// This file is part of Substrate.

// Copyright (C) Parity Technologies (UK) Ltd.

// SPDX-License-Identifier: Apache-2.0

// Licensed under the Apache License, Version 2.0 (the "License");

// you may not use this file except in compliance with the License.

// You may obtain a copy of the License at

//

// 	http://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software

// distributed under the License is distributed on an "AS IS" BASIS,

// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// See the License for the specific language governing permissions and

// limitations under the License.

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

//! Substrate genesis config builder

//!

//! For FRAME based runtimes, this runtime interface provides means to interact with

//! `RuntimeGenesisConfig`. Runtime provides a default `RuntimeGenesisConfig` structure in a form of

//! the JSON blob.

//!

//! For non-FRAME runtimes this interface is intended to build genesis state of the runtime basing

//! on some input arbitrary bytes array. This documentation uses term `RuntimeGenesisConfig`, which

//! for non-FRAME runtimes may be understood as the runtime-side entity representing initial runtime

//! configuration. The representation of the preset is an arbitrary `Vec<u8>` and does not

//! necessarily have to represent a JSON blob.

//!

//! The runtime may provide a number of partial predefined `RuntimeGenesisConfig` configurations in

//! the form of patches which shall be applied on top of the default `RuntimeGenesisConfig`. The

//! patch is a JSON blob, which essentially comprises the list of key-value pairs that are to be

//! customized in the default runtime genesis config. These predefined configurations are referred

//! to as presets.

//!

//! This allows the runtime to provide a number of predefined configs (e.g. for different

//! testnets or development) without neccessity to leak the runtime types outside the itself (e.g.

//! node or chain-spec related tools).

//!

//! This Runtime API allows to interact with `RuntimeGenesisConfig`, in particular:

//! - provide the list of available preset names,

//! - provide a number of named presets of `RuntimeGenesisConfig`,

//! - provide a JSON represention of the default `RuntimeGenesisConfig` (by simply serializing the

//!   default `RuntimeGenesisConfig` struct into JSON format),

//! - deserialize the full `RuntimeGenesisConfig` from given JSON blob and put the resulting

//!   `RuntimeGenesisConfig` structure into the state storage creating the initial runtime's state.

//!   Allows to build customized genesis. This operation internally calls `GenesisBuild::build`

//!   function for all runtime pallets.

//!

//! Providing externalities with an empty storage and putting `RuntimeGenesisConfig` into storage

//! (by calling `build_state`) allows to construct the raw storage of `RuntimeGenesisConfig`

//! which is the foundation for genesis block.

extern crate alloc;

use alloc::vec::Vec;

/// The result type alias, used in build methods. `Err` contains formatted error message.

pub type Result = core::result::Result<(), sp_runtime::RuntimeString>;

/// The type representing preset ID.

pub type PresetId = sp_runtime::RuntimeString;