balanceofsatoshis/display/describe_route.js

const asyncAuto = require('async/auto');
const asyncMap = require('async/map');
const {getNode} = require('ln-service');
const {gray} = require('colorette');
const {greenBright} = require('colorette');
const {redBright} = require('colorette');
const {returnResult} = require('asyncjs-util');

const describeConfidence = require('./describe_confidence');
const formatFeeRate = require('./format_fee_rate');

const aliasColor = n => !!n ? greenBright(n) : '';
const effectiveFeeRate = (n, m) => Number(BigInt(1e6) * BigInt(n) / BigInt(m));
const flatten = arr => [].concat(...arr);
const isEmoji = /(?:[\u261D\u26F9\u270A-\u270D]|\uD83C[\uDF85\uDFC2-\uDFC4\uDFC7\uDFCA-\uDFCC]|\uD83D[\uDC42\uDC43\uDC46-\uDC50\uDC66-\uDC69\uDC6E\uDC70-\uDC78\uDC7C\uDC81-\uDC83\uDC85-\uDC87\uDCAA\uDD74\uDD75\uDD7A\uDD90\uDD95\uDD96\uDE45-\uDE47\uDE4B-\uDE4F\uDEA3\uDEB4-\uDEB6\uDEC0\uDECC]|\uD83E[\uDD18-\uDD1C\uDD1E\uDD1F\uDD26\uDD30-\uDD39\uDD3D\uDD3E\uDDD1-\uDDDD])(?:\uD83C[\uDFFB-\uDFFF])?|(?:[\u231A\u231B\u23E9-\u23EC\u23F0\u23F3\u25FD\u25FE\u2614\u2615\u2648-\u2653\u267F\u2693\u26A1\u26AA\u26AB\u26BD\u26BE\u26C4\u26C5\u26CE\u26D4\u26EA\u26F2\u26F3\u26F5\u26FA\u26FD\u2705\u270A\u270B\u2728\u274C\u274E\u2753-\u2755\u2757\u2795-\u2797\u27B0\u27BF\u2B1B\u2B1C\u2B50\u2B55]|\uD83C[\uDC04\uDCCF\uDD8E\uDD91-\uDD9A\uDDE6-\uDDFF\uDE01\uDE1A\uDE2F\uDE32-\uDE36\uDE38-\uDE3A\uDE50\uDE51\uDF00-\uDF20\uDF2D-\uDF35\uDF37-\uDF7C\uDF7E-\uDF93\uDFA0-\uDFCA\uDFCF-\uDFD3\uDFE0-\uDFF0\uDFF4\uDFF8-\uDFFF]|\uD83D[\uDC00-\uDC3E\uDC40\uDC42-\uDCFC\uDCFF-\uDD3D\uDD4B-\uDD4E\uDD50-\uDD67\uDD7A\uDD95\uDD96\uDDA4\uDDFB-\uDE4F\uDE80-\uDEC5\uDECC\uDED0-\uDED2\uDEEB\uDEEC\uDEF4-\uDEF8]|\uD83E[\uDD10-\uDD3A\uDD3C-\uDD3E\uDD40-\uDD45\uDD47-\uDD4C\uDD50-\uDD6B\uDD80-\uDD97\uDDC0\uDDD0-\uDDE6])|(?:[#\*0-9\xA9\xAE\u203C\u2049\u2122\u2139\u2194-\u2199\u21A9\u21AA\u231A\u231B\u2328\u23CF\u23E9-\u23F3\u23F8-\u23FA\u24C2\u25AA\u25AB\u25B6\u25C0\u25FB-\u25FE\u2600-\u2604\u260E\u2611\u2614\u2615\u2618\u261D\u2620\u2622\u2623\u2626\u262A\u262E\u262F\u2638-\u263A\u2640\u2642\u2648-\u2653\u2660\u2663\u2665\u2666\u2668\u267B\u267F\u2692-\u2697\u2699\u269B\u269C\u26A0\u26A1\u26AA\u26AB\u26B0\u26B1\u26BD\u26BE\u26C4\u26C5\u26C8\u26CE\u26CF\u26D1\u26D3\u26D4\u26E9\u26EA\u26F0-\u26F5\u26F7-\u26FA\u26FD\u2702\u2705\u2708-\u270D\u270F\u2712\u2714\u2716\u271D\u2721\u2728\u2733\u2734\u2744\u2747\u274C\u274E\u2753-\u2755\u2757\u2763\u2764\u2795-\u2797\u27A1\u27B0\u27BF\u2934\u2935\u2B05-\u2B07\u2B1B\u2B1C\u2B50\u2B55\u3030\u303D\u3297\u3299]|\uD83C[\uDC04\uDCCF\uDD70\uDD71\uDD7E\uDD7F\uDD8E\uDD91-\uDD9A\uDDE6-\uDDFF\uDE01\uDE02\uDE1A\uDE2F\uDE32-\uDE3A\uDE50\uDE51\uDF00-\uDF21\uDF24-\uDF93\uDF96\uDF97\uDF99-\uDF9B\uDF9E-\uDFF0\uDFF3-\uDFF5\uDFF7-\uDFFF]|\uD83D[\uDC00-\uDCFD\uDCFF-\uDD3D\uDD49-\uDD4E\uDD50-\uDD67\uDD6F\uDD70\uDD73-\uDD7A\uDD87\uDD8A-\uDD8D\uDD90\uDD95\uDD96\uDDA4\uDDA5\uDDA8\uDDB1\uDDB2\uDDBC\uDDC2-\uDDC4\uDDD1-\uDDD3\uDDDC-\uDDDE\uDDE1\uDDE3\uDDE8\uDDEF\uDDF3\uDDFA-\uDE4F\uDE80-\uDEC5\uDECB-\uDED2\uDEE0-\uDEE5\uDEE9\uDEEB\uDEEC\uDEF0\uDEF3-\uDEF8]|\uD83E[\uDD10-\uDD3A\uDD3C-\uDD3E\uDD40-\uDD45\uDD47-\uDD4C\uDD50-\uDD6B\uDD80-\uDD97\uDDC0\uDDD0-\uDDE6])\uFE0F/g;
const pairEdgeIndex = (pair, key) => `x${Number(!pair.indexOf(key))}`;

