package com.yunhai.flowcenter.service;

import com.fasterxml.jackson.databind.JsonNode;
import com.yunhai.flowcenter.entity.FlwUsageGrant;
import com.yunhai.flowcenter.repository.FlwUsageGrantRepository;
import com.yunhai.platform.apistd.BizException;
import com.yunhai.platform.openapi.base.OpenApiAppClient;
import com.yunhai.platform.utils.exception.ErrorCode;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.util.List;

/**
 * 应用使用授权管理面（2026-10-25 T01）：学校×流程线×稳定主体的授予/撤销/查询。
 *
 * <p>授予时把 appKey 解析成 UserBase 稳定主键 appId 落库（授权对象是主体不是凭据），
 * 并按学校开通事实做发放闸（enforce 开启时未开通拒发）。撤销只置 {@code enabled=0}
 * （不删行，审计与幂等判据保留）；撤权只拦新发起，不回写在途实例与已受理命令。</p>
 */
@Slf4j
@Service
@RequiredArgsConstructor
public class FlowUsageGrantAdminService {

    private final FlwUsageGrantRepository grantRepository;
    private final UserBaseActivationClient activationClient;

    @Autowired(required = false)
    private OpenApiAppClient appClient;

    @org.springframework.beans.factory.annotation.Value("${flow-center.formal-command.enabled:false}")
    private boolean formalEnabled;

    public List<FlwUsageGrant> listByFlow(Long schId, String flowGuid) {
        return grantRepository.findBySchIdAndFlowGuidOrderByUpdateTimeDescIdDesc(schId, flowGuid);
    }

    public List<FlwUsageGrant> listByApp(Long schId, Integer appId) {
        return grantRepository.findBySchIdAndAppIdOrderByUpdateTimeDescIdDesc(schId, appId);
    }

    /**
     * 授予/重申（三元键 upsert）。
     *
     * @throws BizException appKey 不可解析为稳定主体（fail-closed，管理面必须授到真实主体上）；
     *                      enforce 开启且应用未在该校开通或核验不可用
     */
    @Transactional
    public FlwUsageGrant grant(Long schId, String flowGuid, String appKey, String remark, String operator) {
        if (schId == null || schId <= 0 || flowGuid == null || flowGuid.trim().isEmpty()
                || appKey == null || appKey.trim().isEmpty()) {
            throw new BizException(ErrorCode.PARAM_ERROR, "schId/flowGuid/appKey 必填");
        }
        String cleanKey = appKey.trim();
        JsonNode registered = fetchRegistered(cleanKey);
        Integer appId = registered == null ? null : readId(registered);
        if (appId == null) {
            throw new BizException(ErrorCode.PARAM_ERROR,
                    "appKey 未能在 UserBase 解析出稳定应用主体，拒绝授权：" + cleanKey);
        }
        if (activationClient.isEnforce()
                && !activationClient.isAppActivatedAtSchool(appId, schId)) {
            throw new BizException(ErrorCode.FORBIDDEN,
                    "该应用未在学校 " + schId + " 开通，不能授予流程使用许可");
        }
        FlwUsageGrant grant = grantRepository
                .findBySchIdAndFlowGuidAndAppId(schId, flowGuid.trim(), appId)
                .orElseGet(FlwUsageGrant::new);
        boolean isNew = grant.getId() == null;
        if (isNew) {
            grant.setSchId(schId);
            grant.setFlowGuid(flowGuid.trim());
            grant.setAppId(appId);
        }
        if (formalEnabled) {
            String source = registered.path("sourcePrincipalId").asText("");
            try {
                if (!java.util.UUID.fromString(source).toString().equals(source)) throw new IllegalArgumentException();
            } catch (IllegalArgumentException invalid) {
                throw new BizException(ErrorCode.FORBIDDEN, "UserBase 稳定来源未迁移，不能发放正式许可");
            }
            if (!activationClient.isAppActivatedStrict(appId, schId)) throw new BizException(ErrorCode.FORBIDDEN, "学校未开通");
            grant.setSourcePrincipalId(source);
        }
        grant.setAppKeySnapshot(cleanKey);
        grant.setAppNameSnapshot(registered.path("appName").asText(null));
        grant.setEnabled(1);
        grant.setRemark(remark);
        FlwUsageGrant saved = grantRepository.save(grant);
        log.info("[usage-grant] 授予 schId={} flowGuid={} appId={} appKey={} operator={} 新建={}",
                schId, flowGuid, appId, cleanKey, operator, isNew);
        return saved;
    }

    /** 撤销（enabled=0，行保留）；幂等：对已撤销行重复撤销不报错 */
    @Transactional
    public FlwUsageGrant revoke(Long schId, String flowGuid, Integer appId, String remark, String operator) {
        FlwUsageGrant grant = grantRepository
                .findBySchIdAndFlowGuidAndAppId(schId, flowGuid, appId)
                .orElseThrow(() -> new BizException(ErrorCode.PARAM_ERROR,
                        "使用许可不存在：school=" + schId + " flow=" + flowGuid + " app=" + appId));
        grant.setEnabled(0);
        if (remark != null && !remark.trim().isEmpty()) {
            grant.setRemark(remark.trim());
        }
        FlwUsageGrant saved = grantRepository.save(grant);
        log.info("[usage-grant] 撤销 schId={} flowGuid={} appId={} operator={}（只拦新发起，在途不受影响）",
                schId, flowGuid, appId, operator);
        return saved;
    }

    private JsonNode fetchRegistered(String appKey) {
        if (appClient == null) {
            throw new BizException(ErrorCode.UNAUTHORIZED, "UserBase 应用注册通道未装配，拒绝授权");
        }
        try {
            JsonNode node = appClient.getAppByKey(appKey);
            return node == null || node.isNull() ? null : node;
        } catch (RuntimeException e) {
            log.warn("[usage-grant] UserBase 注册解析失败 appKey={}：{}", appKey, e.toString());
            throw new BizException(ErrorCode.UNAUTHORIZED, "UserBase 应用注册解析不可用，请稍后重试");
        }
    }

    private Integer readId(JsonNode registered) {
        JsonNode idNode = registered.path("id");
        return idNode.isNumber() ? idNode.intValue() : null;
    }
}