1 files changed, 108 insertions, 0 deletions
diff --git a/crates/common/tedge_config/src/tedge_config_location.rs b/crates/common/tedge_config/src/tedge_config_location.rs
new file mode 100644
index 00000000..a6f9a844
--- /dev/null
+++ b/crates/common/tedge_config/src/tedge_config_location.rs
@@ -0,0 +1,108 @@
+use std::path::{Path, PathBuf};
+
+const DEFAULT_ETC_PATH: &str = "/etc";
+const TEDGE_CONFIG_FILE: &str = "tedge.toml";
+const TEDGE_CONFIG_FILE_TMP: &str = "tedge.toml.tmp";
+
+/// Information about where `tedge.toml` is located.
+///
+/// Broadly speaking, we distinguish two different locations:
+///
+/// - System-wide locations under `/etc/tedge` or `/usr/local/etc/tedge`.
+/// - User-local locations under `$HOME/.tedge`
+///
+#[derive(Debug, Clone, Eq, PartialEq)]
+pub struct TEdgeConfigLocation {
+    /// Root directory where `tedge.toml` and other tedge related configuration files are located.
+    pub tedge_config_root_path: PathBuf,
+
+    /// Full path to the `tedge.toml` file.
+    pub tedge_config_file_path: PathBuf,
+}
+
+impl TEdgeConfigLocation {
+    pub fn from_custom_root(tedge_config_root_path: impl AsRef<Path>) -> Self {
+        Self {
+            tedge_config_root_path: tedge_config_root_path.as_ref().to_path_buf(),
+            tedge_config_file_path: tedge_config_root_path.as_ref().join(TEDGE_CONFIG_FILE),
+        }
+    }
+
+    /// `tedge.toml` is located in `/etc/tedge`.
+    pub fn from_default_system_location() -> Self {
+        Self::from_custom_root(Path::new(DEFAULT_ETC_PATH).join("tedge"))
+    }
+
+    /// `tedge.toml` is located in `${etc_path}/tedge`.
+    pub fn from_custom_etc_location(custom_etc_path: impl AsRef<Path>) -> Self {
+        Self::from_custom_root(custom_etc_path.as_ref().join("tedge"))
+    }
+
+    /// `tedge.toml` is located in `${home_path}/.tedge`.
+    pub fn from_users_home_location(home_path: impl AsRef<Path>) -> Self {
+        Self::from_custom_root(home_path.as_ref().join(".tedge"))
+    }
+
+    pub fn tedge_config_root_path(&self) -> &Path {
+        &self.tedge_config_root_path
+    }
+    pub fn tedge_config_file_path(&self) -> &Path {
+        &self.tedge_config_file_path
+    }
+
+    pub fn temporary_tedge_config_file_path(&self) -> impl AsRef<Path> {
+        self.tedge_config_root_path.join(TEDGE_CONFIG_FILE_TMP)
+    }
+}
+
+#[test]
+fn test_from_custom_root() {
+    let config_location = TEdgeConfigLocation::from_custom_root("/opt/etc/tedge");
+    assert_eq!(
+        config_location.tedge_config_root_path,
+        PathBuf::from("/opt/etc/tedge")
+    );
+    assert_eq!(
+        config_location.tedge_config_file_path,
+        PathBuf::from("/opt/etc/tedge/tedge.toml")
+    );
+}
+
+#[test]
+fn test_from_default_system_location() {
+    let config_location = TEdgeConfigLocation::from_default_system_location();
+    assert_eq!(
+        config_location.tedge_config_root_path,
+        PathBuf::from("/etc/tedge")
+    );
+    assert_eq!(
+        config_location.tedge_config_file_path,
+        PathBuf::from("/etc/tedge/tedge.toml")
+    );
+}
+
+#[test]
+fn test_from_custom_etc_location() {
+    let config_location = TEdgeConfigLocation::from_custom_etc_location("/usr/local/etc");
+    assert_eq!(
+        config_location.tedge_config_root_path,
+        PathBuf::from("/usr/local/etc/tedge")
+    );
+    assert_eq!(
+        config_location.tedge_config_file_path,
+        PathBuf::from("/usr/local/etc/tedge/tedge.toml")
+    );
+}
+
+#[test]
+fn test_from_users_home_location() {
+    let config_location = TEdgeConfigLocation::from_users_home_location("/home/user");
+    assert_eq!(
+        config_location.tedge_config_root_path,
+        PathBuf::from("/home/user/.tedge")
+    );
+    assert_eq!(
+        config_location.tedge_config_file_path,
+        PathBuf::from("/home/user/.tedge/tedge.toml")
+    );
+}