From 63372201e3db4197ac266f9c5450b814d5709a5e Mon Sep 17 00:00:00 2001
From: Elias Tazartes <elias.tazartes@gmail.com>
Date: Thu, 5 Oct 2023 11:31:21 +0700
Subject: [PATCH] feat: create kakarot core smart contract

---
 crates/evm/src/kakarot_core.cairo | 87 +++++++++++++++++++++++++++++++
 crates/evm/src/lib.cairo          |  3 ++
 2 files changed, 90 insertions(+)
 create mode 100644 crates/evm/src/kakarot_core.cairo

diff --git a/crates/evm/src/kakarot_core.cairo b/crates/evm/src/kakarot_core.cairo
new file mode 100644
index 000000000..f8bf0c388
--- /dev/null
+++ b/crates/evm/src/kakarot_core.cairo
@@ -0,0 +1,87 @@
+use starknet::{ContractAddress, EthAddress, ClassHash};
+
+#[starknet::interface]
+trait IKakarotCore<TContractState> {
+    fn set_native_token(ref self: TContractState, new_address: ContractAddress);
+    fn native_token(self: @TContractState) -> ContractAddress;
+    fn set_deploy_fee(ref self: TContractState, deploy_fee: u128);
+    fn deploy_fee(self: @TContractState) -> u128;
+    fn compute_starknet_address(self: @TContractState, evm_address: EthAddress) -> ContractAddress;
+    fn get_starknet_address(self: @TContractState, evm_address: EthAddress) -> ContractAddress;
+    fn deploy_externally_owned_account(
+        ref self: TContractState, evm_address: EthAddress
+    ) -> ContractAddress;
+    fn eth_call(
+        self: @TContractState,
+        from: EthAddress,
+        to: EthAddress,
+        gas_limit: u128,
+        gas_price: u128,
+        value: u128,
+        data: Span<u8>
+    ) -> Span<u8>;
+    fn eth_send_transaction(
+        ref self: TContractState,
+        to: EthAddress,
+        gas_limit: u128,
+        gas_price: u128,
+        value: u128,
+        data: Span<u8>
+    ) -> Span<u8>;
+    fn upgrade(ref self: TContractState, new_class_hash: ClassHash);
+}
+
+#[derive(Copy, Drop, Serde, starknet::Store)]
+enum ContractTypeStorage {
+    EOA: ContractAddress,
+    ContractAccount: ContractAccountStorage
+}
+
+/// Note: We might not want to implement Copy on the bytecode field, as it'll be an expensive List
+#[derive(Copy, Drop, Serde, starknet::Store)]
+struct ContractAccountStorage {
+    nonce: u128,
+    balance: u256,
+// TODO: add bytecode as a field for ContractAccountStorage
+// bytecode: List
+}
+
+
+#[starknet::contract]
+mod KakarotCore {
+    use starknet::{EthAddress, ContractAddress, ClassHash};
+    use super::{ContractAccountStorage, ContractTypeStorage};
+    #[storage]
+    struct Storage {
+        /// Kakarot storage for accounts: Externally Owned Accounts (EOA) and Contract Accounts (CA)
+        /// EOAs:
+        /// Map their EVM address and their Starknet address
+        /// - starknet_address: the deterministic starknet address (31 bytes) computed given an EVM address (20 bytes)
+        ///
+        /// CAs:
+        /// Map EVM address of a CA and the corresponding Kakarot Core storage -> 
+        /// - nonce (note that this nonce is not the same as the Starknet protocol nonce)
+        /// - current balance in native token (CAs can use this balance as an allowance to spend native Starknet token through Kakarot Core)
+        /// - bytecode of the CA
+        accounts: LegacyMap::<ContractAddress, ContractTypeStorage>,
+        native_token: ContractAddress,
+        deploy_fee: u128,
+        externally_owned_account_class_hash: ClassHash,
+        /// Storage of CAs in EVM is defined as a mapping of key (bytes32) - value (bytes32) pairs
+        contract_account_storage: LegacyMap::<(EthAddress, u256), u256>,
+    // TODO: add ownable as component
+    }
+
+    #[constructor]
+    fn constructor(
+        ref self: ContractState,
+        native_token: ContractAddress,
+        deploy_fee: u128,
+        externally_owned_account_class_hash: ClassHash
+    ) {
+        self.native_token.write(native_token);
+        self.deploy_fee.write(deploy_fee);
+        self.externally_owned_account_class_hash.write(externally_owned_account_class_hash);
+    }
+}
+
diff --git a/crates/evm/src/lib.cairo b/crates/evm/src/lib.cairo
index bbe052589..2b646fde3 100644
--- a/crates/evm/src/lib.cairo
+++ b/crates/evm/src/lib.cairo
@@ -28,6 +28,9 @@ mod model;
 // Stack module
 mod stack;
 
+// Kakarot smart contract
+mod kakarot_core;
+
 // tests
 #[cfg(test)]
 mod tests;