     */
    @lombok.Getter
    @lombok.Setter
    @lombok.NoArgsConstructor
    public static class InviteBindTicketCacheValue {

        private String inviteCode;

        private Long clinicId;

        private Long superiorClinicUserId;

        private String createdAt;
    }
}