file.go 20.4 KB
Newer Older
1
// Copyright (c) 2017-present Mattermost, Inc. All Rights Reserved.
2 3 4 5 6 7 8 9 10
// See License.txt for license information.

package app

import (
	"bytes"
	"crypto/sha256"
	"encoding/base64"
	"fmt"
11 12 13
	"image"
	"image/color"
	"image/draw"
14
	_ "image/gif"
15
	"image/jpeg"
16 17
	"io"
	"io/ioutil"
18
	"mime/multipart"
19
	"net/http"
20 21 22 23 24 25 26 27
	"net/url"
	"os"
	"path"
	"path/filepath"
	"strings"
	"sync"

	l4g "github.com/alecthomas/log4go"
28
	"github.com/disintegration/imaging"
29 30 31
	"github.com/mattermost/platform/model"
	"github.com/mattermost/platform/utils"
	s3 "github.com/minio/minio-go"
32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56
	"github.com/rwcarlsen/goexif/exif"
	_ "golang.org/x/image/bmp"
)

const (
	/*
	  EXIF Image Orientations
	  1        2       3      4         5            6           7          8

	  888888  888888      88  88      8888888888  88                  88  8888888888
	  88          88      88  88      88  88      88  88          88  88      88  88
	  8888      8888    8888  8888    88          8888888888  8888888888          88
	  88          88      88  88
	  88          88  888888  888888
	*/
	Upright            = 1
	UprightMirrored    = 2
	UpsideDown         = 3
	UpsideDownMirrored = 4
	RotatedCWMirrored  = 5
	RotatedCCW         = 6
	RotatedCCWMirrored = 7
	RotatedCW          = 8

	MaxImageSize = 6048 * 4032 // 24 megapixels, roughly 36MB as a raw image
57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86
)

func ReadFile(path string) ([]byte, *model.AppError) {
	if utils.Cfg.FileSettings.DriverName == model.IMAGE_DRIVER_S3 {
		endpoint := utils.Cfg.FileSettings.AmazonS3Endpoint
		accessKey := utils.Cfg.FileSettings.AmazonS3AccessKeyId
		secretKey := utils.Cfg.FileSettings.AmazonS3SecretAccessKey
		secure := *utils.Cfg.FileSettings.AmazonS3SSL
		s3Clnt, err := s3.New(endpoint, accessKey, secretKey, secure)
		if err != nil {
			return nil, model.NewLocAppError("ReadFile", "api.file.read_file.s3.app_error", nil, err.Error())
		}
		bucket := utils.Cfg.FileSettings.AmazonS3Bucket
		minioObject, err := s3Clnt.GetObject(bucket, path)
		defer minioObject.Close()
		if err != nil {
			return nil, model.NewLocAppError("ReadFile", "api.file.read_file.s3.app_error", nil, err.Error())
		}
		if f, err := ioutil.ReadAll(minioObject); err != nil {
			return nil, model.NewLocAppError("ReadFile", "api.file.read_file.s3.app_error", nil, err.Error())
		} else {
			return f, nil
		}
	} else if utils.Cfg.FileSettings.DriverName == model.IMAGE_DRIVER_LOCAL {
		if f, err := ioutil.ReadFile(utils.Cfg.FileSettings.Directory + path); err != nil {
			return nil, model.NewLocAppError("ReadFile", "api.file.read_file.reading_local.app_error", nil, err.Error())
		} else {
			return f, nil
		}
	} else {
87
		return nil, model.NewAppError("ReadFile", "api.file.read_file.configured.app_error", nil, "", http.StatusNotImplemented)
88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321
	}
}

func MoveFile(oldPath, newPath string) *model.AppError {
	if utils.Cfg.FileSettings.DriverName == model.IMAGE_DRIVER_S3 {
		endpoint := utils.Cfg.FileSettings.AmazonS3Endpoint
		accessKey := utils.Cfg.FileSettings.AmazonS3AccessKeyId
		secretKey := utils.Cfg.FileSettings.AmazonS3SecretAccessKey
		secure := *utils.Cfg.FileSettings.AmazonS3SSL
		s3Clnt, err := s3.New(endpoint, accessKey, secretKey, secure)
		if err != nil {
			return model.NewLocAppError("moveFile", "api.file.write_file.s3.app_error", nil, err.Error())
		}
		bucket := utils.Cfg.FileSettings.AmazonS3Bucket

