refactor: improve archive.org URL validation

- Improves archive.org URL validation to ensure the identifier after "/details/" is not empty.
- Updates error message for invalid URLs to provide a more descriptive explanation of the expected format.
- Streamlines error handling in the main function by directly displaying the error message from the validation function.

src/error.rs

@@ -17,7 +17,7 @@ pub enum IaGetError {
     FileSystem(String),
 
     /// URL format or parsing errors
-    #[error("Invalid URL: {0}")]
+    #[error("Invalid archive.org URL: {0}. Expected format: https://archive.org/details/<identifier>[/]")]
     UrlFormat(String),
 
     /// MD5 hash verification failures

src/main.rs

@@ -119,9 +119,7 @@ async fn main() -> std::result::Result<(), Box<dyn std::error::Error>> {
     
     // Validate URL format using consolidated function
     if let Err(e) = validate_archive_url(&cli.url) {
-        spinner.finish_with_message(format!("❌ Invalid archive.org URL format: {}", cli.url));
-        println!("├╼ Archive.org URL is not in the expected format");
-        println!("╰╼ Expected format: https://archive.org/details/<identifier>[/]");
+        spinner.finish_with_message(format!("❌ {}", e));
         return Err(e.into());
     }
 

src/utils.rs

@@ -33,13 +33,15 @@ static URL_REGEX: LazyLock<Regex> = LazyLock::new(|| {
 /// ```
 pub fn validate_archive_url(url: &str) -> Result<()> {
     if URL_REGEX.is_match(url) {
-        Ok(())
-    } else {
-        Err(IaGetError::UrlFormat(format!(
-            "URL '{}' does not match expected format. Expected: https://archive.org/details/<identifier>[/]", 
-            url
-        )))
+        // Further check: ensure there's an identifier after "details/"
+        // and that the identifier is not empty.
+        if let Some(path_segment) = url.split("/details/").nth(1) {
+            if !path_segment.trim_end_matches('/').is_empty() {
+                return Ok(());
+            }
+        }
     }
+    Err(IaGetError::UrlFormat(url.to_string()))
 }
 
 /// Create a progress bar with consistent styling