Moving configuration to another file

Things were getting too messy in the original file, so better start
clean (and right) than trying to fix things.

src/config/config.rs

@@ -0,0 +1,58 @@
+/*
+   DOWNFAV - Download Favourites
+   Copyright (C) 2020-2021  Julio Biason
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Affero General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Affero General Public License for more details.
+
+   You should have received a copy of the GNU Affero General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+use std::collections::HashMap;
+
+use directories::ProjectDirs;
+use elefren::Data;
+
+/// The last seen favourite
+struct Favourite {
+    last: String,
+}
+
+/// Account configuration
+struct AccountConfig {
+    favourite: Favourite,
+    mastodon: Data,
+}
+
+/// Errors from the configuration
+pub enum ConfigError {
+    /// The system can't figure out the path for the configuration file
+    CantFigureConfigPath,
+}
+
+/// The main configuration
+#[derive(serde_derive::Serialize, serde::derive::Deserialize, Debug)]
+pub struct Config(HashMap<String, AccountConfig>);
+
+impl Config {
+    /// Figure out the filename for the configuration file.
+    fn filename() -> Result<Path, ConfigError> {
+        if let Some(proj_dirs) =
+            ProjectDirs::from("me", "JulioBiason", "downfav")
+        {
+            Ok(proj_dirs.config_dir())
+        } else {
+            Error(ConfigError::CantFigureConfigPath)
+        }
+    }
+
+    pub fn new() -> Self {}
+}

src/config/mod.rs

@@ -121,9 +121,6 @@ impl AccountConfig {
         }
         new_configuration
     }
-
-    /// Add an account to the configuration
-    pub fn add_account() {}
 }
 
 impl From<elefren::data::Data> for AccountConfig {