import { Assert } from '../../../Diagnostics/Assert.js';
import {
  makeEventNodeDefinition,
  NodeCategory
} from '../../../Nodes/NodeDefinitions.js';
import { ILifecycleEventEmitter } from '../Abstractions/ILifecycleEventEmitter.js';

type State = {
  onTickEvent?: (() => void) | undefined;
};

const makeInitialState = (): State => ({
  onTickEvent: undefined
});

export const LifecycleOnTick = makeEventNodeDefinition({
  typeName: 'lifecycle/onTick',
  label: 'On Tick',
  category: NodeCategory.Event,
  in: {},
  out: {
    flow: 'flow',
    deltaSeconds: 'float'
  },
  initialState: makeInitialState(),
  init: ({ state, commit, write, graph: { getDependency } }) => {
    Assert.mustBeTrue(state.onTickEvent === undefined);
    let lastTickTime = Date.now();
    const onTickEvent = () => {
      const currentTime = Date.now();
      const deltaSeconds = (currentTime - lastTickTime) * 0.001;
      write('deltaSeconds', deltaSeconds);
      commit('flow');
      lastTickTime = currentTime;
    };

    const lifecycleEventEmitter = getDependency<ILifecycleEventEmitter>(
      'ILifecycleEventEmitter'
    );

    lifecycleEventEmitter?.tickEvent.addListener(onTickEvent);

    return {
      onTickEvent
    };
  },
  dispose: ({ state: { onTickEvent }, graph: { getDependency } }) => {
    Assert.mustBeTrue(onTickEvent !== undefined);

    const lifecycleEventEmitter = getDependency<ILifecycleEventEmitter>(
      'ILifecycleEventEmitter'
    );

    if (onTickEvent)
      lifecycleEventEmitter?.tickEvent.removeListener(onTickEvent);

    return {};
  }
});