package com.xuqm.tenant.service;

import com.xuqm.common.exception.BusinessException;
import com.xuqm.tenant.dto.CreateAppRequest;
import com.xuqm.tenant.entity.AppEntity;
import com.xuqm.tenant.repository.AppRepository;
import org.springframework.stereotype.Service;

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

@Service
public class AppService {

    private final AppRepository appRepository;
    private static final SecureRandom random = new SecureRandom();

    public AppService(AppRepository appRepository) {
        this.appRepository = appRepository;
    }

    public List<AppEntity> listByTenant(String tenantId) {
        return appRepository.findByTenantId(tenantId);
    }

    public AppEntity getById(String id, String tenantId) {
        AppEntity app = appRepository.findById(id)
                .orElseThrow(() -> new BusinessException(404, "应用不存在"));
        if (!app.getTenantId().equals(tenantId)) {
            throw new BusinessException(403, "无权访问该应用");
        }
        return app;
    }

    public AppEntity create(String tenantId, CreateAppRequest req) {
        if (appRepository.existsByPackageNameAndTenantId(req.packageName(), tenantId)) {
            throw new BusinessException("该包名下已存在同名应用");
        }
        AppEntity app = new AppEntity();
        app.setId(UUID.randomUUID().toString());
        app.setTenantId(tenantId);
        app.setPackageName(req.packageName());
        app.setName(req.name());
        app.setDescription(req.description());
        app.setIconUrl(req.iconUrl());
        app.setAppKey(generateAppKey());
        app.setAppSecret(generateSecret());
        app.setCreatedAt(LocalDateTime.now());
        return appRepository.save(app);
    }

    public AppEntity update(String id, String tenantId, CreateAppRequest req) {
        AppEntity app = getById(id, tenantId);
        app.setName(req.name());
        app.setDescription(req.description());
        app.setIconUrl(req.iconUrl());
        return appRepository.save(app);
    }

    public void delete(String id, String tenantId) {
        AppEntity app = getById(id, tenantId);
        appRepository.delete(app);
    }

    private String generateAppKey() {
        return "ak_" + UUID.randomUUID().toString().replace("-", "").substring(0, 24);
    }

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