#!/usr/bin/env node

const fs = require('fs')
const assert = require('assert')
const babylon = require('babylon')
const esprima = require('esprima')
const {Document} = require('tree-sitter-cli/node_modules/tree-sitter')
const jsLanguage = require('..')

const ITERATION_COUNT = 50

if (process.argv.length < 3) {
  console.log('Usage: script/benchmark.js <javascript-file>')
  process.exit(1)
}

const fileName = process.argv[2]
const code = fs.readFileSync(fileName, 'utf8')

profile("Babylon", () => {
  let rootNode = babylon.parse(code);
  assert(rootNode.type === 'File');
});


profile("Esprima", () => {
  let rootNode = esprima.parse(code);
  assert(rootNode.type === 'Program');
});

let document = null

profile('Tree-sitter', () => {
  document = new Document()
    .setInputString(code)
    .setLanguage(jsLanguage)
  document.parse()
  assert(document.rootNode.type === 'program')
})

assert(!/ERROR/.test(document.rootNode.toString()))

function profile (name, action) {
  console.log(name + ':')
  let durations = []

  for (let i = 0; i < ITERATION_COUNT; i++) {
    let startTime = Date.now()
    try {
      action()
    } catch (e) {
      console.log('FAILED', e.message)
      return
    }
    let endTime = Date.now()
    durations.push(endTime - startTime)
  }

  durations.sort((a, b) => a - b)
  const average = durations.reduce((sum, term) => sum + term) / ITERATION_COUNT
  const min = durations[0]
  const max = durations[durations.length - 1]

  console.log('Average:', average, 'Min:', min, 'Max:', max)
}