		var copyConds = s3.NewCopyConditions()
		if err = s3Clnt.CopyObject(bucket, newPath, "/"+path.Join(bucket, oldPath), copyConds); err != nil {
			return model.NewLocAppError("moveFile", "api.file.move_file.delete_from_s3.app_error", nil, err.Error())
		}
		if err = s3Clnt.RemoveObject(bucket, oldPath); err != nil {
			return model.NewLocAppError("moveFile", "api.file.move_file.delete_from_s3.app_error", nil, err.Error())
		}
	} else if utils.Cfg.FileSettings.DriverName == model.IMAGE_DRIVER_LOCAL {
		if err := os.MkdirAll(filepath.Dir(utils.Cfg.FileSettings.Directory+newPath), 0774); err != nil {
			return model.NewLocAppError("moveFile", "api.file.move_file.rename.app_error", nil, err.Error())
		}

		if err := os.Rename(utils.Cfg.FileSettings.Directory+oldPath, utils.Cfg.FileSettings.Directory+newPath); err != nil {
			return model.NewLocAppError("moveFile", "api.file.move_file.rename.app_error", nil, err.Error())
		}
	} else {
		return model.NewLocAppError("moveFile", "api.file.move_file.configured.app_error", nil, "")
	}

	return nil
}

func WriteFile(f []byte, path string) *model.AppError {
	if utils.Cfg.FileSettings.DriverName == model.IMAGE_DRIVER_S3 {
		endpoint := utils.Cfg.FileSettings.AmazonS3Endpoint
		accessKey := utils.Cfg.FileSettings.AmazonS3AccessKeyId
		secretKey := utils.Cfg.FileSettings.AmazonS3SecretAccessKey
		secure := *utils.Cfg.FileSettings.AmazonS3SSL
		s3Clnt, err := s3.New(endpoint, accessKey, secretKey, secure)
		if err != nil {
			return model.NewLocAppError("WriteFile", "api.file.write_file.s3.app_error", nil, err.Error())
		}
		bucket := utils.Cfg.FileSettings.AmazonS3Bucket
		ext := filepath.Ext(path)

		if model.IsFileExtImage(ext) {
			_, err = s3Clnt.PutObject(bucket, path, bytes.NewReader(f), model.GetImageMimeType(ext))
		} else {
			_, err = s3Clnt.PutObject(bucket, path, bytes.NewReader(f), "binary/octet-stream")
		}
		if err != nil {
			return model.NewLocAppError("WriteFile", "api.file.write_file.s3.app_error", nil, err.Error())
		}
	} else if utils.Cfg.FileSettings.DriverName == model.IMAGE_DRIVER_LOCAL {
		if err := writeFileLocally(f, utils.Cfg.FileSettings.Directory+path); err != nil {
			return err
		}
	} else {
		return model.NewLocAppError("WriteFile", "api.file.write_file.configured.app_error", nil, "")
	}

	return nil
}

func writeFileLocally(f []byte, path string) *model.AppError {
	if err := os.MkdirAll(filepath.Dir(path), 0774); err != nil {
		directory, _ := filepath.Abs(filepath.Dir(path))
		return model.NewLocAppError("WriteFile", "api.file.write_file_locally.create_dir.app_error", nil, "directory="+directory+", err="+err.Error())
	}

	if err := ioutil.WriteFile(path, f, 0644); err != nil {
		return model.NewLocAppError("WriteFile", "api.file.write_file_locally.writing.app_error", nil, err.Error())
	}

	return nil
}

func openFileWriteStream(path string) (io.Writer, *model.AppError) {
	if utils.Cfg.FileSettings.DriverName == model.IMAGE_DRIVER_S3 {
		return nil, model.NewLocAppError("openFileWriteStream", "api.file.open_file_write_stream.s3.app_error", nil, "")
	} else if utils.Cfg.FileSettings.DriverName == model.IMAGE_DRIVER_LOCAL {
		if err := os.MkdirAll(filepath.Dir(utils.Cfg.FileSettings.Directory+path), 0774); err != nil {
			return nil, model.NewLocAppError("openFileWriteStream", "api.file.open_file_write_stream.creating_dir.app_error", nil, err.Error())
		}

