Loans

[elicharlese]

use near_sdk::{env, near_bindgen, ext_contract, Promise};
use near_sdk::borsh::{self, BorshDeserialize, BorshSerialize};
use near_sdk::collections::Vector;

#[ext_contract(ext_erc20)]
trait ExtERC20 {
    fn transfer(&mut self, receiver_id: AccountId, amount: u128) -> Promise;
    fn approve(&mut self, spender_id: AccountId, amount: u128) -> Promise;
    fn transfer_from(&mut self, owner_id: AccountId, new_owner_id: AccountId, amount: u128) -> Promise;
}

#[near_bindgen]
#[derive(Default, BorshDeserialize, BorshSerialize)]
struct Flashloan {
    erc20_contract: AccountId,
    amount: u128,
    data: String,
}

#[near_bindgen]
impl Flashloan {
    pub fn flashloan(&mut self, amount: u128, data: String) -> Promise {
        self.amount = amount;
        self.data = data;
        ext_erc20::approve(self.erc20_contract.clone(), amount);
        ext_erc20::transfer(self.erc20_contract.clone(), amount);
        ext_erc20::transfer_from(env::predecessor_account_id(), self.erc20_contract.clone(), amount);
        Promise::new(env::predecessor_account_id()).then(ext_erc20::transfer_from(
            self.erc20_contract.clone(),
            env::predecessor_account_id(),
            amount,
            1,
            &env::current_account_id(),
            0,
            env::prepaid_gas() - 10,
        ))
    }
}