add initial crates and apps

crates/chattyness-error/Cargo.toml

@@ -0,0 +1,17 @@
+[package]
+name = "chattyness-error"
+version.workspace = true
+edition.workspace = true
+
+[dependencies]
+thiserror.workspace = true
+serde.workspace = true
+
+# SSR-only dependencies
+sqlx = { workspace = true, optional = true }
+axum = { workspace = true, optional = true }
+http.workspace = true
+
+[features]
+default = []
+ssr = ["sqlx", "axum"]

crates/chattyness-error/src/lib.rs

@@ -0,0 +1,106 @@
+use serde::{Deserialize, Serialize};
+use thiserror::Error;
+
+/// Application error types for chattyness.
+///
+/// All errors derive From for automatic conversion where applicable.
+#[derive(Error, Debug)]
+pub enum AppError {
+    #[cfg(feature = "ssr")]
+    #[error("Database error: {0}")]
+    Database(#[from] sqlx::Error),
+
+    #[cfg(not(feature = "ssr"))]
+    #[error("Database error: {0}")]
+    Database(String),
+
+    #[error("Validation error: {0}")]
+    Validation(String),
+
+    #[error("Authentication required")]
+    Unauthorized,
+
+    #[error("Forbidden: {0}")]
+    Forbidden(String),
+
+    #[error("Not found: {0}")]
+    NotFound(String),
+
+    #[error("Conflict: {0}")]
+    Conflict(String),
+
+    #[error("Internal error: {0}")]
+    Internal(String),
+
+    #[error("Invalid credentials")]
+    InvalidCredentials,
+
+    #[error("Account suspended or banned")]
+    AccountSuspended,
+
+    #[error("Not a staff member")]
+    NotStaffMember,
+
+    #[error("Password reset required")]
+    PasswordResetRequired,
+}
+
+/// API error response for JSON serialization.
+#[derive(Debug, Serialize, Deserialize)]
+pub struct ErrorResponse {
+    pub error: String,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub code: Option<String>,
+}
+
+impl From<AppError> for ErrorResponse {
+    fn from(err: AppError) -> Self {
+        let code = match &err {
+            AppError::Database(_) => Some("DATABASE_ERROR".to_string()),
+            AppError::Validation(_) => Some("VALIDATION_ERROR".to_string()),
+            AppError::Unauthorized => Some("UNAUTHORIZED".to_string()),
+            AppError::Forbidden(_) => Some("FORBIDDEN".to_string()),
+            AppError::NotFound(_) => Some("NOT_FOUND".to_string()),
+            AppError::Conflict(_) => Some("CONFLICT".to_string()),
+            AppError::Internal(_) => Some("INTERNAL_ERROR".to_string()),
+            AppError::InvalidCredentials => Some("INVALID_CREDENTIALS".to_string()),
+            AppError::AccountSuspended => Some("ACCOUNT_SUSPENDED".to_string()),
+            AppError::NotStaffMember => Some("NOT_STAFF_MEMBER".to_string()),
+            AppError::PasswordResetRequired => Some("PASSWORD_RESET_REQUIRED".to_string()),
+        };
+
+        ErrorResponse {
+            error: err.to_string(),
+            code,
+        }
+    }
+}
+
+#[cfg(feature = "ssr")]
+mod ssr_impl {
+    use super::*;
+    use axum::http::StatusCode;
+    use axum::response::{IntoResponse, Response};
+    use axum::Json;
+
+    impl IntoResponse for AppError {
+        fn into_response(self) -> Response {
+            let status = match &self {
+                AppError::Database(_) => StatusCode::INTERNAL_SERVER_ERROR,
+                AppError::Validation(_) => StatusCode::BAD_REQUEST,
+                AppError::Unauthorized => StatusCode::UNAUTHORIZED,
+                AppError::Forbidden(_) => StatusCode::FORBIDDEN,
+                AppError::NotFound(_) => StatusCode::NOT_FOUND,
+                AppError::Conflict(_) => StatusCode::CONFLICT,
+                AppError::Internal(_) => StatusCode::INTERNAL_SERVER_ERROR,
+                AppError::InvalidCredentials => StatusCode::UNAUTHORIZED,
+                AppError::AccountSuspended => StatusCode::FORBIDDEN,
+                AppError::NotStaffMember => StatusCode::FORBIDDEN,
+                AppError::PasswordResetRequired => StatusCode::FORBIDDEN,
+            };
+
+            let body = ErrorResponse::from(self);
+            (status, Json(body)).into_response()
+        }
+    }
+}