feat(db): Added database setup and basic types (#5)

Co-authored-by: Sharang Parnerkar <parnerkarsharang@gmail.com>
Reviewed-on: #5

src/infrastructure/config.rs

@@ -0,0 +1,253 @@
+//! Configuration structs loaded once at startup from environment variables.
+//!
+//! Each struct provides a `from_env()` constructor that reads `std::env::var`
+//! values. Required variables cause an `Error::ConfigError` on failure;
+//! optional ones default to an empty string.
+
+use secrecy::SecretString;
+
+use super::Error;
+
+// ---------------------------------------------------------------------------
+// Helpers
+// ---------------------------------------------------------------------------
+
+/// Read a required environment variable or return `Error::ConfigError`.
+fn required_env(name: &str) -> Result<String, Error> {
+    std::env::var(name).map_err(|_| Error::ConfigError(format!("{name} is required but not set")))
+}
+
+/// Read an optional environment variable, defaulting to an empty string.
+fn optional_env(name: &str) -> String {
+    std::env::var(name).unwrap_or_default()
+}
+
+// ---------------------------------------------------------------------------
+// KeycloakConfig
+// ---------------------------------------------------------------------------
+
+/// Keycloak OpenID Connect settings for the public (frontend) client.
+///
+/// Also carries the admin service-account credentials used for
+/// server-to-server calls (e.g. user management APIs).
+#[derive(Debug)]
+pub struct KeycloakConfig {
+    /// Base URL of the Keycloak instance (e.g. `http://localhost:8080`).
+    pub url: String,
+    /// Keycloak realm name.
+    pub realm: String,
+    /// Public client ID used by the dashboard frontend.
+    pub client_id: String,
+    /// OAuth redirect URI registered in Keycloak.
+    pub redirect_uri: String,
+    /// Root URL of this application (used for post-logout redirect).
+    pub app_url: String,
+    /// Confidential client ID for admin/server-to-server calls.
+    pub admin_client_id: String,
+    /// Confidential client secret (wrapped for debug safety).
+    pub admin_client_secret: SecretString,
+}
+
+impl KeycloakConfig {
+    /// Load Keycloak configuration from environment variables.
+    ///
+    /// # Errors
+    ///
+    /// Returns `Error::ConfigError` if a required variable is missing.
+    pub fn from_env() -> Result<Self, Error> {
+        Ok(Self {
+            url: required_env("KEYCLOAK_URL")?,
+            realm: required_env("KEYCLOAK_REALM")?,
+            client_id: required_env("KEYCLOAK_CLIENT_ID")?,
+            redirect_uri: required_env("REDIRECT_URI")?,
+            app_url: required_env("APP_URL")?,
+            admin_client_id: optional_env("KEYCLOAK_ADMIN_CLIENT_ID"),
+            admin_client_secret: SecretString::from(optional_env("KEYCLOAK_ADMIN_CLIENT_SECRET")),
+        })
+    }
+
+    /// OpenID Connect authorization endpoint URL.
+    pub fn auth_endpoint(&self) -> String {
+        format!(
+            "{}/realms/{}/protocol/openid-connect/auth",
+            self.url, self.realm
+        )
+    }
+
+    /// OpenID Connect token endpoint URL.
+    pub fn token_endpoint(&self) -> String {
+        format!(
+            "{}/realms/{}/protocol/openid-connect/token",
+            self.url, self.realm
+        )
+    }
+
+    /// OpenID Connect userinfo endpoint URL.
+    pub fn userinfo_endpoint(&self) -> String {
+        format!(
+            "{}/realms/{}/protocol/openid-connect/userinfo",
+            self.url, self.realm
+        )
+    }
+
+    /// OpenID Connect end-session (logout) endpoint URL.
+    pub fn logout_endpoint(&self) -> String {
+        format!(
+            "{}/realms/{}/protocol/openid-connect/logout",
+            self.url, self.realm
+        )
+    }
+}
+
+// ---------------------------------------------------------------------------
+// SmtpConfig
+// ---------------------------------------------------------------------------
+
+/// SMTP mail settings for transactional emails (invites, alerts, etc.).
+#[derive(Debug)]
+pub struct SmtpConfig {
+    /// SMTP server hostname.
+    pub host: String,
+    /// SMTP server port (as string for flexibility, e.g. "587").
+    pub port: String,
+    /// SMTP username.
+    pub username: String,
+    /// SMTP password (wrapped for debug safety).
+    pub password: SecretString,
+    /// Sender address shown in the `From:` header.
+    pub from_address: String,
+}
+
+impl SmtpConfig {
+    /// Load SMTP configuration from environment variables.
+    ///
+    /// All fields are optional; defaults to empty strings when absent.
