waddling_errors_macros/

lib.rs

//! Procedural macros for waddling-errors
//!
//! This crate provides convenient macros for defining error code components,
//! primaries, and sequences with rich metadata support.
//!
//! # Macros
//!
//! - `component!` - Define component enums with automatic ComponentId impl
//! - `primary!` - Define primary enums with automatic PrimaryId impl
//! - `sequence!` - Define sequence constants with metadata
//!
//! # Examples
//!
//! ```ignore
//! use waddling_errors_macros::{component, primary, sequence};
//!
//! component! {
//!     Auth,
//!     Database {
//!         docs: "Database operations",
//!         tags: ["backend"],
//!     },
//! }
//!
//! primary! {
//!     Token,
//!     Connection {
//!         docs: "Connection errors",
//!     },
//! }
//!
//! sequence! {
//!     MISSING(001) {
//!         description: "Item not found",
//!         hints: ["Check if item exists"],
//!     },
//! }
//! ```

use proc_macro::TokenStream;

mod component;
mod diag;
mod doc_gen_attr;
mod doc_gen_macro;
mod in_component;
mod primary;
mod sequence;
mod setup;

/// Define component enums with automatic ComponentId trait implementation.
///
/// # WDP Naming Convention
///
/// Per WDP specification, component names SHOULD use **PascalCase**:
/// - ✅ `Auth`, `Database`, `ApiGateway`, `TokenValidator`
/// - ❌ `AUTH`, `DATABASE`, `API_GATEWAY` (non-standard)
///
/// Error codes follow the format: `E.Component.Primary.SEQUENCE`
/// - Example: `E.Auth.Token.EXPIRED` not `E.AUTH.TOKEN.EXPIRED`
///
/// # Metadata Fields
///
/// Supports all metadata fields in any order:
/// - `description` - Documentation string
/// - `introduced` - Version introduced
/// - `deprecated` - Deprecation notice
/// - `examples` - Array of example error codes
/// - `tags` - Array of category tags
///
/// # Examples
///
/// ```ignore
/// component! {
///     Auth,                    // Simple: "Auth"
///     Database {               // With metadata
///         description: "Database operations",
///         introduced: "1.0.0",
///         tags: ["backend", "storage"],
///     },
/// }
///
/// // Generated code implements ComponentIdDocumented trait:
/// let desc = Component::Database.description();  // Trait method
/// let tags = Component::Database.tags();
/// ```
#[proc_macro]
pub fn component(input: TokenStream) -> TokenStream {
    component::expand(input)
}

/// Define primary enums with automatic PrimaryId trait implementation.
///
/// # WDP Naming Convention
///
/// Per WDP specification, primary names SHOULD use **PascalCase**:
/// - ✅ `Token`, `Connection`, `Validation`, `RateLimit`
/// - ❌ `TOKEN`, `CONNECTION`, `VALIDATION` (non-standard)
///
/// Error codes follow the format: `E.Component.Primary.SEQUENCE`
/// - Example: `E.Database.Connection.TIMEOUT` not `E.DATABASE.CONNECTION.TIMEOUT`
///
/// # Metadata Fields
///
/// Supports all metadata fields in any order:
/// - `description` - Documentation string
/// - `introduced` - Version introduced
/// - `deprecated` - Deprecation notice
/// - `examples` - Array of example error codes
/// - `related` - Array of related primary codes
///
/// # Examples
///
/// ```ignore
/// primary! {
///     Token,                   // Simple: "Token"
///     Connection {             // With metadata
///         description: "Connection errors",
///         related: ["Timeout", "Pool"],
///     },
/// }
///
/// // Generated code implements PrimaryIdDocumented trait:
/// let desc = Primary::Connection.description();  // Trait method
/// let related = Primary::Connection.related();
/// ```
#[proc_macro]
pub fn primary(input: TokenStream) -> TokenStream {
    primary::expand(input)
}

/// Define sequence constants with rich metadata.
///
/// Supports all 5 metadata fields in any order:
/// - `description` - Human-readable description
/// - `typical_severity` - Typical severity level
/// - `hints` - Array of helpful hints
/// - `related` - Array of related sequences
/// - `introduced` - Version introduced
///
/// # Examples
///
/// ```ignore
/// sequence! {
///     MISSING(001),            // Simple
///     CUSTOM(042) {            // With metadata
///         description: "Custom logic error",
///         hints: ["Check business rules", "Verify input"],
///         related: ["043", "044"],
///         introduced: "1.2.0",
///     },
/// }
/// ```
#[proc_macro]
pub fn sequence(input: TokenStream) -> TokenStream {
    sequence::expand(input)
}

