casey-chow/tigertrade

package server

import (
    "bytes"
    log "github.com/Sirupsen/logrus"
    "github.com/aws/aws-sdk-go/aws"
    "github.com/aws/aws-sdk-go/service/s3/s3manager"
    "github.com/disintegration/imaging"
    "github.com/getsentry/raven-go"
    "github.com/julienschmidt/httprouter"
    "github.com/satori/go.uuid"
    "image"
    "image/gif"
    "image/jpeg"
    "image/png"
    "net/http"
)

// CreatePhoto uploads the photo in r to Amazon S3 and writes its location to w
func CreatePhoto(w http.ResponseWriter, r *http.Request, ps httprouter.Params) {
    user := getUsername(r)
    if user == "" {
        Error(w, http.StatusUnauthorized)
        return
    }

    file, fileHeader, err := r.FormFile("file")
    if err != nil {
        raven.CaptureError(err, nil)
        log.WithError(err).Error("error while reading uploaded file")
        Error(w, http.StatusInternalServerError)
        return
    }
    defer file.Close()

    fileUUID := uuid.NewV4().String()
    path := "/photos/" + user + "/" + fileUUID + "/" + fileHeader.Filename

    img, imgType, err := image.Decode(file)
    if err != nil || (imgType != "jpeg" && imgType != "gif" && imgType != "png") {
        if err != nil {
            log.WithError(err).Error("error while parsing image")
        }
        Error(w, http.StatusUnsupportedMediaType)
        return
    }

    resized, err := resizeImage(img, imgType)
    if err != nil {
        raven.CaptureError(err, nil)
        log.WithError(err).Error("error while resizing photo")
        Error(w, http.StatusInternalServerError)
        return
    }

    res, err := uploader.Upload(&s3manager.UploadInput{
        Bucket:       aws.String("tigertrade"),
        CacheControl: aws.String("max-age=31536000, public"),
        Key:          aws.String(path),
        Body:         resized,
    })
    if err != nil {
        raven.CaptureError(err, nil)
        log.WithError(err).Error("error while uploading photo")
        Error(w, http.StatusInternalServerError)
        return
    }

    log.WithField("location", res.Location).Info("successfully uploaded file")

    w.WriteHeader(http.StatusCreated)
    Serve(w, map[string]string{
        "location": res.Location,
    })
}

func resizeImage(img image.Image, imgType string) (*bytes.Buffer, error) {
    var err error
    newImg := imaging.Fit(img, 900, 900, imaging.Lanczos)
    outBuf := new(bytes.Buffer)

    if imgType == "gif" {
        err = gif.Encode(outBuf, newImg, nil)
    } else if imgType == "jpeg" {
        err = jpeg.Encode(outBuf, newImg, &jpeg.Options{Quality: 60})
    } else {
        err = png.Encode(outBuf, newImg)
    }

    return outBuf, err
}