import { PureComponent } from 'react'

import { unregisterEvents, applyUpdatersToPropsAndRegisterEvents } from '../../utils/helper'
import MapContext from '../../map-context'

const eventMap = {
  onClick: 'click',
  onDefaultViewportChanged: 'defaultviewport_changed',
  onStatusChanged: 'status_changed',
}

const updaterMap = {
  options(instance: google.maps.KmlLayer, options: google.maps.KmlLayerOptions): void {
    instance.setOptions(options)
  },
  url(instance: google.maps.KmlLayer, url: string): void {
    instance.setUrl(url)
  },
  zIndex(instance: google.maps.KmlLayer, zIndex: number): void {
    instance.setZIndex(zIndex)
  },
}

interface KmlLayerState {
  kmlLayer: google.maps.KmlLayer | null
}

export interface KmlLayerProps {
  options?: google.maps.KmlLayerOptions
  /** The URL of the KML document to display. */
  url?: string
  /** The z-index of the layer. */
  zIndex?: number
  /** This event is fired when a feature in the layer is clicked. */
  onClick?: (e: google.maps.MouseEvent) => void
  /** This event is fired when the KML layers default viewport has changed. */
  onDefaultViewportChanged?: () => void
  /** This event is fired when the KML layer has finished loading. At this point it is safe to read the status property to determine if the layer loaded successfully. */
  onStatusChanged?: () => void
  /** This callback is called when the kmlLayer instance has loaded. It is called with the kmlLayer instance. */
  onLoad: (kmlLayer: google.maps.KmlLayer) => void
  /** This callback is called when the component unmounts. It is called with the kmlLayer instance. */
  onUnmount: (kmlLayer: google.maps.KmlLayer) => void
}

export class KmlLayer extends PureComponent<KmlLayerProps, KmlLayerState> {
  static contextType = MapContext

  registeredEvents: google.maps.MapsEventListener[] = []

  state: KmlLayerState = {
    kmlLayer: null,
  }

  setKmlLayerCallback = (): void => {
    if (this.state.kmlLayer !== null && this.props.onLoad) {
      this.props.onLoad(this.state.kmlLayer)
    }
  }

  componentDidMount(): void {
    const kmlLayer = new google.maps.KmlLayer({
      ...this.props.options,
      map: this.context,
    })

    this.registeredEvents = applyUpdatersToPropsAndRegisterEvents({
      updaterMap,
      eventMap,
      prevProps: {},
      nextProps: this.props,
      instance: kmlLayer,
    })

    this.setState(function setLmlLayer() {
      return {
        kmlLayer,
      }
    }, this.setKmlLayerCallback)
  }

  componentDidUpdate(prevProps: KmlLayerProps): void {
    if (this.state.kmlLayer !== null) {
      unregisterEvents(this.registeredEvents)

      this.registeredEvents = applyUpdatersToPropsAndRegisterEvents({
        updaterMap,
        eventMap,
        prevProps,
        nextProps: this.props,
        instance: this.state.kmlLayer,
      })
    }
  }

  componentWillUnmount(): void {
    if (this.state.kmlLayer !== null) {
      if (this.props.onUnmount) {
        this.props.onUnmount(this.state.kmlLayer)
      }

      unregisterEvents(this.registeredEvents)

      this.state.kmlLayer.setMap(null)
    }
  }

  render(): React.ReactNode {
    return null
  }
}

export default KmlLayer