package api

import (
    "net/http"
    "fmt"
    "io/ioutil"
)

const bufferSize = 512 * 1024
//获取空间文件
func Get(host string, port int, vid uint64, fid uint64, filename string) ([]byte, error) {
    url := fmt.Sprintf("http://%s:%d/%d/%d/%s", host, port, vid, fid, filename)
    resp, err := http.Get(url)
    if err != nil {
        return nil, err
    }
    defer resp.Body.Close()

    if resp.StatusCode == http.StatusOK {
        return ioutil.ReadAll(resp.Body)
    }else {
        return nil, fmt.Errorf("%d != 200", resp.StatusCode)
    }
}
//获取空间文件   指定字节区间
func GetRange(host string, port int, vid uint64, fid uint64, filename string, start int, length int) ([]byte, error) {
    url := fmt.Sprintf("http://%s:%d/%d/%d/%s", host, port, vid, fid, filename)
    req, _ := http.NewRequest(http.MethodGet, url, nil)
    req.Header.Set("Range", fmt.Sprintf("bytes=%d-%d", start, start + length - 1))
    resp, err := http.DefaultClient.Do(req)
    if err != nil {
        return nil, err
    }
    defer resp.Body.Close()

    if resp.StatusCode == http.StatusPartialContent {
        return ioutil.ReadAll(resp.Body)
    }else {
        return nil, fmt.Errorf("%d != 200", resp.StatusCode)
    }
}