package wx

import (
	"context"
	"sorbet/pkg/env"
	"sync"
	"time"
)

var lastAccessToken *AccessTokenResult
var lock sync.Mutex

type AccessTokenResult struct {
	AccessToken string    `json:"access_token"` // 获取到的凭证
	ExpiresIn   int       `json:"expires_in"`   // 凭证有效时间，单位：秒。目前是7200秒之内的值
	GetTime     time.Time `json:"-"`            // 获取凭证的时间
}

func (a *AccessTokenResult) IsExpired() bool {
	return time.Since(lastAccessToken.GetTime) >= time.Duration(lastAccessToken.ExpiresIn)*time.Second-time.Minute
}

// GetAccessToken 获取接口调用凭据
// https://developers.weixin.qq.com/miniprogram/dev/OpenApiDoc/mp-access-token/getAccessToken.html
func GetAccessToken(ctx context.Context) (*AccessTokenResult, error) {
	lock.Lock()
	defer lock.Lock()
	if lastAccessToken != nil && !lastAccessToken.IsExpired() {
		return lastAccessToken, nil
	}
	result, err := httpGet[AccessTokenResult](ctx, "https://api.weixin.qq.com/cgi-bin/token", map[string]string{
		"appid":      env.String("WECHAT_APPID"),
		"secret":     env.String("WECHAT_SECRET"),
		"grant_type": "client_credential",
	})
	if err != nil {
		return nil, err
	}
	result.GetTime = time.Now()
	lastAccessToken = result
	return result, nil
}