/**
 * Custom hook for fetching historical celestial data
 */
import { useState, useEffect, useRef } from 'react';
import { fetchCelestialPositions } from '../utils/api';
import type { CelestialBody } from '../types';

export function useHistoricalData(selectedDate: Date | null) {
  const [bodies, setBodies] = useState<CelestialBody[]>([]);
  const [loading, setLoading] = useState(false);
  const [error, setError] = useState<string | null>(null);

  // 使用 ref 跟踪上次请求的时间，避免重复请求
  const lastFetchedDateRef = useRef<string | null>(null);

  useEffect(() => {
    if (!selectedDate) {
      return;
    }

    // Track if this effect instance is active
    let isActive = true;

    // 创建午夜时间戳
    const targetDate = new Date(selectedDate);
    targetDate.setUTCHours(0, 0, 0, 0);
    const dateKey = targetDate.toISOString();

    // 如果是同一个时间点，不重复请求
    if (lastFetchedDateRef.current === dateKey) {
      return;
    }

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

        console.log(`[useHistoricalData] Fetching data for ${dateKey}`);

        // Set start and end to the same time to get a single snapshot
        const data = await fetchCelestialPositions(
          targetDate.toISOString(),
          targetDate.toISOString(), // Same as start - single point in time
          '1d'
        );

        // Only update state if this effect is still active
        if (isActive) {
          setBodies(data.bodies);
          lastFetchedDateRef.current = dateKey; // 记录已请求的时间
          console.log(`[useHistoricalData] Loaded ${data.bodies.length} bodies`);
          setLoading(false);
        } else {
          console.log(`[useHistoricalData] Ignored stale data for ${dateKey}`);
        }
      } catch (err) {
        if (isActive) {
          console.error('Failed to fetch historical data:', err);
          setError(err instanceof Error ? err.message : 'Unknown error');
          setLoading(false);
        }
      }
    };

    loadHistoricalData();

    // Cleanup function
    return () => {
      isActive = false;
    };
  }, [selectedDate]);

  return { bodies, loading, error };
}