import { types } from '../actions/actionTypes';
import { panel_names } from '../utils/Config';
import { createDebugHelpers } from '../utils/debug';

// 디버그 헬퍼 설정
const DEBUG_MODE = false;
const { dlog, dwarn, derror } = createDebugHelpers(DEBUG_MODE);

const initialState = {
  // 기존 상태 - 완전히 호환됨
  panels: [],
  lastPanelAction: '', //"", "push", "pop", "update", "reset", "previewPush", "previewPop", "previewUpdate"
  lastFocusTarget: null, // [251114] 마지막 포커스 대상 (panelName + elementId)

  // [251106] 패널 액션 큐 관련 상태 - 기존 기능에 전혀 영향 없음
  panelActionQueue: [], // 처리 대기 중인 패널 액션 큐
  isProcessingQueue: false, // 현재 큐 처리 중인지 여부
  queueError: null, // 큐 처리 중 발생한 에러
  queueStats: {
    totalProcessed: 0, // 총 처리된 액션 수
    failedCount: 0, // 실패한 액션 수
    averageProcessingTime: 0, // 평균 처리 시간
  },

  // [251106] 비동기 액션 관련 상태
  asyncActions: {}, // 실행 중인 비동기 액션들 { actionId: { ... } }
  completedAsyncActions: [], // 완료된 비동기 액션 ID들
  failedAsyncActions: [], // 실패한 비동기 액션 ID들
};

// last one will be on top
const forceTopPanels = [panel_names.ERROR_PANEL, panel_names.INTRO_PANEL, panel_names.DEBUG_PANEL];

export const panelsReducer = (state = initialState, action) => {
  switch (action.type) {
    case types.PUSH_PANEL: {
      dlog('[panelReducer] 🔵 PUSH_PANEL START', {
        newPanelName: action.payload.name,
        currentPanels: state.panels.map((p) => p.name),
        duplicatable: action.duplicatable,
      });

      const panelInfo = action.payload.panelInfo || {};
      const forceTopPanelsInfo = [];
      const newState = [];

      state.panels.forEach((panel) => {
        const forceTopIndex = forceTopPanels.indexOf(panel.name);

        if (forceTopIndex >= 0) {
          forceTopPanelsInfo[forceTopIndex] = panel;
        } else if (panel.name !== action.payload.name || action.duplicatable) {
          newState.push(panel);
        }
      });

      const newPanelForceTopIndex = forceTopPanels.indexOf(action.payload.name);

      if (newPanelForceTopIndex >= 0) {
        forceTopPanelsInfo[newPanelForceTopIndex] = {
          ...action.payload,
          panelInfo,
        };
      } else {
        newState.push({ ...action.payload, panelInfo });
      }

      forceTopPanels.forEach((_, index) => {
        if (forceTopPanelsInfo[index]) {
          newState.push(forceTopPanelsInfo[index]);
        }
      });

      let lastAction = 'push';
      if (
        action.payload.name === panel_names.PLAYER_PANEL ||
        action.payload.name === panel_names.MEDIA_PANEL
      ) {
        if (action.payload.panelInfo.modal) {
          lastAction = 'previewPush';
        }
      }

      dlog('[panelReducer] 🔵 PUSH_PANEL END', {
        resultPanels: newState.map((p) => p.name),
        lastAction,
      });

      return {
        ...state,
        panels: newState,
        lastPanelAction: lastAction,
      };
    }

    case types.POP_PANEL: {
      dlog('[panelReducer] 🔴 POP_PANEL START', {
        targetPanel: action.payload || 'last_panel',
        currentPanels: state.panels.map((p) => p.name),
      });

      let lastAction = 'pop';
      let resultPanels;

      if (action.payload) {
        if (
          state.lastPanelAction.indexOf('preview') === 0 &&
          (action.payload === panel_names.PLAYER_PANEL ||
            action.payload === panel_names.MEDIA_PANEL)
        ) {
          lastAction = 'previewPop';
        }
        resultPanels = state.panels.filter((panel) => panel.name !== action.payload);
      } else {
        if (state.lastPanelAction.indexOf('preview') === 0) {
          lastAction = 'previewPop';
        }
        resultPanels = state.panels.slice(0, state.panels.length - 1);
      }

