Make sure that featured post always has an image

src/main.rs

@@ -33,12 +33,25 @@ fn main() -> Result<(), Box<dyn Error>> {
     entries.retain(|entry| entry.score.is_positive());
 
     entries.par_iter_mut().for_each(|entry| {
-        if entry.image_url.is_some() {
-            entry.score += 1440;
+        if let Some(image_url) = &entry.image_url {
+            match web_fetchers::is_valid_image_url(image_url) {
+                Ok(true) => {
+                    entry.score += 1440;
+                }
+                _ => {
+                    entry.image_url = None;
+                    entry.score += -1440;
+                }
+            }
         } else {
             match web_fetchers::fetch_social_image(entry.link.clone()) {
                 Ok(social_image_url) => {
-                    entry.image_url = Some(social_image_url);
+                    if web_fetchers::is_valid_image_url(&social_image_url).unwrap_or(false) {
+                        entry.image_url = Some(social_image_url);
+                        entry.score += 1440;
+                    } else {
+                        entry.score += -1440;
+                    }
                 }
                 Err(error) => {
                     log::info!("{}: {}", error, entry.link.clone());
@@ -47,7 +60,6 @@ fn main() -> Result<(), Box<dyn Error>> {
             }
         }
     });
-
     entries.retain(|entry| entry.score.is_positive());
 
     // Count occurences of main urls
@@ -66,6 +78,18 @@ fn main() -> Result<(), Box<dyn Error>> {
     // Remove bottom 10% from list
     entries.truncate(entries.len() - (entries.len() as f64 * 0.1).ceil() as usize);
 
+    // Make sure first entry has an image since it is used as the featured post
+    let mut max_iter = 0;
+    while entries.first().unwrap().image_url.is_none() {
+        entries[0].score += -100;
+        entries.sort();
+
+        max_iter += 1;
+        if max_iter > 10000 {
+            break;
+        }
+    }
+
     let index = site_generator::generate_index(entries.clone());
     let index_path = Path::new("output/index.html");
     DirBuilder::new()

src/web_fetchers.rs

@@ -33,3 +33,16 @@ pub fn fetch_social_image(url: String) -> Result<String, Box<dyn std::error::Err
         Err("No social image found".into())
     }
 }
+
+pub fn is_valid_image_url(url: &str) -> Result<bool, Box<dyn std::error::Error>> {
+    let client = reqwest::blocking::Client::new();
+    let response = client.head(url).send()?;
+
+    let status = response.status();
+    let content_type = response.headers().get(reqwest::header::CONTENT_TYPE);
+
+    Ok(status.is_success()
+        && content_type.map_or(false, |ct| {
+            ct.to_str().map_or(false, |s| s.starts_with("image/"))
+        }))
+}