import { useState, useEffect, useCallback } from 'react';
import {
  type YearlyProjection,
  type MonthlyDetail,
  type RecurringItem,
  type RecurringItemCreate,
  type RecurringItemUpdate,
  getYearlyProjection,
  getMonthlyDetail,
  getRecurringItems,
  createRecurringItem,
  updateRecurringItem as apiUpdateItem,
  deleteRecurringItem as apiDeleteItem,
  upsertBalanceOverride,
  deleteBalanceOverride,
} from '@/lib/api';

export function useBudget(initialYear: number) {
  const [year, setYear] = useState(initialYear);
  const [selectedMonth, setSelectedMonth] = useState<number>(new Date().getMonth() + 1);
  const [projection, setProjection] = useState<YearlyProjection | null>(null);
  const [monthDetail, setMonthDetail] = useState<MonthlyDetail | null>(null);
  const [recurringItems, setRecurringItems] = useState<RecurringItem[]>([]);
  const [loading, setLoading] = useState(true);
  const [monthLoading, setMonthLoading] = useState(false);

  const fetchProjection = useCallback(async () => {
    setLoading(true);
    try {
      const { data } = await getYearlyProjection(year);
      setProjection(data);
    } finally {
      setLoading(false);
    }
  }, [year]);

  const fetchMonthDetail = useCallback(async () => {
    setMonthLoading(true);
    try {
      const { data } = await getMonthlyDetail(year, selectedMonth);
      setMonthDetail(data);
    } finally {
      setMonthLoading(false);
    }
  }, [year, selectedMonth]);

  const fetchRecurringItems = useCallback(async () => {
    const { data } = await getRecurringItems();
    setRecurringItems(data);
  }, []);

  useEffect(() => {
    fetchProjection();
    fetchRecurringItems();
  }, [fetchProjection, fetchRecurringItems]);

  useEffect(() => {
    fetchMonthDetail();
  }, [fetchMonthDetail]);

  const addItem = async (data: RecurringItemCreate) => {
    await createRecurringItem(data);
    await Promise.all([fetchProjection(), fetchMonthDetail(), fetchRecurringItems()]);
  };

  const updateItem = async (id: number, data: RecurringItemUpdate) => {
    await apiUpdateItem(id, data);
    await Promise.all([fetchProjection(), fetchMonthDetail(), fetchRecurringItems()]);
  };

  const deleteItem = async (id: number) => {
    await apiDeleteItem(id);
    await Promise.all([fetchProjection(), fetchMonthDetail(), fetchRecurringItems()]);
  };

  const saveBalanceOverride = async (overrideYear: number, month: number, value: number) => {
    await upsertBalanceOverride(overrideYear, month, value);
    await fetchProjection();
  };

  const clearBalanceOverride = async (overrideYear: number, month: number) => {
    await deleteBalanceOverride(overrideYear, month);
    await fetchProjection();
  };

  return {
    year,
    setYear,
    selectedMonth,
    setSelectedMonth,
    projection,
    monthDetail,
    recurringItems,
    loading,
    monthLoading,
    addItem,
    updateItem,
    deleteItem,
    saveBalanceOverride,
    clearBalanceOverride,
    refresh: () => Promise.all([fetchProjection(), fetchMonthDetail(), fetchRecurringItems()]),
  };
}