import { constants } from "./constants";

let errorMsgNoMetamaskAccount = `You haven't chosen any account in MetaMask.
Please choose your initial key in MetaMask and reload the page.
Check POA Network <a href='https://github.com/poanetwork/wiki' target='blank'>wiki</a> for more info.`;

function generateElement(msg) {
  let errorNode = document.createElement("div");
  errorNode.innerHTML = `<div style="line-height: 1.6;">
    ${msg}
  </div>`;
  return errorNode;
}
let getWeb3 = () => {
  return new Promise(function(resolve, reject) {
    // Wait for loading completion to avoid race conditions with web3 injection timing.
    window.addEventListener("load", function() {
      var results;
      var web3 = window.web3;

      // Checking if Web3 has been injected by the browser (Mist/MetaMask)
      if (typeof web3 !== "undefined") {
        // Use Mist/MetaMask's provider.
        var errorMsg = null;
        web3 = new window.Web3(web3.currentProvider);
        web3.version.getNetwork((err, netId) => {
          let netIdName;
          switch (netId) {
            case constants.NETID_SOKOL:
              netIdName = "Sokol";
              console.log("This is sokol");
              break;
            case constants.NETID_DAI_TEST:
              netIdName = "Dai-Test";
              console.log("This is Dai-Test");
              break;
            case constants.NETID_CORE:
              netIdName = "Core";
              console.log("This is Core");
              break;
            case constants.NETID_DAI:
              netIdName = "Dai";
              console.log("This is Dai");
              break;
            default:
              netIdName = "Unknown";
              errorMsg = `You aren't connected to POA Network. 
                  Please switch on Metamask and refresh the page. 
                  Check POA Network <a href='https://github.com/poanetwork/wiki' target='blank'>wiki</a> for more info.
                  <b>Current Network ID</b> is <i>${netId}</i>`;

              console.log("This is an unknown network.", netId);
          }
          results = {
            web3Instance: web3,
            netIdName,
            netId,
            injectedWeb3: true
          };
          document.title = `${netIdName} - Dapp Keys Generation`;
          var defaultAccount = web3.eth.defaultAccount || null;
          if (defaultAccount === null) {
            reject({
              msg: errorMsgNoMetamaskAccount,
              node: generateElement(errorMsgNoMetamaskAccount)
            });
          }
          if (errorMsg !== null) {
            reject({ msg: errorMsg, node: generateElement(errorMsg) });
          }
          resolve(results);
        });

        console.log("Injected web3 detected.");
      } else {
        reject({
          msg: errorMsgNoMetamaskAccount,
          node: generateElement(errorMsgNoMetamaskAccount)
        });
        console.error("Metamask not found");
      }
    });
  });
};

export default getWeb3;