add default builder method

Cargo.toml

@@ -1,10 +1,18 @@
 [package]
 name = "twba-backup-config"
-version = "0.1.3"
+version = "0.1.4"
 edition = "2021"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
 serde = { version = "1.0", features = ["derive"] }
-confique = { version = "0.2" , features= ["json5","toml"]}
+confique = { version = "0.2", features = ["json5", "toml"] }
+tracing = { version = "0.1", optional = true }
+shellexpand = { version = "3.1", optional = true }
+
+[features]
+default = ["tracing", "env", "home"]
+env = []
+tracing = ["dep:tracing"]
+home = ["dep:shellexpand"]

src/lib.rs

@@ -127,3 +127,26 @@ pub struct Twitch {
     #[config(default = 50)]
     pub downloader_thread_count: u64,
 }
+
+pub fn get_default_builder() -> confique::Builder<Conf> {
+    #[cfg(feature = "tracing")]
+    tracing::info!("building default config");
+    let conf = Conf::builder();
+    #[cfg(feature = "env")]
+    let conf = conf.env().file(
+        std::env::var("TWBA_CONFIG")
+            .map(|v| {
+                #[cfg(feature = "tracing")]
+                tracing::info!("using '{}' as primary config source after env", v);
+                v
+            })
+            .unwrap_or_else(|_| {
+                #[cfg(feature = "tracing")]
+                tracing::warn!("could not get config location from env");
+                "./settings.toml".to_string()
+            }),
+    );
+    #[cfg(feature = "home")]
+    let conf = conf.file(shellexpand::tilde("~/twba/config.toml").into_owned());
+    conf
+}