package weChat

import (
	"bytes"
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"github.com/leeqvip/gophp"
	"hospital-open-api/config"
	"hospital-open-api/global"
	"io"
	"net/http"
	"time"
)

// CommonError 微信返回的通用错误 json
type CommonError struct {
	ErrCode int64  `json:"errcode"`
	ErrMsg  string `json:"errmsg"`
}

type GetAccessTokenResponse struct {
	AccessToken string `json:"access_token"`
	ExpiresIn   int64  `json:"expires_in"`

	CommonError
}

type WeChatConfig struct {
	AppId     string `json:"app_id"`
	AppSecret string `json:"app_secret"`
}

// GetConfig 初始化配置
func GetConfig(userType int) *WeChatConfig {
	weChatConfig := &WeChatConfig{}
	if userType == 1 {
		// 患者
		weChatConfig.AppId = config.C.Wechat.PatientAppId
		weChatConfig.AppSecret = config.C.Wechat.PatientAppSecret
	} else if userType == 2 {
		// 医生/药师
		weChatConfig.AppId = config.C.Wechat.DoctorAppId
		weChatConfig.AppSecret = config.C.Wechat.DoctorAppSecret
	}

	return weChatConfig
}

// GetAccessToken 获取access_token
func (c WeChatConfig) GetAccessToken() (string, error) {
	// 检测缓存是否存在access_token
	redisKey := "c:official_account.access_token." + c.AppId + "." + c.AppSecret
	accessToken, _ := global.Redis.Get(context.Background(), redisKey).Result()
	if accessToken != "" {
		// 存在缓存，反序列化
		result, err := gophp.Unserialize([]byte(accessToken))
		if err != nil {
			return "", err
		}

		var ok bool
		accessToken, ok = result.(string)
		if !ok {
			return "", errors.New("失败")
		}
	} else {
		// 不存在缓存，重新获取
		var body []byte

		grantType := "client_credential"

		// 构建 URL
		url := fmt.Sprintf("https://api.weixin.qq.com/cgi-bin/token?grant_type=%s&appid=%s&secret=%s", grantType, c.AppId,
			c.AppSecret)

		body, err := GetRequest(url)
		if err != nil {
			return "", errors.New(err.Error())
		}

		var GetAccessTokenResponse GetAccessTokenResponse
		err = json.Unmarshal(body, &GetAccessTokenResponse)
		if err != nil {
			return "", errors.New(err.Error())
		}

		if GetAccessTokenResponse.ErrCode != 0 {
			return "", errors.New(GetAccessTokenResponse.ErrMsg)
		}

		accessToken = GetAccessTokenResponse.AccessToken
		expiresIn := GetAccessTokenResponse.ExpiresIn

		// 序列化
		redisValue, _ := gophp.Serialize(accessToken)

		// 增加缓存
		global.Redis.Set(context.Background(), redisKey, string(redisValue),
			time.Duration(expiresIn-1500)*time.Second)
	}

	if accessToken == "" {
		return "", errors.New("失败")
	}

	return accessToken, nil
}

// GetRequest 发送 GET 请求并返回响应内容和错误（如果有）
func GetRequest(url string) ([]byte, error) {
	// 发送 GET 请求
	resp, err := http.Get(url)
	if err != nil {
		return nil, err
	}
	defer func(Body io.ReadCloser) {
		_ = Body.Close()
	}(resp.Body)

	// 读取响应内容
	body, err := io.ReadAll(resp.Body)
	if err != nil {
		return nil, err
	}

	return body, nil
}

// PostRequest 统一请求
func PostRequest(url string, requestBody []byte) ([]byte, error) {
	// 发起 POST 请求
	resp, err := http.Post(url, "application/json", bytes.NewBuffer(requestBody))
	if err != nil {
		return nil, err
	}

	defer func(Body io.ReadCloser) {
		_ = Body.Close()
	}(resp.Body)

	body, err := io.ReadAll(resp.Body)
	if err != nil {
		return nil, err
	}

	return body, nil
}