let bucket; //aws上传接口
let bucketname = "ccrb"; //桶
const partsize = 5 * 1024 * 1024; // 5MB

//--------------------------分断上传保证稳定性
//初始化上传
async function init() {
    const credentials = {
        accessKeyId: "AKIATLPEDU37QV5CHLMH",
        secretAccessKey: "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",
    }; //秘钥形式的登录上传
    window.AWS.config.update(credentials);
    window.AWS.config.region = "cn-northwest-1"; //设置区域
    //桶的设置
    bucket = new window.AWS.S3({
        params: {
            Bucket: bucketname
        }
    });
    return bucket;
}

//初始化上传入口
async function initMultipartUpload(key, file) {
    const params = {
        Bucket: bucketname,
        Key: key,
        ContentType: file.type,
        "ACL": "public-read"
    };
    //创建一个续传通道
    const data = await bucket.createMultipartUpload(params).promise();
    return data.UploadId;
}

// 上传文件的某一部分
async function uploadPart(file, keyname, uploadid, pn, start, end) {
    //key可以设置为桶的相对路径，Body为文件， ACL最好要设置
    var params = {
        Bucket: bucketname,
        Key: keyname,
        PartNumber: pn,
        UploadId: uploadid,
        Body: file.slice(start, end)
    };
    const result = await bucket.uploadPart(params).promise();
    return { ETag: result.ETag, PartNumber: pn };
}

// 完成分块上传
async function completeMultipartUpload(parts, keyname, uploadid) {
    const params = {
        Bucket: bucketname,
        Key: keyname,
        MultipartUpload: { Parts: parts },
        UploadId: uploadid
    };
    return await bucket.completeMultipartUpload(params).promise();
}

//中止分块上传
async function abortMultipartUpload(key, uploadid) {
    const params = {
        Bucket: bucketname,
        Key: key,
        UploadId: uploadid
    };
    await bucket.abortMultipartUpload(params).promise();
}

// 实际的上传逻辑
async function uploadFile(file, folderid) {
    folderid = folderid || window.Guid.newGuid(); //分配到一个随机的id里
    var keyname = folderid + "/" + file.name; //保存在指定的文件夹里
    var uploadid = "";
    try {
        init(); // 初始化aws接口
        // 初始化分块上传
        uploadid = await initMultipartUpload(keyname, file);
        // 分块上传文件
        let parts = [];
        let start = 0;
        let end = 0;
        let len = Math.ceil(file.length / partsize); //循环的长度
        //循环上传
        for (let i = 0; i < len; i++) {
            start = i * partsize;
            end = (i + 1) * partsize;
            parts.push(await uploadPart(file, keyname, uploadid, i, start, end));
        }
        // 完成分块上传
        await completeMultipartUpload(parts, keyname, uploadid);
        return uploadid;
    }
    catch (error) {
        // 如果出现错误，中止分块上传
        console.error('An error occurred during file upload:', error);
        await abortMultipartUpload(keyname, uploadid);
    }
}

//--------------------------------下面支持断点续传

//初始化亚马逊参数
async function init() {
    //秘钥形式的登录上传
    const credentials = {
        accessKeyId: "AKIATLPEDU37QV5CHLMH",
        secretAccessKey: "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",
        region: "cn-northwest-1"
    };
    window.AWS.config.update(credentials);
    // window.AWS.config.region = "cn-northwest-1"; //设置区域
    //桶的设置
    bucket = new window.AWS.S3({
        params: {
            Bucket: bucketname
        }
    });
    return bucket;
}

//获取当前文件是否有已上传断点信息
async function getawscheckpoint(key) {
    let partsinfo;
    try {
        const result = await bucket.listMultipartUploads({ Bucket: bucketname, Prefix: key }).promise();
        //获取具体分片信息
        if (result.Uploads.length) {
            uploadid = result.Uploads[result.Uploads.length - 1].UploadId;
            partsinfo = await bucket.listParts({ Bucket: bucketname, Key: key, UploadId: uploadid, }).promise();
        }
    } catch (err) {
        console.log(err);
    }
    return { uploadid, partsinfo };
}

//分段上传
async function awsuploadpart(filestate, file, uploadid, parts, key) {
    var partarr = [];//已完成的数组
    //已完成的分片,转化成提交格式
    const completeparts = parts.map((_) => {
        partarr.push(_.PartNumber);
        return { PartNumber: _.PartNumber, ETag: _.ETag };
    });
    // 分块上传文件
    let uploadpart;
    let start = 0;
    let end = 0;
    let len = Math.ceil(file.size / partsize); //循环的长度
    if (partarr.length) {
        filestate.status = "processing";
        filestate.percent = parseInt((completeparts.length * 100) / len);
    }
    //循环上传
    for (let i = 0; i < len; i++) {
        start = i * partsize;
        end = (i + 1) * partsize;
        if (!partarr.includes(i)) {
            uploadpart = await uploadPart(file, key, uploadid, i + 1, start, end);
            if (uploadpart.ETag != null) {
                completeparts.push(uploadpart);
                filestate.percent = parseInt((completeparts.length * 100) / len);
            }

            else {
                filestate.status = "fail";
                return;
            }
        }
    }
    //提交上传成功信息
    var data = await completeMultipartUpload(completeparts, key, uploadid);
    filestate.status = "success";
    return data;
}

//上传的接口
async function awsupload(file, folderid, filestate) {
    init(); //初始化桶
    const key = (folderid || window.Guid.newGuid()) + "/" + file.name; //需要上传的文件名
    filestate.percent = 0;
    filestate.status = "start";
    //上传的参数
    var params = {
        Bucket: bucketname,
        Key: key
    };
    //设置桶上传文件
    try {
        //检查文件是否已上传
        bucket.headObject(params, async (err, data) => {
            // 没有上传成功，head方法会返回失败
            if (err) {
                //检查是否部分上传
                const { uploadid, partsinfo } = await getawscheckpoint(key, bucket);
                //如果已经部分存在，那么直接在节点续传
                if (uploadid) {
                    //断点续传
                    var data = await awsuploadpart(filestate, file, uploadid, partsinfo.Parts, key);
                    return { data, key, uploadid };
                }
                //不存在，上传新的
                else {
                    const uploadid = await initMultipartUpload(key, file); //初始化文件上传
                    var data = await awsuploadpart(filestate, file, uploadid, [], key);
                    return { data, key, uploadid };
                }
            }
            //如果已经上传成功了，那么直接返回状态百分百
            else if (data) {
                //data存在，上传成功
                filestate.percent = 100;
                filestate.status = "success";
                return { data, key };
            }
        });
    }
    catch (err) {
        filestate.status = "error";
        console.log(err);
    }
}