/// Define complete diagnostic metadata with full 4-part error codes.
///
/// **This macro generates THREE constants**:
/// 1. `E_COMPONENT_PRIMARY_SEQUENCE` - Runtime metadata (always present)
/// 2. `E_COMPONENT_PRIMARY_SEQUENCE_DOCS` - Compile-time docs (with `metadata` feature)
/// 3. `E_COMPONENT_PRIMARY_SEQUENCE_COMPLETE` - Combined (with `metadata` feature)
///
/// # 4-Part Code Format
///
/// `Severity.Component.Primary.Sequence`
///
/// # Visibility Markers
///
/// Fields can have visibility markers to control where they're included:
/// - `'C` - Compile-time only (documentation generation, not in binary)
/// - `'R` - Runtime only (in production binary, not in docs)
/// - `'RC` or `'CR` - Both (default for most fields)
///
/// **Mnemonic**: `'CR` = Compile + Runtime (both contexts)
///
/// # Supported Fields (in any order)
///
/// **Core fields (always present):**
/// - `message` (required) - Message template with `{{field}}` placeholders
/// - `fields` (optional) - Array of non-PII field names used in message (referenced as `{{field}}`)
/// - `pii` (optional) - Array of PII field names (referenced as `{{pii/field}}` in message)
/// - `severity` (optional) - Override the severity from the code
///
/// **Fields with visibility markers:**
/// - `description ['C|'R|'RC|'CR]` - Human-readable description
/// - `hints ['C|'R|'RC|'CR]` - Array of helpful hints
/// - `role ['R|'RC|'CR]` - Role-based visibility
/// - `tags ['R]` - Categorization tags (runtime only)
/// - `related_codes ['R]` - Related error codes (runtime only)
/// - `code_snippet ['C]` - Code examples (compile-time only)
/// - `docs_url ['C]` - Documentation URL (compile-time only)
/// - `introduced ['C]` - Version introduced (compile-time only)
/// - `deprecated ['C]` - Deprecation notice (compile-time only)
///
/// # Examples
///
/// **Basic usage (defaults to 'RC - both contexts):**
/// ```ignore
/// diag! {
///     Error.Auth.Token.MISSING: {
///         message: "Token '{{token}}' not found",
///         fields: [token],
///         description: "API token missing",  // Available in both
///         hints: ["Check your credentials"],  // Available in both
///     },
/// }
/// ```
///
/// **With PII fields:**
/// ```ignore
/// diag! {
///     Error.Auth.Login.FAILED: {
///         message: "Login failed for {{pii/email}} at {{timestamp}}",
///         fields: [timestamp],           // Non-PII: goes to `f` in wire protocol
///         pii: [email],                  // PII: goes to `pii.data` in wire protocol
///         description: "Authentication failed",
///     },
/// }
/// ```
///
/// **Advanced usage with visibility markers:**
/// ```ignore
/// diag! {
///     Error.Auth.Token.MISSING: {
///         message: "Token '{{token}}' not found",
///         fields: [token],
///
///         // Verbose docs for compile-time
///         description 'C: "Detailed explanation for documentation...",
///
///         // Short message for runtime
///         description 'R: "Token missing",
///
///         // Different hints for different audiences
///         hints 'C: ["For developers: Check auth flow", "See RFC 6750"],
///         hints 'R: ["Include Authorization header", "Verify API key"],
///         hints 'CR: ["Contact support if needed"],  // 'RC also works
///
///         // Runtime categorization
///         role 'R: "Public",
///         tags: ["auth", "security"],
///
///         // Compile-time documentation
///         code_snippet: {
///             wrong: "fetch(url)",
///             correct: "fetch(url, { headers: { 'Authorization': 'Bearer <token>' } })",
///         },
///         docs_url: "https://docs.example.com/auth",
///         introduced: "1.0.0",
///     },
/// }
/// ```
///
/// # Generated Code
///
/// This generates THREE constants:
///
/// ```ignore
/// // Always generated (no feature flags)
/// pub const E_AUTH_TOKEN_MISSING: DiagnosticRuntime = /* runtime metadata */;
///
/// // Only with metadata feature
/// #[cfg(feature = "metadata")]
/// pub const E_AUTH_TOKEN_MISSING_DOCS: DiagnosticDocs = /* compile-time docs */;
///
/// #[cfg(feature = "metadata")]
/// pub const E_AUTH_TOKEN_MISSING_COMPLETE: DiagnosticComplete = /* both */;
/// ```
///
/// Frameworks can use the runtime constant for error handling, and the complete
/// constant for documentation generation.
#[proc_macro]
pub fn diag(input: TokenStream) -> TokenStream {
    diag::expand(input)
}

