import { useState, useEffect } from "react";
import { useCurrentTrain } from "@/stateBox/useCurrentTrain";
import { trainDataType } from "@/lib/trainPositionTextArray";

/**
 * 列車の現在位置を計算するカスタムフック
 * 伊予駅の特殊処理を含む
 */
export const useTrainCurrentPosition = (
  train: trainDataType | null,
  stopStationIDList: string[][]
) => {
  const { getPosition } = useCurrentTrain();
  const [currentPosition, setCurrentPosition] = useState<string[]>([]);

  useEffect(() => {
    let position = getPosition(train);
    if (stopStationIDList.length == 0) return;
    if (position) {
      if (position.length > 1) {
        // 伊予駅の特殊処理
        const iyoIndex = stopStationIDList.findIndex((d) => d.includes("U14"));
        
        if (position[0] == "-Iyo") {
          position[0] = stopStationIDList[iyoIndex - 1]?.[0];
        } else if (position[0] == "+Iyo") {
          position[0] = stopStationIDList[iyoIndex + 1]?.[0];
        }
        
        if (position[1] == "+Iyo") {
          position[1] = stopStationIDList[iyoIndex + 1]?.[0];
        } else if (position[1] == "-Iyo") {
          position[1] = stopStationIDList[iyoIndex - 1]?.[0];
        }
      }

      setCurrentPosition(position);
    }
  }, [train, stopStationIDList, getPosition]);

  return currentPosition;
};