Convert replays

convert.js

const {ArgumentParser} = require('argparse');
const glob = require('glob');
const fs = require('fs');
const {round10} = require('round10');

function main() {
  let parser = new ArgumentParser({ description: "minify replay files."});
  parser.addArgument('glob');
  let args = parser.parseArgs();
  let stats = [];
  glob(args.glob, (err, matches) => {
    console.log(`Found ${matches.length} matches`);
    for (let match of matches) {
      console.log(`Processing ${match}`);
      let these_stats = {
        name: match
      };
      let data = fs.readFileSync(match, { encoding: 'utf-8' });
      these_stats.start_length = data.length;
      let result = convert(data);
      these_stats.end_length = result.length;
      fs.writeFileSync(`${match}.min`, result);
      stats.push(these_stats);
    }
    console.dir(stats);
  });
}
main();

function deepEq(a, b) {
  let a_fields = Object.keys(a);
  let b_fields = Object.keys(b);
  if (b_fields.some(f => !a_fields.includes(f))) return false;
  if (a_fields.some(f => !b_fields.includes(f))) return false;
  for (let field in a) {
    if (!(field in b)) return false;
    if (!eq(a[field], b[field])) return false;
  }
  return true;
}

function eq(a, b) {
  if (typeof a === typeof b) {
    if (a !== null && b !== null && typeof a === 'object') {
      return deepEq(a, b);
    } else {
      return a === b;
    }
  } else {
    return false;
  }
}

function convertFrameArray(array, clock) {
  let struct = {
    init: array[0],
    changes: []
  };
  let last_val = struct.init;
  for (let i = 1; i < array.length; i++) {
    let val = array[i];
    if (!eq(val, last_val)) {
      struct.changes.push([val, clock[i]]);
      last_val = val;
    }
  }

  return struct;
}

function convertDenseArray(array) {
  let out = [array[0]];
  let last = out[0];
  for (let i = 1; i < array.length; i++) {
    out.push(last - array[i]);
    last = array[i];
  }
  return out;
}

function convertPlayer(player, clock) {
  // Arrays
  let arrays = ["degree", "bomb", "grip", "flag", "tagpro", "auth", "name", "team", "dead", "draw", "flair"];
  for (let name of arrays) {
    let array = player[name];
    player[name] = convertFrameArray(array, clock);
  }

  // Dense array.
  arrays = ["x", "y", "angle"];
  for (let name of arrays) {
    player[name] = convertDenseArray(player[name]).map(v => round10(v, -2));
  }
  return player;
}

function convertFloorTile(tile, clock) {
  tile.value = convertFrameArray(tile.value, clock);
  return tile;
}

function convert(replay) {
  let struct = JSON.parse(replay);
  let clock = struct.clock.map(Date.parse);
  let players = Object.keys(struct).filter(k => k.startsWith('player'));
  for (let player of players) {
    //console.log(`Editing player ${player}`);
    struct[player] = convertPlayer(struct[player], clock);
  }

  struct.floorTiles = struct.floorTiles.map(t => convertFloorTile(t, clock));
  struct.score = convertFrameArray(struct.score, clock);
  struct.clock = convertDenseArray(clock);

  // Generate dynamically during rendering.
  delete struct.tiles;
  delete struct.wallMap;

  return JSON.stringify(struct);
}