		if fileHandle, err := os.Create(utils.Cfg.FileSettings.Directory + path); err != nil {
			return nil, model.NewLocAppError("openFileWriteStream", "api.file.open_file_write_stream.local_server.app_error", nil, err.Error())
		} else {
			fileHandle.Chmod(0644)
			return fileHandle, nil
		}
	}

	return nil, model.NewLocAppError("openFileWriteStream", "api.file.open_file_write_stream.configured.app_error", nil, "")
}

func closeFileWriteStream(file io.Writer) {
	file.(*os.File).Close()
}

func GetInfoForFilename(post *model.Post, teamId string, filename string) *model.FileInfo {
	// Find the path from the Filename of the form /{channelId}/{userId}/{uid}/{nameWithExtension}
	split := strings.SplitN(filename, "/", 5)
	if len(split) < 5 {
		l4g.Error(utils.T("api.file.migrate_filenames_to_file_infos.unexpected_filename.error"), post.Id, filename)
		return nil
	}

	channelId := split[1]
	userId := split[2]
	oldId := split[3]
	name, _ := url.QueryUnescape(split[4])

	if split[0] != "" || split[1] != post.ChannelId || split[2] != post.UserId || strings.Contains(split[4], "/") {
		l4g.Warn(utils.T("api.file.migrate_filenames_to_file_infos.mismatched_filename.warn"), post.Id, post.ChannelId, post.UserId, filename)
	}

	pathPrefix := fmt.Sprintf("teams/%s/channels/%s/users/%s/%s/", teamId, channelId, userId, oldId)
	path := pathPrefix + name

	// Open the file and populate the fields of the FileInfo
	var info *model.FileInfo
	if data, err := ReadFile(path); err != nil {
		l4g.Error(utils.T("api.file.migrate_filenames_to_file_infos.file_not_found.error"), post.Id, filename, path, err)
		return nil
	} else {
		var err *model.AppError
		info, err = model.GetInfoForBytes(name, data)
		if err != nil {
			l4g.Warn(utils.T("api.file.migrate_filenames_to_file_infos.info.app_error"), post.Id, filename, err)
		}
	}

	// Generate a new ID because with the old system, you could very rarely get multiple posts referencing the same file
	info.Id = model.NewId()
	info.CreatorId = post.UserId
	info.PostId = post.Id
	info.CreateAt = post.CreateAt
	info.UpdateAt = post.UpdateAt
	info.Path = path

	if info.IsImage() {
		nameWithoutExtension := name[:strings.LastIndex(name, ".")]
		info.PreviewPath = pathPrefix + nameWithoutExtension + "_preview.jpg"
		info.ThumbnailPath = pathPrefix + nameWithoutExtension + "_thumb.jpg"
	}

	return info
}

func FindTeamIdForFilename(post *model.Post, filename string) string {
	split := strings.SplitN(filename, "/", 5)
	id := split[3]
	name, _ := url.QueryUnescape(split[4])

	// This post is in a direct channel so we need to figure out what team the files are stored under.
	if result := <-Srv.Store.Team().GetTeamsByUserId(post.UserId); result.Err != nil {
		l4g.Error(utils.T("api.file.migrate_filenames_to_file_infos.teams.app_error"), post.Id, result.Err)
	} else if teams := result.Data.([]*model.Team); len(teams) == 1 {
		// The user has only one team so the post must've been sent from it
		return teams[0].Id
	} else {
		for _, team := range teams {
			path := fmt.Sprintf("teams/%s/channels/%s/users/%s/%s/%s", team.Id, post.ChannelId, post.UserId, id, name)
			if _, err := ReadFile(path); err == nil {
				// Found the team that this file was posted from
				return team.Id
			}
		}
	}

	return ""
}

var fileMigrationLock sync.Mutex

// Creates and stores FileInfos for a post created before the FileInfos table existed.
func MigrateFilenamesToFileInfos(post *model.Post) []*model.FileInfo {
	if len(post.Filenames) == 0 {
		l4g.Warn(utils.T("api.file.migrate_filenames_to_file_infos.no_filenames.warn"), post.Id)
		return []*model.FileInfo{}
	}

	cchan := Srv.Store.Channel().Get(post.ChannelId, true)

