/*!
 * Jodit Editor (https://xdsoft.net/jodit/)
 * License GNU General Public License version 2 or later;
 * Copyright 2013-2019 Valeriy Chupurnov https://xdsoft.net
 */
import { Config } from '../Config';
import {
    COMMAND_KEYS,
    INVISIBLE_SPACE_REG_EXP,
    SPACE_REG_EXP,
} from '../constants';
import { debounce } from '../modules/helpers/async';
import { IJodit, SnapshotType } from '../types';
import { stripTags } from '../modules/helpers/html';

declare module '../Config' {
    interface Config {
        limitWords: false | number;
        limitChars: false | number;
        limitHTML: false;
    }
}

/**
 * @property {boolean | number} limitWords=false limit words count
 */

Config.prototype.limitWords = false;

/**
 * @property {boolean | number} limitChars=false limit chars count
 */
Config.prototype.limitChars = false;

/**
 * @property {boolean} limitHTML=false limit html chars count
 */
Config.prototype.limitHTML = false;

export function limit(jodit: IJodit) {
    if (jodit && (jodit.options.limitWords || jodit.options.limitChars)) {
        const callback = (
            event: KeyboardEvent | null,
            inputText: string = ''
        ): void | boolean => {
            const text: string =
                inputText ||
                (jodit.options.limitHTML ? jodit.value : jodit.getEditorText());

            const words: string[] = text
                .replace(INVISIBLE_SPACE_REG_EXP, '')
                .split(SPACE_REG_EXP)
                .filter((e: string) => e.length);

            if (event && COMMAND_KEYS.indexOf(event.which) !== -1) {
                return;
            }

            if (
                jodit.options.limitWords &&
                jodit.options.limitWords <= words.length
            ) {
                return jodit.options.limitWords === words.length;
            }

            if (
                jodit.options.limitChars &&
                jodit.options.limitChars <= words.join('').length
            ) {
                return jodit.options.limitChars === words.join('').length;
            }

            return;
        };

        let snapshot: SnapshotType | null = null;

        jodit.events
            .on(
                'beforePaste',
                (): false | void => {
                    snapshot = jodit.observer.snapshot.make();
                }
            )
            .on(
                'keydown keyup beforeEnter beforePaste',
                (event: KeyboardEvent): false | void => {
                    if (callback(event) !== void 0) {
                        return false;
                    }
                }
            )
            .on(
                'change',
                debounce((newValue: string, oldValue: string) => {
                    if (
                        callback(
                            null,
                            jodit.options.limitHTML
                                ? newValue
                                : stripTags(newValue)
                        ) === false
                    ) {
                        jodit.value = oldValue;
                    }
                }, jodit.defaultTimeout)
            )
            .on(
                'afterPaste',
                (): false | void => {
                    if (callback(null) === false && snapshot) {
                        jodit.observer.snapshot.restore(snapshot);
                        return false;
                    }
                }
            );
    }
}