add genesis liquidity implementation

substrate/genesis-liquidity/pallet/Cargo.toml

@@ -0,0 +1,46 @@
+[package]
+name = "serai-genesis-liquidity-pallet"
+version = "0.1.0"
+description = "Genesis liquidity pallet for Serai"
+license = "AGPL-3.0-only"
+repository = "https://github.com/serai-dex/serai/tree/develop/substrate/genesis-liquidity/pallet"
+authors = ["Akil Demir <aeg_asd@hotmail.com>"]
+edition = "2021"
+rust-version = "1.77"
+
+[package.metadata.docs.rs]
+all-features = true
+rustdoc-args = ["--cfg", "docsrs"]
+
+[package.metadata.cargo-machete]
+ignored = ["scale", "scale-info"]
+
+[lints]
+workspace = true
+
+
+[dependencies]
+scale = { package = "parity-scale-codec", version = "3", default-features = false, features = ["derive"] }
+scale-info = { version = "2", default-features = false, features = ["derive"] }
+
+frame-system = { git = "https://github.com/serai-dex/substrate", default-features = false }
+frame-support = { git = "https://github.com/serai-dex/substrate", default-features = false }
+
+sp-std = { git = "https://github.com/serai-dex/substrate", default-features = false }
+
+dex-pallet = { package = "serai-dex-pallet", path = "../../dex/pallet", default-features = false }
+coins-pallet = { package = "serai-coins-pallet", path = "../../coins/pallet", default-features = false }
+
+serai-primitives = { path = "../../primitives", default-features = false }
+genesis-liquidity-primitives = { package = "serai-genesis-liquidity-primitives", path = "../primitives", default-features = false }
+
+[features]
+std = [
+  "frame-system/std",
+  "frame-support/std",
+
+  "coins-pallet/std",
+  "dex-pallet/std",
+]
+
+default = ["std"]

substrate/genesis-liquidity/pallet/LICENSE

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+AGPL-3.0-only license
+
+Copyright (c) 2024 Luke Parker
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License Version 3 as
+published by the Free Software Foundation.
+
+This program 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 Affero General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with this program. If not, see <http://www.gnu.org/licenses/>.