+    ///
+    /// # Errors
+    ///
+    /// Currently infallible but returns `Result` for consistency.
+    pub fn from_env() -> Result<Self, Error> {
+        Ok(Self {
+            host: optional_env("SMTP_HOST"),
+            port: optional_env("SMTP_PORT"),
+            username: optional_env("SMTP_USERNAME"),
+            password: SecretString::from(optional_env("SMTP_PASSWORD")),
+            from_address: optional_env("SMTP_FROM_ADDRESS"),
+        })
+    }
+}
+
+// ---------------------------------------------------------------------------
+// ServiceUrls
+// ---------------------------------------------------------------------------
+
+/// URLs and credentials for external services (Ollama, SearXNG, S3, etc.).
+#[derive(Debug)]
+pub struct ServiceUrls {
+    /// Ollama LLM instance base URL.
+    pub ollama_url: String,
+    /// Default Ollama model to use.
+    pub ollama_model: String,
+    /// SearXNG meta-search engine base URL.
+    pub searxng_url: String,
+    /// LangChain service URL.
+    pub langchain_url: String,
+    /// LangGraph service URL.
+    pub langgraph_url: String,
+    /// Langfuse observability URL.
+    pub langfuse_url: String,
+    /// Vector database URL.
+    pub vectordb_url: String,
+    /// S3-compatible object storage URL.
+    pub s3_url: String,
+    /// S3 access key.
+    pub s3_access_key: String,
+    /// S3 secret key (wrapped for debug safety).
+    pub s3_secret_key: SecretString,
+}
+
+impl ServiceUrls {
+    /// Load service URLs from environment variables.
+    ///
+    /// All fields are optional with sensible defaults where applicable.
+    ///
+    /// # Errors
+    ///
+    /// Currently infallible but returns `Result` for consistency.
+    pub fn from_env() -> Result<Self, Error> {
+        Ok(Self {
+            ollama_url: std::env::var("OLLAMA_URL")
+                .unwrap_or_else(|_| "http://localhost:11434".into()),
+            ollama_model: std::env::var("OLLAMA_MODEL").unwrap_or_else(|_| "llama3.1:8b".into()),
+            searxng_url: std::env::var("SEARXNG_URL")
+                .unwrap_or_else(|_| "http://localhost:8888".into()),
+            langchain_url: optional_env("LANGCHAIN_URL"),
+            langgraph_url: optional_env("LANGGRAPH_URL"),
+            langfuse_url: optional_env("LANGFUSE_URL"),
+            vectordb_url: optional_env("VECTORDB_URL"),
+            s3_url: optional_env("S3_URL"),
+            s3_access_key: optional_env("S3_ACCESS_KEY"),
+            s3_secret_key: SecretString::from(optional_env("S3_SECRET_KEY")),
+        })
+    }
+}
+
+// ---------------------------------------------------------------------------
+// StripeConfig
+// ---------------------------------------------------------------------------
+
+/// Stripe billing configuration.
+#[derive(Debug)]
+pub struct StripeConfig {
+    /// Stripe secret API key (wrapped for debug safety).
+    pub secret_key: SecretString,
+    /// Stripe webhook signing secret (wrapped for debug safety).
+    pub webhook_secret: SecretString,
+    /// Stripe publishable key (safe to expose to the frontend).
+    pub publishable_key: String,
+}
+
+impl StripeConfig {
+    /// Load Stripe configuration from environment variables.
+    ///
+    /// # Errors
+    ///
+    /// Currently infallible but returns `Result` for consistency.
+    pub fn from_env() -> Result<Self, Error> {
+        Ok(Self {
+            secret_key: SecretString::from(optional_env("STRIPE_SECRET_KEY")),
+            webhook_secret: SecretString::from(optional_env("STRIPE_WEBHOOK_SECRET")),
+            publishable_key: optional_env("STRIPE_PUBLISHABLE_KEY"),
+        })
+    }
+}
+
+// ---------------------------------------------------------------------------
+// LlmProvidersConfig
+// ---------------------------------------------------------------------------
+
+/// Comma-separated list of enabled LLM provider identifiers.
+///
+/// For example: `LLM_PROVIDERS=ollama,openai,anthropic`
+#[derive(Debug)]
+pub struct LlmProvidersConfig {
+    /// Parsed provider names.
+    pub providers: Vec<String>,
+}
+
+impl LlmProvidersConfig {
+    /// Load the provider list from `LLM_PROVIDERS`.
+    ///
+    /// # Errors
+    ///
+    /// Currently infallible but returns `Result` for consistency.
+    pub fn from_env() -> Result<Self, Error> {
+        let raw = optional_env("LLM_PROVIDERS");
+        let providers: Vec<String> = raw
+            .split(',')
+            .map(|s| s.trim().to_string())
+            .filter(|s| !s.is_empty())
+            .collect();
+        Ok(Self { providers })
+    }
+}