import { AbstractHDWallet } from './abstract-hd-wallet';
import Frisbee from 'frisbee';
const isaac = require('isaac');
const bitcoin = require('bitcoinjs-lib');
const bip39 = require('bip39');
const BigNumber = require('bignumber.js');
const b58 = require('bs58check');

/**
 * HD Wallet (BIP39).
 * In particular, BIP49 (P2SH Segwit)
 * @see https://github.com/bitcoin/bips/blob/master/bip-0049.mediawiki
 */
export class HDSegwitP2SHWallet extends AbstractHDWallet {
  constructor() {
    super();
    this.type = 'HDsegwitP2SH';
    this.usedAddresses = [];
  }

  getTypeReadable() {
    return 'HD SegWit (BIP49 P2SH)';
  }

  generate() {
    let c = 32;
    let totalhex = '';
    for (let i = 0; i < c; i++) {
      let randomNumber = isaac.random();
      randomNumber = Math.floor(randomNumber * 256);
      let n = new BigNumber(randomNumber);
      let hex = n.toString(16);
      if (hex.length === 1) {
        hex = '0' + hex;
      }
      totalhex += hex;
    }
    totalhex = bitcoin.crypto.sha256('hello there' + totalhex).toString('hex');
    totalhex = bitcoin.crypto.sha256(totalhex).toString('hex');
    this.secret = bip39.entropyToMnemonic(totalhex);
  }

  async fetchBalance() {
    try {
      const api = new Frisbee({ baseURI: 'https://www.blockonomics.co' });
      let response = await api.post('/api/balance', { body: JSON.stringify({ addr: this.getXpub() }) });
      // console.log(response);

      if (response && response.body && response.body.response) {
        this.balance = 0;
        this.unconfirmed_balance = 0;
        this.usedAddresses = [];
        for (let addr of response.body.response) {
          this.balance += addr.confirmed;
          this.unconfirmed_balance += addr.unconfirmed;
          this.usedAddresses.push(addr.addr);
        }
        this.balance = new BigNumber(this.balance).div(100000000).toString() * 1;
        this.unconfirmed_balance = new BigNumber(this.unconfirmed_balance).div(100000000).toString() * 1;
        this._lastBalanceFetch = +new Date();
      } else {
        throw new Error('Could not fetch balance from API: ' + response.err);
      }
    } catch (err) {
      console.warn(err);
    }
  }

  _getExternalWIFByIndex(index) {
    index = index * 1; // cast to int
    let mnemonic = this.secret;
    let seed = bip39.mnemonicToSeed(mnemonic);
    let root = bitcoin.HDNode.fromSeedBuffer(seed);
    let path = "m/49'/0'/0'/0/" + index;
    let child = root.derivePath(path);
    return child.keyPair.toWIF();
  }

  _getInternalWIFByIndex(index) {
    index = index * 1; // cast to int
    let mnemonic = this.secret;
    let seed = bip39.mnemonicToSeed(mnemonic);
    let root = bitcoin.HDNode.fromSeedBuffer(seed);
    let path = "m/49'/0'/0'/1/" + index;
    let child = root.derivePath(path);
    return child.keyPair.toWIF();
  }

  _getExternalAddressByIndex(index) {
    index = index * 1; // cast to int
    if (this.external_addresses_cache[index]) return this.external_addresses_cache[index]; // cache hit
    if (!this._xpub) {
      let mnemonic = this.secret;
      let seed = bip39.mnemonicToSeed(mnemonic);
      let root = bitcoin.HDNode.fromSeedBuffer(seed);
      let path = "m/49'/0'/0'/0/" + index;
      let child = root.derivePath(path);

