Add resampled image retrieval functionality and update image URLs

frontend/src/components/resource_card.tsx

@@ -24,7 +24,7 @@ export default function ResourceCard({ resource }: { resource: Resource }) {
         {resource.image != null && (
           <figure>
             <img
-              src={network.getImageUrl(resource.image.id)}
+              src={network.getResampledImageUrl(resource.image.id)}
               alt="cover"
               style={{
                 width: "100%",

frontend/src/network/network.ts

@@ -492,6 +492,10 @@ class Network {
     return `${this.apiBaseUrl}/image/${id}`;
   }
 
+  getResampledImageUrl(id: number): string {
+    return `${this.apiBaseUrl}/image/resampled/${id}`;
+  }
+
   async createResource(
     params: CreateResourceParams,
   ): Promise<Response<number>> {

go.mod

@@ -15,7 +15,10 @@ require (
 	gorm.io/driver/mysql v1.5.7
 )
 
-require github.com/go-sql-driver/mysql v1.7.0 // indirect
+require (
+	github.com/disintegration/imaging v1.6.2 // indirect
+	github.com/go-sql-driver/mysql v1.7.0 // indirect
+)
 
 require (
 	github.com/dustin/go-humanize v1.0.1 // indirect
@@ -47,8 +50,8 @@ require (
 	github.com/valyala/bytebufferpool v1.0.0 // indirect
 	github.com/valyala/fasthttp v1.61.0 // indirect
 	github.com/x448/float16 v0.8.4 // indirect
-	golang.org/x/image v0.27.0
+	golang.org/x/image v0.28.0
 	golang.org/x/net v0.39.0 // indirect
 	golang.org/x/sys v0.32.0 // indirect
-	golang.org/x/text v0.25.0 // indirect
+	golang.org/x/text v0.26.0 // indirect
 )

go.sum

@@ -4,6 +4,8 @@ github.com/chai2010/webp v1.4.0 h1:6DA2pkkRUPnbOHvvsmGI3He1hBKf/bkRlniAiSGuEko=
 github.com/chai2010/webp v1.4.0/go.mod h1:0XVwvZWdjjdxpUEIf7b9g9VkHFnInUSYujwqTLEuldU=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/disintegration/imaging v1.6.2 h1:w1LecBlG2Lnp8B3jk5zSuNqd7b4DXhcjwek1ei82L+c=
+github.com/disintegration/imaging v1.6.2/go.mod h1:44/5580QXChDfwIclfc/PCwrr44amcmDAg8hxG0Ewe4=
 github.com/dustin/go-humanize v1.0.1 h1:GzkhY7T5VNhEkwH0PVJgjz+fX1rhBrR7pRT3mDkpeCY=
 github.com/dustin/go-humanize v1.0.1/go.mod h1:Mu1zIs6XwVuF/gI1OepvI0qD18qycQx+mFykh5fBlto=
 github.com/fxamacker/cbor/v2 v2.8.0 h1:fFtUGXUzXPHTIUdne5+zzMPTfffl3RD5qYnkY40vtxU=
@@ -78,8 +80,11 @@ github.com/xyproto/randomstring v1.0.5/go.mod h1:rgmS5DeNXLivK7YprL0pY+lTuhNQW3i
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.37.0 h1:kJNSjF/Xp7kU0iB2Z+9viTPMW4EqqsrywMXLJOOsXSE=
 golang.org/x/crypto v0.37.0/go.mod h1:vg+k43peMZ0pUMhYmVAWysMK35e6ioLh3wB8ZCAfbVc=
+golang.org/x/image v0.0.0-20191009234506-e7c1f5e7dbb8/go.mod h1:FeLwcggjj3mMvU+oOTbSwawSJRM1uh48EjtB4UJZlP0=
 golang.org/x/image v0.27.0 h1:C8gA4oWU/tKkdCfYT6T2u4faJu3MeNS5O8UPWlPF61w=
 golang.org/x/image v0.27.0/go.mod h1:xbdrClrAUway1MUTEZDq9mz/UpRwYAkFFNUslZtcB+g=
+golang.org/x/image v0.28.0 h1:gdem5JW1OLS4FbkWgLO+7ZeFzYtL3xClb97GaUzYMFE=
+golang.org/x/image v0.28.0/go.mod h1:GUJYXtnGKEUgggyzh+Vxt+AviiCcyiwpsl8iQ8MvwGY=
 golang.org/x/net v0.0.0-20190311183353-d8887717615a/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/net v0.39.0 h1:ZCu7HMWDxpXpaiKdhzIfaltL9Lp31x/3fCP11bc6/fY=
 golang.org/x/net v0.39.0/go.mod h1:X7NRbYVEA+ewNkCNyJ513WmMdQ3BineSwVtN2zD/d+E=
@@ -90,6 +95,8 @@ golang.org/x/sys v0.32.0/go.mod h1:BJP2sWEmIv4KK5OTEluFJCKSidICx8ciO85XgH3Ak8k=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.25.0 h1:qVyWApTSYLk/drJRO5mDlNYskwQznZmkpV2c8q9zls4=
 golang.org/x/text v0.25.0/go.mod h1:WEdwpYrmk1qmdHvhkSTNPm3app7v4rsT8F2UD6+VHIA=
+golang.org/x/text v0.26.0 h1:P42AVeLghgTYr4+xUnTRKDMqpar+PtX7KWuNQL21L8M=
+golang.org/x/text v0.26.0/go.mod h1:QK15LZJUUQVJxhz7wXgxSy/CJaTFjd0G+YLonydOVQA=
 golang.org/x/tools v0.0.0-20190328211700-ab21143f2384/go.mod h1:LCzVGOaR6xXOjkQ3onu1FJEFr0SW1gC7cKk1uF8kGRs=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

