import {LendingPool} from '../../../types/LendingPool';
import {ReserveData, UserReserveData} from './interfaces';
import {
  getLendingRateOracle,
  getIErc20Detailed,
  getMintableErc20,
  getAToken, getStableDebtToken, getVariableDebtToken
} from '../../../helpers/contracts-helpers';
import {tEthereumAddress} from '../../../helpers/types';
import BigNumber from 'bignumber.js';
import {getDb, BRE} from '../../../helpers/misc-utils';

export const getReserveData = async (
  pool: LendingPool,
  reserve: tEthereumAddress
): Promise<ReserveData> => {
  const [reserveData, tokenAddresses, rateOracle, token] = await Promise.all([
    pool.getReserveData(reserve),
    pool.getReserveTokensAddresses(reserve),
    getLendingRateOracle(),
    getIErc20Detailed(reserve),
  ]);

  const stableDebtToken = await getStableDebtToken(tokenAddresses.stableDebtTokenAddress);
  const variableDebtToken = await getVariableDebtToken(tokenAddresses.variableDebtTokenAddress);

  const [principalStableDebt] = await stableDebtToken.getPrincipalSupplyAndAvgRate();

  const scaledVariableDebt = await variableDebtToken.scaledTotalSupply();

  const rate = (await rateOracle.getMarketBorrowRate(reserve)).toString();
  const symbol = await token.symbol();
  const decimals = new BigNumber(await token.decimals());

  const totalLiquidity = new BigNumber(reserveData.availableLiquidity.toString())
    .plus(reserveData.totalStableDebt.toString())
    .plus(reserveData.totalVariableDebt.toString());

  const utilizationRate = new BigNumber(
    totalLiquidity.eq(0)
      ? 0
      : new BigNumber(reserveData.totalStableDebt.toString())
          .plus(reserveData.totalVariableDebt.toString())
          .rayDiv(totalLiquidity)
  );

  return {
    totalLiquidity,
    utilizationRate,
    availableLiquidity: new BigNumber(reserveData.availableLiquidity.toString()),
    totalStableDebt: new BigNumber(reserveData.totalStableDebt.toString()),
    totalVariableDebt: new BigNumber(reserveData.totalVariableDebt.toString()),
    liquidityRate: new BigNumber(reserveData.liquidityRate.toString()),
    variableBorrowRate: new BigNumber(reserveData.variableBorrowRate.toString()),
    stableBorrowRate: new BigNumber(reserveData.stableBorrowRate.toString()),
    averageStableBorrowRate: new BigNumber(reserveData.averageStableBorrowRate.toString()),
    liquidityIndex: new BigNumber(reserveData.liquidityIndex.toString()),
    variableBorrowIndex: new BigNumber(reserveData.variableBorrowIndex.toString()),
    lastUpdateTimestamp: new BigNumber(reserveData.lastUpdateTimestamp),
    principalStableDebt: new BigNumber(principalStableDebt.toString()),
    scaledVariableDebt: new BigNumber(scaledVariableDebt.toString()),
    address: reserve,
    aTokenAddress: tokenAddresses.aTokenAddress,
    symbol,
    decimals,
    marketStableRate: new BigNumber(rate),
  };
};

export const getUserData = async (
  pool: LendingPool,
  reserve: string,
  user: tEthereumAddress,
  sender?: tEthereumAddress
): Promise<UserReserveData> => {
  const [userData, scaledATokenBalance] = await Promise.all([
    pool.getUserReserveData(reserve, user),
    getATokenUserData(reserve, user, pool),
  ]);

  const token = await getMintableErc20(reserve);
  const walletBalance = new BigNumber((await token.balanceOf(sender || user)).toString());

  return {
    scaledATokenBalance: new BigNumber(scaledATokenBalance),
    currentATokenBalance: new BigNumber(userData.currentATokenBalance.toString()),
    currentStableDebt: new BigNumber(userData.currentStableDebt.toString()),
    currentVariableDebt: new BigNumber(userData.currentVariableDebt.toString()),
    principalStableDebt: new BigNumber(userData.principalStableDebt.toString()),
    scaledVariableDebt: new BigNumber(userData.scaledVariableDebt.toString()),
    stableBorrowRate: new BigNumber(userData.stableBorrowRate.toString()),
    liquidityRate: new BigNumber(userData.liquidityRate.toString()),
    usageAsCollateralEnabled: userData.usageAsCollateralEnabled,
    stableRateLastUpdated: new BigNumber(userData.stableRateLastUpdated.toString()),
    walletBalance,
  };
};

export const getReserveAddressFromSymbol = async (symbol: string) => {
  const token = await getMintableErc20(
    (await getDb().get(`${symbol}.${BRE.network.name}`).value()).address
  );

  if (!token) {
    throw `Could not find instance for contract ${symbol}`;
  }
  return token.address;
};

const getATokenUserData = async (reserve: string, user: string, pool: LendingPool) => {
  const aTokenAddress: string = (await pool.getReserveTokensAddresses(reserve)).aTokenAddress;

  const aToken = await getAToken(aTokenAddress);

  const scaledBalance = await aToken.scaledBalanceOf(user);
  return scaledBalance.toString();
};