package com.xuqm.tenant.service;

import com.xuqm.common.exception.BusinessException;
import com.xuqm.tenant.entity.AppEntity;
import com.xuqm.tenant.entity.FeatureServiceEntity;
import com.xuqm.tenant.entity.TenantEntity;
import com.xuqm.tenant.repository.AppRepository;
import com.xuqm.tenant.repository.FeatureServiceRepository;
import com.xuqm.tenant.repository.TenantRepository;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.security.crypto.password.PasswordEncoder;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.security.SecureRandom;
import java.time.LocalDateTime;
import java.util.Base64;
import java.util.List;
import java.util.UUID;

@Service
public class SdkAppProvisioningService {

    private static final SecureRandom RANDOM = new SecureRandom();

    private final AppRepository appRepository;
    private final TenantRepository tenantRepository;
    private final FeatureServiceRepository featureServiceRepository;
    private final PasswordEncoder passwordEncoder;

    @Value("${sdk.bootstrap-app-key:ak_demo_chat}")
    private String bootstrapAppKey;

    @Value("${sdk.bootstrap-app-name:Demo Chat}")
    private String bootstrapAppName;

    @Value("${sdk.bootstrap-app-package:com.xuqm.demo}")
    private String bootstrapAppPackage;

    @Value("${sdk.bootstrap-app-description:XuqmGroup demo app}")
    private String bootstrapAppDescription;

    public SdkAppProvisioningService(AppRepository appRepository,
                                     TenantRepository tenantRepository,
                                     FeatureServiceRepository featureServiceRepository,
                                     PasswordEncoder passwordEncoder) {
        this.appRepository = appRepository;
        this.tenantRepository = tenantRepository;
        this.featureServiceRepository = featureServiceRepository;
        this.passwordEncoder = passwordEncoder;
    }

    @Transactional
    public AppEntity ensureBootstrapApp() {
        return ensureApp(bootstrapAppKey, true);
    }

    @Transactional
    public AppEntity resolveApp(String appId) {
        return appRepository.findByAppKey(appId)
                .or(() -> appRepository.findById(appId))
                .orElseGet(() -> {
                    if (!bootstrapAppKey.equals(appId)) {
                        throw new BusinessException(404, "App not found: " + appId);
                    }
                    return ensureApp(appId, true);
                });
    }

    @Transactional
    public AppEntity ensureApp(String appKey, boolean bootstrapDefaults) {
        AppEntity existing = appRepository.findByAppKey(appKey).orElse(null);
        if (existing != null) {
            if (bootstrapDefaults) {
                ensureFeatureDefaults(existing);
            }
            return existing;
        }

        TenantEntity owner = resolveOwnerTenant();
        AppEntity app = new AppEntity();
        app.setId(UUID.randomUUID().toString());
        app.setTenantId(owner.getId());
        app.setPackageName(bootstrapAppPackage);
        app.setName(bootstrapAppName);
        app.setDescription(bootstrapAppDescription);
        app.setIconUrl(null);
        app.setAppKey(appKey);
        app.setAppSecret(generateSecret());
        app.setCreatedAt(LocalDateTime.now());
        app = appRepository.save(app);

        if (bootstrapDefaults) {
            ensureFeatureDefaults(app);
        }
        return app;
    }

    private TenantEntity resolveOwnerTenant() {
        return tenantRepository.findFirstByOrderByCreatedAtAsc()
                .orElseGet(this::createBootstrapTenant);
    }

    private TenantEntity createBootstrapTenant() {
        TenantEntity tenant = new TenantEntity();
        tenant.setId(UUID.randomUUID().toString());
        tenant.setUsername("system");
        tenant.setPassword(passwordEncoder.encode(generateSecret()));
        tenant.setEmail("system@xuqinmin.com");
        tenant.setNickname("System");
        tenant.setPhone(null);
        tenant.setType(TenantEntity.Type.MAIN);
        tenant.setStatus(TenantEntity.Status.ACTIVE);
        tenant.setParentId(null);
        tenant.setCreatedAt(LocalDateTime.now());
        return tenantRepository.save(tenant);
    }

    private void ensureFeatureDefaults(AppEntity app) {
        featureServiceRepository.findByAppIdAndServiceType(app.getAppKey(), FeatureServiceEntity.ServiceType.IM)
                .stream()
                .findFirst()
                .orElseGet(() -> {
                    FeatureServiceEntity feature = new FeatureServiceEntity();
                    feature.setId(UUID.randomUUID().toString());
                    feature.setAppId(app.getAppKey());
                    feature.setPlatform(FeatureServiceEntity.Platform.ANDROID);
                    feature.setServiceType(FeatureServiceEntity.ServiceType.IM);
                    feature.setEnabled(true);
                    feature.setConfig("""
                            {"allowStrangerMessage":false,"allowFriendRequest":true,"friendRequestMode":"REQUIRE_CONFIRM","allowGroupJoinRequest":true,"blacklistSendSuccess":true,"messageRecallMinutes":2,"historyRetentionDays":7,"conversationPullLimit":100,"multiClientConversationDeleteSync":false}
                            """.trim());
                    feature.setCreatedAt(LocalDateTime.now());
                    return featureServiceRepository.save(feature);
                });

        for (FeatureServiceEntity.Platform platform : List.of(
                FeatureServiceEntity.Platform.ANDROID,
                FeatureServiceEntity.Platform.IOS,
                FeatureServiceEntity.Platform.HARMONY)) {
            for (FeatureServiceEntity.ServiceType serviceType : List.of(
                    FeatureServiceEntity.ServiceType.PUSH,
                    FeatureServiceEntity.ServiceType.UPDATE)) {
                featureServiceRepository.findByAppIdAndPlatformAndServiceType(app.getAppKey(), platform, serviceType)
                        .orElseGet(() -> {
                            FeatureServiceEntity feature = new FeatureServiceEntity();
                            feature.setId(UUID.randomUUID().toString());
                            feature.setAppId(app.getAppKey());
                            feature.setPlatform(platform);
                            feature.setServiceType(serviceType);
                            feature.setEnabled(true);
                            feature.setConfig(null);
                            feature.setCreatedAt(LocalDateTime.now());
                            return featureServiceRepository.save(feature);
                        });
            }
        }
    }

    private String generateSecret() {
        byte[] bytes = new byte[32];
        RANDOM.nextBytes(bytes);
        return Base64.getUrlEncoder().withoutPadding().encodeToString(bytes);
    }
}