      let keyhash = bitcoin.crypto.hash160(child.getPublicKeyBuffer());
      let scriptSig = bitcoin.script.witnessPubKeyHash.output.encode(keyhash);
      let addressBytes = bitcoin.crypto.hash160(scriptSig);
      let outputScript = bitcoin.script.scriptHash.output.encode(addressBytes);
      return (this.external_addresses_cache[index] = bitcoin.address.fromOutputScript(outputScript, bitcoin.networks.bitcoin));
    } else {
      let b58 = require('bs58check');
      // eslint-disable-next-line
      function ypubToXpub(ypub) {
        var data = b58.decode(ypub);
        data = data.slice(4);
        data = Buffer.concat([Buffer.from('0488b21e', 'hex'), data]);
        return b58.encode(data);
      }
      // eslint-disable-next-line
      function nodeToP2shSegwitAddress(hdNode) {
        let pubkeyBuf = hdNode.keyPair.getPublicKeyBuffer();
        let hash = bitcoin.crypto.hash160(pubkeyBuf);
        let redeemScript = bitcoin.script.witnessPubKeyHash.output.encode(hash);
        let hash2 = bitcoin.crypto.hash160(redeemScript);
        let scriptPubkey = bitcoin.script.scriptHash.output.encode(hash2);
        return bitcoin.address.fromOutputScript(scriptPubkey);
      }
      let xpub = ypubToXpub(this._xpub);
      let hdNode = bitcoin.HDNode.fromBase58(xpub);
      let address = nodeToP2shSegwitAddress(hdNode.derive(0).derive(index));
      return (this.external_addresses_cache[index] = address);
    }
  }

  _getInternalAddressByIndex(index) {
    index = index * 1; // cast to int
    if (this.internal_addresses_cache[index]) return this.internal_addresses_cache[index]; // cache hit
    if (!this._xpub) {
      let mnemonic = this.secret;
      let seed = bip39.mnemonicToSeed(mnemonic);
      let root = bitcoin.HDNode.fromSeedBuffer(seed);

      let path = "m/49'/0'/0'/1/" + index;
      let child = root.derivePath(path);

      let keyhash = bitcoin.crypto.hash160(child.getPublicKeyBuffer());
      let scriptSig = bitcoin.script.witnessPubKeyHash.output.encode(keyhash);
      let addressBytes = bitcoin.crypto.hash160(scriptSig);
      let outputScript = bitcoin.script.scriptHash.output.encode(addressBytes);
      return (this.internal_addresses_cache[index] = bitcoin.address.fromOutputScript(outputScript, bitcoin.networks.bitcoin));
    } else {
      let b58 = require('bs58check');
      // eslint-disable-next-line
      function ypubToXpub(ypub) {
        var data = b58.decode(ypub);
        data = data.slice(4);
        data = Buffer.concat([Buffer.from('0488b21e', 'hex'), data]);
        return b58.encode(data);
      }
      // eslint-disable-next-line
      function nodeToP2shSegwitAddress(hdNode) {
        let pubkeyBuf = hdNode.keyPair.getPublicKeyBuffer();
        let hash = bitcoin.crypto.hash160(pubkeyBuf);
        let redeemScript = bitcoin.script.witnessPubKeyHash.output.encode(hash);
        let hash2 = bitcoin.crypto.hash160(redeemScript);
        let scriptPubkey = bitcoin.script.scriptHash.output.encode(hash2);
        return bitcoin.address.fromOutputScript(scriptPubkey);
      }
      let xpub = ypubToXpub(this._xpub);
      let hdNode = bitcoin.HDNode.fromBase58(xpub);
      let address = nodeToP2shSegwitAddress(hdNode.derive(1).derive(index));
      return (this.internal_addresses_cache[index] = address);
    }
  }

  /**
   * Returning ypub actually, not xpub. Keeping same method name
   * for compatibility.
   *
   * @return {String} ypub
   */
  getXpub() {
    if (this._xpub) {
      return this._xpub; // cache hit
    }
    // first, getting xpub
    let mnemonic = this.secret;
    let seed = bip39.mnemonicToSeed(mnemonic);
    let root = bitcoin.HDNode.fromSeedBuffer(seed);

    let path = "m/49'/0'/0'";
    let child = root.derivePath(path).neutered();
    let xpub = child.toBase58();

