/**
 * useAppFlow
 * アプリ全体の画面遷移と参加フロー状態を管理するフック
 * 参加要求の成功失敗と接続状態を統合してシーンへ渡す
 */
import { useCallback, useReducer, useRef } from "react";
import { socketManager } from "@client/network/SocketManager";
import { domain } from "@repo/shared";
import { config } from "@client/config";
import type { GameResultPayload } from "@repo/shared";
import {
  appFlowReducer,
  initialAppFlowData,
} from "./application/appFlowReducer";
import { useSocketSubscriptions } from "./useSocketSubscriptions";

/** アプリフロー管理フックの公開状態と操作を表す型 */
type AppFlowState = {
  scenePhase: domain.app.ScenePhaseType;
  room: domain.room.Room | null;
  myId: string | null;
  gameResult: GameResultPayload | null;
  joinErrorMessage: string | null;
  isJoining: boolean;
  requestJoin: (payload: domain.room.JoinRoomPayload) => void;
  returnToTitle: (options?: { leaveRoom?: boolean }) => void;
};

type JoinState = {
  isJoining: boolean;
  joinFailure: JoinFailure | null;
};

type JoinFailureReason =
  | domain.room.JoinRoomRejectedPayload["reason"]
  | "timeout";

type JoinFailure = {
  reason: JoinFailureReason;
  roomId?: string;
};

type JoinAction =
  | { type: "start" }
  | { type: "complete"; joinFailure: JoinFailure | null };

const initialJoinState: JoinState = {
  isJoining: false,
  joinFailure: null,
};

const joinReducer = (state: JoinState, action: JoinAction): JoinState => {
  if (action.type === "start") {
    return {
      isJoining: true,
      joinFailure: null,
    };
  }

  if (action.type === "complete") {
    return {
      isJoining: false,
      joinFailure: action.joinFailure,
    };
  }

  return state;
};

/** アプリ全体のシーン状態と参加要求フローを管理するフック */
export const useAppFlow = (): AppFlowState => {
  const [appFlow, dispatchAppFlow] = useReducer(
    appFlowReducer,
    initialAppFlowData,
  );
  const [joinState, dispatchJoin] = useReducer(joinReducer, initialJoinState);
  const joinTimeoutRef = useRef<ReturnType<typeof setTimeout> | null>(null);
  const joinRejectedHandlerRef = useRef<
    ((payload: domain.room.JoinRoomRejectedPayload) => void) | null
  >(null);

  const clearJoinRejectedHandler = useCallback(() => {
    if (!joinRejectedHandlerRef.current) {
      return;
    }

    socketManager.title.offJoinRejected(joinRejectedHandlerRef.current);
    joinRejectedHandlerRef.current = null;
  }, []);

  const clearJoinTimeout = useCallback(() => {
    if (!joinTimeoutRef.current) {
      return;
    }

    clearTimeout(joinTimeoutRef.current);
    joinTimeoutRef.current = null;
  }, []);

  const completeJoinRequest = useCallback(
    (joinFailure: JoinFailure | null = null) => {
      clearJoinTimeout();
      clearJoinRejectedHandler();
      dispatchJoin({ type: "complete", joinFailure });
    },
    [clearJoinRejectedHandler, clearJoinTimeout],
  );

  const getJoinErrorMessage = useCallback(
    (joinFailure: JoinFailure | null): string | null => {
      if (!joinFailure) {
        return null;
      }

      if (joinFailure.reason === "full") {
        return `ルーム ${joinFailure.roomId ?? ""} は満員です`;
      }

      if (joinFailure.reason === "duplicate") {
        return `ルーム ${joinFailure.roomId ?? ""} への参加要求が重複しました`;
      }

      if (joinFailure.reason === "timeout") {
        return "参加要求がタイムアウトしました，もう一度お試しください";
      }

      return null;
    },
    [],
  );

  const requestJoin = useCallback(
    (payload: domain.room.JoinRoomPayload) => {
      if (joinState.isJoining) {
        return;
      }

      completeJoinRequest();
      dispatchJoin({ type: "start" });

      const handleJoinRejected = (
        payload: domain.room.JoinRoomRejectedPayload,
      ) => {
        completeJoinRequest({
          reason: payload.reason,
          roomId: payload.roomId,
        });
      };

      joinRejectedHandlerRef.current = handleJoinRejected;
      socketManager.title.onceJoinRejected(handleJoinRejected);

      joinTimeoutRef.current = setTimeout(() => {
        completeJoinRequest({ reason: "timeout" });
      }, config.GAME_CONFIG.JOIN_REQUEST_TIMEOUT_MS);

      socketManager.title.joinRoom(payload);
    },
    [completeJoinRequest, joinState.isJoining],
  );

  const returnToTitle = useCallback(
    (options?: { leaveRoom?: boolean }) => {
      completeJoinRequest();
      dispatchAppFlow({
        type: "resetToTitle",
        clearMyId: Boolean(options?.leaveRoom),
      });

      if (!options?.leaveRoom) {
        return;
      }

      socketManager.socket.disconnect();
      socketManager.socket.connect();
    },
    [completeJoinRequest],
  );

  useSocketSubscriptions({
    completeJoinRequest,
    dispatchAppFlow,
  });

  return {
    scenePhase: appFlow.scenePhase,
    room: appFlow.room,
    myId: appFlow.myId,
    gameResult: appFlow.gameResult,
    joinErrorMessage: getJoinErrorMessage(joinState.joinFailure),
    isJoining: joinState.isJoining,
    requestJoin,
    returnToTitle,
  };
};