Add Dex pallet (#407)

* Move pallet-asset-conversion

* update licensing

* initial integration

* Integrate Currency & Assets types

* integrate liquidity tokens

* fmt

* integrate dex pallet tests

* fmt

* compilation error fixes

* integrate dex benchmarks

* fmt

* cargo clippy

* replace all occurrences of "asset" with "coin"

* add the actual add liq/swap logic to in-instructions

* add client side & tests

* fix deny

* Lint and changes

- Renames InInstruction::AddLiquidity to InInstruction::SwapAndAddLiquidity
- Makes create_pool an internal function
- Makes dex-pallet exclusively create pools against a native coin
- Removes various fees
- Adds new crates to GH workflow

* Fix rebase artifacts

* Correct other rebase artifact

* Correct CI specification for liquidity-tokens

* Correct primitives' test to the standardized pallet account scheme

---------

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

substrate/coins/pallet/Cargo.toml

@@ -24,6 +24,8 @@ sp-runtime = { git = "https://github.com/serai-dex/substrate", default-features
 
 pallet-transaction-payment = { git = "https://github.com/serai-dex/substrate", default-features = false }
 
+dex-primitives = { package = "serai-dex-primitives", path = "../../dex/primitives", default-features = false }
+
 serai-primitives = { path = "../../primitives", default-features = false }
 coins-primitives = { package = "serai-coins-primitives", path = "../primitives", default-features = false }
 
@@ -38,6 +40,8 @@ std = [
 
   "pallet-transaction-payment/std",
 
+  "dex-primitives/std",
+
   "serai-primitives/std",
   "coins-primitives/std",
 ]

substrate/coins/pallet/src/lib.rs

@@ -14,12 +14,14 @@ pub mod pallet {
 
   use pallet_transaction_payment::{Config as TpConfig, OnChargeTransaction};
 
+  use dex_primitives::{Currency, Coins as CoinsTrait};
+
   use serai_primitives::*;
   pub use coins_primitives as primitives;
   use primitives::*;
 
   #[pallet::config]
-  pub trait Config: frame_system::Config<AccountId = Public> + TpConfig {
+  pub trait Config: frame_system::Config<AccountId = Public> {
     type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
   }
 
@@ -72,12 +74,13 @@ pub mod pallet {
   impl<T: Config> BuildGenesisConfig for GenesisConfig<T> {
     fn build(&self) {
       // initialize the supply of the coins
-      for c in COINS.iter() {
+      // TODO: Don't use COINS yet GenesisConfig so we can safely expand COINS
+      for c in &COINS {
         Supply::<T>::set(c, 0);
       }
 
       // initialize the genesis accounts
-      for (account, balance) in self.accounts.iter() {
+      for (account, balance) in &self.accounts {
         Pallet::<T>::mint(*account, *balance).unwrap();
       }
     }
@@ -214,7 +217,75 @@ pub mod pallet {
     }
   }
 
-  impl<T: Config> OnChargeTransaction<T> for Pallet<T> {
+  impl<T: Config> Currency<T::AccountId> for Pallet<T> {
+    type Balance = SubstrateAmount;
+
+    fn balance(of: &Public) -> Self::Balance {
+      Self::balance(*of, Coin::Serai).0
+    }
+
+    /// TODO: make sure of coin precision here.
+    fn minimum_balance() -> Self::Balance {
+      1
+    }
+
+    fn transfer(
+      from: &Public,
+      to: &Public,
+      amount: Self::Balance,
+    ) -> Result<Self::Balance, DispatchError> {
+      let balance = Balance { coin: Coin::Serai, amount: Amount(amount) };
+      Self::transfer_internal(*from, *to, balance)?;
+      Ok(amount)
+    }
+
+    fn mint(to: &Public, amount: Self::Balance) -> Result<Self::Balance, DispatchError> {
+      Self::mint(*to, Balance { coin: Coin::native(), amount: Amount(amount) })?;
+      Ok(amount)
+    }
+  }
+
+  // TODO: Have DEX implement for Coins, not Coins implement for Coins
+  impl<T: Config> CoinsTrait<T::AccountId> for Pallet<T> {
+    type Balance = SubstrateAmount;
+    type CoinId = Coin;
+
+    // TODO: Swap the order of these arguments
+    fn balance(coin: Self::CoinId, of: &Public) -> Self::Balance {
+      Self::balance(*of, coin).0
+    }
+
+    fn minimum_balance(_: Self::CoinId) -> Self::Balance {
+      1
+    }
+
+    // TODO: Move coin next to amount
+    fn transfer(
+      coin: Self::CoinId,
+      from: &Public,
+      to: &Public,
+      amount: Self::Balance,
+    ) -> Result<Self::Balance, DispatchError> {
+      let balance = Balance { coin, amount: Amount(amount) };
+      Self::transfer_internal(*from, *to, balance)?;
+      Ok(amount)
+    }
+
+    // TODO: Move coin next to amount
+    fn mint(
+      coin: Self::CoinId,
+      to: &Public,
+      amount: Self::Balance,
+    ) -> Result<Self::Balance, DispatchError> {
+      Self::mint(*to, Balance { coin, amount: Amount(amount) })?;
+      Ok(amount)
+    }
+  }
+
+  impl<T: Config> OnChargeTransaction<T> for Pallet<T>
+  where
+    T: TpConfig,
+  {
     type Balance = SubstrateAmount;
     type LiquidityInfo = Option<SubstrateAmount>;
 

substrate/coins/primitives/src/lib.rs

@@ -12,7 +12,7 @@ use scale_info::TypeInfo;
 
 use serai_primitives::{Balance, SeraiAddress, ExternalAddress, Data, system_address};
 
-pub const FEE_ACCOUNT: SeraiAddress = system_address(b"FeeAccount");
+pub const FEE_ACCOUNT: SeraiAddress = system_address(b"Coins-fees");
 
 #[derive(
   Clone, PartialEq, Eq, Debug, Serialize, Deserialize, Encode, Decode, MaxEncodedLen, TypeInfo,
@@ -46,6 +46,6 @@ fn address() {
   use sp_runtime::traits::TrailingZeroInput;
   assert_eq!(
     FEE_ACCOUNT,
-    SeraiAddress::decode(&mut TrailingZeroInput::new(b"FeeAccount")).unwrap()
+    SeraiAddress::decode(&mut TrailingZeroInput::new(b"Coins-fees")).unwrap()
   );
 }