'use strict';

import { formatDateTime } from '../../../BottomDock/Timeline/DateFormats';
import createReactClass from 'create-react-class';
import Description from '../../../Preview/Description';
import DOMPurify from 'dompurify/dist/purify';
import FeatureInfoPanel from '../../../FeatureInfo/FeatureInfoPanel';
import Legend from '../../../Workbench/Controls/Legend';
import PropTypes from 'prop-types';
import React from 'react';
import ReactDOM from 'react-dom';

const PrintView = createReactClass({
    displayName: 'PrintView',

    propTypes: {
        terria: PropTypes.object,
        viewState: PropTypes.object,
        window: PropTypes.object,
        readyCallback: PropTypes.func
    },

    getInitialState() {
        return {
            mapImageDataUrl: undefined,
            ready: false,
            printingStarted: false
        };
    },

    componentDidMount() {
        return this.props.terria.currentViewer.captureScreenshot().then(mapImageDataUrl => {
            // We need to periodically check whether all images are loaded.
            // We can theoretically do that either with a setInterval on the original TerriaJS window,
            // or on the print view window. But:
            //    * Chrome (as of v66.0.3359.139 anyway) seems to aggressively suspend setInterval calls in background
            // tabs, so only a setInterval on the print view window works reliably.
            //    * Internet Explorer 11 does not seem to allow a cross-window setInterval call, so only a setInterval
            // on the original TerriaJS window works reliably.
            // So, we'll do both.

            const printWindow = this.props.window;
            const mainWindow = window;

            const printWindowIntervalId = printWindow.setInterval(this.checkForImagesReady, 200);
            const mainWindowIntervalId = mainWindow.setInterval(this.checkForImagesReady, 200);

            this._stopCheckingForImages = () => {
                printWindow.clearInterval(printWindowIntervalId);
                mainWindow.clearInterval(mainWindowIntervalId);
                this._stopCheckingForImages = undefined;
            };

            this.setState({
                mapImageDataUrl: mapImageDataUrl
            });
        });
    },

    componentWillUnmount() {
        this.stopCheckingForImages();
    },

    componentDidUpdate() {
        if (this.state.ready && !this.state.printingStarted) {
            if (this.props.readyCallback) {
                this.props.readyCallback(this.props.window);
            }
            this.setState({
                printingStarted: true
            });
        }
    },

    stopCheckingForImages() {
        if (this._stopCheckingForImages) {
            this._stopCheckingForImages();
        }
    },

    checkForImagesReady() {
        if (this.state.ready) {
            return;
        }

        const imageTags = this.props.window.document.getElementsByTagName('img');
        if (imageTags.length === 0) {
            return;
        }

        let allImagesReady = true;
        for (let i = 0; allImagesReady && i < imageTags.length; ++i) {
            allImagesReady = imageTags[i].complete;
        }

        if (allImagesReady) {
            this.stopCheckingForImages();
            this.setState({
                ready: allImagesReady
            });
        }
    },

    render() {
        if (!this.state.mapImageDataUrl) {
            return <div>Creating print view...</div>;
        }

        return (
            <div>
                <p>
                    <img className="map-image" src={this.state.mapImageDataUrl} alt="Map snapshot" />
                </p>
                <h1>Legends</h1>
                {this.props.terria.nowViewing.items.map(this.renderLegend)}
                {this.renderFeatureInfo()}
                <h1>Dataset Details</h1>
                {this.props.terria.nowViewing.items.map(this.renderDetails)}
                <h1>Map Credits</h1>
                <ul>
                    {this.props.terria.currentViewer.getAllAttribution().map(this.renderAttribution)}
                </ul>
                <If condition={this.props.terria.configParameters.printDisclaimer}>
                    <h1>Print Disclaimer</h1>
                    <p>{this.props.terria.configParameters.printDisclaimer.text}</p>
                </If>
            </div>
        );
    },

    renderAttribution(attribution) {
        // For reasons I don't entirely understanding, using parseCustomHtmlToReact instead
        // of dangerouslySetInnerHTML here doesn't work in IE11 or Edge. All elements after
        // the first attribution end up just completely missing from the DOM.
        const html = { __html: DOMPurify.sanitize(attribution) };
        return (<li key={attribution} dangerouslySetInnerHTML={html}></li>);
    },

