// Copyright 2017-2018 Parity Technologies (UK) Ltd.
// This file is part of Substrate.

// Substrate 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.

// Substrate 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 Substrate.  If not, see <http://www.gnu.org/licenses/>.

//! Transaction validity interface.

use rstd::prelude::*;

/// Priority for a transaction. Additive. Higher is better.
pub type TransactionPriority = u64;

/// Minimum number of blocks a transaction will remain valid for.
/// `TransactionLongevity::max_value()` means "forever".
pub type TransactionLongevity = u64;

/// Tag for a transaction. No two transactions with the same tag should be placed on-chain.
pub type TransactionTag = Vec<u8>;

/// Information on a transaction's validity and, if valid, on how it relates to other transactions.
#[derive(Clone, PartialEq, Eq, Encode, Decode)]
#[cfg_attr(feature = "std", derive(Debug))]
pub enum TransactionValidity {
	Invalid,
	Valid {
		priority: TransactionPriority,
		requires: Vec<TransactionTag>,
		provides: Vec<TransactionTag>,
		longevity: TransactionLongevity
	},
	Unknown,
}