server/api/image.go

@@ -71,10 +71,30 @@ func handleDeleteImage(c fiber.Ctx) error {
 	})
 }
 
+func handleGetResampledImage(c fiber.Ctx) error {
+	idStr := c.Params("id")
+	if idStr == "" {
+		return model.NewRequestError("Image ID is required")
+	}
+	id, err := strconv.Atoi(idStr)
+	if err != nil {
+		return model.NewRequestError("Invalid image ID")
+	}
+	image, err := service.GetResampledImage(uint(id))
+	if err != nil {
+		return err
+	}
+	contentType := http.DetectContentType(image)
+	c.Set("Content-Type", contentType)
+	c.Set("Cache-Control", "public, max-age=31536000")
+	return c.Send(image)
+}
+
 func AddImageRoutes(api fiber.Router) {
 	image := api.Group("/image")
 	{
 		image.Put("/", handleUploadImage)
+		image.Get("/resampled/:id", handleGetResampledImage)
 		image.Get("/:id", handleGetImage)
 		image.Delete("/:id", handleDeleteImage)
 	}

server/service/image.go

@@ -3,12 +3,14 @@ package service
 import (
 	"bytes"
 	"errors"
+	"github.com/disintegration/imaging"
 	"image"
 	"net/http"
 	"nysoure/server/dao"
 	"nysoure/server/model"
 	"nysoure/server/utils"
 	"os"
+	"strconv"
 	"time"
 
 	"github.com/gofiber/fiber/v3/log"
@@ -24,6 +26,10 @@ import (
 	"github.com/chai2010/webp"
 )
 
+const (
+	resampledMaxPixels = 1280 * 720
+)
+
 func init() {
 	// Start a goroutine to delete unused images every hour
 	go func() {
@@ -152,11 +158,83 @@ func deleteImage(id uint) error {
 	}
 
 	imageDir := utils.GetStoragePath() + "/images/"
-
 	_ = os.Remove(imageDir + i.FileName)
 
+	resampledDir := utils.GetStoragePath() + "/resampled/"
+	_ = os.Remove(resampledDir + strconv.Itoa(int(i.ID)) + ".webp")
+
 	if err := dao.DeleteImage(id); err != nil {
 		return err
 	}
 	return nil
 }
+
+func GetResampledImage(id uint) ([]byte, error) {
+	i, err := dao.GetImageByID(id)
+	if err != nil {
+		return nil, err
+	}
+
+	data, err := getOrCreateResampledImage(i)
+	if err != nil {
+		log.Error("Error getting or creating resampled image:", err)
+		return nil, model.NewInternalServerError("Error processing image")
+	}
+
+	return data, nil
+}
+
+func getOrCreateResampledImage(i model.Image) ([]byte, error) {
+	baseDir := utils.GetStoragePath() + "/resampled/"
+	if _, err := os.Stat(baseDir); os.IsNotExist(err) {
+		if err := os.MkdirAll(baseDir, 0755); err != nil {
+			return nil, err
+		}
+	}
+
+	resampledFilepath := baseDir + strconv.Itoa(int(i.ID)) + ".webp"
+	if _, err := os.Stat(resampledFilepath); err != nil {
+		if !os.IsNotExist(err) {
+			return nil, err
+		}
+	} else {
+		return os.ReadFile(resampledFilepath)
+	}
+
+	originalFilepath := utils.GetStoragePath() + "/images/" + i.FileName
+	if _, err := os.Stat(originalFilepath); os.IsNotExist(err) {
+		return nil, model.NewNotFoundError("Original image not found")
+	}
+	imgData, err := os.ReadFile(originalFilepath)
+	if err != nil {
+		return nil, errors.New("failed to read original image file")
+	}
+	if i.Width*i.Height <= resampledMaxPixels {
+		return imgData, nil
+	}
+
+	log.Info("Resampling image", "id", i.ID, "original size", i.Width, "x", i.Height)
+	img, _, err := image.Decode(bytes.NewReader(imgData))
+	if err != nil {
+		return nil, errors.New("failed to decode original image data")
+	}
+	pixels := img.Bounds().Dx() * img.Bounds().Dy()
+	if pixels <= resampledMaxPixels {
+		return imgData, nil // No need to resample if the image is small enough
+	}
+
+	scale := float64(resampledMaxPixels) / float64(pixels)
+	dstWidth := int(float64(img.Bounds().Dx()) * scale)
+	dstHeight := int(float64(img.Bounds().Dy()) * scale)
+	dstImg := imaging.Resize(img, dstWidth, dstHeight, imaging.Lanczos)
+
+	buf := new(bytes.Buffer)
+	if err := webp.Encode(buf, dstImg, &webp.Options{Quality: 80}); err != nil {
+		return nil, errors.New("failed to encode resampled image data to webp format")
+	}
+	if err := os.WriteFile(resampledFilepath, buf.Bytes(), 0644); err != nil {
+		return nil, errors.New("failed to save resampled image file")
+	}
+
+	return buf.Bytes(), nil
+}