'use strict';

import defined from 'terriajs-cesium/Source/Core/defined';
import CesiumMath from 'terriajs-cesium/Source/Core/Math';
import Ellipsoid from 'terriajs-cesium/Source/Core/Ellipsoid';
import FeatureInfoCatalogItem from './FeatureInfoCatalogItem.jsx';
import Loader from '../Loader.jsx';
import ObserveModelMixin from '../ObserveModelMixin';
import React from 'react';
import createReactClass from 'create-react-class';
import PropTypes from 'prop-types';
import knockout from 'terriajs-cesium/Source/ThirdParty/knockout';
import Entity from 'terriajs-cesium/Source/DataSources/Entity';
import Icon from "../Icon.jsx";
import { LOCATION_MARKER_DATA_SOURCE_NAME, addMarker, removeMarker, markerVisible } from '../../Models/LocationMarkerUtils';
import prettifyCoordinates from '../../Map/prettifyCoordinates';

import Styles from './feature-info-panel.scss';
import classNames from 'classnames';

const FeatureInfoPanel = createReactClass({
    displayName: 'FeatureInfoPanel',
    mixins: [ObserveModelMixin],

    propTypes: {
        terria: PropTypes.object.isRequired,
        viewState: PropTypes.object.isRequired,
        printView: PropTypes.bool
    },

    componentDidMount() {
        const createFakeSelectedFeatureDuringPicking = true;
        const terria = this.props.terria;
        this._pickedFeaturesSubscription = knockout.getObservable(terria, 'pickedFeatures').subscribe(() => {
            const pickedFeatures = terria.pickedFeatures;
            if (!defined(pickedFeatures)) {
                terria.selectedFeature = undefined;
            } else {
                if (createFakeSelectedFeatureDuringPicking) {
                    const fakeFeature = new Entity({
                        id: 'Pick Location'
                    });
                    fakeFeature.position = pickedFeatures.pickPosition;
                    terria.selectedFeature = fakeFeature;
                } else {
                    terria.selectedFeature = undefined;
                }
                if (defined(pickedFeatures.allFeaturesAvailablePromise)) {
                    pickedFeatures.allFeaturesAvailablePromise.then(() => {
                        // We only show features that are associated with a catalog item, so make sure the one we select to be
                        // open initially is one we're actually going to show.
                        const featuresShownAtAll = pickedFeatures.features.filter(x => defined(determineCatalogItem(terria.nowViewing, x)));
                        terria.selectedFeature = featuresShownAtAll.filter(featureHasInfo)[0];
                        if (!defined(terria.selectedFeature) && (featuresShownAtAll.length > 0)) {
                            // Handles the case when no features have info - still want something to be open.
                            terria.selectedFeature = featuresShownAtAll[0];
                        }
                    });
                }
            }
        });
    },

    componentWillUnmount() {
        if (defined(this._pickedFeaturesSubscription)) {
            this._pickedFeaturesSubscription.dispose();
            this._pickedFeaturesSubscription = undefined;
        }
    },

    getFeatureInfoCatalogItems() {
        const {catalogItems, featureCatalogItemPairs} = getFeaturesGroupedByCatalogItems(this.props.terria);

        return catalogItems
            .filter(catalogItem => defined(catalogItem))
            .map((catalogItem, i) => {
                // From the pairs, select only those with this catalog item, and pull the features out of the pair objects.
                const features = featureCatalogItemPairs.filter(pair => pair.catalogItem === catalogItem).map(pair => pair.feature);
                return (
                    <FeatureInfoCatalogItem
                        key={i}
                        viewState={this.props.viewState}
                        catalogItem={catalogItem}
                        features={features}
                        terria={this.props.terria}
                        onToggleOpen={this.toggleOpenFeature}
                        printView={this.props.printView}
                    />
                );
            });
    },

    close() {
        this.props.viewState.featureInfoPanelIsVisible = false;

