// @flow

import * as React from 'react';
import { Component, View } from 'reactxp';

import SvgMap from './SvgMap';

export type MapProps = {
  center: [number, number], // longitude, latitude
  offset: [number, number], // offset [x, y] from the center of the map
  zoomLevel: 'high' | 'medium' | 'low',
  showMarker: boolean,
  markerStyle: 'secure' | 'unsecure',
  style: Object,
};

type MapState = {
  bounds: {
    width: number,
    height: number
  }
};

export default class Map extends Component<MapProps, MapState> {
  state = {
    bounds: {
      width: 0,
      height: 0,
    },
  };

  render() {
    const { width, height } = this.state.bounds;
    const readyToRenderTheMap = (width > 0 && height > 0);
    return (
      <View style={ this.props.style } onLayout={ this._onLayout }>
        { readyToRenderTheMap && (
          <SvgMap width={ width }
            height={ height }
            center={ this.props.center }
            offset={ this.props.offset }
            zoomLevel={ this._zoomLevel(this.props.zoomLevel) }
            showMarker={ this.props.showMarker  }
            markerImagePath={ this._markerImage(this.props.markerStyle)  } />
        ) }
      </View>
    );
  }

  shouldComponentUpdate(nextProps: MapProps, nextState: MapState) {
    const oldProps = this.props;
    const oldState = this.state;
    return (
      oldProps.center[0] !== nextProps.center[0] ||
      oldProps.center[1] !== nextProps.center[1] ||

      oldProps.offset[0] !== nextProps.offset[0] ||
      oldProps.offset[1] !== nextProps.offset[1] ||

      oldProps.zoomLevel !== nextProps.zoomLevel ||
      oldProps.showMarker !== nextProps.showMarker ||
      oldProps.markerStyle !== nextProps.markerStyle ||

      oldState.bounds.width !== nextState.bounds.width ||
      oldState.bounds.height !== nextState.bounds.height
    );
  }

  _onLayout = (layoutInfo) => {
    this.setState({
      bounds: {
        width: layoutInfo.width,
        height: layoutInfo.height,
      }
    });
  }

  // TODO: Remove zoom level in favor of center + coordinate span
  _zoomLevel(variant: $PropertyType<MapProps, 'zoomLevel'>) {
    switch(variant) {
    case 'high': return 1;
    case 'medium': return 20;
    case 'low': return 40;
    default:
      throw new Error(`Invalid enumeration type: ${variant}`);
    }
  }

  _markerImage(style: $PropertyType<MapProps, 'markerStyle'>) {
    switch(style) {
    case 'secure':
      return './assets/images/location-marker-secure.svg';
    case 'unsecure':
      return './assets/images/location-marker-unsecure.svg';
    default:
      throw new Error(`Invalid enumeration type: ${style}`);
    }
  }

}