/** Describe a route

  {
    lnd: <Authenticated LND API Object>
    route: {
      [confidence]: <Route Confidence Score Out Of One Million Number>
      fee: <Total Fee Tokens To Pay Number>
      fee_mtokens: <Total Fee Millitokens To Pay String>
      hops: [{
        channel: <Standard Format Channel Id String>
        channel_capacity: <Channel Capacity Tokens Number>
        fee: <Fee Number>
        fee_mtokens: <Fee Millitokens String>
        forward: <Forward Tokens Number>
        forward_mtokens: <Forward Millitokens String>
        public_key: <Public Key Hex String>
        timeout: <Timeout Block Height Number>
      }]
      [messages]: [{
        type: <Message Type Number String>
        value: <Message Raw Value Hex Encoded String>
      }]
      mtokens: <Total Millitokens To Pay String>
      [payment]: <Payment Identifier Hex String>
      safe_fee: <Payment Forwarding Fee Rounded Up Tokens Number>
      safe_tokens: <Payment Sent Tokens Rounded Up Number>
      timeout: <Expiration Block Height Number>
      tokens: <Total Tokens To Pay Number>
      [total_mtokens]: <Total Millitokens String>
    }
    [tagged]: [{
      icons: [<Icon String>]
      public_key: <Public Key Hex String>
    }]
  }

  @returns via cbk or Promise
  {
    description: [<Hop Description String>]
  }
*/
module.exports = ({lnd, route, tagged}, cbk) => {
  return new Promise((resolve, reject) => {
    return asyncAuto({
      // Check arguments
      validate: cbk => {
        if (!lnd) {
          return cbk([400, 'ExpectedLndObjectToGenerateRouteDescription']);
        }

        if (!route) {
          return cbk([400, 'ExpectedRouteToGenerateRouteDescriptionFor']);
        }

        return cbk();
      },

      // Get the node aliases
      getAliases: ['validate', ({}, cbk) => {
        return asyncMap(route.hops, (hop, cbk) => {
          return getNode({
            lnd,
            is_omitting_channels: true,
            public_key: hop.public_key,
          },
          (err, res) => {
            if (!!err) {
              return cbk(null, {alias: String(), id: hop.public_key});
            }

            const regularAlias = res.alias.replace(isEmoji, String()).trim();

            const tags = (tagged || []).find(node => {
              return node.public_key === hop.public_key;
            });

            const icons = !tags ? [] : tags.icons;

            const alias = [].concat(icons).concat(regularAlias).join(' ');

            return cbk(null, {alias, id: hop.public_key});
          });
        },
        cbk);
      }],

      // Assemble the description
      description: ['getAliases', ({getAliases}, cbk) => {
        const {confidence} = route;

        const {description} = describeConfidence({confidence});

        const path = route.hops.map((hop, i, hops) => {
          const {alias} = getAliases.find(n => n.id === hop.public_key);
          const {channel} = hop;
          const delta = !i ? null : hops[i - 1].timeout - hops[i].timeout;
          const isFinal = i === hops.length - 1 && hops.length !== 1;
          const pair = [(hops[i - 1] || {}).public_key, hop.public_key].sort();

          const edgeIndex = pairEdgeIndex(pair, hop.public_key);
          const expiry = delta > 240 ? redBright(` Expiry +${delta}`) : '';
          const feeMtokens = isFinal ? hops[i-1].fee_mtokens : hop.fee_mtokens;
          const forwarder = `${aliasColor(alias)} ${hop.public_key}`.trim();

          const feeRate = effectiveFeeRate(feeMtokens, hop.forward_mtokens);

          const rate = formatFeeRate({rate: feeRate}).display;

          const forward = `${forwarder}. Fee rate: ${rate}${expiry}`;

          if (!i) {
            return [`${gray(channel)} ${description || String()}`, forward];
          } else if (i === hops.length - [i].length) {
            return [`${gray(channel + edgeIndex)}`];
          } else {
            return [`${gray(channel + edgeIndex)}`, forward];
          }
        });

        return cbk(null, {description: flatten(path)});
      }],
    },
    returnResult({reject, resolve, of: 'description'}, cbk));
  });
};