如何在 Django 中處理用戶圖片並自動轉換為 WebP 格式

from django.db import models
from django.contrib.auth.models import User
from PIL import Image
from io import BytesIO
import boto3
import uuid
from django.conf import settings


class Profile(models.Model):
    user = models.OneToOneField(User, on_delete=models.CASCADE, related_name="profile")
    photo = models.ImageField(upload_to="profile_photos/", blank=True, null=True)
    bio = models.TextField(max_length=200, null=True)
    location = models.CharField(max_length=50, null=True)
    is_client = models.BooleanField(default=True, null=True)
    is_freelancer = models.BooleanField(default=False, null=True)
    freelancer_verified = models.BooleanField(default=False, null=True)

    def save(self, *args, **kwargs):
        """
        保存模型時，自動將上傳的圖片轉換為 WebP 格式並上傳到 AWS S3，
        同時將 photo 字段更新為 WebP 圖片的 S3 URL。
        """
        # 保存原始圖片，確保能獲取文件對象
        super().save(*args, **kwargs)

        if self.photo:  # 確保 photo 字段存在
            try:
                # 打開圖片並轉換為 WebP 格式
                image = Image.open(self.photo)
                webp_image_io = BytesIO()
                image.save(webp_image_io, format="WEBP", quality=85)
                webp_image_io.seek(0)

                # 生成唯一文件名
                unique_filename = f"profile_photos/{uuid.uuid4()}.webp"

                # 上傳到 S3
                s3 = boto3.client('s3', region_name=settings.AWS_S3_REGION_NAME)
                s3.upload_fileobj(
                    webp_image_io,
                    settings.AWS_STORAGE_BUCKET_NAME,
                    unique_filename,
                    ExtraArgs={"ContentType": "image/webp"}
                )

                # 覆蓋 photo 字段為 WebP 文件的 S3 URL
                self.photo.name = unique_filename

                # 再次保存模型，更新 photo 字段
                super().save(*args, **kwargs)
            except Exception as e:
                print(f"圖片處理或上傳失敗：{e}")

    def __str__(self):
        """
        返回用戶名及其 Profile 的表示。
        """
        return f"{self.user.username}'s Profile"

AWS_S3_REGION_NAME = "your-region"  # 例如 "us-east-1"
AWS_STORAGE_BUCKET_NAME = "your-bucket-name"
AWS_ACCESS_KEY_ID = "your-access-key"
AWS_SECRET_ACCESS_KEY = "your-secret-key"