"use server";

import { redirect } from "next/navigation";
import { auth } from "@/auth";
import { clearDraft, readDraft, writeLastBookingReference } from "@/lib/booking-draft/cookie";
import { prisma } from "@/lib/db/prisma";
import { resolveCustomerForBooking } from "@/services/customer/customer.service";
import { createBooking } from "@/services/scheduling/booking.service";
import { getFirstFriendlyMessage } from "../error-messages";

export interface ConfirmBookingResult {
  success: boolean;
  error?: string;
}

/**
 * The only action that actually creates an appointment. Resolves *which*
 * customer this is via CustomerService (never trusts a client-supplied
 * customerId — see docs/phase-4-summary.md, "Security"), then hands off
 * entirely to BookingService.createBooking, which re-validates the slot
 * inside a transaction before committing — this action does not decide
 * whether the slot is actually available.
 */
export async function confirmBookingAction(businessId: string): Promise<ConfirmBookingResult> {
  const draft = await readDraft(businessId);

  if (draft.serviceIds.length === 0 || !draft.startAt) {
    return { success: false, error: "Your booking details are incomplete — please start again." };
  }
  if (!draft.policyAcknowledged) {
    return { success: false, error: "Please acknowledge the cancellation policy to continue." };
  }

  const session = await auth();

  let customerId: string;
  try {
    if (session?.user?.id) {
      const resolved = await resolveCustomerForBooking(prisma, { businessId, userId: session.user.id });
      customerId = resolved.customerId;
    } else {
      if (!draft.guest) {
        return { success: false, error: "Please provide your contact details first." };
      }
      const resolved = await resolveCustomerForBooking(prisma, { businessId, guest: draft.guest });
      customerId = resolved.customerId;
    }
  } catch {
    return { success: false, error: "We couldn't confirm your details. Please try again." };
  }

  const result = await createBooking(prisma, {
    businessId,
    customerId,
    serviceIds: draft.serviceIds,
    staffId: draft.staffId,
    startAt: new Date(draft.startAt),
    notes: draft.notes,
  });

  if (!result.success) {
    return { success: false, error: getFirstFriendlyMessage(result.validation) };
  }

  await writeLastBookingReference(result.appointment.id);
  await clearDraft();
  redirect("/book/confirmation");
}