// 3rd party.
import React from 'react';
import ReactDOM from 'react-dom';
// 2nd party.
import {create as createClient} from '@avocado/client/socket';
import {compose} from '@avocado/core';
import {Stage} from '@avocado/graphics';
import {ActionRegistry, InputPacket} from '@avocado/input';
import {Vector} from '@avocado/math';
import {EventEmitter, Property} from '@avocado/mixins';
import {SocketIoParser} from '@avocado/packet';
import {
  StateKeysPacket,
  StatePacket,
  Synchronizer,
  Unpacker,
} from '@avocado/state';
import {clearAnimation, setAnimation} from '@avocado/timing';
import {World} from '@avocado/physics/matter/world';
import {Room, RoomView} from '@avocado/topdown';
// 1st party.
import {augmentParserWithThroughput} from '../common/parser-throughput';
import {WorldTime} from '../common/world-time';
import Ui from './ui';
import DebugUi from './ui/debug';

const decorate = compose(
  EventEmitter,
  Property('isDebugging', {
    track: true,
  }),
  Property('selfEntity', {
    track: true,
  }),
  Property('selfEntityUuid', {
    track: true,
  }),
);

export class App extends decorate(class {}) {

  constructor() {
    super();
    const config = this.readConfig();
    // Room.
    this.room = new Room();
    // World time.
    this.worldTime = new WorldTime();
    // Graphics.
    this.lastIntensity = undefined;
    this.renderHandle = undefined;
    this.stage = new Stage(config.visibleSize, config.visibleScale);
    const roomView = new RoomView(this.room, this.stage.renderer);
    this.stage.addChild(roomView);
    // Listen for new entities.
    this.room.on('entityAdded', this.onRoomEntityAdded, this);
    // Input.
    this.actionRegistry = new ActionRegistry();
    this.actionRegistry.mapKeysToActions(config.actionKeyMap);
    this.actionState = this.actionRegistry.state;
    this.inputHandle = undefined;
    this.isFocused = false;
    this.lastIsFocused = undefined;
    this.onBlur = this.onBlur.bind(this);
    this.onFocus = this.onFocus.bind(this);
    // Global keys.
    this.onGlobalKeydown = this.onGlobalKeydown.bind(this);
    window.addEventListener('keydown', this.onGlobalKeydown);
    this.pointingAt = [-1, -1];
    this.pointerMovementHandle = undefined;
    // Net.
    this.AugmentedParser = augmentParserWithThroughput(SocketIoParser);
    this.hasReceivedState = false;
    this.isConnected = false;
    this.socket = undefined;
    // Debugging.
    this.isDebugging = false;
    // Simulation.
    this.simulationHandle = undefined;
    this.world = config.doPhysicsSimulation ? new World() : undefined;
    this.room.world = this.world;
    // State synchronization.
    this.state = undefined;
    this.synchronizer = new Synchronizer({
      room: this.room,
      worldTime: this.worldTime,
    });
    this.unpacker = new Unpacker();
  }

  applyLighting() {
    let intensity = 0;
    if (this.worldTime.hour >= 21 || this.worldTime.hour < 4) {
      intensity = 0.8;
    }
    if (this.worldTime.hour >= 4 && this.worldTime.hour < 7) {
      intensity = 0.8 * ((7 - this.worldTime.hour) / 3);
    }
    if (this.worldTime.hour >= 18 && this.worldTime.hour < 21) {
      intensity = 0.8 * ((3 - (21 - this.worldTime.hour)) / 3);
    }
    intensity = Math.floor(intensity * 1000) / 1000;
    if (intensity !== this.lastIntensity || this.isFocused !== this.lastIsFocused) {
      this.stage.removeAllFilters();
      if (!this.isFocused) {
        this.stage.paused(intensity);
      }
      else {
        this.stage.night(intensity);
      }
      this.lastIntensity = intensity;
      this.lastIsFocused = this.isFocused;
    }
  }

  connect() {
    const config = this.readConfig();
    this.socket = createClient(config.connectionUrl, {
      parser: this.AugmentedParser,
    });
    this.socket.on('connect', () => {
      this.room.layers.destroy();
      this.selfEntity = undefined;
      this.selfEntityUuid = undefined;
      this.isConnected = true;
    });
    this.socket.on('disconnect', () => {
      this.hasReceivedState = false;
      this.isConnected = false;
      this.stopRendering();
      this.stopSimulation();
      this.stopProcessingInput();
    });
    this.socket.on('packet', this.onPacket, this);
  }

