// Copyright 2021 Parity Technologies (UK) Ltd.
// This file is part of Cumulus.

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

//! Cumulus parachain inherent
//!
//! The [`ParachainInherentData`] is the data that is passed by the collator to the parachain runtime.
//! The runtime will use this data to execute messages from other parachains/the relay chain or to
//! read data from the relay chain state. When the parachain is validated by a parachain validator on
//! the relay chain, this data is checked for correctnes. If the data passed by the collator to the
//! runtime isn't correct, the parachain candidate is considered invalid.
//!
//! Use [`ParachainInherentData::create_at`] to create the [`ParachainInherentData`] at a given
//! relay chain block to include it in a parachain block.

#![cfg_attr(not(feature = "std"), no_std)]

use cumulus_primitives_core::{
	InboundDownwardMessage, InboundHrmpMessage, ParaId, PersistedValidationData,
};

use scale_info::TypeInfo;
use sp_inherents::InherentIdentifier;
use sp_std::{collections::btree_map::BTreeMap, vec::Vec};

#[cfg(feature = "std")]
mod client_side;
#[cfg(feature = "std")]
pub use client_side::*;
#[cfg(feature = "std")]
mod mock;
#[cfg(feature = "std")]
pub use mock::MockValidationDataInherentDataProvider;

/// The identifier for the parachain inherent.
pub const INHERENT_IDENTIFIER: InherentIdentifier = *b"sysi1337";

/// The inherent data that is passed by the collator to the parachain runtime.
#[derive(codec::Encode, codec::Decode, sp_core::RuntimeDebug, Clone, PartialEq, TypeInfo)]
pub struct ParachainInherentData {
	pub validation_data: PersistedValidationData,
	/// A storage proof of a predefined set of keys from the relay-chain.
	///
	/// Specifically this witness contains the data for:
	///
	/// - the current slot number at the given relay parent
	/// - active host configuration as per the relay parent,
	/// - the relay dispatch queue sizes
	/// - the list of egress HRMP channels (in the list of recipients form)
	/// - the metadata for the egress HRMP channels
	pub relay_chain_state: sp_trie::StorageProof,
	/// Downward messages in the order they were sent.
	pub downward_messages: Vec<InboundDownwardMessage>,
	/// HRMP messages grouped by channels. The messages in the inner vec must be in order they
	/// were sent. In combination with the rule of no more than one message in a channel per block,
	/// this means `sent_at` is **strictly** greater than the previous one (if any).
	pub horizontal_messages: BTreeMap<ParaId, Vec<InboundHrmpMessage>>,
}