substrate/genesis-liquidity/pallet/src/lib.rs

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+#![cfg_attr(not(feature = "std"), no_std)]
+
+#[allow(clippy::cast_possible_truncation, clippy::no_effect_underscore_binding)]
+#[frame_support::pallet]
+pub mod pallet {
+  use super::*;
+  use frame_system::{pallet_prelude::*, RawOrigin};
+  use frame_support::{pallet_prelude::*, sp_runtime::SaturatedConversion};
+
+  use sp_std::{vec, collections::btree_map::BTreeMap};
+
+  use dex_pallet::{Pallet as Dex, Config as DexConfig};
+  use coins_pallet::{
+    primitives::{OutInstructionWithBalance, OutInstruction},
+    Config as CoinsConfig, Pallet as Coins, AllowMint,
+  };
+
+  use serai_primitives::*;
+  pub use genesis_liquidity_primitives as primitives;
+  use primitives::*;
+
+  /// LiquidityTokens Pallet as an instance of coins pallet.
+  pub type LiquidityTokens<T> = coins_pallet::Pallet<T, coins_pallet::Instance1>;
+
+  #[pallet::config]
+  pub trait Config:
+    frame_system::Config + DexConfig + CoinsConfig + coins_pallet::Config<coins_pallet::Instance1>
+  {
+    type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
+  }
+
+  #[pallet::error]
+  pub enum Error<T> {
+    GenesisPeriodEnded,
+    AmountOverflowed,
+    NotEnoughLiquidity,
+    CanOnlyRemoveFullAmount,
+  }
+
+  #[pallet::event]
+  #[pallet::generate_deposit(fn deposit_event)]
+  pub enum Event<T: Config> {
+    GenesisLiquidityAdded { by: SeraiAddress, balance: Balance },
+    GenesisLiquidityRemoved { by: SeraiAddress, balance: Balance },
+    GenesisLiquidityAddedToPool { coin1: Balance, coin2: Balance },
+    EconomicSecurityReached { network: NetworkId },
+  }
+
+  #[pallet::pallet]
+  pub struct Pallet<T>(PhantomData<T>);
+
+  #[pallet::storage]
+  pub(crate) type Liquidity<T: Config> =
+    StorageDoubleMap<_, Identity, Coin, Blake2_128Concat, PublicKey, SubstrateAmount, OptionQuery>;
+
+  #[pallet::storage]
+  pub(crate) type LiquidityTokensPerAddress<T: Config> =
+    StorageDoubleMap<_, Identity, Coin, Blake2_128Concat, PublicKey, SubstrateAmount, OptionQuery>;
+
+  #[pallet::storage]
+  pub(crate) type EconomicSecurityReached<T: Config> =
+    StorageMap<_, Identity, NetworkId, BlockNumberFor<T>, ValueQuery>;
+
+  #[pallet::hooks]
+  impl<T: Config> Hooks<BlockNumberFor<T>> for Pallet<T> {
+    fn on_finalize(n: BlockNumberFor<T>) {
+      // Distribute the genesis sri to pools after a month
+      if n > BLOCKS_PER_MONTH.into() {
+        // mint the SRI
+        Coins::<T>::mint(
+          GENESIS_LIQUIDITY_ACCOUNT.into(),
+          Balance { coin: Coin::Serai, amount: Amount(GENESIS_SRI) },
+        )
+        .unwrap();
+
+        // get coin values & total
+        let mut account_values = BTreeMap::new();
+        let mut pool_values = BTreeMap::new();
+        let mut total_value: u64 = 0;
+        for coin in COINS {
+          // TODO: following line is just a place holder till we get the actual coin value
+          // in terms of btc.
+          let value = Dex::<T>::security_oracle_value(coin).unwrap_or(Amount(0)).0;
+          account_values.insert(coin, vec![]);
+          let mut pool_amount: u64 = 0;
+          for (account, amount) in Liquidity::<T>::iter_prefix(coin) {
+            pool_amount += amount;
+            let value_this_addr = amount * value;
+            account_values.get_mut(&coin).unwrap().push((account, value_this_addr))
+          }
+
+          let pool_value = pool_amount * value;
+          total_value += pool_value;
+          pool_values.insert(coin, (pool_amount, pool_value));
+        }
+
+        // add the liquidity per pool
+        for (coin, (amount, value)) in &pool_values {
+          let sri_amount = (GENESIS_SRI * value) / total_value;
+          let origin = RawOrigin::Signed(GENESIS_LIQUIDITY_ACCOUNT.into());
+          Dex::<T>::add_liquidity(
+            origin.into(),
+            *coin,
+            *amount,
+            sri_amount,
+            *amount,
+            sri_amount,
+            GENESIS_LIQUIDITY_ACCOUNT.into(),
+          )
+          .unwrap();
+
+          // set liquidity tokens per account
+          let tokens = LiquidityTokens::<T>::balance(GENESIS_LIQUIDITY_ACCOUNT.into(), *coin).0;
+          let mut total_tokens_this_coin: u64 = 0;
+          for (acc, value) in account_values.get(coin).unwrap() {
+            let liq_tokens_this_acc = (tokens * value) / pool_values.get(coin).unwrap().1;
+            total_tokens_this_coin += liq_tokens_this_acc;
+            LiquidityTokensPerAddress::<T>::set(coin, acc, Some(liq_tokens_this_acc));
+          }
+          assert_eq!(tokens, total_tokens_this_coin);
+        }
+
+        // we shouldn't have any coin left in our account at this moment, including SRI.
+        for coin in COINS {
+          assert_eq!(Coins::<T>::balance(GENESIS_LIQUIDITY_ACCOUNT.into(), coin), Amount(0));
+        }
+      }
+
+      // we accept we reached economic security once we can mint smallest amount of a network's coin
+      for coin in COINS {
+        let existing = EconomicSecurityReached::<T>::get(coin.network());
+        if existing == 0u32.into() &&
+          <T as CoinsConfig>::AllowMint::is_allowed(&Balance { coin, amount: Amount(1) })
+        {