/// Attribute macro for automatic documentation generation
///
/// Wraps `diag!` and generates registration code for specified formats.
///
/// # Examples
///
/// ```ignore
/// #[doc_gen("json", "html")]
/// diag! {
///     E.Auth.Token.MISSING: {
///         message: "Token not found",
///         // ...
///     },
/// }
/// ```
///
/// This generates a `__doc_gen_registry` module with format tracking.
#[proc_macro_attribute]
pub fn doc_gen(attr: TokenStream, item: TokenStream) -> TokenStream {
    doc_gen_attr::expand(attr, item)
}

/// Generates documentation registration function for a diagnostic.
///
/// This macro creates a registration function that can be called to register
/// a diagnostic with a DocRegistry for documentation generation.
///
/// # Example
/// ```rust,ignore
/// // Define diagnostic
/// diag! {
///     E.Auth.Token.EXPIRED: {
///         message: "Token expired",
///         // ...
///     },
/// }
///
/// // Generate registration code
/// doc_gen_register! {
///     E.Auth.Token.EXPIRED => ["json", "html"]
/// }
///
/// // Later, use the generated function:
/// let mut registry = DocRegistry::new("myapp", "1.0.0");
/// register_e_auth_token_expired_complete_for_doc_gen(&mut registry);
/// ```
#[proc_macro]
pub fn doc_gen_register(input: TokenStream) -> TokenStream {
    doc_gen_macro::expand(input)
}

/// Mark modules or files as belonging to a specific component.
///
/// This attribute enables:
/// - **Discovery**: Find all files in a component via grep or IDE search
/// - **Navigation**: IDE integration for "jump to component" features
/// - **Documentation**: Auto-group errors by component in generated docs
/// - **Organization**: Track scattered components across different folders
///
/// # Syntax
///
/// ```ignore
/// #[in_component(ComponentName)]
/// ```
///
/// # Examples
///
/// **Marking a folder** (via mod.rs):
/// ```ignore
/// // src/auth/mod.rs
/// #[in_component(Auth)]
///
/// mod token;
/// mod session;
/// ```
///
/// **Marking scattered files**:
/// ```ignore
/// // src/api/middleware.rs
/// #[in_component(Auth)]  // Auth logic here too!
///
/// use waddling_errors::diag;
/// // ... Auth-related errors ...
/// ```
///
/// **Finding all Auth components**:
/// ```bash
/// grep -r "#\[in_component(Auth)\]" src/
/// ```
///
/// # Metadata Generated
///
/// The macro creates a hidden module with:
/// - Component name constant
/// - Module path (for IDE integration)
/// - File path (for tooling)
/// - Marker trait (for discovery)
#[proc_macro_attribute]
pub fn in_component(attr: TokenStream, item: TokenStream) -> TokenStream {
    in_component::expand(attr, item)
}

/// Configure module paths for waddling-errors definitions.
///
/// This macro sets up path aliases that `diag!` uses to resolve component,
/// primary, and sequence definitions. This enables flexible project structure
/// where definitions can be placed in any module.
///
/// **Must be called once at the crate root (lib.rs or main.rs).**
///
/// # Syntax
///
/// ```ignore
/// waddling_errors::setup! {
///     components = crate::my_components,
///     primaries = crate::error_primaries,
///     sequences = crate::my_sequences,
/// }
/// ```
///
/// # What it Generates
///
/// ```ignore
/// pub(crate) mod __wd_paths {
///     pub use crate::my_components as components;
///     pub use crate::error_primaries as primaries;
///     pub use crate::my_sequences as sequences;
/// }
/// ```
///
/// # Why Use This
///
/// Without `setup!`, `diag!` expects definitions at fixed paths:
/// - `crate::components::*`
/// - `crate::primaries::*`
/// - `crate::sequences::*`
///
/// With `setup!`, you can place definitions anywhere and `diag!` will find them.
///
/// # Example Project Structure
///
/// ```ignore
/// // src/lib.rs
/// waddling_errors::setup! {
///     components = crate::errors::components,
///     primaries = crate::errors::primaries,
///     sequences = crate::errors::sequences,
/// }
///
/// mod errors {
///     pub mod components { /* component! definitions */ }
///     pub mod primaries { /* primary! definitions */ }
///     pub mod sequences { /* sequence! definitions */ }
/// }
///
/// mod api {
///     // diag! here works - finds definitions via __wd_paths
///     diag! { E.Api.Auth.001: { ... } }
/// }
/// ```
///
/// # Partial Configuration
///
/// You can specify only some paths - others will use defaults:
///
/// ```ignore
/// waddling_errors::setup! {
///     sequences = crate::my_sequences,
///     // components defaults to crate::components
///     // primaries defaults to crate::primaries
/// }
/// ```
///
/// # No Collision Between Crates
///
/// Each crate has its own `__wd_paths` module (via `crate::`), so a library
/// using waddling-errors won't collide with an application using it too.
#[proc_macro]
pub fn setup(input: TokenStream) -> TokenStream {
    setup::expand(input)
}