Clean things up a bit

src/config.rs

@@ -0,0 +1,75 @@
+use crate::actions::transmission::TransmissionConfig;
+use crate::args::Args;
+use color_eyre::eyre::{eyre, Result, WrapErr};
+use directories::ProjectDirs;
+use figment::providers::Env;
+use figment::{
+    providers::{Format, Toml},
+    Figment,
+};
+use figment_file_provider_adapter::FileAdapter;
+use log::debug;
+use serde::{Deserialize, Serialize};
+use std::collections::HashMap;
+use std::path::{Path, PathBuf};
+
+/// Configuration for a Reddit source
+#[derive(Debug, Serialize, Deserialize)]
+pub struct SourceConfig {
+    pub username: String,
+    pub title_filter: Option<String>,
+}
+
+/// Main application configuration
+#[derive(Debug, Serialize, Deserialize)]
+pub struct Config {
+    #[serde(default)]
+    pub transmission: Option<TransmissionConfig>,
+
+    #[serde(default)]
+    pub sources: HashMap<String, SourceConfig>,
+}
+
+/// Loads the configuration from the specified file or default location
+pub fn load_config(args: &Args) -> Result<Config> {
+    let mut conf_extractor = Figment::new();
+    let config_file_path: Option<PathBuf> = match &args.config {
+        Some(path) => Some(Path::new(path).to_path_buf()),
+        None => ProjectDirs::from("fr", "enoent", "reddit-magnet")
+            .map(|p| p.config_dir().join("config.toml")),
+    };
+    match config_file_path {
+        Some(path) => {
+            if path.exists() {
+                debug!("Reading configuration from {:?}", path);
+                conf_extractor = conf_extractor.merge(FileAdapter::wrap(Toml::file_exact(path)));
+            } else {
+                debug!("Configuration file doesn't exist at {:?}", path);
+            }
+        }
+        None => {
+            debug!("No configuration file specified, using default configuration");
+        }
+    }
+
+    let conf: Config = conf_extractor
+        .merge(FileAdapter::wrap(Env::prefixed("REDDIT_MAGNET_")))
+        .extract()
+        .wrap_err_with(|| "Invalid configuration or insufficient command line arguments")?;
+
+    if conf.sources.is_empty() {
+        return Err(eyre!("No sources found in configuration. Please add at least one source to your configuration file.").into());
+    }
+
+    Ok(conf)
+}
+
+/// Gets the database path from the command line arguments or default location
+pub fn get_db_path(args: &Args) -> Result<PathBuf> {
+    match &args.db {
+        Some(path) => Ok(PathBuf::from(path)),
+        None => ProjectDirs::from("fr", "enoent", "reddit-magnet")
+            .map(|p| p.data_dir().join("reddit-magnet.db"))
+            .ok_or_else(|| eyre!("Could not determine data directory")),
+    }
+}