'use strict';
/**
 * Copyright (c) 2017 Baidu.com, Inc. All Rights Reserved
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
 * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations under the License.
 *
 * @file baseClient
 * @author baiduAip
 */
const DevAuth = require('../auth/devAuth');

const DevAuthToken = require('../auth/devAuthToken');


/**
 * 无授权判断状态
 *
 * @const
 * @type {number}
 */
const AUTHTYPE_INIT = 0;

/**
 * 确定为云用户
 *
 * @const
 * @type {number}
 */
const AUTHTYPE_BCE = 1;

/**
 * 确定为开发者用户（手动输入token模式,以及token中包含了正确的scope）
 *
 * @const
 * @type {number}
 */
const AUTHTYPE_DEV = 2;

/**
 * 获取开发者token成功用户
 *
 * @const
 * @type {number}
 */
const AUTHTYPE_DEV_OR_BCE = 3;


/**
 * 初始状态
 *
 * @const
 * @type {number}
 */
const STATUS_INIT = 0;

/**
 * 获取开发者token中
 *
 * @const
 * @type {number}
 */
const STATUS_AUTHTYPE_REQESTING = 1;

/**
 * 获取开发者token成功，或者确定为云用户
 *
 * @const
 * @type {number}
 */
const STATUS_READY = 2;

/**
 * 非法ak，sk
 *
 * @const
 * @type {number}
 */
const STATUS_ERROR = -1;

 /**
 * BaseClient类
 * 各具体接口类基类，处理鉴权逻辑等
 *
 * @constructor
 * @param {string} appid appid.
 * @param {string} ak The access key.
 * @param {string} sk The security key.
 */
class BaseClient {
    constructor(appId, ak, sk, options) {
        this.appId = 0;
        this.ak = ak;
        this.sk = sk;

        this.options = options || {};

        this.authType = AUTHTYPE_INIT;
        this.status = STATUS_INIT;

        this.pms;
        this.devAccessToken = null;

        this.devAuth = new DevAuth(this.ak, this.sk);

        this.authTypeReq();

    }
    setAccessToken(token, expireTime) {
        let et = expireTime || DevAuthToken.DEFAULT_EXPIRE_DURATION;
        this.devAccessToken = new DevAuthToken(token, et, null);
        this.authType = AUTHTYPE_DEV;
        this.status = STATUS_READY;
    }
    authTypeReq() {
        // 请求access_token服务
        this.status = STATUS_AUTHTYPE_REQESTING;
        this.pms = this.devAuth.getToken().then(this.gotDevAuthSuccess.bind(this),
        this.gotDevAuthFail.bind(this));
        // 初始化client对象后立即发生的第一次异常，如果没有立即调用具体请求接口的话（必须有promise catch）
        // 将无法被捕获获取token的request网络异常，为了避免UnhandledPromiseRejectionWarning
        // 此处直接catch住,待代用具体接口时候再返回获取token时的异常，减少程序复杂度
        this.pms.catch(function (error) {
        }.bind(this));
        return this.pms;
    }
    gotDevAuthSuccess(token) {
        // 如果用户没有手动调用setAccessToken设置access_token
        if (this.authType !== AUTHTYPE_DEV) {
            this.devAccessToken = token;
            this.authType = AUTHTYPE_DEV_OR_BCE;
        }
        this.status = STATUS_READY;
    }
    gotDevAuthFail(err) {
        // 获取token时鉴权服务器返回失败信息
        if (err.errorType === DevAuth.EVENT_ERRTYPE_NORMAL) {
            // 可能是百度云的ak，sk
            this.authType = AUTHTYPE_BCE;
            this.status = STATUS_READY;
            return;
        }

        // 获取token时发生了网络错误
        // 或者是发生了服务器返回数据格式异常
        if (err.errorType === DevAuth.EVENT_ERRTYPE_NETWORK
            || err.errorType === DevAuth.EVENT_ERRTYPE_ILLEGAL_RESPONSE) {
            this.status = STATUS_ERROR;
            throw err;
        }
    }
    doRequest(requestInfo, httpClient) {

        // 如果获取token失败
        if (this.status === STATUS_ERROR) {
            this.authTypeReq();
        }

        return this.pms.then(function () {
            // 预检函数，返回是否token过期
            let isTokenExpired = this.preRequest(requestInfo);

            if (isTokenExpired === false) {
                // 鉴权方式确定，请求接口
                return httpClient.postWithInfo(requestInfo)
            } else {
                // 如果token过期了，说明是需要重新获取access_token
                // 待重新获取完后继续请求接口
                return this.pms.then(function () {
                    this.preRequest(requestInfo);
                    return httpClient.postWithInfo(requestInfo);
                }.bind(this))
            }
        }.bind(this));
    }
    checkDevPermission(requestInfo) {
        // 是否跳过这个检查（从speech.baidu.com创建的应用，调用语音接口需要跳过）
        if (this.options.isSkipScopeCheck === true) {
            return true;
        }
        // 检查是否拥有AI平台接口权限
        return this.devAccessToken.hasScope(requestInfo.scope);
    }
    preRequest(requestInfo) {

        // 获取access_token失败，使用百度云签名方式调用
        if (this.authType === AUTHTYPE_BCE) {
            requestInfo.makeBceOptions(this.ak, this.sk);
            return false;
        }

        // 获取access_token成功，或者调用setAccessToken设置的access_token
        if (this.authType === AUTHTYPE_DEV_OR_BCE || this.authType === AUTHTYPE_DEV) {
            // 拥有AI平台接口权限
            if (this.checkDevPermission(requestInfo) || this.authType === AUTHTYPE_DEV) {

                // 判断access_token是否过期
                if (!this.devAccessToken.isExpired()) {
                    requestInfo.makeDevOptions(this.devAccessToken);
                    return false;
                }
                // access_token过期重新获取
                this.authTypeReq();
                return true;
            } else {
                // 使用百度云签名方式访问调用
                requestInfo.makeBceOptions(this.ak, this.sk);
            }
        }
        return false;
    }
 }

module.exports = BaseClient;