/*
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';

import React from 'react';
import ReactDOM from 'react-dom';
import highlight from 'highlight.js';
import * as HtmlUtils from '../../../HtmlUtils';
import * as linkify from 'linkifyjs';
import linkifyElement from 'linkifyjs/element';
import linkifyMatrix from '../../../linkify-matrix';
import sdk from '../../../index';
import ScalarAuthClient from '../../../ScalarAuthClient';
import Modal from '../../../Modal';
import SdkConfig from '../../../SdkConfig';
import dis from '../../../dispatcher';
import { _t } from '../../../languageHandler';
import UserSettingsStore from "../../../UserSettingsStore";
import MatrixClientPeg from '../../../MatrixClientPeg';
import {RoomMember} from 'matrix-js-sdk';
import classNames from 'classnames';

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,
        };
    },

    copyToClipboard: function(text) {
        const textArea = document.createElement("textarea");
        textArea.value = text;
        document.body.appendChild(textArea);
        textArea.select();
        try {
            const successful = document.execCommand('copy');
        } catch (err) {
            console.log('Unable to copy');
        }
        document.body.removeChild(textArea);
    },

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

        // pillifyLinks BEFORE linkifyElement because plain room/user URLs in the composer
        // are still sent as plaintext URLs. If these are ever pillified in the composer,
        // we should be pillify them here by doing the linkifying BEFORE the pillifying.
        this.pillifyLinks(this.refs.content.children);
        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++) {
                        if (UserSettingsStore.getSyncedSetting("enableSyntaxHighlightLanguageDetection", false)) {
                            highlight.highlightBlock(blocks[i])
                        } else {
                            // Only syntax highlight if there's a class starting with language-
                            let classes = blocks[i].className.split(/\s+/).filter(function (cl) {
                                return cl.startsWith('language-');
                            });

                            if (classes.length != 0) {
                                highlight.highlightBlock(blocks[i]);
                            }
                        }
                    }
                }, 10);
            }
            // add event handlers to the 'copy code' buttons
            const buttons = ReactDOM.findDOMNode(this).getElementsByClassName("mx_EventTile_copyButton");
            for (let i = 0; i < buttons.length; i++) {
                buttons[i].onclick = (e) => {
                    const copyCode = buttons[i].parentNode.getElementsByTagName("code")[0];
                    this.copyToClipboard(copyCode.textContent);
                };
            }
        }
    },

    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) {
                // de-dup the links (but preserve ordering)
                const seen = new Set();
                links = links.filter((link) => {
                    if (seen.has(link)) return false;
                    seen.add(link);
                    return true;
                });

                this.setState({ links: links });

                // 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 });
                }
            }
        }
    },

    pillifyLinks: function(nodes) {
        const MemberAvatar = sdk.getComponent('avatars.MemberAvatar');
        const RoomAvatar = sdk.getComponent('avatars.RoomAvatar');
        for (let i = 0; i < nodes.length; i++) {
            const node = nodes[i];
            if (node.tagName === "A" && node.getAttribute("href")) {
                const href = node.getAttribute("href");
                // HtmlUtils transforms `matrix.to` links to local links, so match against
                // user or room app links.
                const match = /^#\/(user|room)\/(.*)$/.exec(href) || [];
                const resourceType = match[1]; // "user" or "room"
                const resourceId = match[2]; // user ID or room ID
                if (match && resourceType && resourceId) {
                    let avatar;
                    let roomId;
                    let room;
                    let member;
                    let userId;
                    switch (resourceType) {
                        case "user":
                            roomId = this.props.mxEvent.getRoomId();
                            room = MatrixClientPeg.get().getRoom(roomId);
                            userId = resourceId;
                            member = room.getMember(userId) ||
                                new RoomMember(null, userId);
                            avatar = <MemberAvatar member={member} width={16} height={16} name={userId}/>;
                        break;
                        case "room":
                            room = resourceId[0] === '#' ?
                                MatrixClientPeg.get().getRooms().find((r) => {
                                    return r.getCanonicalAlias() === resourceId;
                                }) : MatrixClientPeg.get().getRoom(resourceId);
                            if (room) {
                                avatar = <RoomAvatar room={room} width={16} height={16}/>;
                            }
                        break;
                    }
                    if (avatar) {
                        const avatarContainer = document.createElement('span');
                        node.className = classNames(
                            "mx_MTextBody_pill",
                            {
                                "mx_UserPill": match[1] === "user",
                                "mx_RoomPill": match[1] === "room",
                                "mx_UserPill_me":
                                    userId === MatrixClientPeg.get().credentials.userId,
                            },
                        );
                        ReactDOM.render(avatar, avatarContainer);
                        node.insertBefore(avatarContainer, node.firstChild);
                    }
                }
            } else if (node.children && node.children.length) {
                this.pillifyLinks(node.children);
            }
        }
    },

    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.getAttribute("href"));
                }
            }
            else if (node.tagName === "PRE" || node.tagName === "CODE" ||
                    node.tagName === "BLOCKQUOTE") {
                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 true;
        }
        else {
            var url = node.getAttribute("href");
            var host = url.match(/^https?:\/\/(.*?)(\/|$)/)[1];

            // never preview matrix.to links (if anything we should give a smart
            // preview of the room/user they point to: nobody needs to be reminded
            // what the matrix.to site looks like).
            if (host == 'matrix.to') return false;

            if (node.textContent.toLowerCase().trim().startsWith(host.toLowerCase())) {
                // it's a "foo.pl" style link
                return false;
            }
            else {
                // it's a [foo bar](http://foo.com) style link
                return true;
            }
        }
    },

    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();
    },

    onEmoteSenderClick: function(event) {
        const mxEvent = this.props.mxEvent;
        dis.dispatch({
            action: 'insert_displayname',
            user_id: mxEvent.getSender(),
        });
    },

    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.

        // 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: _t("Add an Integration"),
                description:
                    <div>
                        {_t("You are about to be taken to a third-party site so you can " +
                            "authenticate your account for use with %(integrationsUrl)s. " +
                            "Do you wish to continue?", { integrationsUrl: integrationsUrl })}
                    </div>,
                button: _t("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">
                        *&nbsp;
                        <EmojiText
                            className="mx_MEmoteBody_sender"
                            onClick={this.onEmoteSenderClick}
                        >
                            {name}
                        </EmojiText>
                        &nbsp;
                        { 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>
                );
        }
    },
});