Go+gRPC-Gateway(V2) 微服务实战，小程序登录鉴权服务(六)：客户端基础库 TS 实战

export namespace SDK {
}

const serverAddr = 'http://localhost:8080'
const AUTH_ERR= 'AUTH_ERR'
const authData = {
    token: '',
    expiryMs: 0
}
interface RequestOption<REQ, RES> {
    method: 'GET'|'PUT'|'POST'|'DELETE'
    path: string
    data: REQ
    respMarshaller: (r: object)=>RES
}
interface AuthOption {
    attachAuthHeader: boolean
    retryOnAuthError: boolean
}

export function wxLogin(): Promise<WechatMiniprogram.LoginSuccessCallbackResult> {
        return new Promise((resolve, reject) => {
            wx.login({
                success: resolve,
                fail: reject,
            })
        })
    }

export function sendRequest<REQ, RES>(o: RequestOption<REQ, RES>, a: AuthOption): Promise<RES> {
        const authOpt = a || {
            attachAuthHeader: true,
        }
        return new Promise((resolve, reject) => {
            const header: Record<string, any> = {}
            if (authOpt.attachAuthHeader) {
                if (authData.token && authData.expiryMs >= Date.now()) {
                    header.authorization = 'Bearer '+ authData.token
                } else {
                    reject(AUTH_ERR)
                    return
                }
            }
            wx.request({
                url: serverAddr + o.path,
                method: o.method,
                data: o.data,
                header,
                success: res => {
                    if(res.statusCode === 401) {
                        reject(AUTH_ERR)
                    } else if (res.statusCode >= 400) {
                        reject(res)
                    } else {
                        resolve(
                            o.respMarshaller(
                                camelcaseKeys(res.data as object, { deep: true }),
                            )
                        )
                    }
                },
                fail: reject
            })
        })
    }

export async function login() {
    if (authData.token && authData.expiryMs >= Date.now()) {
        return 
    }
    const wxResp = await wxLogin()
    const reqTimeMs = Date.now()
    const resp = await sendRequest<auth.v1.ILoginRequest, auth.v1.ILoginResponse>({
        method: "POST",
        path: "/v1/auth/login",
        data: {
            code: wxResp.code,
        },
        respMarshaller: auth.v1.LoginResponse.fromObject
    }, {
        attachAuthHeader: false, 
        retryOnAuthError: false,
    })
    authData.token = resp.accessToken!
    authData.expiryMs = reqTimeMs + resp.expiresIn! * 1000
}

export async function sendRequestWithAuthRetry<REQ, RES>(o: RequestOption<REQ, RES>, a?: AuthOption): Promise<RES> {
    const authOpt = a || {
        attachAuthHeader: true,
        retryOnAuthError: true,
    }
    try {
        await login()
        return sendRequest(o, authOpt)
    } catch(err) {
        if(err === AUTH_ERR && authOpt.retryOnAuthError) {
            authData.token = ''
            authData.expiryMs = 0
            return sendRequestWithAuthRetry(o, {
                attachAuthHeader: authOpt.attachAuthHeader,
                retryOnAuthError: false
            })
        } else {
            throw err
        }
    }
}

export namespace TodoService {
    export function CreateTodo(req: todo.v1.ICreateTodoRequest): Promise<todo.v1.ICreateTodoResponse>{
        return SDK.sendRequestWithAuthRetry({
            method: "POST",
            path: "/v1/todo",
            data: req,
            respMarshaller: todo.v1.CreateTodoResponse.fromObject
        })
    }
}