// Zustand store for app-level shared state (persisted to sessionStorage).
// No provider needed — import useAppStore or useAppContext anywhere.

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

interface AppState {
  loanCalculation: { calculationId: string; principalAmount: number; annualInterestRate: number; loanTermMonths: number; monthlyPayment: number; totalAmountPaid: number; totalInterestPaid: number; amortizationSchedule: Array<{ paymentNumber: number; paymentAmount: number; principalPortion: number; interestPortion: number; remainingBalance: number }> } | null;
  setLoanCalculation: (value: { calculationId: string; principalAmount: number; annualInterestRate: number; loanTermMonths: number; monthlyPayment: number; totalAmountPaid: number; totalInterestPaid: number; amortizationSchedule: Array<{ paymentNumber: number; paymentAmount: number; principalPortion: number; interestPortion: number; remainingBalance: number }> } | null) => void;
  sessionId: string;
  clearSession: () => void;
}

const useAppStore = create<AppState>()((
  persist(
    (set) => ({
    sessionId: crypto.randomUUID(),
    loanCalculation: null,
    setLoanCalculation: (value) => set({ loanCalculation: value }),
    clearSession: () => set({ sessionId: crypto.randomUUID(), loanCalculation: null }),
    }),
    {
      name: 'simple_loan_calculator_session',
      storage: createJSONStorage(() => sessionStorage),
    },
  )
));

// Convenience alias — pages import useAppContext.
const useAppContext = useAppStore;

export { useAppStore, useAppContext };