RENVM Bridge Swap Protocol

Lets add a smart contract to be able to swap HZ for other tokens, using RENVM as our bridge to create interoperability between blockchains.
Sure, we can create a smart contract to enable swapping of HZ tokens with other tokens using RENVM as the bridge.

To do this, we need to integrate the RENVM SDK into our smart contract. The RENVM SDK allows us to communicate with the RENVM network and to swap tokens across different blockchains.

Here is an example code for a smart contract that allows swapping of HZ tokens with Ethereum's native token (ETH) using RENVM:

rust
Copy code
use renvm_sdk::{
    GatewayInterface, 
    GatewayRequest, 
    GatewayResponse, 
    GatewayTransport, 
    GatewayTransportError,
};

#[program]
mod hz_swap {
    use super::*;

    #[state]
    pub struct HZSwap {
        pub owner: Pubkey,
        pub hz_account: Pubkey,
        pub eth_account: Pubkey,
        pub renvm_gateway: Pubkey,
    }

    impl HZSwap {
        pub fn new(ctx: Context<Initialize>, owner: Pubkey, hz_account: Pubkey, eth_account: Pubkey, renvm_gateway: Pubkey) -> ProgramResult {
            let hz_swap = &mut ctx.accounts.hz_swap;
            hz_swap.owner = owner;
            hz_swap.hz_account = hz_account;
            hz_swap.eth_account = eth_account;
            hz_swap.renvm_gateway = renvm_gateway;
            Ok(())
        }

        pub fn swap_to_eth(&mut self, ctx: Context<SwapToEth>, hz_amount: u64) -> ProgramResult {
            let request = GatewayRequest::new(
                self.hz_account, 
                self.eth_account, 
                hz_amount, 
                GatewayInterface::Eth,
            );
            let response = self.renvm_gateway.request(&request)?;

            if response.get_network() == GatewayInterface::Eth {
                let mut eth_account = ctx.accounts.eth_account;
                eth_account.amount += response.get_amount();
            } else {
                return Err(ProgramError::InvalidAccountData);
            }

            let mut hz_account = ctx.accounts.hz_account;
            hz_account.amount -= hz_amount;

            Ok(())
        }

        pub fn swap_to_hz(&mut self, ctx: Context<SwapToHZ>, eth_amount: u64) -> ProgramResult {
            let request = GatewayRequest::new(
                self.eth_account, 
                self.hz_account, 
                eth_amount, 
                GatewayInterface::Btc,
            );
            let response = self.renvm_gateway.request(&request)?;

            if response.get_network() == GatewayInterface::Btc {
                let mut hz_account = ctx.accounts.hz_account;
                hz_account.amount += response.get_amount();
            } else {
                return Err(ProgramError::InvalidAccountData);
            }

            let mut eth_account = ctx.accounts.eth_account;
            eth_account.amount -= eth_amount;

            Ok(())
        }
    }

    #[derive(Accounts)]
    pub struct Initialize<'info> {
        #[account(init, payer = user, space = 8 + 32 + 32 + 32)]
        pub hz_swap: Account<'info, HZSwap>,
        #[account(mut)]
        pub user: Signer<'info>,
        pub system_program: Program<'info, System>,
    }

    #[derive(Accounts)]
    pub struct SwapToEth<'info> {
        #[account(mut)]
        pub hz_account: Signer<'info>,
        #[account(mut)]
        pub eth_account: Signer<'info>,
        #[account(mut)]
        pub hz_swap: Signer<'info>,
        #[account(mut)]
        pub renvm_gateway: AccountInfo<'info>,
        pub system_program