feat: Trying to load several config paths

- Config::load now returns Option<Self> instead of Self
- Updated README to contain new possible config paths

README.md

@@ -49,7 +49,13 @@ $ ./aliveline
 
 ## Configuration
 Aliveline tries to find config at:  
-- `$XDG_CONFIG_DIR/aliveline/config.toml`  
+- `$ALIVELINE_CONFIG`
+- `$XDG_CONFIG_HOME/aliveline/config.toml`  
+- `$XDG_CONFIG_HOME/.aliveline`  
+- `$HOME/.config/aliveline/config.toml`  
+- `$HOME/.config/.aliveline`  
+- `$HOME/.aliveline/config.toml`  
+- `$HOME/.aliveline`  
 - `./config.toml` (relative to working directory)  
 
 If config isn't found, Aliveline uses default values defined in [config.toml](https://2ndbeam.ru/git/2ndbeam/aliveline/src/branch/master/config.toml).  

src/config.rs

@@ -20,14 +20,16 @@ impl Default for Colors {
 }
 
 #[derive(Serialize, Deserialize, Clone, PartialEq, Eq, Debug)]
-#[serde(default)]
 pub struct Config {
     /// directory, where config is located
     #[serde(skip)]
     pub conf_path: PathBuf,
     pub log_path: PathBuf,
+    #[serde(default)]
     pub colors: Colors,
+    #[serde(default)]
     pub event_colors: Vec<u32>,
+    #[serde(default)]
     pub text_colors: Vec<u32>,
 }
 
@@ -90,13 +92,13 @@ impl Config {
         }
     }
 
-    pub fn load(path: PathBuf) -> Self {
+    pub fn load(path: PathBuf) -> Option<Self> {
         if let Ok(toml_string) = std::fs::read_to_string(path.clone()) {
             if let Ok(mut conf) = toml::from_str::<Config>(&toml_string) {
                 conf.conf_path = path.parent().unwrap().into();
-                return conf;
+                return Some(conf);
             }
         }
-        Config::new(path)
+        None
     }
 }

src/lib.rs

@@ -4,16 +4,47 @@ use std::{hash::{DefaultHasher, Hash, Hasher}, path::PathBuf};
 pub mod config;
 pub mod log;
 
-pub fn load_config() -> Config {
-    if let Ok(path_str) = std::env::var("XDG_CONFIG_HOME") {
-        let mut path = PathBuf::from(path_str);
-        path.push("aliveline");
-        path.push("config.toml");
-        return Config::load(path);
+fn try_config_path(var: &'static str, path: &[&'static str]) -> Option<Config> {
+    match std::env::var(var) {
+        Ok(path_start) => {
+            let mut pathbuf = PathBuf::from(path_start);
+            for entry in path.iter() {
+                pathbuf.push(entry);
+            }
+            Config::load(pathbuf)
+        },
+        Err(_) => None,
     }
-    Config::new(PathBuf::from("./config.toml"))
 }
 
+/// This function tries to load config from several places (in order):  
+/// - $ALIVELINE_CONFIG
+/// - $XDG_CONFIG_HOME/aliveline/config.toml  
+/// - $XDG_CONFIG_HOME/.aliveline  
+/// - $HOME/.config/aliveline/config.toml
+/// - $HOME/.config/.aliveline
+/// - $HOME/.aliveline
+/// as a last resort it defaults to current working directory (./config.toml)
+pub fn load_config() -> Config {
+    let places = [
+        ("ALIVELINE_CONFIG", vec![]),
+        ("XDG_CONFIG_HOME", vec!["aliveline", "config.toml"]),
+        ("XDG_CONFIG_HOME", vec![".aliveline"]),
+        ("HOME", vec![".config", "aliveline", "config.toml"]),
+        ("HOME", vec![".config", ".aliveline"]),
+        ("HOME", vec![".aliveline", "config.toml"]),
+        ("HOME", vec![".aliveline"]),
+    ];
+    for (place_var, place) in places {
+        if let Some(conf) = try_config_path(place_var, place.as_slice()) {
+            println!("Found config at ${place_var} / {place:?}");
+            return conf;
+        }
+        println!("Config not found at ${place_var} / {place:?}");
+    }
+    println!("Using last resort config path ./config.toml");
+    Config::new(PathBuf::from("./config.toml"))
+}
 /// Get random-like color id in range 0..16 by computing string hash
 pub fn color_id_from_name(name: String) -> i32 {
     let mut s = DefaultHasher::new();