refactor(cable): always create default cable channels in user directory if no cable channels exist (#213)

Fixes #212

crates/television/cable.rs

@@ -24,6 +24,8 @@ const DEFAULT_CABLE_CHANNELS: &str =
 const DEFAULT_CABLE_CHANNELS: &str =
     include_str!("../../cable/windows-channels.toml");
 
+const DEFAULT_CABLE_CHANNELS_FILE_NAME: &str = "default_channels.toml";
+
 /// Load the cable configuration from the config directory.
 ///
 /// Cable is loaded by compiling all files that match the following
@@ -45,16 +47,7 @@ pub fn load_cable_channels() -> Result<CableChannels> {
     // filter the files that match the pattern
     let file_paths = files
         .filter_map(|f| f.ok().map(|f| f.path()))
-        .filter(|p| {
+        .filter(|p| is_cable_file_format(p) && p.is_file());
-            p.extension()
-                .and_then(|e| e.to_str())
-                .map_or(false, |e| e.to_lowercase() == CABLE_FILE_FORMAT)
-        })
-        .filter(|p| {
-            p.file_stem()
-                .and_then(|s| s.to_str())
-                .map_or(false, |s| s.ends_with(CABLE_FILE_NAME_SUFFIX))
-        });
 
     let user_defined_prototypes = file_paths.fold(Vec::new(), |mut acc, p| {
         let r: ChannelPrototypes = toml::from_str(
@@ -66,21 +59,48 @@ pub fn load_cable_channels() -> Result<CableChannels> {
         acc
     });
 
+    // If no user defined prototypes are found, write the default prototypes for the current
+    // platform to the config directory
+    if user_defined_prototypes.is_empty() {
+        debug!("No user defined cable channels found");
+        // write the default cable channels to the config directory
+        let default_channels_path =
+            config_dir.join(DEFAULT_CABLE_CHANNELS_FILE_NAME);
+        std::fs::write(default_channels_path, DEFAULT_CABLE_CHANNELS)?;
+    }
+
     debug!("Loaded cable channels: {:?}", user_defined_prototypes);
 
-    let default_prototypes: ChannelPrototypes =
-        toml::from_str(DEFAULT_CABLE_CHANNELS)
-            .expect("Unable to parse default cable channels");
-
     let mut cable_channels = HashMap::new();
-    // chaining default with user defined prototypes so that users may override the
+    for prototype in user_defined_prototypes {
-    // default prototypes
-    for prototype in default_prototypes
-        .prototypes
-        .into_iter()
-        .chain(user_defined_prototypes)
-    {
         cable_channels.insert(prototype.name.clone(), prototype);
     }
     Ok(CableChannels(cable_channels))
 }
+
+fn is_cable_file_format<P>(p: P) -> bool
+where
+    P: AsRef<std::path::Path>,
+{
+    let p = p.as_ref();
+    p.file_stem()
+        .and_then(|s| s.to_str())
+        .map_or(false, |s| s.ends_with(CABLE_FILE_NAME_SUFFIX))
+        && p.extension()
+            .and_then(|e| e.to_str())
+            .map_or(false, |e| e.to_lowercase() == CABLE_FILE_FORMAT)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_is_cable_file() {
+        let path = std::path::Path::new("cable_channels.toml");
+        assert!(is_cable_file_format(path));
+
+        let path = std::path::Path::new(DEFAULT_CABLE_CHANNELS_FILE_NAME);
+        assert!(is_cable_file_format(path));
+    }
+}