Refactor to use temp directory and update surf

Change from using res directory for image downloads to using temp directories.
Update surf to v2 which required changing the way Content-Type headers are
read from.

Cargo.toml

@@ -19,6 +19,6 @@ kuchiki = "0.8.1"
 lazy_static = "1.3.9"
 md5 = "0.7.0"
 regex = "1.3.9"
-surf = "1.0.3"
+surf = "2.1.0"
 structopt = { version = "0.3" }
 url = "2.1.1"

src/extractor.rs

@@ -62,22 +62,23 @@ impl Extractor {
     pub async fn download_images(&mut self, article_origin: &Url) -> async_std::io::Result<()> {
         let mut async_download_tasks = Vec::with_capacity(self.img_urls.len());
         self.extract_img_urls();
-        println!("Downloading images to res/");
+        println!("Downloading images...");
         for img_url in &self.img_urls {
             let img_url = img_url.0.clone();
             let abs_url = get_absolute_url(&img_url, article_origin);
+
             async_download_tasks.push(task::spawn(async move {
                 let mut img_response = surf::get(&abs_url).await.expect("Unable to retrieve file");
                 let img_content: Vec<u8> = img_response.body_bytes().await.unwrap();
                 let img_mime = img_response
-                    .header("Content-Type")
+                    .content_type()
-                    .map(|header| header.to_string());
+                    .map(|mime| mime.essence().to_string());
                 let img_ext = img_response
-                    .header("Content-Type")
+                    .content_type()
-                    .and_then(map_mime_type_to_ext)
+                    .map(|mime| map_mime_subtype_to_ext(mime.subtype()).to_string())
                     .unwrap();
-
+                let mut img_path = std::env::temp_dir();
-                let img_path = format!("res/{}{}", hash_url(&abs_url), &img_ext);
+                img_path.push(format!("{}.{}", hash_url(&abs_url), &img_ext));
                 let mut img_file = File::create(&img_path)
                     .await
                     .expect("Unable to create file");
@@ -86,7 +87,19 @@ impl Extractor {
                     .await
                     .expect("Unable to save to file");
 
-                (img_url, img_path, img_mime)
+                (
+                    img_url,
+                    img_path
+                        .file_name()
+                        .map(|os_str_name| {
+                            os_str_name
+                                .to_str()
+                                .expect("Unable to get image file name")
+                                .to_string()
+                        })
+                        .unwrap(),
+                    img_mime,
+                )
             }));
         }
 
@@ -123,21 +136,15 @@ fn hash_url(url: &str) -> String {
     format!("{:x}", md5::compute(url.as_bytes()))
 }
 
-/// Handles getting the extension from a given MIME type. The extension starts with a dot
+/// Handles getting the extension from a given MIME subtype.
-fn map_mime_type_to_ext(mime_type: &str) -> Option<String> {
+fn map_mime_subtype_to_ext(subtype: &str) -> &str {
-    mime_type
+    if subtype == ("svg+xml") {
-        .split("/")
+        return "svg";
-        .last()
+    } else if subtype == "x-icon" {
-        .map(|format| {
+        "ico"
-            if format == ("svg+xml") {
+    } else {
-                return "svg";
+        subtype
-            } else if format == "x-icon" {
+    }
-                "ico"
-            } else {
-                format
-            }
-        })
-        .map(|format| String::from(".") + format)
 }
 
 fn get_absolute_url(url: &str, request_url: &Url) -> String {
@@ -204,23 +211,15 @@ mod test {
 
     #[test]
     fn test_map_mime_type_to_ext() {
-        let mime_types = vec![
+        let mime_subtypes = vec![
-            "image/apng",
+            "apng", "bmp", "gif", "x-icon", "jpeg", "png", "svg+xml", "tiff", "webp",
-            "image/bmp",
-            "image/gif",
-            "image/x-icon",
-            "image/jpeg",
-            "image/png",
-            "image/svg+xml",
-            "image/tiff",
-            "image/webp",
         ];
-        let exts = mime_types
+        let exts = mime_subtypes
             .into_iter()
-            .map(|mime_type| map_mime_type_to_ext(mime_type).unwrap())
+            .map(|mime_type| map_mime_subtype_to_ext(mime_type))
             .collect::<Vec<_>>();
         assert_eq!(
-            vec![".apng", ".bmp", ".gif", ".ico", ".jpeg", ".png", ".svg", ".tiff", ".webp"],
+            vec!["apng", "bmp", "gif", "ico", "jpeg", "png", "svg", "tiff", "webp"],
             exts
         );
     }

src/main.rs

@@ -2,9 +2,8 @@
 extern crate lazy_static;
 
 use std::fs::File;
-use std::path::Path;
 
-use async_std::{fs::create_dir, fs::remove_dir_all, task};
+use async_std::task;
 use epub_builder::{EpubBuilder, EpubContent, ZipLibrary};
 use structopt::StructOpt;
 use url::Url;
@@ -50,11 +49,6 @@ fn download(urls: Vec<String>) {
             let mut extractor = Extractor::from_html(&html);
             extractor.extract_content(&url);
             if extractor.article().is_some() {
-                if !Path::new("res/").exists() {
-                    create_dir("res/")
-                        .await
-                        .expect("Unable to create res/ output folder");
-                }
                 extractor
                     .download_images(&Url::parse(&url).unwrap())
                     .await
@@ -79,14 +73,14 @@ fn download(urls: Vec<String>) {
                 epub.add_content(EpubContent::new("code.xhtml", html_buf.as_bytes()))
                     .unwrap();
                 for img in extractor.img_urls {
-                    let file_path = format!("{}", &img.0);
+                    let mut file_path = std::env::temp_dir();
+                    file_path.push(&img.0);
 
-                    let img_buf = File::open(file_path).expect("Can't read file");
+                    let img_buf = File::open(&file_path).expect("Can't read file");
-                    epub.add_resource(img.0, img_buf, img.1.unwrap()).unwrap();
+                    epub.add_resource(file_path.file_name().unwrap(), img_buf, img.1.unwrap())
+                        .unwrap();
                 }
                 epub.generate(&mut out_file).unwrap();
-                println!("Cleaning up");
-                remove_dir_all("res/").await.unwrap();
                 println!("Created {:?}", file_name);
             }
         }