// Copyright 2019-2022 Parity Technologies (UK) Ltd.
// This file is part of subxt.
//
// subxt 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.
//
// subxt 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 subxt.  If not, see <http://www.gnu.org/licenses/>.

use crate::StorageEntry;
use codec::{
    Codec,
    Encode,
    EncodeLike,
};
use core::fmt::Debug;
use sp_runtime::traits::{
    AtLeast32Bit,
    Extrinsic,
    Hash,
    Header,
    MaybeSerializeDeserialize,
    Member,
    Verify,
};

/// Runtime types.
// Note: the 'static bound isn't strictly required, but currently deriving TypeInfo
// automatically applies a 'static bound to all generic types (including this one),
// and so until that is resolved, we'll keep the (easy to satisfy) constraint here.
pub trait Config: 'static {
    /// Account index (aka nonce) type. This stores the number of previous
    /// transactions associated with a sender account.
    type Index: Parameter + Member + Default + AtLeast32Bit + Copy + scale_info::TypeInfo;

    /// The block number type used by the runtime.
    type BlockNumber: Parameter
        + Member
        + Default
        + Copy
        + core::hash::Hash
        + core::str::FromStr;

    /// The output of the `Hashing` function.
    type Hash: Parameter
        + Member
        + MaybeSerializeDeserialize
        + Ord
        + Default
        + Copy
        + std::hash::Hash
        + AsRef<[u8]>
        + AsMut<[u8]>
        + scale_info::TypeInfo;

    /// The hashing system (algorithm) being used in the runtime (e.g. Blake2).
    type Hashing: Hash<Output = Self::Hash>;

    /// The user account identifier type for the runtime.
    type AccountId: Parameter + Member;

    /// The address type. This instead of `<frame_system::Trait::Lookup as StaticLookup>::Source`.
    type Address: Codec + Clone + PartialEq;

    /// The block header.
    type Header: Parameter
        + Header<Number = Self::BlockNumber, Hash = Self::Hash>
        + serde::de::DeserializeOwned;

    /// Signature type.
    type Signature: Verify + Encode + Send + Sync + 'static;

    /// Extrinsic type within blocks.
    type Extrinsic: Parameter + Extrinsic + Debug + MaybeSerializeDeserialize;
}

/// Parameter trait copied from `substrate::frame_support`
pub trait Parameter: Codec + EncodeLike + Clone + Eq + Debug {}
impl<T> Parameter for T where T: Codec + EncodeLike + Clone + Eq + Debug {}

/// Default set of commonly used types by Substrate runtimes.
// Note: We only use this at the type level, so it should be impossible to
// create an instance of it.
pub enum DefaultConfig {}

impl Config for DefaultConfig {
    type Index = u32;
    type BlockNumber = u32;
    type Hash = sp_core::H256;
    type Hashing = sp_runtime::traits::BlakeTwo256;
    type AccountId = sp_runtime::AccountId32;
    type Address = sp_runtime::MultiAddress<Self::AccountId, u32>;
    type Header =
        sp_runtime::generic::Header<Self::BlockNumber, sp_runtime::traits::BlakeTwo256>;
    type Signature = sp_runtime::MultiSignature;
    type Extrinsic = sp_runtime::OpaqueExtrinsic;
}

/// Trait to fetch data about an account.
pub trait AccountData {
    /// The runtime storage entry from which the account data can be fetched.
    /// Usually generated by the `subxt` macro.
    type StorageEntry: StorageEntry;

    /// The type of the account id to fetch the account data for.
    type AccountId;

    /// The type of the account nonce returned from storage.
    type Index;

    /// Create a new storage entry key from the account id.
    fn storage_entry(account_id: Self::AccountId) -> Self::StorageEntry;

    /// Get the nonce from the storage entry value.
    fn nonce(result: &<Self::StorageEntry as StorageEntry>::Value) -> Self::Index;
}