Add support for merging articles into a single epub

This is still experimental as it lacks validation of the target file name

src/cli.rs

@@ -26,6 +26,13 @@ It takes a url and downloads the article content from it and saves it to an epub
                 .long("file")
                 .help("Input file containing links")
                 .takes_value(true),
+        )
+        .arg(
+            Arg::with_name("output_name")
+                .long("merge")
+                .help("Merge multiple articles into a single epub")
+                .long_help("Merge multiple articles into a single epub that will be given the name provided")
+                .takes_value(true),
         );
     let arg_matches = app.get_matches();
     let mut urls: Vec<String> = match arg_matches.value_of("file") {
@@ -57,12 +64,21 @@ It takes a url and downloads the article content from it and saves it to an epub
 
     let mut app_config = AppConfig::new();
     app_config.set_urls(urls);
+    if let Some(name) = arg_matches.value_of("output_name") {
+        let file_name = if name.ends_with(".epub") && name.len() > 5 {
+            name.to_owned()
+        } else {
+            name.to_owned() + ".epub"
+        };
+        app_config.set_merged(file_name);
+    }
     app_config
 }
 
 pub struct AppConfig {
     urls: Vec<String>,
     max_conn: usize,
+    merged: Option<String>,
 }
 
 impl AppConfig {
@@ -70,6 +86,7 @@ impl AppConfig {
         Self {
             urls: vec![],
             max_conn: 8,
+            merged: None,
         }
     }
 
@@ -77,10 +94,18 @@ impl AppConfig {
         self.urls.extend(urls);
     }
 
+    fn set_merged(&mut self, name: String) {
+        self.merged = Some(name);
+    }
+
     pub fn urls(&self) -> &Vec<String> {
         &self.urls
     }
     pub fn max_conn(&self) -> usize {
         self.max_conn
     }
+
+    pub fn merged(&self) -> Option<&String> {
+        self.merged.as_ref()
+    }
 }

src/epub.rs

@@ -4,10 +4,52 @@ use epub_builder::{EpubBuilder, EpubContent, ZipLibrary};
 
 use crate::extractor::{self, Extractor};
 
-pub fn generate_epub(extractor: Extractor) {
+pub fn generate_epubs(articles: Vec<Extractor>, merged: Option<&String>) {
+    match merged {
+        Some(name) => {
+            let mut epub = EpubBuilder::new(ZipLibrary::new().unwrap()).unwrap();
+            epub.inline_toc();
+            epub = articles
+                .iter()
+                .enumerate()
+                .fold(epub, |mut epub, (idx, article)| {
+                    let mut html_buf = Vec::new();
+                    extractor::serialize_to_xhtml(article.article().unwrap(), &mut html_buf)
+                        .expect("Unable to serialize to xhtml");
+                    let html_str = std::str::from_utf8(&html_buf).unwrap();
+                    epub.metadata("title", replace_metadata_value(name))
+                        .unwrap();
+                    let section_name = article.metadata().title();
+                    epub.add_content(
+                        EpubContent::new(format!("article_{}.xhtml", idx), html_str.as_bytes())
+                            .title(replace_metadata_value(section_name)),
+                    )
+                    .unwrap();
+
+                    article.img_urls.iter().for_each(|img| {
+                        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");
+                        epub.add_resource(
+                            file_path.file_name().unwrap(),
+                            img_buf,
+                            img.1.as_ref().unwrap(),
+                        )
+                        .unwrap();
+                    });
+                    epub
+                });
+            let mut out_file = File::create(&name).unwrap();
+            epub.generate(&mut out_file).unwrap();
+            println!("Created {:?}", name);
+        }
+        None => {
+            for article in articles {
+                let mut epub = EpubBuilder::new(ZipLibrary::new().unwrap()).unwrap();
                 let file_name = format!(
                     "{}.epub",
-        extractor
+                    article
                         .metadata()
                         .title()
                         .replace("/", " ")
@@ -15,22 +57,18 @@ pub fn generate_epub(extractor: Extractor) {
                 );
                 let mut out_file = File::create(&file_name).unwrap();
                 let mut html_buf = Vec::new();
-    extractor::serialize_to_xhtml(extractor.article().unwrap(), &mut html_buf)
+                extractor::serialize_to_xhtml(article.article().unwrap(), &mut html_buf)
                     .expect("Unable to serialize to xhtml");
-    let html_buf = std::str::from_utf8(&html_buf).unwrap();
+                let html_str = std::str::from_utf8(&html_buf).unwrap();
-    let mut epub = EpubBuilder::new(ZipLibrary::new().unwrap()).unwrap();
+                if let Some(author) = article.metadata().byline() {
-    if let Some(author) = extractor.metadata().byline() {
                     epub.metadata("author", replace_metadata_value(author))
                         .unwrap();
                 }
-    epub.metadata(
+                epub.metadata("title", replace_metadata_value(article.metadata().title()))
-        "title",
-        replace_metadata_value(extractor.metadata().title()),
-    )
                     .unwrap();
-    epub.add_content(EpubContent::new("index.xhtml", html_buf.as_bytes()))
+                epub.add_content(EpubContent::new("index.xhtml", html_str.as_bytes()))
                     .unwrap();
-    for img in extractor.img_urls {
+                for img in article.img_urls {
                     let mut file_path = std::env::temp_dir();
                     file_path.push(&img.0);
 
@@ -41,6 +79,9 @@ pub fn generate_epub(extractor: Extractor) {
                 epub.generate(&mut out_file).unwrap();
                 println!("Created {:?}", file_name);
             }
+        }
+    }
+}
 
 /// Replaces characters that have to be escaped before adding to the epub's metadata
 fn replace_metadata_value(value: &str) -> String {

src/main.rs

@@ -15,7 +15,7 @@ mod http;
 mod moz_readability;
 
 use cli::AppConfig;
-use epub::generate_epub;
+use epub::generate_epubs;
 use extractor::Extractor;
 use http::{download_images, fetch_url};
 
@@ -28,9 +28,10 @@ fn main() {
 }
 
 fn download(app_config: AppConfig) {
-    task::block_on(async {
+    let articles = task::block_on(async {
         let urls_iter = app_config.urls().iter().map(|url| fetch_url(url));
         let mut responses = stream::from_iter(urls_iter).buffered(app_config.max_conn());
+        let mut articles = Vec::new();
         while let Some(fetch_result) = responses.next().await {
             match fetch_result {
                 Ok((url, html)) => {
@@ -43,11 +44,13 @@ fn download(app_config: AppConfig) {
                         download_images(&mut extractor, &Url::parse(&url).unwrap())
                             .await
                             .expect("Unable to download images");
-                        generate_epub(extractor);
+                        articles.push(extractor);
                     }
                 }
                 Err(e) => println!("{}", e),
             }
         }
-    })
+        articles
+    });
+    generate_epubs(articles, app_config.merged());
 }