import { Action } from './model.js'
import { update } from './game.js'
import { newGame } from './spawn.js'
import { view } from './view.js'
import { map as mapIO, randomSeed, drawScene } from './io.js'
import { keyDowns, interval, map, filterMap, merge, scan, startWith } from './stream.js'
import { keyToAction } from './input.js'

export const TICK_MS = 150

// Everything that can happen to the game: a Tick every TICK_MS, and a Turn for each steering key.
export const classicActions = merge(
  map(interval(TICK_MS), () => Action.Tick),
  filterMap(keyDowns, keyToAction))

// Actions folded into game states. startWith puts the initial state first so it is drawn right away.
export const states = (seed, actions) =>
  startWith(scan(actions, update, newGame(seed)), newGame(seed))

export const render = (state) => drawScene(view(state))

// The whole program as a value: get a seed, then turn the stream of states into a stream of drawings.
// Nothing runs here; runtime.js interprets it.
export const main = mapIO(randomSeed, (seed) => map(states(seed, classicActions), render))