add opml.rs, oops

src/opml.rs

@@ -0,0 +1,72 @@
+use crate::ImportOptions;
+use anyhow::{Context, Result};
+
+pub(crate) fn import(options: ImportOptions) -> Result<()> {
+    let mut conn = rusqlite::Connection::open(options.database_path)?;
+
+    crate::rss::initialize_db(&mut conn)?;
+
+    let opml_file =
+        std::fs::File::open(options.opml_path).context("must provide a valid OPML file")?;
+
+    let mut opml_reader = std::io::BufReader::new(opml_file);
+
+    let opml_document =
+        opml::OPML::from_reader(&mut opml_reader).context("unable to parse provided OPML file")?;
+
+    let http_client = ureq::AgentBuilder::new()
+        .timeout_read(options.network_timeout)
+        .build();
+
+    let feed_urls = get_feed_urls(&opml_document);
+
+    let mut successful_imports = 0;
+    let mut failed_imports = vec![];
+
+    for feed_url in feed_urls {
+        eprintln!(">>>>>>>>>>");
+        eprintln!("{}: starting import", feed_url);
+        match crate::rss::subscribe_to_feed(&http_client, &mut conn, &feed_url) {
+            Ok(_feed_id) => {
+                eprintln!("{feed_url}: OK");
+                successful_imports += 1;
+            }
+            Err(e) => {
+                eprintln!("ERROR: {:?}", e);
+                failed_imports.push(feed_url);
+            }
+        };
+        eprintln!("<<<<<<<<<<");
+    }
+
+    eprintln!();
+    eprintln!("{successful_imports} feeds imported");
+    eprintln!("{} feeds failed to import", failed_imports.len());
+
+    if !failed_imports.is_empty() {
+        eprintln!();
+
+        for failed_import_url in failed_imports {
+            eprintln!("{failed_import_url} failed to import");
+        }
+    }
+
+    Ok(())
+}
+
+// outlines can be nested within other outlines in a tree structure,
+// so we have to traverse them
+fn get_feed_urls(opml_document: &opml::OPML) -> Vec<String> {
+    let mut outlines_stack = opml_document.body.outlines.to_owned();
+    let mut feed_urls = vec![];
+
+    while let Some(this_outline) = outlines_stack.pop() {
+        outlines_stack.extend_from_slice(&this_outline.outlines);
+
+        if let Some(xml_url) = this_outline.xml_url {
+            feed_urls.push(xml_url);
+        }
+    }
+
+    feed_urls
+}