WordGrid/ui/src/utils.ts

import {Letter} from "word_grid";
import {LocationType, PlayableLetterData} from "./elements";

export function addNTimes<T>(array: T[], toAdd: T, times: number) {
    for (let i=0; i<times; i++) {
        array.push(toAdd);
    }
}

export function mergeTrays(existing: PlayableLetterData[], newer: (Letter | undefined)[]): PlayableLetterData[] {

    let trayLength = Math.max(existing.length, newer.length);

    // we may need to check against the existing tray to retain whatever user reorderings there are
    const freeSpots = new Array<number | null>();
    for (let i = 0; i<trayLength; i++) {
        freeSpots.push(i);
    }

    existing.filter((x) => {
        return x !== undefined && x !== null;
    }).forEach((x) => {
        if (x.location === LocationType.TRAY) {
            freeSpots[x.index] = null;
        }
    });

    const firstNotNull = (): number => {
        for (let i of freeSpots) {
            if (i !== null) {
                freeSpots[i] = null;
                return i;
            }
        }

        return null;
    }

    return newer.map((ld, i) => {
        if (ld !== undefined) {

            if (existing[i] !== undefined && existing[i] !== null && existing[i].location === LocationType.TRAY) {
                ld["index"] = existing[i].index;
            } else {
                ld["index"] = firstNotNull();
            }
            ld["location"] = LocationType.TRAY;
        }
        return ld as PlayableLetterData;
    });

}