    renderLegend(catalogItem) {
        if (!catalogItem.isMappable) {
            return null;
        }

        return (
            <div key={catalogItem.uniqueId} className="layer-legends">
                <div className="layer-title">{catalogItem.name}</div>
                {catalogItem.discreteTime && <div className="layer-time">Time: {formatDateTime(catalogItem.discreteTime)}</div>}
                <Legend item={catalogItem} />
            </div>
        );
    },

    renderDetails(catalogItem) {
        if (!catalogItem.isMappable) {
            return null;
        }

        const nowViewingItem = catalogItem.nowViewingCatalogItem || catalogItem;
        return (
            <div key={catalogItem.uniqueId} className="layer-details">
                <h2>{catalogItem.name}</h2>
                <Description item={nowViewingItem} printView={true} />
            </div>
        );
    },

    renderFeatureInfo() {
        if (!this.props.viewState.featureInfoPanelIsVisible || !this.props.terria.pickedFeatures ||
            !this.props.terria.pickedFeatures.features || this.props.terria.pickedFeatures.features.length === 0) {
            return null;
        }

        return (
            <div className="feature-info">
                <h1>Feature Information</h1>
                <FeatureInfoPanel terria={this.props.terria} viewState={this.props.viewState} printView={true} />
            </div>
        );
    }
});

PrintView.Styles = `
    .tjs-_base__list-reset {
        list-style: none;
        padding-left: 0;
        margin: 0;
    }

    .background {
        width: 100%;
        fill: rgba(255, 255, 255, 1.0);
    }

    .map-image {
        max-width: 95vw;
        max-height: 95vh;
    }

    .layer-legends {
        display: inline;
        float: left;
        padding-left: 20px;
        padding-right: 20px;
    }

    .layer-title {
        font-weight: bold;
    }

    h1, h2, h3 {
        clear: both;
    }

    .tjs-_form__input {
        width: 80%;
    }
`;

/**
 * Creates a new printable view.
 *
 * @param {Terria} options.terria The Terria instance.
 * @param {ViewState} options.viewState The terria ViewState instance.
 * @param {Window} [options.printWindow] The window in which to create the print view. This is usually a new window created with
 *                 `window.open()` or an iframe's `contentWindow`. If undefined, a new window (tab) will be created.
 * @param {Function} [options.readyCallback] A function that is called when the print view is ready to be used. The function is
 *                   given the print view window as its only parameter.
 * @param {Function} [options.closeCallback] A function that is called when the print view is closed. The function is given
 *                   the print view window as its only parameter.
 */
PrintView.create = function(options) {
    const { terria, viewState, printWindow = window.open(), readyCallback, closeCallback } = options;

    if (closeCallback) {
        printWindow.addEventListener('unload', () => {
            closeCallback(printWindow);
        });
    }

    // Open and immediately close the document. This works around a problem in Firefox that is
    // captured here: https://bugzilla.mozilla.org/show_bug.cgi?id=667227.
    // Essentially, when we first create an iframe, it has no document loaded and asynchronously
    // starts a load of "about:blank". If we access the document object and start manipulating it
    // before that async load completes, a new document will be automatically created. But then
    // when the async load completes, the original, automatically-created document gets unloaded
    // and the new "about:blank" gets swapped in. End result: everything we add to the DOM before
    // the async load complete gets lost and Firefox ends up printing a blank page.
    // Explicitly opening and then closing a new document _seems_ to avoid this.
    printWindow.document.open();
    printWindow.document.close();

    printWindow.document.head.innerHTML = `
        <meta charset="UTF-8">
        <title>${terria.appName} Print View</title>
        <style>${PrintView.Styles}</style>
        `;
    printWindow.document.body.innerHTML = '<div id="print"></div>';

    const printView = <PrintView terria={terria} viewState={viewState} window={printWindow} readyCallback={readyCallback} />;
    ReactDOM.render(printView, printWindow.document.getElementById('print'));
};

module.exports = PrintView;