      dlog('[panelReducer] 🔴 POP_PANEL END', {
        resultPanels: resultPanels.map((p) => p.name),
        lastAction,
      });

      return {
        ...state,
        panels: resultPanels,
        lastPanelAction: lastAction,
      };
    }
    case types.UPDATE_PANEL: {
      let lastIndex = -1;
      let lastAction = 'update';
      const hasDetailPanel = state.panels.some((p) => p.name === panel_names.DETAIL_PANEL);
      const isPlayerPanel =
        action.payload.name === panel_names.PLAYER_PANEL ||
        action.payload.name === panel_names.PLAYER_PANEL_NEW;
      const existingPanel = state.panels.find((p) => p.name === action.payload.name);
      let nextPanelInfo = action.payload.panelInfo || {};

      // lockModalFalse 플래그 처리: DetailPanel이 스택에 있거나 lock이 이미 true면 modal=true 업데이트를 차단
      if (isPlayerPanel && existingPanel) {
        const lockFlag =
          existingPanel.panelInfo?.lockModalFalse === true || nextPanelInfo.lockModalFalse === true;

        // unlock 명시 시 그대로 진행
        if (nextPanelInfo.lockModalFalse === false) {
          // do nothing
        } else if (lockFlag && nextPanelInfo.modal === true) {
          nextPanelInfo = {
            ...nextPanelInfo,
            modal: false,
            modalContainerId: undefined,
            lockModalFalse: true,
            modalStyle: undefined,
            modalScale: undefined,
            shouldShrinkTo1px: false,
            isHidden: false,
          };
        } else if (lockFlag && nextPanelInfo.modal === undefined && hasDetailPanel) {
          nextPanelInfo = {
            ...nextPanelInfo,
            modal:
              existingPanel.panelInfo?.modal === true ? false : existingPanel.panelInfo?.modal,
            modalContainerId:
              existingPanel.panelInfo?.modal === true
                ? undefined
                : existingPanel.panelInfo?.modalContainerId,
            lockModalFalse: true,
            modalStyle: existingPanel.panelInfo?.modal === true ? undefined : nextPanelInfo.modalStyle,
            modalScale: existingPanel.panelInfo?.modal === true ? undefined : nextPanelInfo.modalScale,
            shouldShrinkTo1px: false,
            isHidden: false,
          };
        } else if (hasDetailPanel && nextPanelInfo.modal === true) {
          // DetailPanel 존재 시 modal=true 업데이트 차단
          nextPanelInfo = {
            ...nextPanelInfo,
            modal: false,
            modalContainerId: undefined,
            modalStyle: undefined,
            modalScale: undefined,
            shouldShrinkTo1px: false,
            isHidden: false,
          };
        }
      }
      // 배열의 끝에서부터 시작하여 조건에 맞는 마지막 인덱스 찾기
      for (let i = state.panels.length - 1; i >= 0; i--) {
        if (state.panels[i].name === action.payload.name) {
          lastIndex = i;
          break; // 조건에 맞는 첫 번째 요소를 찾으면 루프 종료
        }
      }
      const newPanels = state.panels.map((panel, index) =>
        index === lastIndex
          ? {
              ...panel,
              panelInfo: { ...panel.panelInfo, ...nextPanelInfo },
            }
          : panel
      );
      if (newPanels.length > 0) {
        const lastPanel = newPanels[newPanels.length - 1];
        if (
          (lastPanel.name === panel_names.PLAYER_PANEL ||
            lastPanel.name === panel_names.MEDIA_PANEL) &&
          lastPanel.panelInfo.modal
        ) {
          lastAction = 'previewUpdate';
        }
      }
      return {
        ...state,
        panels: newPanels,
        lastPanelAction: lastAction,
      };
    }
    case types.RESET_PANELS: {
      dlog('[panelReducer] 🟢 RESET_PANELS START', {
        currentPanels: state.panels.map((p) => p.name),
        payloadProvided: !!action.payload,
      });

      const updatedPanels = action.payload
        ? action.payload.map((panel) => ({
            ...panel,
            panelInfo: panel.panelInfo || {},
          }))
        : [];

      dlog('[panelReducer] 🟢 RESET_PANELS END', {
        resultPanels: updatedPanels.map((p) => p.name),
      });

      return {
        ...state,
        panels: updatedPanels,
        lastPanelAction: 'reset',
      };
    }

