os struct

src/lib.rs

@@ -1,8 +1,11 @@
 pub mod cli;
-pub mod parsing;
 pub mod models;
+pub mod os;
+pub mod parsing;
 pub mod table;
 
+const APP_NAME: &'static str = "ECB-rates";
+
 pub mod ecb_url {
     pub const TODAY: &'static str = "https://www.ecb.europa.eu/stats/eurofxref/eurofxref-daily.xml";
 

src/os.rs

@@ -0,0 +1,47 @@
+use std::env;
+use std::path::PathBuf;
+
+use crate::APP_NAME;
+
+pub enum Os {
+    Windows,
+    Mac,
+    Unix,
+}
+
+impl Os {
+    pub fn get_current() -> Option<Self> {
+        let os_str = env::consts::OS;
+        if os_str == "windows" {
+            Some(Os::Windows)
+        } else if os_str == "macos" {
+            Some(Os::Mac)
+        } else if os_str == "linux" || os_str.contains("bsd") {
+            Some(Os::Unix)
+        } else {
+            None
+        }
+    }
+
+    pub fn get_config_path(&self) -> Result<PathBuf, std::env::VarError> {
+        let config_home = match self {
+            Os::Windows => PathBuf::from(env::var("APPDATA")?),
+            Os::Mac => {
+                let mut pb = PathBuf::from(env::var("HOME")?);
+                pb.push("Library");
+                pb.push("Application Support");
+                pb
+            }
+            Os::Unix => match env::var("XDG_CONFIG_HOME") {
+                Ok(k) => PathBuf::from(k),
+                Err(_) => {
+                    let mut home = PathBuf::from(env::var("HOME")?);
+                    home.push(".config");
+                    home
+                }
+            },
+        };
+
+        Ok(config_home.join(APP_NAME))
+    }
+}