// Copyright 2024 Moonbeam foundation

// This file is part of Moonbeam.

// Moonbeam is free software: you can redistribute it and/or modify

// it under the terms of the GNU General Public License as published by

// the Free Software Foundation, either version 3 of the License, or

// (at your option) any later version.

// Moonbeam is distributed in the hope that it will be useful,

// but WITHOUT ANY WARRANTY; without even the implied warranty of

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License

// along with Moonbeam.  If not, see <http://www.gnu.org/licenses/>.

/// A trait for querying a value by a key.

pub trait GetByKey<Key, Value> {

	/// Return the value.

	fn get(k: &Key) -> Value;

}

/// Create new implementations of the `GetByKey` trait.

///

/// The implementation is typically used like a map or set.

///

/// Example:

/// ```ignore

/// use primitives::CurrencyId;

/// parameter_type_with_key! {

///     pub Rates: |currency_id: CurrencyId| -> u32 {

///         match currency_id {

///             CurrencyId::DOT => 1,

///             CurrencyId::KSM => 2,

///             _ => 3,

///         }

///     }

/// }

/// ```

#[macro_export]

macro_rules! parameter_type_with_key {

	(

		pub $name:ident: |$k:ident: $key:ty| -> $value:ty $body:block;

	) => {

		pub struct $name;

		impl $crate::get_by_key::GetByKey<$key, $value> for $name {

				$body

		}

	};

}

#[cfg(test)]

mod tests {

	use super::*;

	parameter_type_with_key! {

		pub Test: |k: u32| -> u32 {

			match k {

				1 => 1,

				_ => 2,

			}

		};

	}

	#[test]

}