	// There's a weird bug that rarely happens where a post ends up with duplicate Filenames so remove those
	filenames := utils.RemoveDuplicatesFromStringArray(post.Filenames)

	var channel *model.Channel
	if result := <-cchan; result.Err != nil {
		l4g.Error(utils.T("api.file.migrate_filenames_to_file_infos.channel.app_error"), post.Id, post.ChannelId, result.Err)
		return []*model.FileInfo{}
	} else {
		channel = result.Data.(*model.Channel)
	}

	// Find the team that was used to make this post since its part of the file path that isn't saved in the Filename
	var teamId string
	if channel.TeamId == "" {
		// This post was made in a cross-team DM channel so we need to find where its files were saved
		teamId = FindTeamIdForFilename(post, filenames[0])
	} else {
		teamId = channel.TeamId
	}

	// Create FileInfo objects for this post
	infos := make([]*model.FileInfo, 0, len(filenames))
	if teamId == "" {
		l4g.Error(utils.T("api.file.migrate_filenames_to_file_infos.team_id.error"), post.Id, filenames)
	} else {
		for _, filename := range filenames {
			info := GetInfoForFilename(post, teamId, filename)
			if info == nil {
				continue
			}

			infos = append(infos, info)
		}
	}

	// Lock to prevent only one migration thread from trying to update the post at once, preventing duplicate FileInfos from being created
	fileMigrationLock.Lock()
	defer fileMigrationLock.Unlock()

	if result := <-Srv.Store.Post().Get(post.Id); result.Err != nil {
		l4g.Error(utils.T("api.file.migrate_filenames_to_file_infos.get_post_again.app_error"), post.Id, result.Err)
		return []*model.FileInfo{}
	} else if newPost := result.Data.(*model.PostList).Posts[post.Id]; len(newPost.Filenames) != len(post.Filenames) {
		// Another thread has already created FileInfos for this post, so just return those
322
		if result := <-Srv.Store.FileInfo().GetForPost(post.Id, true, false); result.Err != nil {
323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361
			l4g.Error(utils.T("api.file.migrate_filenames_to_file_infos.get_post_file_infos_again.app_error"), post.Id, result.Err)
			return []*model.FileInfo{}
		} else {
			l4g.Debug(utils.T("api.file.migrate_filenames_to_file_infos.not_migrating_post.debug"), post.Id)
			return result.Data.([]*model.FileInfo)
		}
	}

	l4g.Debug(utils.T("api.file.migrate_filenames_to_file_infos.migrating_post.debug"), post.Id)

	savedInfos := make([]*model.FileInfo, 0, len(infos))
	fileIds := make([]string, 0, len(filenames))
	for _, info := range infos {
		if result := <-Srv.Store.FileInfo().Save(info); result.Err != nil {
			l4g.Error(utils.T("api.file.migrate_filenames_to_file_infos.save_file_info.app_error"), post.Id, info.Id, info.Path, result.Err)
			continue
		}

		savedInfos = append(savedInfos, info)
		fileIds = append(fileIds, info.Id)
	}

	// Copy and save the updated post
	newPost := &model.Post{}
	*newPost = *post

	newPost.Filenames = []string{}
	newPost.FileIds = fileIds

	// Update Posts to clear Filenames and set FileIds
	if result := <-Srv.Store.Post().Update(newPost, post); result.Err != nil {
		l4g.Error(utils.T("api.file.migrate_filenames_to_file_infos.save_post.app_error"), post.Id, newPost.FileIds, post.Filenames, result.Err)
		return []*model.FileInfo{}
	} else {
		return savedInfos
	}
}

func GeneratePublicLink(siteURL string, info *model.FileInfo) string {
362 363 364 365 366
	hash := GeneratePublicLinkHash(info.Id, *utils.Cfg.FileSettings.PublicLinkSalt)
	return fmt.Sprintf("%s/files/%v/public?h=%s", siteURL, info.Id, hash)
}

