1 files changed, 120 insertions, 0 deletions
diff --git a/lib/warden-core/src/config/mod.rs b/lib/warden-core/src/config/mod.rs
new file mode 100644
index 0000000..9d0c937
--- /dev/null
+++ b/lib/warden-core/src/config/mod.rs
@@ -0,0 +1,120 @@
+pub mod cli;
+mod log_level;
+
+use std::path::PathBuf;
+
+use clap::ValueEnum;
+pub use cli::Cli;
+pub use cli::Commands;
+use serde::Deserialize;
+use tracing_subscriber::EnvFilter;
+
+use crate::WardenError;
+use crate::config::cli::CliEnvironment;
+use crate::config::cli::database::Database;
+
+#[derive(Deserialize, Default, Debug, ValueEnum, Clone, Copy)]
+#[serde(rename_all = "lowercase")]
+pub enum Environment {
+    Development,
+    #[default]
+    Production,
+}
+
+impl From<CliEnvironment> for Environment {
+    fn from(value: CliEnvironment) -> Self {
+        match value {
+            CliEnvironment::Dev | CliEnvironment::Development => Self::Development,
+            CliEnvironment::Prod | CliEnvironment::Production => Self::Production,
+        }
+    }
+}
+
+#[derive(Debug, Clone)]
+pub struct Configuration {
+    pub server: Server,
+    pub database: Database,
+}
+
+#[derive(Debug, Clone)]
+pub struct Server {
+    pub port: u16,
+    pub environment: Environment,
+    pub log_level: EnvFilter,
+    pub log_dir: PathBuf,
+    pub timeout_secs: u64,
+}
+
+impl Server {
+    fn merge(cli: &Cli, file: &Cli, missing: &mut Vec<&str>) -> Result<Self, WardenError> {
+        let port = cli.server.port.or(file.server.port);
+
+        if port.is_none() {
+            missing.push("server.port");
+        }
+
+        let timeout = cli.server.timeout_secs.or(file.server.timeout_secs);
+
+        if timeout.is_none() {
+            missing.push("server.timeout");
+        }
+
+        let log_dir = cli.server.log_dir.clone().or(file.server.log_dir.clone());
+
+        if log_dir.is_none() {
+            missing.push("server.log_dir");
+        }
+
+        let log_level = cli
+            .server
+            .log_level
+            .as_ref()
+            .or(file.server.log_level.as_ref())
+            .map(ToOwned::to_owned);
+
+        if log_level.is_none() {
+            missing.push("server.log_level");
+        }
+
+        let environment = cli.server.environment.or(file.server.environment);
+
+        if environment.is_none() {
+            missing.push("server.environment");
+        }
+
+        if !missing.is_empty() {
+            let err = missing
+                .iter()
+                .map(|f| format!("  - {}", f))
+                .collect::<Vec<_>>()
+                .join("\n");
+            return Err(WardenError::Config(err));
+        }
+
+        let log_level =
+            tracing_subscriber::EnvFilter::try_from_default_env().unwrap_or_else(|_| {
+                // axum logs rejections from built-in extractors with the `axum::rejection`
+                // target, at `TRACE` level. `axum::rejection=trace` enables showing those events
+                log_level.unwrap().into()
+            });
+
+        Ok(Self {
+            port: port.unwrap(),
+            environment: environment.unwrap().into(),
+            log_dir: log_dir.unwrap(),
+            timeout_secs: timeout.unwrap(),
+            log_level,
+        })
+    }
+}
+
+impl Configuration {
+    pub fn merge(cli: &Cli, file: &Cli) -> Result<Self, WardenError> {
+        let mut missing = Vec::new();
+
+        let server = Server::merge(cli, file, &mut missing)?;
+        let database = Database::merge(&cli.database, &file.database)?;
+
+        Ok(Self { server, database })
+    }
+}