    // [251106] 패널 액션 큐 관련 reducer 케이스들
    case types.ENQUEUE_PANEL_ACTION: {
      dlog('[panelReducer] 🟠 ENQUEUE_PANEL_ACTION', {
        action: action.payload.action,
        queueId: action.payload.id,
        currentQueueLength: state.panelActionQueue.length,
      });

      const newQueueItem = action.payload;
      const updatedQueue = [...state.panelActionQueue, newQueueItem];

      return {
        ...state,
        panelActionQueue: updatedQueue,
        queueError: null, // 에러 초기화
      };
    }

    case types.PROCESS_PANEL_QUEUE: {
      dlog('[panelReducer] 🟡 PROCESS_PANEL_QUEUE', {
        isProcessing: state.isProcessingQueue,
        queueLength: state.panelActionQueue.length,
      });

      // 이미 처리 중이거나 큐가 비어있으면 아무것도 하지 않음
      if (state.isProcessingQueue || state.panelActionQueue.length === 0) {
        return state;
      }

      // 큐의 첫 번째 아이템을 가져옴
      const firstQueueItem = state.panelActionQueue[0];
      const remainingQueue = state.panelActionQueue.slice(1);

      dlog('[panelReducer] 🟡 PROCESSING_QUEUE_ITEM', {
        action: firstQueueItem.action,
        queueId: firstQueueItem.id,
        remainingQueueLength: remainingQueue.length,
      });

      // 실제 패널 액션을 실행하여 새로운 상태 계산
      let newState = state;
      const startTime = Date.now();

      try {
        switch (firstQueueItem.action) {
          case 'PUSH_PANEL': {
            const mockAction = {
              type: types.PUSH_PANEL,
              payload: firstQueueItem.panel,
              duplicatable: firstQueueItem.duplicatable,
            };
            newState = panelsReducer(state, mockAction);
            break;
          }
          case 'POP_PANEL': {
            const mockAction = {
              type: types.POP_PANEL,
              payload: firstQueueItem.panelName,
            };
            newState = panelsReducer(state, mockAction);
            break;
          }
          case 'UPDATE_PANEL': {
            const mockAction = {
              type: types.UPDATE_PANEL,
              payload: firstQueueItem.panelInfo,
            };
            newState = panelsReducer(state, mockAction);
            break;
          }
          case 'RESET_PANELS': {
            const mockAction = {
              type: types.RESET_PANELS,
              payload: firstQueueItem.panels,
            };
            newState = panelsReducer(state, mockAction);
            break;
          }
          default:
            dwarn('[panelReducer] ⚠️ UNKNOWN_QUEUE_ACTION', firstQueueItem.action);
            newState = state;
        }

        const processingTime = Date.now() - startTime;
        const newTotalProcessed = state.queueStats.totalProcessed + 1;
        const newAverageTime =
          (state.queueStats.averageProcessingTime * state.queueStats.totalProcessed +
            processingTime) /
          newTotalProcessed;

        dlog('[panelReducer] ✅ QUEUE_ITEM_PROCESSED', {
          action: firstQueueItem.action,
          queueId: firstQueueItem.id,
          processingTime,
          newTotalProcessed,
        });

        return {
          ...newState,
          panelActionQueue: remainingQueue,
          isProcessingQueue: remainingQueue.length > 0,
          queueStats: {
            ...newState.queueStats,
            totalProcessed: newTotalProcessed,
            averageProcessingTime: Math.round(newAverageTime * 100) / 100,
          },
        };
      } catch (error) {
        derror('[panelReducer] ❌ QUEUE_PROCESSING_ERROR', {
          action: firstQueueItem.action,
          queueId: firstQueueItem.id,
          error: error.message,
        });

        return {
          ...state,
          panelActionQueue: remainingQueue,
          isProcessingQueue: remainingQueue.length > 0,
          queueError: {
            action: firstQueueItem.action,
            queueId: firstQueueItem.id,
            error: error.message,
            timestamp: Date.now(),
          },
          queueStats: {
            ...state.queueStats,
            failedCount: state.queueStats.failedCount + 1,
          },
        };
      }
    }

    case types.CLEAR_PANEL_QUEUE: {
      dlog('[panelReducer] 🔵 CLEAR_PANEL_QUEUE', {
        currentQueueLength: state.panelActionQueue.length,
      });

      return {
        ...state,
        panelActionQueue: [],
        isProcessingQueue: false,
        queueError: null,
      };
    }

    case types.SET_QUEUE_PROCESSING: {
      dlog('[panelReducer] 🟣 SET_QUEUE_PROCESSING', {
        isProcessing: action.payload.isProcessing,
        queueLength: state.panelActionQueue.length,
      });

      return {
        ...state,
        isProcessingQueue: action.payload.isProcessing,
      };
    }

