import axios from 'axios';
import { BannerAlertSeverity } from '../../component-library/components/Banners/Banner';
import { strings } from '../../../locales/i18n';
import { PopularList } from '../../util/networks/customNetworks';

import { toHex } from '@metamask/controller-utils';

export type Alert = {
  alertError: string;
  alertSeverity: BannerAlertSeverity;
  alertOrigin: string;
}

const findPopularNetwork = (rpcUrl: string, chainId: string) =>
  PopularList.some((network) => {
    const { origin } = new URL(network.rpcUrl);
    return origin === rpcUrl && network.chainId === chainId;
  });

const findPopularNetworkName = (name: string, chainId: string) =>
  PopularList.some(
    (network) =>
      network.nickname.toLowerCase() === name?.toLowerCase() &&
      network.chainId === chainId,
  );

const findPopularNetworkSymbol = (symbol: string, chainId: string) =>
  PopularList.some(
    (network) => network.ticker === symbol && network.chainId === chainId,
  );

const checkSafeNetwork = async (
  chainIdDecimal: string,
  rpcUrl: string,
  nickname: string,
  ticker: string,
): Promise<Alert[]> => {
  const EVM_NATIVE_TOKEN_DECIMALS = 18;

  const response = await axios.get('https://chainid.network/chains.json');
  const safeChainsList = response.data;

  const matchedChains = safeChainsList.filter(
    (chain: { chainId: number }) => chain.chainId.toString() === chainIdDecimal,
  );

  if (!matchedChains.length) {
    return [{
      alertError: strings('add_custom_network.unrecognized_chain_id'),
      alertSeverity: BannerAlertSeverity.Error,
      alertOrigin: 'unknown_chain',
    }]
  }

  const alertsForMatchedChains = matchedChains.map((matchedChain) => {
    const alerts = [];
    const { origin } = new URL(rpcUrl);
    if (
      !matchedChain.rpc
        ?.map((rpc: string) => new URL(rpc).origin)
        .includes(origin) &&
      !findPopularNetwork(origin, toHex(chainIdDecimal))
    ) {
      alerts.push({
        alertError: strings('add_custom_network.invalid_rpc_url'),
        alertSeverity: BannerAlertSeverity.Error,
        alertOrigin: 'rpc_url',
      });
    }
    if (matchedChain.nativeCurrency?.decimals !== EVM_NATIVE_TOKEN_DECIMALS) {
      alerts.push({
        alertError: strings('add_custom_network.invalid_chain_token_decimals'),
        alertSeverity: BannerAlertSeverity.Warning,
        alertOrigin: 'decimals',
      });
    }
    if (
      matchedChain.name?.toLowerCase() !== nickname?.toLowerCase() &&
      !findPopularNetworkName(nickname, toHex(chainIdDecimal))
    ) {
      alerts.push({
        alertError: strings('add_custom_network.unrecognized_chain_name'),
        alertSeverity: BannerAlertSeverity.Warning,
        alertOrigin: 'chain_name',
      });
    }
    if (
      matchedChain.nativeCurrency?.symbol !== ticker &&
      !findPopularNetworkSymbol(ticker, toHex(chainIdDecimal))
    ) {
      alerts.push({
        alertError: strings('add_custom_network.unrecognized_chain_ticker'),
        alertSeverity: BannerAlertSeverity.Warning,
        alertOrigin: 'chain_ticker',
      });
    }

    return alerts;
  })

  // less alerts means a better match
  const bestMatchedAlerts = alertsForMatchedChains.reduce((best, current) => {
    return current.length < best.length ? current : best;
  }, alertsForMatchedChains[0])

  return bestMatchedAlerts;
};

export default checkSafeNetwork;