  createMoveToNormal(position) {
    if (!this.selfEntity) {
      return;
    }
    const realEntityPosition = Vector.sub(
      this.selfEntity.position,
      this.selfEntity.camera.realOffset,
    );
    const magnitude = Vector.magnitude(position, realEntityPosition);
    if (magnitude < 8) {
      return;
    }
    const diff = Vector.sub(position, realEntityPosition);
    return Vector.normalize(diff);
  }

  createReactContainer() {
    const reactContainer = window.document.createElement('div');
    reactContainer.className = 'react';
    reactContainer.style.width = '100%';
    reactContainer.style.height = '100%';
    return reactContainer;
  }

  eventIsInUi(event) {
    let walk = event.target;
    while (walk) {
      if (walk === this.stage.ui) {
        return true;
      }
      walk = walk.parentNode;
    }
    return false;
  }

  isPointingAtAnything() {
    return -1 !== this.pointingAt[0] && -1 !== this.pointingAt[1];
  }

  onBlur() {
    this.isFocused = false;
  }

  onFocus() {
    this.isFocused = true;
  }

  onGlobalKeydown(event) {
    switch (event.key) {
      case 'F2':
        this.isDebugging = !this.isDebugging;
        break;
    }
  }

  onPacket(packet) {
    if (packet instanceof StateKeysPacket) {
      this.unpacker.registerKeys(packet.data);
    }
    if (packet instanceof StatePacket) {
      const patch = this.unpacker.unpack(packet.data);
      // Yank out self entity.
      if (!this.selfEntityUuid) {
        for (const step of patch) {
          const {op, path, value} = step;
          if ('add' === op && '/selfEntity' === path) {
            this.selfEntityUuid = value;
          }
        }
      }
      this.synchronizer.patchState(patch);
      if (!this.hasReceivedState) {
        this.startProcessingInput();
        this.startSimulation();
        this.startRendering();
        this.hasReceivedState = true;
      }
    }
  }

  onPointerDown(event) {
    if (!this.eventIsInUi(event)) {
      return;
    }
    this.pointingAt = event.position;
  }

  onPointerMove(event) {
    if (!this.eventIsInUi(event)) {
      return;
    }
    if (!this.isPointingAtAnything()) {
      return;
    }
    this.pointingAt = event.position;
  }

  onPointerUp(event) {
    this.pointingAt = [-1, -1];
  }

  onRoomEntityAdded(entity) {
    // Traits that shouldn't be on client.
    const noClientTraits = [
      'behaved',
      'informed',
    ];
    // If there's no physics, then remove physical trait.
    if (!this.room.world) {
      noClientTraits.push('physical');
    }
    // Traits that only make sense for our self entity on the client.
    const selfEntityOnlyTraits = [
      'controllable',
      'followed',
    ];
    const nixedTraits = selfEntityOnlyTraits.concat(noClientTraits);
    for (let i = 0; i < nixedTraits.length; ++i) {
      const type = nixedTraits[i];
      if (entity.is(type)) {
        entity.removeTrait(type);
      }
    }
    // Client only traits.
    const clientOnlyTraits = [
      'staged',
    ];
    for (let i = 0; i < clientOnlyTraits.length; ++i) {
      const type = clientOnlyTraits[i];
      entity.addTrait(type);
    }
    entity.stage = this.stage;
    // Set self entity.
    if (this.selfEntityUuid) {
      if (entity === this.room.findEntity(this.selfEntityUuid)) {
        this.selfEntity = entity;
        this.selfEntityUuid = undefined;
        // Add back our self entity traits.
        for (const type of selfEntityOnlyTraits) {
          entity.addTrait(type);
        }
        const {camera} = entity;
        this.stage.camera = camera;
        // Avoid the initial 'lerp.
        camera.realPosition = camera.position;
      }
    }
  }

