GoLang_Project/previewer/application/functions.go

79 lines
1.6 KiB
Go

package application
import (
"bytes"
"image"
"io/ioutil"
"log"
"net/http"
"net/url"
"strconv"
"strings"
"errors"
"image/jpeg"
"github.com/nfnt/resize"
)
type Query struct {
Height int
Width int
URL *url.URL
}
func BuildQuery(u *url.URL) (q Query, err error) {
t := strings.Split(u.Path, "/")
q.Width,err=strconv.Atoi(t[2])
if err!=nil {
return Query{}, errors.New("width must be an integer")
}
q.Height,err=strconv.Atoi(t[3])
if err!=nil {
return Query{}, errors.New("height must be an integer")
}
tn := "http://"+strings.Join(t[4:],"/")
q.URL,err=q.URL.Parse(tn)
if err!=nil {
return Query{}, errors.New("not valid url")
}
return q,nil
}
func (q Query) id() string {
return strconv.Itoa(q.Width)+"/"+strconv.Itoa(q.Height)+"/"+q.URL.Path
}
func (q Query) fromOrigin() ([]byte, http.Header, error) {
client := &http.Client{}
req, err := http.NewRequest("GET", "https://" + q.URL.Host + "/" + q.URL.Path, nil)
if err != nil {
return nil, nil, err
}
req.Close = true
res, err := client.Do(req)
if err != nil {
return nil, nil, err
}
body, err := ioutil.ReadAll(res.Body)
if err != nil {
return nil, nil, err
}
if err = res.Body.Close(); err != nil {
return nil, nil, err
}
return body, res.Header, nil
}
func (q Query) resize(b []byte) ([]byte, error) {
i,_,err := image.Decode(bytes.NewReader(b))
if err != nil {
return nil, err
}
log.Println("ресайзим")
m := resize.Resize(uint(q.Width), uint(q.Height), i, resize.Bicubic)
var g []byte
s := bytes.NewBuffer(g)
if err = jpeg.Encode(s,m,nil); err != nil {
return nil, err
}
return g, nil
}