import {InputEvent} from './input-consts';
import {computeInputData} from './compute-input-data';

import type {Manager} from '../manager';
import type {RawInput} from './types';

/**
 * handle input events
 */
export function inputHandler(manager: Manager, eventType: InputEvent, input: RawInput) {
  const pointersLen = input.pointers.length;
  const changedPointersLen = input.changedPointers.length;
  const isFirst = eventType & InputEvent.Start && pointersLen - changedPointersLen === 0;
  const isFinal =
    eventType & (InputEvent.End | InputEvent.Cancel) && pointersLen - changedPointersLen === 0;

  input.isFirst = Boolean(isFirst);
  input.isFinal = Boolean(isFinal);

  if (isFirst) {
    manager.session = {};
  }

  // source event is the normalized value of the domEvents
  // like 'touchstart, mouseup, pointerdown'
  input.eventType = eventType;

  // compute scale, rotation etc
  const processedInput = computeInputData(manager, input);

  // emit secret event
  manager.emit('hammer.input', processedInput);

  manager.recognize(processedInput);
  manager.session.prevInput = processedInput;
}