Add database connection configuration

src/server/config.rs

@@ -1,8 +1,78 @@
 use serde::Deserialize;
 
+#[derive(Debug, Clone, Deserialize)]
+pub struct DatabaseConfig {
+    #[serde(flatten)]
+    connection: DatabaseConnectionConfig,
+}
+
+impl DatabaseConfig {
+    /// Get the configured database connection URI
+    pub fn connection_uri(&self) -> String {
+        self.connection.as_uri()
+    }
+}
+
+#[derive(Debug, Clone, Deserialize)]
+#[serde(untagged)]
+enum DatabaseConnectionConfig {
+    FromUrl {
+        url: String,
+    },
+    FromParts {
+        host: String,
+        port: Option<u16>,
+        database: Option<String>,
+        username: Option<String>,
+        password: Option<String>,
+    },
+}
+
+impl DatabaseConnectionConfig {
+    /// Convert this configuration into the Postgres connection URI
+    pub fn as_uri(&self) -> String {
+        match self {
+            Self::FromUrl { url } => url.clone(),
+            Self::FromParts {
+                host,
+                port,
+                database,
+                username,
+                password,
+            } => {
+                let mut url = "postgres://".to_string();
+
+                if let Some(username) = username {
+                    url.push_str(username);
+
+                    if let Some(password) = password {
+                        url.push_str(&format!(":{password}"));
+                    }
+
+                    url.push('@');
+                }
+
+                url.push_str(host);
+
+                if let Some(port) = port {
+                    url.push_str(&format!(":{port}"));
+                }
+
+                if let Some(database) = database {
+                    url.push_str(&format!("/{database}"));
+                }
+
+                url
+            }
+        }
+    }
+}
+
 #[derive(Debug, Clone, Deserialize)]
 /// Top-level application configuration
-pub struct Config {}
+pub struct Config {
+    pub database: DatabaseConfig,
+}
 
 /// Parse configuration from the expected files and environment variables
 pub fn load_config() -> Result<Config, config::ConfigError> {