import { BillingLocation, BilledTo } from '@evidencija-rezija/shared-code';

/**
 * Checks if billFwdStatus should be updated to "pending" based on attachment status
 * @param location - The billing location containing the bill
 * @param currentBillId - The ID of the bill being updated (to exclude from check)
 * @param hasNewAttachment - Whether a new attachment is being added to the current bill
 * @returns true if billFwdStatus should be set to "pending"
 */
export const shouldUpdateBillFwdStatusWhenAttached = (
    location: BillingLocation,
    currentBillId: string | undefined,
    hasNewAttachment: boolean
): boolean => {
    // Only proceed if a new attachment is being added
    if (!hasNewAttachment) {
        return false;
    }

    // Check billFwdEnabled is true
    if (location.billFwdEnabled !== true) {
        return false;
    }

    // Check billFwdStrategy is "when-attached"
    if (location.billFwdStrategy !== "when-attached") {
        return false;
    }

    // Check bills have already been sent or are pending -> don't sent them again
    if (location.billFwdStatus === "pending" || location.billFwdStatus === "sent") {
        return false;
    }

    // Check if ALL other bills have attachments
    const otherBills = location.bills.filter(bill => bill._id !== currentBillId);
    // filter only bills billed to tenant
    // because bills billed to landlord should not trigger forwarding
    const billsPayedByTenant = otherBills.filter(bill => bill.billedTo === BilledTo.Tenant);

    if(billsPayedByTenant.length === 0) {
        // No other bills billed to tenant exist, so do not trigger forwarding
        return false;
    }

    const allOtherBillsHaveAttachments = billsPayedByTenant.every(bill => bill.attachment !== null);

    return allOtherBillsHaveAttachments;
};

/**
 * Checks if billFwdStatus should be updated to "pending" based on paid status
 * @param location - The billing location containing the bill
 * @param currentBillId - The ID of the bill being updated (to exclude from check)
 * @param isPaid - Whether the current bill is being marked as paid
 * @returns true if billFwdStatus should be set to "pending"
 */
export const shouldUpdateBillFwdStatusWhenPayed = (
    location: BillingLocation,
    currentBillId: string | undefined,
    isPaid: boolean
): boolean => {
    // Only proceed if the bill is being marked as paid
    if (!isPaid) {
        return false;
    }

    // Check billFwdEnabled is true
    if (location.billFwdEnabled !== true) {
        return false;
    }

    // Check billFwdStrategy is "when-payed"
    if (location.billFwdStrategy !== "when-payed") {
        return false;
    }

    // Check bills have already been sent or are pending -> don't sent them again
    if (location.billFwdStatus === "pending" || location.billFwdStatus === "sent") {
        return false;
    }

    // Check if ALL other bills are paid
    const otherBills = location.bills.filter(bill => bill._id !== currentBillId);
    // filter only bills billed to tenant
    // because bills billed to landlord should not trigger forwarding
    const billsPayedByTenant = otherBills.filter(bill => bill.billedTo === BilledTo.Tenant);

    if(billsPayedByTenant.length === 0) {
        // No other bills billed to tenant exist, so do not trigger forwarding
        return false;
    }

    const allOtherBillsPaid = billsPayedByTenant.every(bill => bill.paid === true);

    return allOtherBillsPaid;
};