Coins pallet (#399)

* initial implementation

* add function to get a balance of an account

* add support for multiple coins

* rename pallet to "coins-pallet"

* replace balances, assets and tokens pallet with coins pallet in runtime

* add total supply info

* update client side for new Coins pallet

* handle fees

* bug fixes

* Update FeeAccount test

* Fmt

* fix pr comments

* remove extraneous Imbalance type

* Minor tweaks

---------

Co-authored-by: Luke Parker <lukeparker5132@gmail.com>

substrate/coins/primitives/Cargo.toml

@@ -0,0 +1,28 @@
+[package]
+name = "serai-coins-primitives"
+version = "0.1.0"
+description = "Serai coins primitives"
+license = "MIT"
+authors = ["Luke Parker <lukeparker5132@gmail.com>"]
+edition = "2021"
+
+[package.metadata.docs.rs]
+all-features = true
+rustdoc-args = ["--cfg", "docsrs"]
+
+[dependencies]
+zeroize = { version = "^1.5", features = ["derive"], optional = true }
+
+serde = { version = "1", default-features = false, features = ["derive", "alloc"] }
+
+scale = { package = "parity-scale-codec", version = "3", default-features = false, features = ["derive"] }
+scale-info = { version = "2", default-features = false, features = ["derive"] }
+
+serai-primitives = { path = "../../primitives", default-features = false }
+
+[dev-dependencies]
+sp-runtime = { git = "https://github.com/serai-dex/substrate", default-features = false }
+
+[features]
+std = ["zeroize", "serde/std", "scale/std", "scale-info/std", "sp-runtime/std", "serai-primitives/std"]
+default = ["std"]

substrate/coins/primitives/LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2023 Luke Parker
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

substrate/coins/primitives/src/lib.rs

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+#![cfg_attr(docsrs, feature(doc_cfg))]
+#![cfg_attr(docsrs, feature(doc_auto_cfg))]
+#![cfg_attr(not(feature = "std"), no_std)]
+
+#[cfg(feature = "std")]
+use zeroize::Zeroize;
+
+use serde::{Serialize, Deserialize};
+
+use scale::{Encode, Decode, MaxEncodedLen};
+use scale_info::TypeInfo;
+
+use serai_primitives::{Balance, SeraiAddress, ExternalAddress, Data, system_address};
+
+pub const FEE_ACCOUNT: SeraiAddress = system_address(b"FeeAccount");
+
+#[derive(
+  Clone, PartialEq, Eq, Debug, Serialize, Deserialize, Encode, Decode, MaxEncodedLen, TypeInfo,
+)]
+#[cfg_attr(feature = "std", derive(Zeroize))]
+pub struct OutInstruction {
+  pub address: ExternalAddress,
+  pub data: Option<Data>,
+}
+
+#[derive(
+  Clone, PartialEq, Eq, Debug, Serialize, Deserialize, Encode, Decode, MaxEncodedLen, TypeInfo,
+)]
+#[cfg_attr(feature = "std", derive(Zeroize))]
+pub struct OutInstructionWithBalance {
+  pub instruction: OutInstruction,
+  pub balance: Balance,
+}
+
+#[derive(
+  Clone, PartialEq, Eq, Debug, Serialize, Deserialize, Encode, Decode, MaxEncodedLen, TypeInfo,
+)]
+#[cfg_attr(feature = "std", derive(Zeroize))]
+pub enum Destination {
+  Native(SeraiAddress),
+  External(OutInstruction),
+}
+
+#[test]
+fn address() {
+  use sp_runtime::traits::TrailingZeroInput;
+  assert_eq!(
+    FEE_ACCOUNT,
+    SeraiAddress::decode(&mut TrailingZeroInput::new(b"FeeAccount")).unwrap()
+  );
+}