roezio/config: implement Config.new

Signed-off-by: Maxime “pep” Buquet <pep@bouah.net>

src/config.rs

@@ -92,15 +92,18 @@ impl<'a> Config<'a> {
         filename: P,
         defaults: HashMap<&'a str, HashMap<&'a str, ConfigValue>>,
         default_section: Option<&'a str>,
-    ) -> Self {
+    ) -> Result<Self, Error> {
-        // TODO: read ini file.
+        let filename: PathBuf = filename.into();
+        let mut ini = Ini::new();
+        ini.load(filename.clone())
+            .map_err(|_| Error::UnableToOpenConfigFile(filename.clone()))?;
 
-        Config {
+        Ok(Config {
-            filename: filename.into(),
+            filename,
             defaults,
             default_section: default_section.unwrap_or("default"),
             ini: Ini::new(),
-        }
+        })
     }
 
     /// Sets a key/value pair in memory and updates the config file.

src/error.rs

@@ -18,6 +18,7 @@ use crate::config::ConfigValue;
 use std::error::Error as StdError;
 use std::fmt;
 use std::io;
+use std::path::PathBuf;
 
 #[derive(Debug)]
 pub(crate) enum Error {
@@ -25,6 +26,7 @@ pub(crate) enum Error {
     UnableToCreateConfigDir,
     InvalidConfigValueType(ConfigValue),
     InvalidValueType(String),
+    UnableToOpenConfigFile(PathBuf),
 }
 
 impl fmt::Display for Error {
@@ -34,6 +36,9 @@ impl fmt::Display for Error {
             Error::UnableToCreateConfigDir => write!(f, "Unable to create config dir"),
             Error::InvalidConfigValueType(err) => write!(f, "Invalid ConfigValue type: {}", err),
             Error::InvalidValueType(err) => write!(f, "Invalid value type: {}", err),
+            Error::UnableToOpenConfigFile(err) => {
+                write!(f, "Unable to open config file: {}", err.display())
+            }
         }
     }
 }