feature: Allows for specifying a cover image for your book

3 files changed, 35 insertions, 2 deletions

diff --git a/src/epub.rs b/src/epub.rs
index 10e5937..765f213 100644
--- a/src/epub.rs
+++ b/src/epub.rs
@@ -100,6 +100,21 @@ fn install_fonts(assets : &PathBuf, fonts : &Vec<&str>) -> Result<(), Error> {
     Ok(())
 }
 
+fn install_cover(cover : &PathBuf) -> Result<String, Error> {
+    let extension = cover.extension()
+        .ok_or(Error(String::from("cover lacks an extension")))?
+        .to_str()
+        .ok_or(Error(String::from("cover extension is not valid utf-8")))?;
+
+    let mut dst = PathBuf::from("OEBPS");
+    dst.push(format!("cover.{}", extension));
+
+    std::fs::copy(cover, dst)
+        .map_err(|_| Error(format!("cannot copy {:?}", cover)))?;
+
+    Ok(extension.into())
+}
+
 pub fn generate(project : &Project<String>, assets : &PathBuf) -> Result<(), Error> {
 
     let tera = compile_templates!(template_dir(assets)?.as_str());
@@ -116,6 +131,10 @@ pub fn generate(project : &Project<String>, assets : &PathBuf) -> Result<(), Err
         &PathBuf::from("OEBPS/Style/main.css")
     )?;
 
+    let cover_extension = project.cover.clone().map(|cov| install_cover(&cov))
+    // from Option<Result<_, E>> to Result<Option<_>, E>
+        .map_or(Ok(None), |r| r.map(Some))?;
+
     let fonts = vec![
         "et-book-roman-line-figures.ttf",
         "et-book-bold-line-figures.ttf",
@@ -127,6 +146,7 @@ pub fn generate(project : &Project<String>, assets : &PathBuf) -> Result<(), Err
     let mut ctx = Context::new();
     ctx.insert("title", &project.title);
     ctx.insert("author", &project.author);
+    ctx.insert("cover_extension", &cover_extension);
     ctx.insert("files", &files);
     ctx.insert("fonts", &fonts);
     write_template_to(
diff --git a/src/project.rs b/src/project.rs
index a0a9aed..05d0f33 100644
--- a/src/project.rs
+++ b/src/project.rs
@@ -56,7 +56,8 @@ impl Chapter<Vec<PathBuf>> {
 pub struct Project<A> {
     pub author: String,
     pub title: String,
-    pub chapters: Vec<Chapter<A>>
+    pub chapters: Vec<Chapter<A>>,
+    pub cover: Option<PathBuf>,
 }
 
 impl Project<Vec<PathBuf>> {
@@ -108,6 +109,11 @@ impl Project<Vec<PathBuf>> {
     {
         let author = self.author;
         let title = self.title;
+        let cover = self.cover
+            .map(|x| fs::canonicalize(&x)
+                 .map_err(|_| Error(String::from("cannot compute a canonical path for the cover"))))
+            // from Option<Result<_, E>> to Result<Option<_>, E>
+            .map_or(Ok(None), |r| r.map(Some))?;
 
         self.chapters.into_iter()
             .map(|chapter| chapter.load_and_render(typo))
@@ -115,7 +121,8 @@ impl Project<Vec<PathBuf>> {
             .map(|x| Project {
                 author: author,
                 title: title,
-                chapters: x
+                chapters: x,
+                cover: cover,
             })
     }
 }
diff --git a/templates/content.opf b/templates/content.opf
index 823f9d6..b5dad1c 100644
--- a/templates/content.opf
+++ b/templates/content.opf
@@ -6,6 +6,9 @@
     <dc:creator opf:role="aut">{{ author }}</dc:creator>
     <dc:type>text</dc:type>
     <dc:description>Ceci est une description</dc:description>
+    {% if cover_extension %}
+    <meta name="cover" content="coverimage"/>
+    {% endif %}
   </metadata>
   <manifest>
     <item href="toc.ncx" id="ncx" media-type="application/x-dtbncx+xml" />
@@ -16,6 +19,9 @@
     {% for f in files %}
     <item href="Text/{{ f }}" id="{{ f }}" media-type="application/xhtml+xml" />
     {% endfor %}
+    {% if cover_extension %}
+    <item href="cover.{{ cover_extension }}" id="coverimage" media-type="image/jpeg" properties="cover-image" />
+    {% endif %}
   </manifest>
   <spine toc="ncx">
     {% for f in files %}