'use strict';

import classNames from 'classnames';
import React from 'react';

import PropTypes from 'prop-types';
import createReactClass from 'create-react-class';

import defaultValue from 'terriajs-cesium/Source/Core/defaultValue';
import defined from 'terriajs-cesium/Source/Core/defined';
import clone from 'terriajs-cesium/Source/Core/clone';

import CatalogGroup from '../../../Models/CatalogGroup';
import CsvCatalogItem from '../../../Models/CsvCatalogItem';
import Dropdown from '../../Generic/Dropdown';
import Polling from '../../../Models/Polling';
import raiseErrorToUser from '../../../Models/raiseErrorToUser';
import TableStyle from '../../../Models/TableStyle';
import Icon from "../../Icon.jsx";

import Styles from './chart-expand-and-download-buttons.scss';

// This displays both an "expand" button, which enables a new catalog item based on the chart data,
// and a "download" button, which downloads the data.
//
const ChartExpandAndDownloadButtons = createReactClass({

    propTypes: {
        terria: PropTypes.object.isRequired,
        // Either provide URLs to the expanded data.
        sources: PropTypes.array,
        sourceNames: PropTypes.array,
        downloads: PropTypes.array,
        downloadNames: PropTypes.array,
        // Optional polling info that would need to be transferred to any standalone catalog item.
        pollSources: PropTypes.array,
        pollSeconds: PropTypes.oneOfType([PropTypes.string, PropTypes.number]),
        pollReplace: PropTypes.bool,
        updateCounter: PropTypes.any,  // Change this to trigger an update.
        // Or, provide a tableStructure directly.
        tableStructure: PropTypes.object,
        //
        catalogItem: PropTypes.object,
        title: PropTypes.string,
        colors: PropTypes.array,
        feature: PropTypes.object,
        id: PropTypes.oneOfType([PropTypes.string, PropTypes.number]),
        columnNames: PropTypes.array,
        columnUnits: PropTypes.array,
        xColumn: PropTypes.oneOfType([PropTypes.string, PropTypes.number]),
        yColumns: PropTypes.array,
        canDownload: PropTypes.bool,
        raiseToTitle: PropTypes.bool
    },

    expandButton() {
        if (defined(this.props.sources)) {
            expand(this.props, this.props.sources.length - 1);
        } else {
            expand(this.props); // Will expand from this.props.tableStructure.
        }
    },

    expandDropdown(selected, sourceIndex) {
        expand(this.props, sourceIndex);
    },

    render() {
        if (!defined(this.props.sources) && !defined(this.props.tableStructure)) {
            return null;
        }
        // The downloads and download names default to the sources and source names if not defined.
        const downloads = this.props.downloads || this.props.sources;
        const downloadNames = this.props.downloadNames || this.props.sourceNames;
        let downloadButton;
        if (defined(this.props.sourceNames)) {
            const dropdownTheme = {
                dropdown: Styles.dropdown,
                list: Styles.dropdownList,
                button: Styles.dropdownBtn,
                btnOption: Styles.dropdownBtnOption
            };

            const sourceNameObjects = this.props.sourceNames.map(name => { return {name: name}; });
            const nameAndHrefObjects = downloadNames.map((name, i) => { return {name: name, href: downloads[i]}; });
            if (this.props.canDownload) {
                const downloadDropdownTheme = clone(dropdownTheme);
                downloadDropdownTheme.button = classNames(Styles.btnSmall, Styles.btnDownload);
                downloadButton = <Dropdown selectOption={this.downloadDropdown} options={nameAndHrefObjects} theme={downloadDropdownTheme}>Download&nbsp;▾</Dropdown>;
            }

            return (
                <div className={classNames(Styles.chartExpand, {[Styles.raiseToTitle]: this.props.raiseToTitle})}>
                    <div className={Styles.chartDropdownButton}>
                        <Dropdown selectOption={this.expandDropdown} options={sourceNameObjects} theme={dropdownTheme}>
                            Expand&nbsp;▾
                        </Dropdown>
                        {downloadButton}
                    </div>
                </div>
            );
        }
        if (this.props.canDownload && defined(downloads)) {
            const href = downloads[0];
            downloadButton = <a className={classNames(Styles.btnSmall, Styles.aDownload)} href={href}><Icon glyph={Icon.GLYPHS.download}/></a>;
        }
        return (
            <div className={Styles.chartExpand}>
                <button type='button' className={Styles.btnChartExpand} onClick={this.expandButton}>Expand</button>{downloadButton}
            </div>
        );
    }

});

/**
 * Reads chart data from a URL or tableStructure into a CsvCatalogItem, which shows it in the bottom dock.
 * @private
 */
function expand(props, sourceIndex) {
    const terria = props.terria;
    const url = defined(sourceIndex) ? props.sources[sourceIndex] : undefined;

