import '@polymer/paper-icon-button/paper-icon-button.js';
import '@polymer/paper-toggle-button/paper-toggle-button.js';
import { html } from '@polymer/polymer/lib/utils/html-tag.js';
import { PolymerElement } from '@polymer/polymer/polymer-element.js';

import { STATES_OFF } from '../../common/const.js';
import computeStateDomain from '../../common/entity/compute_state_domain.js';

class HaEntityToggle extends PolymerElement {
  static get template() {
    return html`
    <style>
      :host {
        white-space: nowrap;
        min-width: 38px;
      }
      paper-icon-button {
        color: var(--paper-icon-button-inactive-color, var(--primary-text-color));
        transition: color .5s;
      }
      paper-icon-button[state-active] {
        color: var(--paper-icon-button-active-color, var(--primary-color));
      }
      paper-toggle-button {
        cursor: pointer;
        --paper-toggle-button-label-spacing: 0;
        padding: 13px 5px;
        margin: -4px -5px;
      }
    </style>

    <template is="dom-if" if="[[stateObj.attributes.assumed_state]]">
      <paper-icon-button icon="hass:flash-off" on-click="turnOff" state-active$="[[!isOn]]"></paper-icon-button>
      <paper-icon-button icon="hass:flash" on-click="turnOn" state-active$="[[isOn]]"></paper-icon-button>
    </template>
    <template is="dom-if" if="[[!stateObj.attributes.assumed_state]]">
      <paper-toggle-button checked="[[toggleChecked]]" on-change="toggleChanged"></paper-toggle-button>
    </template>
`;
  }

  static get properties() {
    return {
      hass: Object,
      stateObj: {
        type: Object,
        observer: 'stateObjObserver'
      },

      toggleChecked: {
        type: Boolean,
        value: false,
      },

      isOn: {
        type: Boolean,
        computed: 'computeIsOn(stateObj)',
        observer: 'isOnChanged',
      },
    };
  }

  ready() {
    super.ready();
    this.addEventListener('click', ev => this.onTap(ev));
    this.forceStateChange();
  }

  onTap(ev) {
    ev.stopPropagation();
  }

  toggleChanged(ev) {
    const newVal = ev.target.checked;

    if (newVal && !this.isOn) {
      this.callService(true);
    } else if (!newVal && this.isOn) {
      this.callService(false);
    }
  }

  isOnChanged(newVal) {
    this.toggleChecked = newVal;
  }

  forceStateChange() {
    if (this.toggleChecked === this.isOn) {
      this.toggleChecked = !this.toggleChecked;
    }
    this.toggleChecked = this.isOn;
  }

  turnOn() {
    this.callService(true);
  }

  turnOff() {
    this.callService(false);
  }

  computeIsOn(stateObj) {
    return stateObj && !STATES_OFF.includes(stateObj.state);
  }

  stateObjObserver(newVal, oldVal) {
    if (!oldVal || !newVal) return;
    if (this.computeIsOn(newVal) === this.computeIsOn(oldVal)) {
      // stateObj changed but isOn is the same. Make sure toggle is in the right position.
      this.forceStateChange();
    }
  }

  // We call updateToggle after a successful call to re-sync the toggle
  // with the state. It will be out of sync if our service call did not
  // result in the entity to be turned on. Since the state is not changing,
  // the resync is not called automatic.
  callService(turnOn) {
    const stateDomain = computeStateDomain(this.stateObj);
    let serviceDomain;
    let service;

    if (stateDomain === 'lock') {
      serviceDomain = 'lock';
      service = turnOn ? 'unlock' : 'lock';
    } else if (stateDomain === 'cover') {
      serviceDomain = 'cover';
      service = turnOn ? 'open_cover' : 'close_cover';
    } else if (stateDomain === 'group') {
      serviceDomain = 'homeassistant';
      service = turnOn ? 'turn_on' : 'turn_off';
    } else {
      serviceDomain = stateDomain;
      service = turnOn ? 'turn_on' : 'turn_off';
    }

    const currentState = this.stateObj;
    this.hass.callService(
      serviceDomain, service,
      { entity_id: this.stateObj.entity_id }
    )
      .then(() => {
        setTimeout(() => {
          // If after 2 seconds we have not received a state update
          // reset the switch to it's original state.
          if (this.stateObj === currentState) {
            this.forceStateChange();
          }
        }, 2000);
      });
  }
}

customElements.define('ha-entity-toggle', HaEntityToggle);