func GeneratePublicLinkV3(siteURL string, info *model.FileInfo) string {
367
	hash := GeneratePublicLinkHash(info.Id, *utils.Cfg.FileSettings.PublicLinkSalt)
368
	return fmt.Sprintf("%s%s/public/files/%v/get?h=%s", siteURL, model.API_URL_SUFFIX_V3, info.Id, hash)
369 370 371 372 373 374 375 376 377
}

func GeneratePublicLinkHash(fileId, salt string) string {
	hash := sha256.New()
	hash.Write([]byte(salt))
	hash.Write([]byte(fileId))

	return base64.RawURLEncoding.EncodeToString(hash.Sum(nil))
}
378

379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426
func UploadFiles(teamId string, channelId string, userId string, fileHeaders []*multipart.FileHeader, clientIds []string) (*model.FileUploadResponse, *model.AppError) {
	if len(utils.Cfg.FileSettings.DriverName) == 0 {
		return nil, model.NewAppError("uploadFile", "api.file.upload_file.storage.app_error", nil, "", http.StatusNotImplemented)
	}

	resStruct := &model.FileUploadResponse{
		FileInfos: []*model.FileInfo{},
		ClientIds: []string{},
	}

	previewPathList := []string{}
	thumbnailPathList := []string{}
	imageDataList := [][]byte{}

	for i, fileHeader := range fileHeaders {
		file, fileErr := fileHeader.Open()
		defer file.Close()
		if fileErr != nil {
			return nil, model.NewAppError("UploadFiles", "api.file.upload_file.bad_parse.app_error", nil, fileErr.Error(), http.StatusBadRequest)
		}

		buf := bytes.NewBuffer(nil)
		io.Copy(buf, file)
		data := buf.Bytes()

		info, err := DoUploadFile(teamId, channelId, userId, fileHeader.Filename, data)
		if err != nil {
			return nil, err
		}

		if info.PreviewPath != "" || info.ThumbnailPath != "" {
			previewPathList = append(previewPathList, info.PreviewPath)
			thumbnailPathList = append(thumbnailPathList, info.ThumbnailPath)
			imageDataList = append(imageDataList, data)
		}

		resStruct.FileInfos = append(resStruct.FileInfos, info)

		if len(clientIds) > 0 {
			resStruct.ClientIds = append(resStruct.ClientIds, clientIds[i])
		}
	}

	HandleImages(previewPathList, thumbnailPathList, imageDataList)

	return resStruct, nil
}

427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583
func DoUploadFile(teamId string, channelId string, userId string, rawFilename string, data []byte) (*model.FileInfo, *model.AppError) {
	filename := filepath.Base(rawFilename)

	info, err := model.GetInfoForBytes(filename, data)
	if err != nil {
		err.StatusCode = http.StatusBadRequest
		return nil, err
	}

	info.Id = model.NewId()
	info.CreatorId = userId

	pathPrefix := "teams/" + teamId + "/channels/" + channelId + "/users/" + userId + "/" + info.Id + "/"
	info.Path = pathPrefix + filename

	if info.IsImage() {
		// Check dimensions before loading the whole thing into memory later on
		if info.Width*info.Height > MaxImageSize {
			err := model.NewLocAppError("uploadFile", "api.file.upload_file.large_image.app_error", map[string]interface{}{"Filename": filename}, "")
			err.StatusCode = http.StatusBadRequest
			return nil, err
		}

		nameWithoutExtension := filename[:strings.LastIndex(filename, ".")]
		info.PreviewPath = pathPrefix + nameWithoutExtension + "_preview.jpg"
		info.ThumbnailPath = pathPrefix + nameWithoutExtension + "_thumb.jpg"
	}

	if err := WriteFile(data, info.Path); err != nil {
		return nil, err
	}

	if result := <-Srv.Store.FileInfo().Save(info); result.Err != nil {
		return nil, result.Err
	}

	return info, nil
}

func HandleImages(previewPathList []string, thumbnailPathList []string, fileData [][]byte) {
	for i, data := range fileData {
		go func(i int, data []byte) {
			img, width, height := prepareImage(fileData[i])
			if img != nil {
				go generateThumbnailImage(*img, thumbnailPathList[i], width, height)
				go generatePreviewImage(*img, previewPathList[i], width)
			}
		}(i, data)
	}
}

func prepareImage(fileData []byte) (*image.Image, int, int) {
	// Decode image bytes into Image object
	img, imgType, err := image.Decode(bytes.NewReader(fileData))
	if err != nil {
		l4g.Error(utils.T("api.file.handle_images_forget.decode.error"), err)
		return nil, 0, 0
	}

	width := img.Bounds().Dx()
	height := img.Bounds().Dy()