    // Set the table style so that the names and units of the columns appear immediately, not with a delay.
    const tableStyleOptions = {
        columns: {}
    };
    const maxColumnNamesAndUnits = Math.max(props.columnNames && props.columnNames.length || 0, props.columnUnits && props.columnUnits.length || 0);
    for (let columnNumber = 0; columnNumber < maxColumnNamesAndUnits; columnNumber++) {
        tableStyleOptions.columns[columnNumber] = {};
        if (defined(props.columnNames) && props.columnNames[columnNumber]) {
            tableStyleOptions.columns[columnNumber].name = props.columnNames[columnNumber];
        }
        if (defined(props.columnUnits) && props.columnUnits[columnNumber]) {
            tableStyleOptions.columns[columnNumber].units = props.columnUnits[columnNumber];
        }
    }
    // Set the active columns via tableStyle too.
    // This is a bit inconsistent with the above, since above we index with column number
    // and here we may be indexing with number or id or name.
    // But it works. (TableStyle.columns may have multiple references to the same column.)
    if (defined(props.xColumn)) {
        tableStyleOptions.xAxis = props.xColumn;
    }
    if (defined(props.yColumns)) {
        props.yColumns.forEach(nameOrIndex => {
            if (!defined(tableStyleOptions.columns[nameOrIndex])) {
                tableStyleOptions.columns[nameOrIndex] = {};
            }
            tableStyleOptions.columns[nameOrIndex].active = true;
        });
    }
    const options = {
        tableStyle: new TableStyle(tableStyleOptions)
    };

    const newCatalogItem = new CsvCatalogItem(terria, url, options);
    let tableStructure = props.tableStructure;
    if (defined(props.colors) && props.colors.length >= tableStructure.columns.length) {
        newCatalogItem.getNextColor = index => props.colors[index];
    }

    // For CSV data with a URL, we could just use the usual csvCatalogItem._load to load this from the url.
    // However, we also want this to work with urls that may be interpreted differently according to CatalogItem.loadIntoTableStructure.
    // So use the parent catalogItem's loadIntoTableStructure (if available) to do the load.
    // Note that CsvCatalogItem's _load function checks for data first, and only loads the URL if no data is present, so we won't double up.
    if (!defined(tableStructure) && defined(props.catalogItem) && defined(props.catalogItem.loadIntoTableStructure)) {
        tableStructure = props.catalogItem.loadIntoTableStructure(url);
    }
    newCatalogItem.data = tableStructure;
    // Without this, if the chart data comes via the proxy, it would be cached for the default period of 2 weeks.
    // So, retain the same `cacheDuration` as the parent data file.
    // You can override this with the `pollSeconds` attribute (coming!).
    // If neither is set, it should default to a small duration rather than 2 weeks - say 1 minute.
    newCatalogItem.cacheDuration = defaultValue(props.catalogItem.cacheDuration, '1m');
    newCatalogItem.name = props.title || (props.feature && props.feature.name) || 'Chart';
    newCatalogItem.id = newCatalogItem.name + (props.id ? (' ' + props.id) : '') + ' (' + props.catalogItem.name + ')';

    if (defined(props.pollSeconds)) {
        const pollSources = props.pollSources;
        newCatalogItem.polling = new Polling({
            seconds: props.pollSeconds,
            url: (defined(sourceIndex) && defined(pollSources)) ? pollSources[Math.min(sourceIndex, pollSources.length - 1)] : undefined,
            replace: props.pollReplace
        });
    }
    const group = terria.catalog.upsertCatalogGroup(CatalogGroup, 'Chart Data', 'A group for chart data.');
    group.isOpen = true;
    const existingChartItemIds = group.items.map(item => item.uniqueId);
    const existingIndex = existingChartItemIds.indexOf(newCatalogItem.uniqueId);
    let existingColors;
    let activeConcepts;
    if (existingIndex >= 0) {
        // First, keep a copy of the active items and colors used, so we can keep them the same with the new chart.
        const oldCatalogItem = group.items[existingIndex];
        activeConcepts = oldCatalogItem.tableStructure.columns.map(column => column.isActive);
        existingColors = oldCatalogItem.tableStructure.columns.map(column => column.color);
        oldCatalogItem.isEnabled = false;
        group.remove(oldCatalogItem);
    }
    group.add(newCatalogItem);
    newCatalogItem.isLoading = true;
    newCatalogItem.isMappable = false;
    terria.catalog.chartableItems.push(newCatalogItem);  // Notify the chart panel so it shows "loading".
    newCatalogItem.isEnabled = true;  // This loads it as well.
    // Is there a better way to set up an action to occur once the file has loaded?
    newCatalogItem.load().then(() => {
        // Enclose in try-catch rather than otherwise so that if load itself fails, we don't do this at all.
        try {
            newCatalogItem.sourceCatalogItem = props.catalogItem;
            const tableStructure = newCatalogItem.tableStructure;
            tableStructure.sourceFeature = props.feature;
            if (defined(existingColors)) {
                tableStructure.columns.forEach((column, columnNumber) => {
                    column.color = existingColors[columnNumber];
                });
            }
            if (defined(activeConcepts) && activeConcepts.some(a => a)) {
                tableStructure.columns.forEach((column, columnNumber) => {
                    column.isActive = activeConcepts[columnNumber];
                });
            }
            newCatalogItem.setChartable();
        } catch(e) {
            // This does not actually make it to the user.
            return raiseErrorToUser(terria, e);
        }
    });
}

module.exports = ChartExpandAndDownloadButtons;