import { requestJson } from './apiClient';

function normalizeItems(items) {
    if (Array.isArray(items)) return items;
    if (items && typeof items === 'object') return [items];
    return [];
}

export const CouponService = {
    async listCoupons({ page, limit, id, tenant_id, tenant_code, tenant_name, keyword, type, status, created_at_from, created_at_to, sortField, sortOrder } = {}) {
        const iso = (d) => {
            if (!d) return undefined;
            const date = d instanceof Date ? d : new Date(d);
            if (Number.isNaN(date.getTime())) return undefined;
            return date.toISOString();
        };

        const query = {
            page,
            limit,
            id,
            tenant_id,
            tenant_code,
            tenant_name,
            keyword,
            type,
            status,
            created_at_from: iso(created_at_from),
            created_at_to: iso(created_at_to)
        };
        if (sortField && sortOrder) {
            if (sortOrder === 1) query.asc = sortField;
            if (sortOrder === -1) query.desc = sortField;
        }

        const data = await requestJson('/super/v1/coupons', { query });
        return {
            page: data?.page ?? page ?? 1,
            limit: data?.limit ?? limit ?? 10,
            total: data?.total ?? 0,
            items: normalizeItems(data?.items)
        };
    },
    async createCoupon(tenantID, form = {}) {
        if (!tenantID) throw new Error('tenantID is required');
        return requestJson(`/super/v1/tenants/${tenantID}/coupons`, {
            method: 'POST',
            body: normalizeCouponForm(form)
        });
    },
    async getCoupon(tenantID, couponID) {
        if (!tenantID) throw new Error('tenantID is required');
        if (!couponID) throw new Error('couponID is required');
        return requestJson(`/super/v1/tenants/${tenantID}/coupons/${couponID}`);
    },
    async updateCoupon(tenantID, couponID, form = {}) {
        if (!tenantID) throw new Error('tenantID is required');
        if (!couponID) throw new Error('couponID is required');
        return requestJson(`/super/v1/tenants/${tenantID}/coupons/${couponID}`, {
            method: 'PUT',
            body: normalizeCouponForm(form)
        });
    },
    async grantCoupon(tenantID, couponID, userIDs = []) {
        if (!tenantID) throw new Error('tenantID is required');
        if (!couponID) throw new Error('couponID is required');
        if (!Array.isArray(userIDs) || userIDs.length === 0) throw new Error('userIDs is required');
        return requestJson(`/super/v1/tenants/${tenantID}/coupons/${couponID}/grant`, {
            method: 'POST',
            body: { user_ids: userIDs }
        });
    }
};

function normalizeCouponForm(form) {
    const iso = (d) => {
        if (!d) return undefined;
        const date = d instanceof Date ? d : new Date(d);
        if (Number.isNaN(date.getTime())) return undefined;
        return date.toISOString();
    };

    return {
        title: form.title,
        description: form.description,
        type: form.type,
        value: form.value,
        min_order_amount: form.min_order_amount,
        max_discount: form.max_discount,
        total_quantity: form.total_quantity,
        start_at: iso(form.start_at),
        end_at: iso(form.end_at)
    };
}