	// Fill in the background of a potentially-transparent png file as white
	if imgType == "png" {
		dst := image.NewRGBA(img.Bounds())
		draw.Draw(dst, dst.Bounds(), image.NewUniform(color.White), image.Point{}, draw.Src)
		draw.Draw(dst, dst.Bounds(), img, img.Bounds().Min, draw.Over)
		img = dst
	}

	// Flip the image to be upright
	orientation, _ := getImageOrientation(fileData)

	switch orientation {
	case UprightMirrored:
		img = imaging.FlipH(img)
	case UpsideDown:
		img = imaging.Rotate180(img)
	case UpsideDownMirrored:
		img = imaging.FlipV(img)
	case RotatedCWMirrored:
		img = imaging.Transpose(img)
	case RotatedCCW:
		img = imaging.Rotate270(img)
	case RotatedCCWMirrored:
		img = imaging.Transverse(img)
	case RotatedCW:
		img = imaging.Rotate90(img)
	}

	return &img, width, height
}

func getImageOrientation(imageData []byte) (int, error) {
	if exifData, err := exif.Decode(bytes.NewReader(imageData)); err != nil {
		return Upright, err
	} else {
		if tag, err := exifData.Get("Orientation"); err != nil {
			return Upright, err
		} else {
			orientation, err := tag.Int(0)
			if err != nil {
				return Upright, err
			} else {
				return orientation, nil
			}
		}
	}
}

func generateThumbnailImage(img image.Image, thumbnailPath string, width int, height int) {
	thumbWidth := float64(utils.Cfg.FileSettings.ThumbnailWidth)
	thumbHeight := float64(utils.Cfg.FileSettings.ThumbnailHeight)
	imgWidth := float64(width)
	imgHeight := float64(height)

	var thumbnail image.Image
	if imgHeight < thumbHeight && imgWidth < thumbWidth {
		thumbnail = img
	} else if imgHeight/imgWidth < thumbHeight/thumbWidth {
		thumbnail = imaging.Resize(img, 0, utils.Cfg.FileSettings.ThumbnailHeight, imaging.Lanczos)
	} else {
		thumbnail = imaging.Resize(img, utils.Cfg.FileSettings.ThumbnailWidth, 0, imaging.Lanczos)
	}

	buf := new(bytes.Buffer)
	if err := jpeg.Encode(buf, thumbnail, &jpeg.Options{Quality: 90}); err != nil {
		l4g.Error(utils.T("api.file.handle_images_forget.encode_jpeg.error"), thumbnailPath, err)
		return
	}

	if err := WriteFile(buf.Bytes(), thumbnailPath); err != nil {
		l4g.Error(utils.T("api.file.handle_images_forget.upload_thumb.error"), thumbnailPath, err)
		return
	}
}

func generatePreviewImage(img image.Image, previewPath string, width int) {
	var preview image.Image
	if width > int(utils.Cfg.FileSettings.PreviewWidth) {
		preview = imaging.Resize(img, utils.Cfg.FileSettings.PreviewWidth, utils.Cfg.FileSettings.PreviewHeight, imaging.Lanczos)
	} else {
		preview = img
	}

	buf := new(bytes.Buffer)

	if err := jpeg.Encode(buf, preview, &jpeg.Options{Quality: 90}); err != nil {
		l4g.Error(utils.T("api.file.handle_images_forget.encode_preview.error"), previewPath, err)
		return
	}

	if err := WriteFile(buf.Bytes(), previewPath); err != nil {
		l4g.Error(utils.T("api.file.handle_images_forget.upload_preview.error"), previewPath, err)
		return
	}
}
584 585 586 587 588 589 590 591

func GetFileInfo(fileId string) (*model.FileInfo, *model.AppError) {
	if result := <-Srv.Store.FileInfo().Get(fileId); result.Err != nil {
		return nil, result.Err
	} else {
		return result.Data.(*model.FileInfo), nil
	}
}