import { BookingApprovalStep } from './entities/booking-approval-step.entity';
import { Booking } from './entities/booking.entity';

export interface BookingNextStep {
  action: string;
  description: string;
  requiredRole?: string;
}

export function computeNextStep(
  booking: Pick<Booking, 'status' | 'paymentCurrency'>,
  nextPendingStep?: Pick<BookingApprovalStep, 'requiredRole' | 'stepOrder'> | null,
): BookingNextStep | null {
  const { status } = booking;

  switch (status) {
    case 'SUBMITTED':
      return {
        action: 'ACCEPT_INTAKE',
        description: 'Line Staff must accept the submission to begin approval',
      };
    case 'PENDING_APPROVAL':
    case 'APPROVED_PENDING_SIGNATURE':
      if (nextPendingStep) {
        return {
          action: 'APPROVE_STEP',
          requiredRole: nextPendingStep.requiredRole,
          description: `${nextPendingStep.requiredRole} must approve step ${nextPendingStep.stepOrder}`,
        };
      }
      return {
        action: 'APPROVE_STEP',
        description: 'Complete the pending approval step in sequence',
      };
    case 'APPROVED':
      return {
        action: 'CUSTOMER_SIGN',
        description: 'Contract generated; customer must sign',
      };
    case 'CONTRACT_READY':
      return {
        action: 'CUSTOMER_SIGN',
        description: 'Customer must sign the contract',
      };
    case 'SIGNED_CUSTOMER':
      return {
        action: 'STAFF_SIGN',
        description: 'Internal staff must counter-sign the contract',
      };
    case 'FULLY_EXECUTED':
      return {
        action: 'AWAIT_PAYMENT',
        description: 'Awaiting customer payment',
      };
    case 'PAID':
      return {
        action: 'START_TRANSIT',
        description: 'Mark shipment as in transit',
      };
    case 'IN_TRANSIT':
      return {
        action: 'COMPLETE',
        description: 'Mark shipment complete',
      };
    default:
      return null;
  }
}
