mod constants;

use proc_macro::TokenStream;

/// Transforms `pub const` items in a module into equivalent functions.
///
/// Constants without `{param}` placeholders become `fn NAME() -> String`.
/// Constants with `{param}` placeholders become `fn NAME(param: impl AsRef<str>) -> String`,
/// using `format!()` to fill in the placeholders.
///
/// The entire module is annotated with `#[allow(non_snake_case)]`.
///
/// # Example
///
/// ```ignore
/// #[rorolala_internal_macros::constants]
/// pub mod paths {
///     pub const ROLA_DRAFT_DIR: &str = ".rola";
///     pub const ROLA_BINDED_BUCKET_FILE: &str = ".rola/BIND/{bucket}";
/// }
/// ```
///
/// expands to:
///
/// ```ignore
/// #[allow(non_snake_case)]
/// pub mod paths {
///     pub fn ROLA_DRAFT_DIR() -> String {
///         ".rola".to_string()
///     }
///     pub fn ROLA_BINDED_BUCKET_FILE(bucket: impl AsRef<str>) -> String {
///         format!(".rola/BIND/{bucket}", bucket = bucket.as_ref())
///     }
/// }
/// ```
#[proc_macro_attribute]
pub fn constants(attr: TokenStream, item: TokenStream) -> TokenStream {
    constants::expand(attr, item)
}