import type { BagSlotRecord } from '../types/MergeTypes';

/** 背包棋盘（纯数据，默认 5 槽） */
export class BagBoard {
    readonly slotCount: number;
    private _slots: (BagSlotRecord | null)[];

    constructor(slotCount = 5) {
        this.slotCount = slotCount;
        this._slots = new Array(slotCount).fill(null);
    }

    get slots(): readonly (BagSlotRecord | null)[] {
        return this._slots;
    }

    getSlot(index: number): BagSlotRecord | null {
        return this._slots[index] ?? null;
    }

    isEmpty(index: number): boolean {
        return this._slots[index] == null;
    }

    findEmptySlot(): number {
        return this._slots.findIndex((s) => s == null);
    }

    setSlot(index: number, record: BagSlotRecord | null): void {
        if (index < 0 || index >= this.slotCount) return;
        this._slots[index] = record;
    }

    clearSlot(index: number): void {
        this.setSlot(index, null);
    }

    fillSlots(records: BagSlotRecord[]): void {
        for (let i = 0; i < this.slotCount; i++) {
            this._slots[i] = records[i] ?? null;
        }
    }
}