    // bitcoinjs does not support ypub yet, so we just convert it from xpub
    let data = b58.decode(xpub);
    data = data.slice(4);
    data = Buffer.concat([Buffer.from('049d7cb2', 'hex'), data]);
    this._xpub = b58.encode(data);
    return this._xpub;
  }

  /**
   * @inheritDoc
   */
  async fetchTransactions() {
    try {
      if (this.usedAddresses.length === 0) {
        // just for any case, refresh balance (it refreshes internal `this.usedAddresses`)
        await this.fetchBalance();
      }

      let addresses = this.usedAddresses.join('|');
      addresses += '|' + this._getExternalAddressByIndex(this.next_free_address_index);
      addresses += '|' + this._getInternalAddressByIndex(this.next_free_change_address_index);

      const api = new Frisbee({ baseURI: 'https://blockchain.info' });
      this.transactions = [];
      let offset = 0;

      while (1) {
        let response = await api.get('/multiaddr?active=' + addresses + '&n=100&offset=' + offset);

        if (response && response.body) {
          if (response.body.txs && response.body.txs.length === 0) {
            break;
          }

          this._lastTxFetch = +new Date();

          // processing TXs and adding to internal memory
          if (response.body.txs) {
            for (let tx of response.body.txs) {
              let value = 0;

              for (let input of tx.inputs) {
                // ----- INPUTS

                if (input.prev_out && input.prev_out.addr && this.weOwnAddress(input.prev_out.addr)) {
                  // this is outgoing from us
                  value -= input.prev_out.value;
                }
              }

              for (let output of tx.out) {
                // ----- OUTPUTS

                if (output.addr && this.weOwnAddress(output.addr)) {
                  // this is incoming to us
                  value += output.value;
                }
              }

              tx.value = value; // new BigNumber(value).div(100000000).toString() * 1;

              this.transactions.push(tx);
            }

            if (response.body.txs.length < 100) {
              // this fetch yilded less than page size, thus requesting next batch makes no sense
              break;
            }
          } else {
            break; // error ?
          }
        } else {
          throw new Error('Could not fetch transactions from API: ' + response.err); // breaks here
        }

        offset += 100;
      }
    } catch (err) {
      console.warn(err);
    }
  }

  /**
   * @inheritDoc
   */
  async fetchUtxo() {
    const api = new Frisbee({
      baseURI: 'https://blockchain.info',
    });

    // unspent?active=$address

    if (this.usedAddresses.length === 0) {
      // just for any case, refresh balance (it refreshes internal `this.usedAddresses`)
      await this.fetchBalance();
    }

    let addresses = this.usedAddresses.join('|');
    addresses += '|' + this._getExternalAddressByIndex(this.next_free_address_index);
    addresses += '|' + this._getInternalAddressByIndex(this.next_free_change_address_index);

    let utxos = [];

    let response;
    try {
      response = await api.get('/unspent?active=' + addresses + '&limit=1000');
      // this endpoint does not support offset of some kind o_O
      // so doing only one call
      let json = response.body;
      if (typeof json === 'undefined' || typeof json.unspent_outputs === 'undefined') {
        throw new Error('Could not fetch UTXO from API' + response.err);
      }

      for (let unspent of json.unspent_outputs) {
        // a lil transform for signer module
        unspent.txid = unspent.tx_hash;
        unspent.vout = unspent.tx_output_n;
        unspent.amount = unspent.value;

        let chunksIn = bitcoin.script.decompile(Buffer.from(unspent.script, 'hex'));
        unspent.address = bitcoin.address.fromOutputScript(chunksIn);
        utxos.push(unspent);
      }
    } catch (err) {
      console.warn(err);
    }

    this.utxo = utxos;
  }

  weOwnAddress(addr) {
    let hashmap = {};
    for (let a of this.usedAddresses) {
      hashmap[a] = 1;
    }

    return hashmap[addr] === 1;
  }
}