import { createMWC }  from '@src/dexm/mwc'

const MAX_TRIALS = 1
const MAX_LOOPS = 100000000

// basic generator settings
// const a = 43
const b = 52
const r = 3

// format generator output 
// to ensure it could be usable as an object hash key
// concatenation or array reduction
const output = (arr) => {
  // console.log(arr)
  //return arr.reduce((acc, val) => b * acc + val, 0)
  return arr.join(':')
}

/**
 * shoot the generator sequence
 *
 * @param {Number} a: the generator multiplier
 * @param {array<number>} seeds: generator seed
 */
const shoot = (a, seeds) => {
  const store = {}
  const generator = createMWC(a, b, r)
  
  // iterations
  let i = 1
  
  // function result
  let result = 0
  
  // SOME METRICS
  let newly = 0
  let crashes = 0

  generator.init(seeds)
  generator.next() // avoid collision at fist loop ?

  store[output(seeds)] = 0
  console.log('seeds: %s', seeds.join(':'))

  // shoot test loop
  while (i++ < MAX_LOOPS) {
    const generated = generator.next()
    const val = output(generated)

    //console.log('generated: %s', generated.join(':'))
    if(i % 1000000 === 0) console.log(i)

    if(store.hasOwnProperty(val)) {
      result = i
      crashes++
      // console.log('#### coolision : %s', i)
      // break
    } else {
      store[val] = i
      newly++
    }

    // console.log('store[%s]: %s', val, store[val])
    // console.log('     %s', generated.join(':'))
  }

  // basic metrics display
  console.log('crashes: %s', crashes)
  console.log('new values: %s', newly)
  
  //console.log(result)
  return result
}

// main test
const test = () => {
  let max_loops = 0
  let a_max = 0
  
  let seeds = [1, 1, 1, 1]

  for(let k = 0; k < MAX_TRIALS; k++) {
     //const a = 4 * Math.floor(52 * Math.random()) - 1
     const a = 1717
     const shots_count = shoot(a, seeds)

     console.log('k: %s a: %s', k, a)
     // console.log('a: %s', a)
     // console.log('shots_count=%s', shots_count)

     if(shots_count > max_loops) {
       max_loops = shots_count
       a_max = a
     }
  }

  console.log('%s loops %s times....', a_max, max_loops)
}

console.log('TEST')
test()
console.log('END.')