  // Stub for now!
  readConfig() {
    return {
      actionKeyMap: {
        'w': 'MoveUp',
        'a': 'MoveLeft',
        's': 'MoveDown',
        'd': 'MoveRight',
      },
      connectionUrl: window.location.href,
      doPhysicsSimulation: true,
      inputFrequency: 1 / 60,
      pointerMovementFrequency: 1 / 15,
      simulationFrequency: 1 / 60,
      visibleScale: [1, 1],
      visibleSize: [320, 180],
    };
  }

  renderIntoDom(node) {
    // Lol, Apple...
    node.addEventListener('touchmove', (event) => {
      event.preventDefault();
    });
    // Add graphics stage.
    this.stage.addToDom(node);
    // UI.
    const reactContainer = this.createReactContainer();
    this.stage.ui.appendChild(reactContainer);
    const UiComponent = <Ui
      socket={this.socket}
      worldTime={this.worldTime}
    />;
    ReactDOM.render(UiComponent, reactContainer);
    // Debug UI.
    const debugUiNode = node.querySelector('.debug-container');
    const DebugUiComponent = <DebugUi
      actionRegistry={this.actionRegistry}
      app={this}
      Parser={this.AugmentedParser}
      socket={this.socket}
      stage={this.stage}
    />;
    ReactDOM.render(DebugUiComponent, debugUiNode, () => {
      this.stage.resolveUiRendered();
    });
  }

  startProcessingInput() {
    const config = this.readConfig();
    this.actionRegistry.listen(this.stage.element);
    // Pointer input.
    this.stage.on('pointerDown', this.onPointerDown, this);
    this.stage.on('pointerMove', this.onPointerMove, this);
    this.stage.on('pointerUp', this.onPointerUp, this);
    // Blur/focus.
    this.stage.element.addEventListener('blur', this.onBlur);
    this.stage.element.addEventListener('focus', this.onFocus);
    // Input messages.
    this.inputHandle = setInterval(() => {
      if (this.actionState !== this.actionRegistry.state) {
        this.actionState = this.actionRegistry.state;
        this.socket.send(InputPacket.fromState(this.actionState));
      }
    }, 1000 * config.inputFrequency);
    // Mouse/touch movement.
    this.pointerMovementHandle = setInterval(() => {
      do {
        let normal;
        if (this.isPointingAtAnything()) {
          const toVector = Vector.scale(this.pointingAt, this.isDebugging ? 2 : 1);
          normal = this.createMoveToNormal(toVector);
          if (normal) {
            this.actionRegistry.state = this.actionRegistry.state.withMutations((state) => {
              if (normal[0]) {
                state.set('MoveToX', Math.floor(normal[0] * 127));
              }
              if (normal[1]) {
                state.set('MoveToY', Math.floor(normal[1] * 127));
              }
            });
            break;
          }
        }
        this.actionRegistry.state = this.actionRegistry.state.withMutations((state) => {
          if (!normal || 0 === normal[0]) {
            state.delete('MoveToX');
          }
          if (!normal || 0 === normal[1]) {
            state.delete('MoveToY');
          }
        });
      } while (false);
    }, 1000 * config.pointerMovementFrequency);
    // Focus the stage.
    this.stage.focus();
    this.isFocused = true;
  }

  startRendering() {
    let lastTime = performance.now();
    this.renderHandle = setAnimation(() => {
      const now = performance.now();
      const elapsed = (now - lastTime) / 1000;
      lastTime = now;
      this.applyLighting();
      this.stage.render();
    });
  }

  startSimulation() {
    const config = this.readConfig();
    let lastTime = performance.now();
    this.simulationHandle = setInterval(() => {
      const now = performance.now();
      const elapsed = (now - lastTime) / 1000;
      lastTime = now;
      // Inject input.
      if (this.selfEntity) {
        this.selfEntity.inputState = this.actionState.toJS();
      }
      // Tick synchronized.
      this.synchronizer.tick(elapsed);
      this.state = this.synchronizer.state;
    }, 1000 * config.simulationFrequency);
  }

  stopProcessingInput() {
    clearInterval(this.pointerMovementHandle);
    this.pointerMovementHandle = undefined;
    clearInterval(this.inputHandle);
    this.inputHandle = undefined;
    this.stage.element.removeEventListener('focus', this.onFocus);
    this.stage.element.removeEventListener('blur', this.onBlur);
    this.stage.off('pointerUp', this.onPointerUp, this);
    this.stage.off('pointerMove', this.onPointerMove, this);
    this.stage.off('pointerDown', this.onPointerDown, this);
    this.actionRegistry.stopListening();
  }

  stopRendering() {
    clearAnimation(this.renderHandle);
    this.renderHandle = undefined;
  }

  stopSimulation() {
    clearInterval(this.simulationHandle);
    this.simulationHandle = undefined;
  }

}