server/project/src/services/RagfairCategoriesService.ts

import { PaymentHelper } from "@spt/helpers/PaymentHelper";
import { IRagfairOffer } from "@spt/models/eft/ragfair/IRagfairOffer";
import { ISearchRequestData, OfferOwnerType } from "@spt/models/eft/ragfair/ISearchRequestData";
import { MemberCategory } from "@spt/models/enums/MemberCategory";
import { ILogger } from "@spt/models/spt/utils/ILogger";
import { inject, injectable } from "tsyringe";

@injectable()
export class RagfairCategoriesService {
    constructor(
        @inject("PrimaryLogger") protected logger: ILogger,
        @inject("PaymentHelper") protected paymentHelper: PaymentHelper,
    ) {}

    /**
     * Get a dictionary of each item the play can see in their flea menu, filtered by what is available for them to buy
     * @param offers All offers in flea
     * @param searchRequestData Search criteria requested
     * @param fleaUnlocked Can player see full flea yet (level 15 by default)
     * @returns KVP of item tpls + count of offers
     */
    public getCategoriesFromOffers(
        offers: IRagfairOffer[],
        searchRequestData: ISearchRequestData,
        fleaUnlocked: boolean,
    ): Record<string, number> {
        // Get offers valid for search request, then reduce them down to just the counts
        return offers
            .filter((offer) => {
                const isTraderOffer = offer.user.memberType === MemberCategory.TRADER;

                // Not level 15 and offer is from player, skip
                if (!(fleaUnlocked || isTraderOffer)) {
                    return false;
                }

                // Remove items not for money when `removeBartering` is enabled
                if (
                    searchRequestData.removeBartering &&
                    (offer.requirements.length > 1 || !this.paymentHelper.isMoneyTpl(offer.requirements[0]._tpl))
                ) {
                    return false;
                }

                // Remove when filter set to players only + offer is from trader
                if (searchRequestData.offerOwnerType === OfferOwnerType.PLAYEROWNERTYPE && isTraderOffer) {
                    return false;
                }

                // Remove when filter set to traders only + offer is not from trader
                if (searchRequestData.offerOwnerType === OfferOwnerType.TRADEROWNERTYPE && !isTraderOffer) {
                    return false;
                }

                // Passed checks, its a valid offer to process
                return true;
            })
            .reduce((acc, offer) => {
                const itemTpl = offer.items[0]._tpl;
                // Increment the category or add if doesnt exist
                acc[itemTpl] = (acc[itemTpl] || 0) + 1;

                return acc;
            }, {});
    }
}