'use strict';
const React = require('react');
const PropTypes = require('prop-types');
import createReactClass from 'create-react-class';
const defined = require('terriajs-cesium/Source/Core/defined');
const Ray = require('terriajs-cesium/Source/Core/Ray');
const IntersectionTests = require('terriajs-cesium/Source/Core/IntersectionTests');
const Ellipsoid = require('terriajs-cesium/Source/Core/Ellipsoid');
const Tween = require('terriajs-cesium/Source/ThirdParty/Tween');
const CesiumMath = require('terriajs-cesium/Source/Core/Math');
const Cartesian3 = require('terriajs-cesium/Source/Core/Cartesian3');
import Icon from "../../Icon.jsx";
import Styles from './zoom_control.scss';

// Map zoom control
const ZoomControl = createReactClass({

    propTypes: {
        terria: PropTypes.object
    },

    flyToPosition(scene, position, durationMilliseconds) {
        const camera = scene.camera;
        const startPosition = camera.position;
        const endPosition = position;

        // temp
        durationMilliseconds = 200;

        const controller = scene.screenSpaceCameraController;
        controller.enableInputs = false;

        scene.tweens.add({
            duration: durationMilliseconds / 1000.0,
            easingFunction: Tween.Easing.Sinusoidal.InOut,
            startObject: {
                time: 0.0
            },
            stopObject: {
                time: 1.0
            },
            update(value) {
                if (scene.isDestroyed()) {
                    return;
                }
                scene.camera.position.x = CesiumMath.lerp(startPosition.x, endPosition.x, value.time);
                scene.camera.position.y = CesiumMath.lerp(startPosition.y, endPosition.y, value.time);
                scene.camera.position.z = CesiumMath.lerp(startPosition.z, endPosition.z, value.time);
            },
            complete() {
                if (controller.isDestroyed()) {
                    return;
                }
                controller.enableInputs = true;
            },
            cancel() {
                if (controller.isDestroyed()) {
                    return;
                }
                controller.enableInputs = true;
            }
        });
    },

    getCameraFocus(scene) {
        const ray = new Ray(scene.camera.positionWC, scene.camera.directionWC);
        const intersections = IntersectionTests.rayEllipsoid(ray, Ellipsoid.WGS84);
        if (defined(intersections)) {
            return Ray.getPoint(ray, intersections.start);
        }
        // Camera direction is not pointing at the globe, so use the ellipsoid horizon point as
        // the focal point.
        return IntersectionTests.grazingAltitudeLocation(ray, Ellipsoid.WGS84);
    },

    zoomIn() {
        const cartesian3Scratch = new Cartesian3();
        this.props.terria.analytics.logEvent('navigation', 'click', 'zoomIn');

        if (defined(this.props.terria.leaflet)) {
            this.props.terria.leaflet.map.zoomIn(1);
        }

        if (defined(this.props.terria.cesium)) {
            const scene = this.props.terria.cesium.scene;
            const camera = scene.camera;
            const focus = this.getCameraFocus(scene);
            const direction = Cartesian3.subtract(focus, camera.position, cartesian3Scratch);
            const movementVector = Cartesian3.multiplyByScalar(direction, 2.0 / 3.0, cartesian3Scratch);
            const endPosition = Cartesian3.add(camera.position, movementVector, cartesian3Scratch);
            this.flyToPosition(scene, endPosition);
        }

        this.props.terria.currentViewer.notifyRepaintRequired();
    },

    zoomOut() {
        const cartesian3Scratch = new Cartesian3();
        this.props.terria.analytics.logEvent('navigation', 'click', 'zoomOut');

        if (defined(this.props.terria.leaflet)) {
            this.props.terria.leaflet.map.zoomOut(1);
        }

        if (defined(this.props.terria.cesium)) {
            const scene = this.props.terria.cesium.scene;
            const camera = scene.camera;
            const focus = this.getCameraFocus(scene);
            const direction = Cartesian3.subtract(focus, camera.position, cartesian3Scratch);
            const movementVector = Cartesian3.multiplyByScalar(direction, -2.0, cartesian3Scratch);
            const endPosition = Cartesian3.add(camera.position, movementVector, cartesian3Scratch);
            this.flyToPosition(scene, endPosition);
        }
        this.props.terria.currentViewer.notifyRepaintRequired();
    },

    zoomReset() {
        this.props.terria.analytics.logEvent('navigation', 'click', 'reset');
        this.props.terria.currentViewer.zoomTo(this.props.terria.homeView, 1.5);
    },

    render() {
        return (
            <div className={Styles.zoomControl}>
                <ul className={Styles.list}>
                    <li>
                        <button type='button' onClick={this.zoomIn} className={Styles.increase} title='zoom in'>
                            <Icon glyph={Icon.GLYPHS.increase}/>
                        </button>
                    </li>
                    <li>
                        <button type='button' onClick={this.zoomReset} className={Styles.refresh} title='reset zoom'>
                            <Icon glyph={Icon.GLYPHS.refresh}/>
                        </button>
                    </li>
                    <li>
                        <button type='button' onClick={this.zoomOut} className={Styles.decrease} title='zoom out'>
                            <Icon glyph={Icon.GLYPHS.decrease}/>
                        </button>
                    </li>
                </ul>
            </div>
        );
    }
});
module.exports = ZoomControl;