const router = require('koa-router')()
const fs = require('fs')
    , crypto = require('crypto')


//  全局路由
router.prefix('/fileStorage')
router.get('/', async (ctx, next) => {
    await ctx.render('index', {
        title: 'Hello Koa 2!'
    })
})

let readFileMd5 = (url) =>{
    return new Promise((reslove) => {
        let md5sum = crypto.createHash('md5');
        let stream = fs.createReadStream(url);
        stream.on('data', function(chunk) {
            md5sum.update(chunk);
        });
        stream.on('end', function() {
            let fileMd5 = md5sum.digest('hex');
            reslove(fileMd5);
        })
    })
}

router.post('/putfile', async (ctx) => {
    const arg = ctx.request.body
    const file = ctx.request.files.file
    if(file instanceof Array){
        return ctx.body = {
            message:'上传失败，不支持多文件。',
            status:'error',
        };
    }else if(!file){
        return ctx.body = {
            message:'上传失败，文件不存在。',
            status:'error',
        };
    }
    console.log(file.newFilename)
    console.log(arg.md5)
    const md5 = await readFileMd5(file.filepath)
    console.log(md5)
    if(md5 == arg.md5){
        const createTime = new Date().getTime()
        const [rows, fields] = await global.SQL.execute('SELECT * FROM `file` WHERE `md5` = ?', [arg.md5]);
        let filename = createTime.toString() + parseInt(Math.random() * 10000000000000).toString(16) +'.'+ file.newFilename.split('.').slice(-1)
        if(rows.length == 0){
            await global.SQL.execute('INSERT INTO `file` (md5, filename, createTime, filesize) VALUES (?, ?, ?, ?)', [arg.md5, filename, createTime, file.size]);
            const reader = fs.createReadStream(file.filepath); // 创建可读流
            const upStream = fs.createWriteStream(global.dirname + '/fileStorage/' + filename); // 创建可写流
            reader.pipe(upStream); // 可读流通过管道写入可写流
        }else{
            filename = rows[0].filename
        }
        return ctx.body = {
            message:'上传成功',
            state: true,
            data:{
                md5,
                filename
            }
        };
    }else{
        return ctx.body = {
            message:'文件损坏',
            state:false,
        };
    }

    // const file = ctx.request.files.file; // 获取上传文件
    // const reader = fs.createReadStream(file.filepath); // 创建可读流
    // const upStream = fs.createWriteStream('./StaticFile_Backup/' + ctx.request.body.dirname + '/' + ctx.request.body.key); // 创建可写流
    // reader.pipe(upStream); // 可读流通过管道写入可写流
});

router.get('/string', async (ctx, next) => {
    ctx.body = 'koa2 string'
})

router.get('/json', async (ctx, next) => {
    ctx.body = {
        title: 'koa2 json'
    }
})

module.exports = router