Add very basic crawl job

Loops through feeds and adds items from each feed.

src/jobs/crawl.rs

@@ -0,0 +1,36 @@
+use feed_rs::parser;
+use reqwest::Client;
+use sqlx::PgPool;
+use tracing::info;
+
+use crate::models::feed::get_feeds;
+use crate::models::item::{upsert_items, CreateItem};
+
+/// For every feed in the database, fetches the feed, parses it, and saves new items to the
+/// database.
+pub async fn crawl(pool: &PgPool) -> anyhow::Result<()> {
+    let client = Client::new();
+    let feeds = get_feeds(pool).await?;
+    for feed in feeds {
+        let bytes = client.get(feed.url).send().await?.bytes().await?;
+        let parsed_feed = parser::parse(&bytes[..])?;
+        let mut payload = Vec::with_capacity(parsed_feed.entries.len());
+        for entry in parsed_feed.entries {
+            let item = CreateItem {
+                title: entry
+                    .title
+                    .map_or_else(|| "No title".to_string(), |t| t.content),
+                url: entry
+                    .links
+                    .get(0)
+                    .map_or_else(|| "https://example.com".to_string(), |l| l.href.clone()),
+                description: entry.summary.map(|s| s.content),
+                feed_id: feed.id,
+            };
+            payload.push(item);
+        }
+        let items = upsert_items(pool, payload).await?;
+        info!("Created {} items for feed {}", items.len(), feed.id);
+    }
+    Ok(())
+}