        // give the close animation time to finish before unselecting, to avoid jumpiness
        setTimeout(() => {
            this.props.terria.pickedFeatures = undefined;
            this.props.terria.selectedFeature = undefined;
        }, 200);
    },

    toggleCollapsed() {
        this.props.viewState.featureInfoPanelIsCollapsed = !this.props.viewState.featureInfoPanelIsCollapsed;
    },

    toggleOpenFeature(feature) {
        const terria = this.props.terria;
        if (feature === terria.selectedFeature) {
            terria.selectedFeature = undefined;
        } else {
            terria.selectedFeature = feature;
        }
    },

    getMessageForNoResults() {
        if (this.props.terria.nowViewing.hasItems) {
            // feature info shows up becuase data has been added for the first time
            if (this.props.viewState.firstTimeAddingData) {
                this.props.viewState.firstTimeAddingData = false;
                return "Click on the map to learn more about a location";
            }
            // if clicking on somewhere that has no data
            return "No data is available here - try another location.";
        } else {
            return "Click 'Add Data' to add data to the map.";
        }
    },

    addManualMarker(longitude, latitude) {
        addMarker(this.props.terria, {
            name: "User Selection",
            location: {
                latitude: latitude,
                longitude: longitude
            }
        });
    },

    pinClicked(longitude, latitude) {
        if (!markerVisible(this.props.terria)) {
            this.addManualMarker(longitude, latitude);
        } else {
            removeMarker(this.props.terria);
        }
    },

    locationUpdated(longitude, latitude) {
        if (defined(latitude) && defined (longitude) && markerVisible(this.props.terria)) {
            removeMarker(this.props.terria);
            this.addManualMarker(longitude, latitude);
        }
    },

    renderLocationItem(cartesianPosition) {
        const catographic = Ellipsoid.WGS84.cartesianToCartographic(cartesianPosition);
        const latitude = CesiumMath.toDegrees(catographic.latitude);
        const longitude = CesiumMath.toDegrees(catographic.longitude);
        const pretty = prettifyCoordinates(longitude, latitude);
        this.locationUpdated(longitude, latitude);

        const that = this;
        const pinClicked = function() {
            that.pinClicked(longitude, latitude);
        };

        const locationButtonStyle = markerVisible(this.props.terria) ? Styles.btnLocationSelected : Styles.btnLocation;

        return (
            <div className={Styles.location}>
                <span>Lat / Lon&nbsp;</span>
                <span>
                    {pretty.latitude + ", " + pretty.longitude}
                    {!this.props.printView && <button type='button' onClick={pinClicked}  className={locationButtonStyle}>
                        <Icon glyph={Icon.GLYPHS.location}/>
                    </button>}
                </span>
            </div>
        );
    },

    render() {
        const terria = this.props.terria;
        const viewState = this.props.viewState;

        const featureInfoCatalogItems = this.getFeatureInfoCatalogItems();
        const panelClassName = classNames(Styles.panel, {
            [Styles.isCollapsed]: viewState.featureInfoPanelIsCollapsed,
            [Styles.isVisible]: viewState.featureInfoPanelIsVisible
        });

        let position;
        if (defined(terria.selectedFeature) && defined(terria.selectedFeature.position)) {
            // If the clock is avaliable then use it, otherwise don't.
            let clock;
            if (defined(terria.clock)) {
                clock = terria.clock.currentTime;
            }

            // If there is a selected feature then use the feature location.
            position = terria.selectedFeature.position.getValue(clock);

            // If position is invalid then don't use it.
            // This seems to be fixing the symptom rather then the cause, but don't know what is the true cause this ATM.
            if (isNaN(position.x) || isNaN(position.y) || isNaN(position.z)) {
                position = undefined;
            }
        }
        if (!defined(position)) {
            // Otherwise use the location picked.
            if (defined(terria.pickedFeatures) && defined(terria.pickedFeatures.pickPosition)) {
                position = terria.pickedFeatures.pickPosition;
            }
        }

        const locationElements = (
            <If condition={position}>
                <li>{this.renderLocationItem(position)}</li>
            </If>
        );

