'use client';

import { create } from 'zustand';
import { persist, createJSONStorage } from 'zustand/middleware';

// Persist booking form state across page navigations (e.g. when the user
// switches language mid-flow). sessionStorage so it's per-tab and cleared
// when the tab closes. Bumping STORE_VERSION invalidates old persisted state.
const STORE_VERSION = 1;

export type Step = 'products' | 'details' | 'pickup' | 'review';

export type BookingFormState = {
  step: Step;
  quantities: Record<string, number>;
  contactName: string;
  email: string;
  phone: string;
  orgName: string;
  orgNumber: string;
  address: string;
  postalCode: string;
  city: string;
  country: string;
  pickupSlotId: string | null;
  notes: string;
  confirm: boolean;
};

type BookingFormActions = {
  setStep: (step: Step) => void;
  setQuantity: (productId: string, qty: number) => void;
  patch: (partial: Partial<BookingFormState>) => void;
  reset: () => void;
};

const initial: BookingFormState = {
  step: 'products',
  quantities: {},
  contactName: '',
  email: '',
  phone: '',
  orgName: '',
  orgNumber: '',
  address: '',
  postalCode: '',
  city: '',
  country: 'SE',
  pickupSlotId: null,
  notes: '',
  confirm: false,
};

export const useBookingStore = create<BookingFormState & BookingFormActions>()(
  persist(
    (set) => ({
      ...initial,
      setStep: (step) => set({ step }),
      setQuantity: (productId, qty) =>
        set((s) => {
          const q = { ...s.quantities };
          if (qty <= 0) delete q[productId];
          else q[productId] = Math.min(999, Math.floor(qty));
          return { quantities: q };
        }),
      patch: (partial) => set(partial as BookingFormState),
      reset: () => set({ ...initial }),
    }),
    {
      name: 'boka-gasol247:booking-form',
      version: STORE_VERSION,
      storage: createJSONStorage(() =>
        typeof window === 'undefined'
          ? // SSR no-op
            {
              getItem: () => null,
              setItem: () => {},
              removeItem: () => {},
            }
          : window.sessionStorage,
      ),
      // Don't persist `confirm` (re-check each session) or `step` if user
      // hasn't started filling anything. Keeps the experience clean if they
      // close and reopen a tab with stale state.
      partialize: (s) => ({
        step: s.step,
        quantities: s.quantities,
        contactName: s.contactName,
        email: s.email,
        phone: s.phone,
        orgName: s.orgName,
        orgNumber: s.orgNumber,
        address: s.address,
        postalCode: s.postalCode,
        city: s.city,
        country: s.country,
        pickupSlotId: s.pickupSlotId,
        notes: s.notes,
      }),
    },
  ),
);