/**
 * 网络图片管理器
 * 仅原生平台支持下载
 */
let NetImageMgr = {
    /**
     * 初始化
     *
     * @author Pyden
     * @date 2019-03-21
     */
    init () {
        if (!CC_JSB) {
            this._isDownloadingMap = {};
            this._storagePath = '';
            this._inited = false;
            return;
        }

        this._isDownloadingMap = {};
        this._storagePath = cc.path.join(jsb.fileUtils.getWritablePath(), 'image');
        this._inited = jsb.fileUtils.createDirectory(this._storagePath);
        if (!this._inited) {
            G.LogUtils.log('Failed to create storage path, NetImageMgr won\'t work correctly');
            return;
        }
        let searchPaths = jsb.fileUtils.getSearchPaths();
        searchPaths.unshift(this._storagePath);
        searchPaths.unshift('image');
        jsb.fileUtils.setSearchPaths(searchPaths);

        this._downloader = new jsb.Downloader();
        this._downloader.setOnFileTaskSuccess(this._onSucceed.bind(this));
        this._downloader.setOnTaskError(this._onError.bind(this));
    },


    /**
     * 获取存储图片的文件夹路径
     *
     * @author Pyden
     * @date 2019-03-21
     * @returns {string} 存储图片的文件夹路径
     */
    getImageDirPath () {
        return this._storagePath;
    },

    /**
     * 获取图片文件的全路径。优先级：图片下载路径 > 热更新路径 > 包内
     *
     * @author Pyden
     * @date 2019-03-21
     * @param {string} filename 文件名称
     * @returns {string} 图片文件的全路径。文件不存在时，返回undefined
     */
    getImageFullPath (filename) {
        if (!CC_JSB) {
            return undefined;
        }

        // 优先搜索路径里面的（即图片下载路径）
        let fullPath = jsb.fileUtils.fullPathForFilename(filename);

        return fullPath;
    },

    /**
     * 获取指定url的图片文件的全路径
     *
     * @author Pyden
     * @date 2019-03-21
     * @param {string} url 文件下载url
     * @returns {string} 图片文件的全路径。文件不存在时，返回undefined
     */
    getImageFullPathWithUrl (url) {
        let filename = this._getFilename(url);
        return this.getImageFullPath(filename);
    },

    /**
     * 清除图片缓存
     *
     * @author Pyden
     * @date 2019-03-21
     * @returns {boolean} 是否成功
     */
    clearImageDir () {
        if (!CC_JSB) {
            return false;
        }

        let ok = jsb.fileUtils.removeDirectory(this._storagePath);
        if (ok) {
            this._inited = jsb.fileUtils.createDirectory(this._storagePath);
        }

        return ok;
    },

    /**
     * 下载图片文件
     *
     * @author Pyden
     * @date 2019-03-21
     * @param {string} url 图片文件url
     * @returns {boolean} 是否正常下载
     */
    downloadImage (url) {
        if (!this._inited) {
            G.LogUtils.log('Failed to downloadImage, init failed');
            return false;
        }

        let filename = this._getFilename(url);
        if (!filename || filename.length == 0) {
            G.LogUtils.log('Failed to downloadImage, url error');
            return false;
        }

        let isDownloading = this._getIsDownloading(filename);
        if (isDownloading) {
            G.LogUtils.log('Did downloadImage');
            return true;
        }

        this._setIsDownloading(filename, true);
        G.LogUtils.log('开始下载图片 (' + url + ')');

        let savePath = this._getImageSavePath(filename);
        this._downloader.createDownloadFileTask(url, savePath);

        return true;
    },

    /**
     * 获取图片网络下载地址
     *
     * @author libo
     * @date 2019-05-21
     * @param {string} imageName 图片文件名
     * @returns
     */
    getImageFullUrl (imageName) {
        if (!imageName || imageName.length == 0) {
            return imageName;
        }

        return cc.path.join(window.JMC.RES_ROOT_URL, 'ssmj/res_h5/icon_img/' + imageName);
    },


    /**
     * 获取图片文件存储路径
     *
     * @author Pyden
     * @date 2019-03-21
     * @param {string} filename 文件名称
     * @returns {string} 图片文件存储路径
     */
    _getImageSavePath (filename) {
        return cc.path.join(this._storagePath, filename);
    },

    /**
     * 获取文件名称
     *
     * @author Pyden
     * @date 2019-03-21
     * @param {string} url 文件路径
     * @returns {string} 文件名称（带后缀）
     */
    _getFilename (url) {
        return cc.path.basename(url);
    },

    /**
     * 判断文件是否正在下载
     *
     * @author Pyden
     * @date 2019-03-21
     * @param {string} filename 文件名称
     * @returns {boolean} 是否正在下载
     */
    _getIsDownloading (filename) {
        return this._isDownloadingMap[filename];
    },

    /**
     * 设置文件是否正在下载
     *
     * @author Pyden
     * @date 2019-03-21
     * @param {string} filename 文件名称
     * @param {boolean} value 是否正在下载
     */
    _setIsDownloading (filename, value) {
        this._isDownloadingMap[filename] = value;
    },

    /**
     * 下载任务成功的回调
     *
     * @author Pyden
     * @date 2019-03-21
     * @param {DownloadTask} task 下载任务
     */
    _onSucceed (task) {
        G.LogUtils.log('下载图片成功 (' + task.requestURL + ')');
        let url = task.requestURL;
        let filename = this._getFilename(url);
        this._setIsDownloading(filename, false);

        cc.game.emit('e_mgr_net_image_download_ok', url);
    },

    /**
     * 下载任务失败的回调
     *
     * @author Pyden
     * @date 2019-03-21
     * @param {DownloadTask} task 下载任务
     * @param {int} errorCode 错误码
     * @param {int} errorCodeInternal 内部错误码
     * @param {string} errorStr 错误信息
     */
    _onError (task, errorCode, errorCodeInternal, errorStr) {
        G.LogUtils.log('下载图片失败 (' + task.requestURL + '): ' + errorStr + '(' + errorCode + ')');

        let url = task.requestURL;
        let filename = this._getFilename(url);
        this._setIsDownloading(filename, false);

        cc.game.emit('e_net_image_download_error', url, errorCode, errorCodeInternal, errorStr);
    }
};

module.exports = NetImageMgr;