        return (
            <div
                className={panelClassName}
                aria-hidden={!viewState.featureInfoPanelIsVisible}>
                {!this.props.printView && <div className={Styles.header}>
                    <button type='button' onClick={ this.toggleCollapsed } className={Styles.btnPanelHeading}>
                        Feature Information
                    </button>
                    <button type='button' onClick={ this.close } className={Styles.btnCloseFeature}
                            title="Close data panel">
                        <Icon glyph={Icon.GLYPHS.close}/>
                    </button>
                </div>}
                <ul className={Styles.body}>
                    {this.props.printView && locationElements}
                    <Choose>
                        <When condition={viewState.featureInfoPanelIsCollapsed || !viewState.featureInfoPanelIsVisible}>
                        </When>
                        <When condition={defined(terria.pickedFeatures) && terria.pickedFeatures.isLoading}>
                            <li><Loader/></li>
                        </When>
                        <When condition={!featureInfoCatalogItems || featureInfoCatalogItems.length === 0}>
                            <li className={Styles.noResults}>{this.getMessageForNoResults()}</li>
                        </When>
                        <Otherwise>
                            {featureInfoCatalogItems}
                        </Otherwise>
                    </Choose>
                    {!this.props.printView && locationElements}
                </ul>
            </div>
        );
    },
});

/**
 * Returns an object of {catalogItems, featureCatalogItemPairs}.
 */
function getFeaturesGroupedByCatalogItems(terria) {
    if (!defined(terria.pickedFeatures)) {
        return {catalogItems: [], featureCatalogItemPairs: []};
    }
    const features = terria.pickedFeatures.features;
    const featureCatalogItemPairs = [];  // Will contain objects of {feature, catalogItem}.
    const catalogItems = []; // Will contain a list of all unique catalog items.

    features.forEach(feature => {
        // Why was this here? Surely changing the feature objects is not a good side-effect?
        // if (!defined(feature.position)) {
        //     feature.position = terria.pickedFeatures.pickPosition;
        // }
        const catalogItem = determineCatalogItem(terria.nowViewing, feature);
        featureCatalogItemPairs.push({
            catalogItem: catalogItem,
            feature: feature
        });
        if (catalogItems.indexOf(catalogItem) === -1) {  // Note this works for undefined too.
            catalogItems.push(catalogItem);
        }
    });

    return {catalogItems, featureCatalogItemPairs};
}

/**
 * Figures out what the catalog item for a feature is.
 *
 * @param nowViewing {@link NowViewing} to look in the items for.
 * @param feature Feature to match
 * @returns {CatalogItem}
 */
function determineCatalogItem(nowViewing, feature) {
    if (!defined(nowViewing)) {
        // So that specs do not need to define a nowViewing.
        return undefined;
    }

    // "Data sources" (eg. czml, geojson, kml, csv) have an entity collection defined on the entity
    // (and therefore the feature).
    // Then match up the data source on the feature with a now-viewing item's data source.
    //
    // Gpx, Ogr, WebFeatureServiceCatalogItem, ArcGisFeatureServerCatalogItem, WebProcessingServiceCatalogItem
    // all have a this._geoJsonItem, which we also need to check.
    let result;
    let i;
    let item;
    if (defined(feature.entityCollection) && defined(feature.entityCollection.owner)) {
        const dataSource = feature.entityCollection.owner;

        if (dataSource.name === LOCATION_MARKER_DATA_SOURCE_NAME) {
            return {
                name: 'Location Marker'
            };
        }

        for (i = nowViewing.items.length - 1; i >= 0; i--) {
            item = nowViewing.items[i];
            if (item.dataSource === dataSource) {
                result = item;
                break;
            }
        }
        return result;
    }

    // If there is no data source, but there is an imagery layer (eg. ArcGIS),
    // we can match up the imagery layer on the feature with a now-viewing item.
    if (defined(feature.imageryLayer)) {
        const imageryLayer = feature.imageryLayer;
        for (i = nowViewing.items.length - 1; i >= 0; i--) {
            if (nowViewing.items[i].imageryLayer === imageryLayer) {
                result = nowViewing.items[i];
                break;
            }
        }
        return result;
    }
}

/**
 * Determines whether the passed feature has properties or a description.
 */
function featureHasInfo(feature) {
    return (defined(feature.properties) || defined(feature.description));
}

module.exports = FeatureInfoPanel;