const lightningPayReq = require('bolt11');
const bitcoin = require('bitcoinjs-lib');


class LightningWallet {

  constructor(privateKey, coinType) {
    const network = bitcoin.networks[coinType];
    const keyPair = bitcoin.ECPair.fromWIF(privateKey, network);
    const pubKey = keyPair.getPublicKeyBuffer();

    const scriptPubKey = bitcoin.script.witnessPubKeyHash.output.encode(bitcoin.crypto.hash160(pubKey));
    const address = bitcoin.address.fromOutputScript(scriptPubKey, network);


    this.privateKey = privateKey;
    this.coinType = coinType;
    this.address = address;
  }

  sign(encoded) { return lightningPayReq.sign(encoded, this.privateKey) }

  decode(invoice) { return lightningPayReq.decode(invoice) }

  encode(satoshis) {
    const encoded = lightningPayReq.encode({
      "coinType": this.coinType,
      "satoshis": satoshis,
      "tags": [
        {
          "tagName": "payment_hash",
          "data": bitcoin.crypto.sha256(this.coinType + satoshis + new Date().toUTCString()).toString("hex")
        },
        {
          "tagName": "fallback_address",
          "data": {
            "address": this.address
          }
        }
      ]
    })

    return encoded
  }
}

module.exports = LightningWallet