package controller

import (
	"context"

	"github.com/gogf/gf/v2/errors/gerror"
	"github.com/gogf/gf/v2/frame/g"
	"github.com/gogf/gf/v2/util/gconv"
	"github.com/tiger1103/gfast/v3/api/v1/system"
	"github.com/tiger1103/gfast/v3/internal/app/system/service"
)

var (
	TenantBalance = tenantBalanceController{}
)

type tenantBalanceController struct{}

// callerUser 归属校验只取租户字段（调用方经 X-User-Info 头携带用户信息）
type callerUser struct {
	TenantId uint64 `json:"tenantId"`
}

// callerTenantId 从 X-User-Info 头解析调用方租户 id；头缺失/解析失败返回 0
func (c *tenantBalanceController) callerTenantId(ctx context.Context) uint64 {
	r := g.RequestFromCtx(ctx)
	if r == nil {
		return 0
	}
	userInfoHeader := r.Header.Get("X-User-Info")
	if userInfoHeader == "" {
		return 0
	}
	var caller callerUser
	if err := gconv.Struct(userInfoHeader, &caller); err != nil {
		return 0
	}
	return caller.TenantId
}

// Balance 查询租户余额（内部接口，供 model-gateway 调用；调用方只能查询自己所属租户）
func (c *tenantBalanceController) Balance(ctx context.Context, req *system.TenantBalanceReq) (res *system.TenantBalanceRes, err error) {
	if caller := c.callerTenantId(ctx); caller == 0 || caller != req.TenantId {
		return nil, gerror.New("无权查询该租户余额")
	}
	res = new(system.TenantBalanceRes)
	res.Tenant, err = service.Tenant().GetTenantDetails(ctx, req.TenantId)
	return
}

// Deduct 扣减租户余额（内部接口；surplus 传负值走 Edit 的 Counter 增量即扣减；调用方只能扣减自己所属租户）
func (c *tenantBalanceController) Deduct(ctx context.Context, req *system.TenantDeductReq) (res *system.TenantDeductRes, err error) {
	if caller := c.callerTenantId(ctx); caller == 0 || caller != uint64(req.Id) {
		return nil, gerror.New("无权扣减该租户余额")
	}
	err = service.Tenant().Edit(ctx, &system.TenantEditReq{Id: req.Id, Surplus: req.Surplus})
	return
}