import { useCallback, useEffect, useMemo, useState } from 'react';

import { getHourlyPlantStats, getPlantStats } from '../services/solarApi';
import {
  formatHourlyChartData,
  formatPeriodChartData,
  toLocalIsoDate,
} from '../utils/statsChart';

const buildPeriodParams = (period, selectedDate) => {
  const year = selectedDate.getFullYear();
  const month = selectedDate.getMonth() + 1;

  if (period === 'day') return { period, year, month };
  return { period, year };
};

const formatUpdatedAt = (value) => {
  if (!value) return '-';
  const date = new Date(value);
  if (Number.isNaN(date.getTime())) return '-';
  return date.toLocaleTimeString('ko-KR', { hour: '2-digit', minute: '2-digit' });
};

export default function usePlantStats(plant, period, selectedDate) {
  const [chartData, setChartData] = useState([]);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState(null);

  const reload = useCallback(async () => {
    try {
      setLoading(true);
      setError(null);

      if (period === 'today') {
        const result = await getHourlyPlantStats(plant.id, toLocalIsoDate(selectedDate));
        setChartData(formatHourlyChartData(result?.data || [], selectedDate));
      } else {
        const result = await getPlantStats(
          plant.id,
          buildPeriodParams(period, selectedDate),
        );
        setChartData(formatPeriodChartData(period, result?.data || [], selectedDate));
      }
    } catch (requestError) {
      setError(requestError.message);
      setChartData([]);
    } finally {
      setLoading(false);
    }
  }, [period, plant.id, selectedDate]);

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

  const todayData = useMemo(() => {
    if (period !== 'today' || toLocalIsoDate(selectedDate) !== toLocalIsoDate(new Date())) {
      return null;
    }

    const latestLog = plant.latest_log;
    if (!latestLog) return null;

    return {
      currentKw: Number(latestLog.current_kw) || 0,
      todayKwh: Number(latestLog.today_kwh) || 0,
      updatedAt: formatUpdatedAt(latestLog.created_at),
    };
  }, [period, plant.latest_log, selectedDate]);

  return { chartData, loading, error, reload, todayData };
}