/*
Copyright 2016 Aviral Dasgupta
Copyright 2018 Michael Telatynski <7t3chguy@gmail.com>
Copyright 2017, 2018, 2021 The Matrix.org Foundation C.I.C.

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.
*/

import React from "react";
import { uniqBy, sortBy } from "lodash";
import { Room } from "matrix-js-sdk/src/models/room";

import { _t } from '../languageHandler';
import AutocompleteProvider from './AutocompleteProvider';
import { MatrixClientPeg } from '../MatrixClientPeg';
import QueryMatcher from './QueryMatcher';
import { PillCompletion } from './Components';
import { makeRoomPermalink } from "../utils/permalinks/Permalinks";
import { ICompletion, ISelectionRange } from "./Autocompleter";
import RoomAvatar from '../components/views/avatars/RoomAvatar';
import SpaceStore from "../stores/SpaceStore";

const ROOM_REGEX = /\B#\S*/g;

// Prefer canonical aliases over non-canonical ones
function canonicalScore(displayedAlias: string, room: Room): number {
    return displayedAlias === room.getCanonicalAlias() ? 0 : 1;
}

function matcherObject(room: Room, displayedAlias: string, matchName = "") {
    return {
        room,
        matchName,
        displayedAlias,
    };
}

export default class RoomProvider extends AutocompleteProvider {
    protected matcher: QueryMatcher<Room>;

    constructor() {
        super(ROOM_REGEX);
        this.matcher = new QueryMatcher([], {
            keys: ['displayedAlias', 'matchName'],
        });
    }

    protected getRooms() {
        const cli = MatrixClientPeg.get();
        let rooms = cli.getVisibleRooms();

        // if spaces are enabled then filter them out here as they get their own autocomplete provider
        if (SpaceStore.spacesEnabled) {
            rooms = rooms.filter(r => !r.isSpaceRoom());
        }

        return rooms;
    }

    async getCompletions(
        query: string,
        selection: ISelectionRange,
        force = false,
        limit = -1,
    ): Promise<ICompletion[]> {
        let completions = [];
        const { command, range } = this.getCurrentCommand(query, selection, force);
        if (command) {
            // the only reason we need to do this is because Fuse only matches on properties
            let matcherObjects = this.getRooms().reduce((aliases, room) => {
                if (room.getCanonicalAlias()) {
                    aliases = aliases.concat(matcherObject(room, room.getCanonicalAlias(), room.name));
                }
                if (room.getAltAliases().length) {
                    const altAliases = room.getAltAliases().map(alias => matcherObject(room, alias));
                    aliases = aliases.concat(altAliases);
                }
                return aliases;
            }, []);
            // Filter out any matches where the user will have also autocompleted new rooms
            matcherObjects = matcherObjects.filter((r) => {
                const tombstone = r.room.currentState.getStateEvents("m.room.tombstone", "");
                if (tombstone && tombstone.getContent() && tombstone.getContent()['replacement_room']) {
                    const hasReplacementRoom = matcherObjects.some(
                        (r2) => r2.room.roomId === tombstone.getContent()['replacement_room'],
                    );
                    return !hasReplacementRoom;
                }
                return true;
            });

            this.matcher.setObjects(matcherObjects);
            const matchedString = command[0];
            completions = this.matcher.match(matchedString, limit);
            completions = sortBy(completions, [
                (c) => canonicalScore(c.displayedAlias, c.room),
                (c) => c.displayedAlias.length,
            ]);
            completions = uniqBy(completions, (match) => match.room);
            completions = completions.map((room) => {
                return {
                    completion: room.displayedAlias,
                    completionId: room.room.roomId,
                    type: "room",
                    suffix: ' ',
                    href: makeRoomPermalink(room.displayedAlias),
                    component: (
                        <PillCompletion title={room.room.name} description={room.displayedAlias}>
                            <RoomAvatar width={24} height={24} room={room.room} />
                        </PillCompletion>
                    ),
                    range,
                };
            }).filter((completion) => !!completion.completion && completion.completion.length > 0);
        }
        return completions;
    }

    getName() {
        return _t('Rooms');
    }

    renderCompletions(completions: React.ReactNode[]): React.ReactNode {
        return (
            <div
                className="mx_Autocomplete_Completion_container_pill mx_Autocomplete_Completion_container_truncate"
                role="presentation"
                aria-label={_t("Room Autocomplete")}
            >
                { completions }
            </div>
        );
    }
}