    // [251106] 비동기 패널 액션 관련 reducer 케이스들
    case types.ENQUEUE_ASYNC_PANEL_ACTION: {
      dlog('[panelReducer] 🟠 ENQUEUE_ASYNC_PANEL_ACTION', {
        actionId: action.payload.id,
        timestamp: action.payload.timestamp,
      });

      return {
        ...state,
        asyncActions: {
          ...state.asyncActions,
          [action.payload.id]: {
            ...action.payload,
            status: 'running',
            startTime: Date.now(),
          },
        },
        queueError: null, // 에러 초기화
      };
    }

    case types.COMPLETE_ASYNC_PANEL_ACTION: {
      dlog('[panelReducer] ✅ COMPLETE_ASYNC_PANEL_ACTION', {
        actionId: action.payload.actionId,
        timestamp: action.payload.timestamp,
      });

      const asyncAction = state.asyncActions[action.payload.actionId];
      const executionTime = asyncAction ? Date.now() - asyncAction.startTime : 0;

      // 실행 중인 액션에서 제거하고 완료된 액션에 추가
      const newAsyncActions = { ...state.asyncActions };
      delete newAsyncActions[action.payload.actionId];

      return {
        ...state,
        asyncActions: newAsyncActions,
        completedAsyncActions: [
          ...state.completedAsyncActions,
          {
            actionId: action.payload.actionId,
            result: action.payload.result,
            executionTime,
            completedAt: action.payload.timestamp,
          },
        ].slice(-100), // 최근 100개만 유지
        queueError: null,
        queueStats: {
          ...state.queueStats,
          totalProcessed: state.queueStats.totalProcessed + 1,
          averageProcessingTime:
            Math.round(
              ((state.queueStats.averageProcessingTime * state.queueStats.totalProcessed +
                executionTime) /
                (state.queueStats.totalProcessed + 1)) *
                100
            ) / 100,
        },
      };
    }

    case types.FAIL_ASYNC_PANEL_ACTION: {
      derror('[panelReducer] ❌ FAIL_ASYNC_PANEL_ACTION', {
        actionId: action.payload.actionId,
        error: action.payload.error?.message || 'Unknown error',
        timestamp: action.payload.timestamp,
      });

      const asyncAction = state.asyncActions[action.payload.actionId];
      const executionTime = asyncAction ? Date.now() - asyncAction.startTime : 0;

      // 실행 중인 액션에서 제거하고 실패한 액션에 추가
      const newAsyncActions = { ...state.asyncActions };
      delete newAsyncActions[action.payload.actionId];

      return {
        ...state,
        asyncActions: newAsyncActions,
        failedAsyncActions: [
          ...state.failedAsyncActions,
          {
            actionId: action.payload.actionId,
            error: action.payload.error,
            executionTime,
            failedAt: action.payload.timestamp,
          },
        ].slice(-100), // 최근 100개만 유지
        queueError: {
          actionId: action.payload.actionId,
          error: action.payload.error,
          timestamp: action.payload.timestamp,
        },
        queueStats: {
          ...state.queueStats,
          failedCount: state.queueStats.failedCount + 1,
        },
      };
    }

    // [251114] 명시적 포커스 이동
    case types.FOCUS_PANEL: {
      dlog('[panelReducer] 🎯 FOCUS_PANEL', {
        panelName: action.payload.panelName,
        focusTarget: action.payload.focusTarget,
        timestamp: action.payload.timestamp,
      });

      return {
        ...state,
        lastFocusTarget: {
          panelName: action.payload.panelName,
          focusTarget: action.payload.focusTarget,
          timestamp: action.payload.timestamp,
        },
      };
    }

    default:
      return state;
  }
};