import type { CustomTrainData, OperationLogs } from "@/lib/CommonTypes";
import type { IconDisplayMode } from "@/lib/iconDisplayMode";
import { resolveOperationIconPair } from "@/lib/operationLogIcon";
import { resolveTrainDataIcon } from "@/lib/trainDataIcon";

export type TrainIconEntry = {
  vehicle_info_img: string;
  vehicle_info_right_img: string;
  vehicle_info_url: string;
};

type TrainDataForIcon = Pick<
  CustomTrainData,
  "train_info_img" | "train_info_img_hub" | "vehicle_info_url"
>;

const extractOrderNumber = (trainId: string): number => {
  const parts = trainId.split(",");
  if (parts.length <= 1) return Infinity;

  const num = parseInt(parts[1].trim(), 10);
  return isNaN(num) ? Infinity : num;
};

const findMatchingTrainId = (
  operation: OperationLogs,
  trainNum: string,
): string | null => {
  const allTrainIds = [
    ...(operation.train_ids || []),
    ...(operation.related_train_ids || []),
  ];

  for (const trainId of allTrainIds) {
    const prefix = trainId.split(",")[0];
    if (prefix === trainNum) return trainId;
  }

  return null;
};

export const sortOperationsForTrainIcon = (
  operations: OperationLogs[],
  trainNum: string,
): OperationLogs[] =>
  [...operations].sort((a, b) => {
    const aTrainId = findMatchingTrainId(a, trainNum);
    const bTrainId = findMatchingTrainId(b, trainNum);

    if (!aTrainId || !bTrainId) {
      return aTrainId ? -1 : bTrainId ? 1 : 0;
    }

    return extractOrderNumber(aTrainId) - extractOrderNumber(bTrainId);
  });

export const resolveTrainIconEntries = ({
  trainNum,
  customTrainData,
  todayOperation,
  iconDisplayMode,
}: {
  trainNum: string;
  customTrainData: TrainDataForIcon;
  todayOperation: OperationLogs[];
  iconDisplayMode: IconDisplayMode;
}): TrainIconEntry[] => {
  const fallbackIcon = resolveTrainDataIcon(customTrainData, iconDisplayMode);

  if (todayOperation.length > 0) {
    return sortOperationsForTrainIcon(todayOperation, trainNum)
      .map((operation) => {
        const { forward, rear } = resolveOperationIconPair(
          operation,
          iconDisplayMode,
          fallbackIcon,
        );

        return {
          vehicle_info_img: forward,
          vehicle_info_right_img: rear,
          vehicle_info_url: operation.vehicle_info_url,
        };
      })
      .filter((entry) => entry.vehicle_info_img || entry.vehicle_info_right_img);
  }

  if (!fallbackIcon) return [];

  return [
    {
      vehicle_info_img: fallbackIcon,
      vehicle_info_right_img: fallbackIcon,
      vehicle_info_url: customTrainData.vehicle_info_url || "",
    },
  ];
};