Add ThumbnailResponse struct with content_type and extension helper

examples/thumbnail.rs

@@ -14,37 +14,58 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
 
     // Download thumbnail (small size, default)
     println!("Downloading thumbnail...");
-    let thumbnail = client
+    let response = client
         .assets()
         .thumbnail(asset_id)
         .size(AssetMediaSize::Thumbnail)
         .execute()
         .await?;
 
-    fs::write("/path/to/output/thumbnail.jpg", &thumbnail)?;
-    println!("Saved thumbnail: {} bytes", thumbnail.len());
+    println!("Content type: {}", response.content_type());
+    println!("Extension: {:?}", response.extension());
+
+    let ext = response.extension().unwrap_or("jpg");
+    let output_path = format!("/path/to/output/thumbnail.{}", ext);
+    fs::write(&output_path, response.data())?;
+    println!(
+        "Saved thumbnail: {} bytes to {}",
+        response.data().len(),
+        output_path
+    );
 
     // Download preview (medium size)
-    let preview = client
+    let response = client
         .assets()
         .thumbnail(asset_id)
         .size(AssetMediaSize::Preview)
         .execute()
         .await?;
 
-    fs::write("/path/to/output/preview.jpg", &preview)?;
-    println!("Saved preview: {} bytes", preview.len());
+    let ext = response.extension().unwrap_or("jpg");
+    let output_path = format!("/path/to/output/preview.{}", ext);
+    fs::write(&output_path, response.data())?;
+    println!(
+        "Saved preview: {} bytes to {}",
+        response.data().len(),
+        output_path
+    );
 
     // Download fullsize
-    let fullsize = client
+    let response = client
         .assets()
         .thumbnail(asset_id)
         .size(AssetMediaSize::Fullsize)
         .execute()
         .await?;
 
-    fs::write("/path/to/output/fullsize.jpg", &fullsize)?;
-    println!("Saved fullsize: {} bytes", fullsize.len());
+    let ext = response.extension().unwrap_or("jpg");
+    let output_path = format!("/path/to/output/fullsize.{}", ext);
+    fs::write(&output_path, response.data())?;
+    println!(
+        "Saved fullsize: {} bytes to {}",
+        response.data().len(),
+        output_path
+    );
 
     Ok(())
 }

src/apis/assets.rs

@@ -8,6 +8,44 @@ use crate::{
     models::{AssetId, AssetMediaSize, AssetResponse, AssetUploadResponse, DeleteAssetsRequest},
 };
 
+/// Response from downloading a thumbnail containing image data and metadata
+#[derive(Debug, Clone)]
+pub struct ThumbnailResponse {
+    /// The image data as bytes
+    pub data: bytes::Bytes,
+    /// The MIME type of the image (e.g., "image/jpeg", "image/png", "image/webp")
+    pub content_type: String,
+}
+
+impl ThumbnailResponse {
+    /// Get the file extension based on content type
+    pub fn extension(&self) -> Option<&str> {
+        match self.content_type.as_str() {
+            "image/jpeg" | "image/jpg" => Some("jpg"),
+            "image/png" => Some("png"),
+            "image/webp" => Some("webp"),
+            "image/gif" => Some("gif"),
+            "image/tiff" => Some("tiff"),
+            _ => None,
+        }
+    }
+
+    /// Get the content type
+    pub fn content_type(&self) -> &str {
+        &self.content_type
+    }
+
+    /// Get the data
+    pub fn data(&self) -> &bytes::Bytes {
+        &self.data
+    }
+
+    /// Convert to owned bytes
+    pub fn into_data(self) -> bytes::Bytes {
+        self.data
+    }
+}
+
 /// API for managing assets (photos and videos)
 #[derive(Debug, Clone)]
 pub struct AssetsApi {
@@ -338,7 +376,7 @@ impl ThumbnailBuilder {
     }
 
     /// Execute the request
-    pub async fn execute(self) -> Result<bytes::Bytes> {
+    pub async fn execute(self) -> Result<ThumbnailResponse> {
         let path = format!("/assets/{}/thumbnail", self.id);
         let mut req = self.client.get(&path);
 
@@ -357,7 +395,17 @@ impl ThumbnailBuilder {
         }
 
         let response = self.client.execute(req.build()?).await?;
-        let bytes = response.bytes().await?;
-        Ok(bytes)
+
+        // Get content type from response headers
+        let content_type = response
+            .headers()
+            .get("content-type")
+            .and_then(|ct| ct.to_str().ok())
+            .map(String::from)
+            .unwrap_or_else(|| "application/octet-stream".to_string());
+
+        let data = response.bytes().await?;
+
+        Ok(ThumbnailResponse { data, content_type })
     }
 }