/*
Copyright 2015, 2016 OpenMarket Ltd

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

'use strict';

var React = require('react');
var ReactDOM = require('react-dom');
var highlight = require('highlight.js');
var HtmlUtils = require('../../../HtmlUtils');
var linkify = require('linkifyjs');
var linkifyElement = require('linkifyjs/element');
var linkifyMatrix = require('../../../linkify-matrix');
var sdk = require('../../../index');
var ScalarAuthClient = require("../../../ScalarAuthClient");
var Modal = require("../../../Modal");
var SdkConfig = require('../../../SdkConfig');
var UserSettingsStore = require('../../../UserSettingsStore');

linkifyMatrix(linkify);

module.exports = React.createClass({
    displayName: 'TextualBody',

    propTypes: {
        /* the MatrixEvent to show */
        mxEvent: React.PropTypes.object.isRequired,

        /* a list of words to highlight */
        highlights: React.PropTypes.array,

        /* link URL for the highlights */
        highlightLink: React.PropTypes.string,

        /* should show URL previews for this event */
        showUrlPreview: React.PropTypes.bool,

        /* callback for when our widget has loaded */
        onWidgetLoad: React.PropTypes.func,
    },

    getInitialState: function() {
        return {
            // the URLs (if any) to be previewed with a LinkPreviewWidget
            // inside this TextualBody.
            links: [],

            // track whether the preview widget is hidden
            widgetHidden: false,
        };
    },

    componentDidMount: function() {
        this._unmounted = false;

        linkifyElement(this.refs.content, linkifyMatrix.options);
        this.calculateUrlPreview();

        if (this.props.mxEvent.getContent().format === "org.matrix.custom.html") {
            const blocks = ReactDOM.findDOMNode(this).getElementsByTagName("code");
            if (blocks.length > 0) {
                // Do this asynchronously: parsing code takes time and we don't
                // need to block the DOM update on it.
                setTimeout(() => {
                    if (this._unmounted) return;
                    for (let i = 0; i < blocks.length; i++) {
                        highlight.highlightBlock(blocks[i]);
                    }
                }, 10);
            }
        }
    },

    componentDidUpdate: function() {
        this.calculateUrlPreview();
    },

    componentWillUnmount: function() {
        this._unmounted = true;
    },

    shouldComponentUpdate: function(nextProps, nextState) {
        //console.log("shouldComponentUpdate: ShowUrlPreview for %s is %s", this.props.mxEvent.getId(), this.props.showUrlPreview);

        // exploit that events are immutable :)
        return (nextProps.mxEvent.getId() !== this.props.mxEvent.getId() ||
                nextProps.highlights !== this.props.highlights ||
                nextProps.highlightLink !== this.props.highlightLink ||
                nextProps.showUrlPreview !== this.props.showUrlPreview ||
                nextState.links !== this.state.links ||
                nextState.widgetHidden !== this.state.widgetHidden);
    },

    calculateUrlPreview: function() {
        //console.log("calculateUrlPreview: ShowUrlPreview for %s is %s", this.props.mxEvent.getId(), this.props.showUrlPreview);

        if (this.props.showUrlPreview && !this.state.links.length) {
            var links = this.findLinks(this.refs.content.children);
            if (links.length) {
                this.setState({ links: links.map((link)=>{
                    return link.getAttribute("href");
                })});

                // lazy-load the hidden state of the preview widget from localstorage
                if (global.localStorage) {
                    var hidden = global.localStorage.getItem("hide_preview_" + this.props.mxEvent.getId());
                    this.setState({ widgetHidden: hidden });
                }
            }
        }
    },

    findLinks: function(nodes) {
        var links = [];
        for (var i = 0; i < nodes.length; i++) {
            var node = nodes[i];
            if (node.tagName === "A" && node.getAttribute("href"))
            {
                if (this.isLinkPreviewable(node)) {
                    links.push(node);
                }
            }
            else if (node.tagName === "PRE" || node.tagName === "CODE") {
                continue;
            }
            else if (node.children && node.children.length) {
                links = links.concat(this.findLinks(node.children));
            }
        }
        return links;
    },

    isLinkPreviewable: function(node) {
        // don't try to preview relative links
        if (!node.getAttribute("href").startsWith("http://") &&
            !node.getAttribute("href").startsWith("https://"))
        {
            return false;
        }

