export class CrsClient {
    /**
     * @param config { {cloudKey: string, token: string, clientHost: string, jpegQuality: number} }
     * @param canvas { HTMLCanvasElement }
     */

    base64_decode(input) { // 解码，配合decodeURIComponent使用
        var base64EncodeChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
        var output = "";
        var chr1, chr2, chr3;
        var enc1, enc2, enc3, enc4;
        var i = 0;
        input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");
        while (i < input.length) {
            enc1 = base64EncodeChars.indexOf(input.charAt(i++));
            enc2 = base64EncodeChars.indexOf(input.charAt(i++));
            enc3 = base64EncodeChars.indexOf(input.charAt(i++));
            enc4 = base64EncodeChars.indexOf(input.charAt(i++));
            chr1 = (enc1 << 2) | (enc2 >> 4);
            chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
            chr3 = ((enc3 & 3) << 6) | enc4;
            output = output + String.fromCharCode(chr1);
            if (enc3 != 64) {
                output = output + String.fromCharCode(chr2);
            }
            if (enc4 != 64) {
                output = output + String.fromCharCode(chr3);
            }
        }
        return this.utf8_decode(output);
    }
    utf8_decode(utftext) { // utf-8解码
        var string = '';
        let i = 0;
        let c = 0;
        let c1 = 0;
        let c2 = 0;
        while (i < utftext.length) {
            c = utftext.charCodeAt(i);
            if (c < 128) {
                string += String.fromCharCode(c);
                i++;
            } else if ((c > 191) && (c < 224)) {
                c1 = utftext.charCodeAt(i + 1);
                string += String.fromCharCode(((c & 31) << 6) | (c1 & 63));
                i += 2;
            } else {
                c1 = utftext.charCodeAt(i + 1);
                c2 = utftext.charCodeAt(i + 2);
                string += String.fromCharCode(((c & 15) << 12) | ((c1 & 63) << 6) | (c2 & 63));
                i += 3;
            }
        }
        return string;
    }

    constructor(config, canvas) {
        this.config = config;
        this.canvas = canvas;
        this.context = canvas.getContext('2d');
    }

    /**
     * 发起一次CRS请求
     * @param frame { {data: ArrayBuffer, height: number, width: number} } 相机帧
     * @return {Promise}
     */
    queryImage(frame) {
        /*
         * 从相机帧开始，发起一次CRS请求的步骤：
         * 1. 将相机帧画到canvas上
         * 2. 调用canvas.toDataURL得到JPEG图片的base64 (需要小程序基础库2.12.0及以上)
         * 3. 填充请求参数
         * 4. 发送CRS请求并返回
         */
        let ctxImageData = this.context.createImageData(frame.width, frame.height); //#1
        ctxImageData.data.set(new Uint8ClampedArray(frame.data)); //#1
        this.context.putImageData(ctxImageData, 0, 0); //#1
        let dataUrl = this.canvas.toDataURL("image/jpeg", this.config.quality); //#2
        let base64 = dataUrl.substr(23); //#2 去除dataURL头，留下文件内容

        const params = { //#3 添加cloudKey参数
            image: base64,
            notracking: "true",
            appId: '20239cb7aa12abd58af820458711fea0'
        };

        return new Promise((resolve, reject) => { //#4 发送CRS请求
            let token = wx.getStorageSync('token')
            console.log(token);
            wx.request({
                url: `http://6db69340022abbad5fa30787b96a3d4b.cn1.crs.easyar.com:8080/search/`,
                method: 'post',
                data: params,
                header: {
                    'Authorization': token,
                    'content-type': 'application/json'
                },
                success: res => {
                    console.log(res, '成功');
                    var base64 = res.data.result.target.meta
                    console.log(res.data.result.target.meta, '123123');
                    let web = this.base64_decode(base64)
                    console.log(this.base64_decode(base64));
                    let index = 2
                    wx.navigateTo({
                        url: '../out/index?web=' + web + '&index=' + index,
                    })
                },
                fail: err => {
                    console.log(err);
                },
            });
        });
    }
}