+          EconomicSecurityReached::<T>::set(coin.network(), n);
+          Self::deposit_event(Event::EconomicSecurityReached { network: coin.network() });
+        }
+      }
+    }
+  }
+
+  impl<T: Config> Pallet<T> {
+    /// Add genesis liquidity for the given account. All accounts that provide liquidity
+    /// will receive the genesis SRI according to their liquidity ratio.
+    pub fn add_coin_liquidity(account: PublicKey, balance: Balance) -> DispatchResult {
+      // check we are still in genesis period
+      if Self::genesis_ended() {
+        Err(Error::<T>::GenesisPeriodEnded)?;
+      }
+
+      // mint the coins
+      Coins::<T>::mint(GENESIS_LIQUIDITY_ACCOUNT.into(), balance)?;
+
+      // save
+      let existing = Liquidity::<T>::get(balance.coin, account).unwrap_or(0);
+      let new = existing.checked_add(balance.amount.0).ok_or(Error::<T>::AmountOverflowed)?;
+      Liquidity::<T>::set(balance.coin, account, Some(new));
+
+      Self::deposit_event(Event::GenesisLiquidityAdded { by: account.into(), balance });
+      Ok(())
+    }
+
+    /// Remove the provided genesis liquidity for an account. If called pre-economic security era,
+    pub fn remove_coin_liquidity(
+      account: PublicKey,
+      balance: Balance,
+      out_address: ExternalAddress,
+    ) -> DispatchResult {
+      let origin = RawOrigin::Signed(GENESIS_LIQUIDITY_ACCOUNT.into());
+
+      // check we are still in genesis period
+      if Self::genesis_ended() {
+        // check user have enough to remove
+        let existing = LiquidityTokensPerAddress::<T>::get(balance.coin, account).unwrap_or(0);
+        if balance.amount.0 > existing {
+          Err(Error::<T>::NotEnoughLiquidity)?;
+        }
+
+        // remove liquidity from pool
+        let prev_sri = Coins::<T>::balance(GENESIS_LIQUIDITY_ACCOUNT.into(), Coin::Serai);
+        let prev_coin = Coins::<T>::balance(GENESIS_LIQUIDITY_ACCOUNT.into(), balance.coin);
+        Dex::<T>::remove_liquidity(
+          origin.clone().into(),
+          balance.coin,
+          balance.amount.0,
+          1,
+          1,
+          GENESIS_LIQUIDITY_ACCOUNT.into(),
+        )?;
+        let current_sri = Coins::<T>::balance(GENESIS_LIQUIDITY_ACCOUNT.into(), Coin::Serai);
+        let current_coin = Coins::<T>::balance(GENESIS_LIQUIDITY_ACCOUNT.into(), balance.coin);
+
+        // burn the SRI if necessary
+        let mut sri = current_sri.0 - prev_sri.0;
+        let burn_sri_amount = (sri *
+          (GENESIS_SRI_TRICKLE_FEED - Self::blocks_since_ec_security(&balance.coin))) /
+          GENESIS_SRI_TRICKLE_FEED;
+        Coins::<T>::burn(
+          origin.clone().into(),
+          Balance { coin: Coin::Serai, amount: Amount(burn_sri_amount) },
+        )?;
+        sri -= burn_sri_amount;
+
+        // transfer to owner
+        let coin_out = current_coin.0 - prev_coin.0;
+        Coins::<T>::transfer(
+          origin.clone().into(),
+          account,
+          Balance { coin: balance.coin, amount: Amount(coin_out) },
+        )?;
+        Coins::<T>::transfer(
+          origin.into(),
+          account,
+          Balance { coin: Coin::Serai, amount: Amount(sri) },
+        )?;
+
+        // save
+        let existing = LiquidityTokensPerAddress::<T>::get(balance.coin, account).unwrap_or(0);
+        let new = existing.checked_sub(balance.amount.0).ok_or(Error::<T>::AmountOverflowed)?;
+        LiquidityTokensPerAddress::<T>::set(balance.coin, account, Some(new));
+      } else {
+        let existing = Liquidity::<T>::get(balance.coin, account).unwrap_or(0);
+        if balance.amount.0 > existing || balance.amount.0 == 0 {
+          Err(Error::<T>::NotEnoughLiquidity)?;
+        }
+        if balance.amount.0 < existing {
+          Err(Error::<T>::CanOnlyRemoveFullAmount)?;
+        }
+
+        // TODO: do internal transfer instead?
+        let origin = RawOrigin::Signed(GENESIS_LIQUIDITY_ACCOUNT.into());
+        let instruction = OutInstructionWithBalance {
+          instruction: OutInstruction { address: out_address, data: None },
+          balance,
+        };
+        Coins::<T>::burn_with_instruction(origin.into(), instruction)?;
+
+        // save
+        Liquidity::<T>::set(balance.coin, account, None);
+      }
+
+      Self::deposit_event(Event::GenesisLiquidityRemoved { by: account.into(), balance });
+      Ok(())
+    }
+
+    // Returns the number of blocks since the coin's network reached economic security first time.
+    // If the network is yet to be reached that threshold 0 is returned, and maximum of
+    // GENESIS_SRI_TRICKLE_FEED returned.
+    fn blocks_since_ec_security(coin: &Coin) -> u64 {
+      let ec_security_block =
+        EconomicSecurityReached::<T>::get(coin.network()).saturated_into::<u64>();
+      let current = <frame_system::Pallet<T>>::block_number().saturated_into::<u64>();
+      if ec_security_block > 0 {
+        let diff = current - ec_security_block;
+        if diff > GENESIS_SRI_TRICKLE_FEED {
+          return GENESIS_SRI_TRICKLE_FEED;
+        }
+
+        return diff;
+      }
+
+      0
+    }
+
+    fn genesis_ended() -> bool {
+      <frame_system::Pallet<T>>::block_number() >= BLOCKS_PER_MONTH.into()
+    }
+  }
+}
+
+pub use pallet::*;