        // as a random heuristic to avoid highlighting things like "foo.pl"
        // we require the linked text to either include a / (either from http://
        // or from a full foo.bar/baz style schemeless URL) - or be a markdown-style
        // link, in which case we check the target text differs from the link value.
        // TODO: make this configurable?
        if (node.textContent.indexOf("/") > -1)
        {
            return node;
        }
        else {
            var url = node.getAttribute("href");
            var host = url.match(/^https?:\/\/(.*?)(\/|$)/)[1];
            if (node.textContent.toLowerCase().trim().startsWith(host.toLowerCase())) {
                // it's a "foo.pl" style link
                return;
            }
            else {
                // it's a [foo bar](http://foo.com) style link
                return node;
            }
        }
    },

    onCancelClick: function(event) {
        this.setState({ widgetHidden: true });
        // FIXME: persist this somewhere smarter than local storage
        if (global.localStorage) {
            global.localStorage.setItem("hide_preview_" + this.props.mxEvent.getId(), "1");
        }
        this.forceUpdate();
    },

    getEventTileOps: function() {
        var self = this;
        return {
            isWidgetHidden: function() {
                return self.state.widgetHidden;
            },

            unhideWidget: function() {
                self.setState({ widgetHidden: false });
                if (global.localStorage) {
                    global.localStorage.removeItem("hide_preview_" + self.props.mxEvent.getId());
                }
            },
        }
    },

    onStarterLinkClick: function(starterLink, ev) {
        ev.preventDefault();
        // We need to add on our scalar token to the starter link, but we may not have one!
        // In addition, we can't fetch one on click and then go to it immediately as that
        // is then treated as a popup!
        // We can get around this by fetching one now and showing a "confirmation dialog" (hurr hurr)
        // which requires the user to click through and THEN we can open the link in a new tab because
        // the window.open command occurs in the same stack frame as the onClick callback.

        let integrationsEnabled = UserSettingsStore.isFeatureEnabled("integration_management");
        if (!integrationsEnabled) {
            var ErrorDialog = sdk.getComponent("dialogs.ErrorDialog");
            Modal.createDialog(ErrorDialog, {
                title: "Integrations disabled",
                description: "You need to enable the Labs option 'Integrations Management' in your Riot user settings first.",
            });
            return;
        }

        // Go fetch a scalar token
        let scalarClient = new ScalarAuthClient();
        scalarClient.connect().then(() => {
            let completeUrl = scalarClient.getStarterLink(starterLink);
            let QuestionDialog = sdk.getComponent("dialogs.QuestionDialog");
            let integrationsUrl = SdkConfig.get().integrations_ui_url;
            Modal.createDialog(QuestionDialog, {
                title: "Add an Integration",
                description:
                    <div>
                        You are about to taken to a third-party site so you can authenticate your account for use with {integrationsUrl}.<br/>
                        Do you wish to continue?
                    </div>,
                button: "Continue",
                onFinished: function(confirmed) {
                    if (!confirmed) {
                        return;
                    }
                    let width  = window.screen.width  > 1024 ? 1024 : window.screen.width;
                    let height = window.screen.height > 800  ? 800 : window.screen.height;
                    let left = (window.screen.width - width) / 2;
                    let top = (window.screen.height - height) / 2;
                    window.open(completeUrl, '_blank', `height=${height}, width=${width}, top=${top}, left=${left},`);
                },
            });
        });
    },

    render: function() {
        const EmojiText = sdk.getComponent('elements.EmojiText');
        var mxEvent = this.props.mxEvent;
        var content = mxEvent.getContent();

        var body = HtmlUtils.bodyToHtml(content, this.props.highlights, {});

        if (this.props.highlightLink) {
            body = <a href={ this.props.highlightLink }>{ body }</a>;
        }
        else if (content.data && typeof content.data["org.matrix.neb.starter_link"] === "string") {
            body = <a href="#" onClick={ this.onStarterLinkClick.bind(this, content.data["org.matrix.neb.starter_link"]) }>{ body }</a>;
        }

        var widgets;
        if (this.state.links.length && !this.state.widgetHidden && this.props.showUrlPreview) {
            var LinkPreviewWidget = sdk.getComponent('rooms.LinkPreviewWidget');
            widgets = this.state.links.map((link)=>{
                return <LinkPreviewWidget
                            key={ link }
                            link={ link }
                            mxEvent={ this.props.mxEvent }
                            onCancelClick={ this.onCancelClick }
                            onWidgetLoad={ this.props.onWidgetLoad }/>;
            });
        }

        switch (content.msgtype) {
            case "m.emote":
                const name = mxEvent.sender ? mxEvent.sender.name : mxEvent.getSender();
                return (
                    <span ref="content" className="mx_MEmoteBody mx_EventTile_content">
                        * <EmojiText>{name}</EmojiText> { body }
                        { widgets }
                    </span>
                );
            case "m.notice":
                return (
                    <span ref="content" className="mx_MNoticeBody mx_EventTile_content">
                        { body }
                        { widgets }
                    </span>
                );
            default: // including "m.text"
                return (
                    <span ref="content" className="mx_MTextBody mx_EventTile_content">
                        { body }
                        { widgets }
                    </span>
                );
        }
    },
});