feat: add pandoc plugin for document conversion and implement error reporting for failed conversion routes

plugins/pandoc/Cargo.toml

@@ -11,11 +11,11 @@ repository.workspace = true
 [package.metadata.convertis]
 id = "pandoc"
 api-version = 2
-debian-dependencies = ["pandoc"]
+debian-dependencies = ["pandoc", "texlive-latex-recommended"]
-rpm-dependencies = ["/usr/bin/pandoc"]
+rpm-dependencies = ["/usr/bin/pandoc", "texlive-collection-latexrecommended"]
 
 [lib]
 crate-type = ["cdylib"]
 
 [dependencies]
-convertis-plugin-api.workspace = true
+convertis-plugin-api.workspace = true

src/catalog.rs

@@ -54,6 +54,7 @@ const IMAGES: &[&str] = &["png", "jpeg", "gif", "webp", "bmp", "tiff", "ico"];
 const MAGICK_IMAGES: &[&str] = &[
     "png", "jpeg", "gif", "webp", "bmp", "tiff", "ico", "avif", "heic", "jxl", "svg", "pdf",
 ];
+const DOCUMENTS: &[&str] = &["md", "html", "pdf", "docx", "ltx", "epub"];
 
 fn all_pairs(formats: &[&str], scores: (u8, u8, u8)) -> Vec<Conversion> {
     tracing::trace!(
@@ -165,6 +166,12 @@ pub fn official_plugins() -> Vec<PluginMetadata> {
                 .map(|from| Conversion::file(from, "text", (255, 180, 230)))
                 .collect(),
         ),
+        metadata(
+            "pandoc",
+            "convertis-pandoc",
+            "Pandoc document conversion",
+            all_pairs(DOCUMENTS, (240, 210, 180)),
+        ),
     ];
 
     let mut to_frames: Vec<_> = VIDEO_INPUTS
@@ -296,5 +303,6 @@ mod tests {
             recommend_packages("mp4", "frames"),
             vec!["convertis-ffmpeg-video-to-frames"]
         );
+        assert_eq!(recommend_packages("html", "pdf"), vec!["convertis-pandoc"]);
     }
 }

src/main.rs

@@ -260,6 +260,7 @@ fn main() {
     }
     let options = parse_options(&args.options).unwrap_or_else(|error| fail(error));
     let mut banned = Vec::new();
+    let mut route_failures = Vec::new();
 
     let result = loop {
         tracing::debug!(
@@ -277,6 +278,14 @@ fn main() {
             &banned,
         ) else {
             tracing::debug!("no installed conversion route was found");
+            if !route_failures.is_empty() {
+                let failures = route_failures
+                    .iter()
+                    .map(|(plugin, error)| format!("{plugin}: {error}"))
+                    .collect::<Vec<_>>()
+                    .join("; ");
+                fail(format!("all conversion routes failed: {failures}"));
+            }
             let packages = catalog::recommend_packages(&detected.format, &target);
             tracing::trace!(?packages, "resolved package recommendations");
             if packages.is_empty() {
@@ -348,6 +357,7 @@ fn main() {
             }
             Err((error, plugin)) => {
                 tracing::warn!("plugin {plugin} failed: {error}; trying another route");
+                route_failures.push((plugin.clone(), error));
                 banned.push(plugin);
                 tracing::trace!(?banned, "updated failed-plugin exclusion list");
             }