const sharp = require("sharp");


getFileSuffix = (fileName, splitChar) => {
    // 取字符最后一次出现的位置（根据需要选择）
    const first = fileName.lastIndexOf(splitChar);
    const namelength = fileName.length; //取到文件名长度
    return fileName.substring(first + 1, namelength); //截取获得后缀名
} 
getFilePath = (fileName, splitChar) => {
    // 取字符最后一次出现的位置（根据需要选择）
    const first = fileName.lastIndexOf(splitChar);
    const namelength = fileName.length;
    return fileName.substring(0, first);
}
getMetadata = async(path) => {
    return await sharp(path).metadata();
}
resizeImage = async(params) => {
    const {path,height,width} = params;
    const targetPath = getFilePath(path,'.') + '-tmp.' + getFileSuffix(path,'.');
    try {
        await sharp(path)
        .resize({
            width: width,
            height: height
        })
        .toFile(targetPath);
        return targetPath;
    } catch (error) {
        console.log(error);
    }
}
module.exports = {
    getFileSuffix,
    getMetadata,
    resizeImage
}