function base64ImgtoFile(dataurl, filename = 'file') {
    let arr = dataurl.split(',')
    let mime = arr[0].match(/:(.*?);/)[1]
    let bstr = atob(arr[1])
    let n = bstr.length
    let u8arr = new Uint8Array(n)
    while (n--) {
        u8arr[n] = bstr.charCodeAt(n)
    }
    return new File([u8arr], `${filename}.jpg`, {
        type: mime
    })
}

function fileToBase64(file:File):Promise<string>{
    return new Promise((resolve, reject) => {
        const reader = new FileReader();
        reader.onload = function (event) {
            resolve(event.target!.result as string)
        };
        reader.readAsDataURL(file);
    })
}

function bufferToBase64(buffer) {
    if(buffer == undefined)return Promise.resolve('')
    const reader = new FileReader();
    reader.readAsDataURL(new Blob([buffer], { type: 'image/jpeg' }));
    return new Promise((resolve, reject) => {
        reader.onloadend = () => {
        const base64String = reader.result;
        resolve(base64String);
        };
        reader.onerror = reject;
    });
}

function base64ToArrayBuffer(base64) {
    const binaryStr = atob(base64);
    const len = binaryStr.length;
    const bytes = new Uint8Array(len);
    for (let i = 0; i < len; i++) {
        bytes[i] = binaryStr.charCodeAt(i);
    }
    return bytes.buffer;
}

Buffer.from(buffer)

const arrayBuffer = buffer.buffer