import _ from 'lodash';
import { AnyAction } from 'redux';
import { DataSourceSrv, LocationUpdate } from '@grafana/runtime';

import { stopQueryState, parseUrlState, DEFAULT_RANGE, GetExploreUrlArguments } from 'app/core/utils/explore';
import { ExploreId, ExploreItemState, ExploreState } from 'app/types/explore';
import { updateLocation } from '../../../core/actions';
import { paneReducer, stateSave } from './explorePane';
import { createAction } from '@reduxjs/toolkit';
import { makeExplorePaneState } from './utils';
import { DataQuery, TimeRange } from '@grafana/data';
import { ThunkResult } from '../../../types';
import { getDatasourceSrv } from '../../plugins/datasource_srv';
import { changeDatasource } from './datasource';
import { runQueries, setQueriesAction } from './query';
import { TimeSrv } from '../../dashboard/services/TimeSrv';
import { PanelModel } from 'app/features/dashboard/state';

//
// Actions and Payloads
//

/**
 * Close the split view and save URL state.
 */
export interface SplitCloseActionPayload {
  itemId: ExploreId;
}
export const splitCloseAction = createAction<SplitCloseActionPayload>('explore/splitClose');

/**
 * Open the split view and copy the left state to be the right state.
 * The right state is automatically initialized.
 * The copy keeps all query modifications but wipes the query results.
 */
export interface SplitOpenPayload {
  itemState: ExploreItemState;
}
export const splitOpenAction = createAction<SplitOpenPayload>('explore/splitOpen');

export interface SyncTimesPayload {
  syncedTimes: boolean;
}
export const syncTimesAction = createAction<SyncTimesPayload>('explore/syncTimes');

export const richHistoryUpdatedAction = createAction<any>('explore/richHistoryUpdated');

/**
 * Resets state for explore.
 */
export interface ResetExplorePayload {
  force?: boolean;
}
export const resetExploreAction = createAction<ResetExplorePayload>('explore/resetExplore');

//
// Action creators
//

/**
 * Open the split view and the right state is automatically initialized.
 * If options are specified it initializes that pane with the datasource and query from options.
 * Otherwise it copies the left state to be the right state. The copy keeps all query modifications but wipes the query
 * results.
 */
export function splitOpen<T extends DataQuery = any>(options?: {
  datasourceUid: string;
  query: T;
  // Don't use right now. It's used for Traces to Logs interaction but is hacky in how the range is actually handled.
  range?: TimeRange;
}): ThunkResult<void> {
  return async (dispatch, getState) => {
    // Clone left state to become the right state
    const leftState: ExploreItemState = getState().explore[ExploreId.left];
    const rightState: ExploreItemState = {
      ...leftState,
    };
    const queryState = getState().location.query[ExploreId.left] as string;
    const urlState = parseUrlState(queryState);

    if (options) {
      rightState.queries = [];
      rightState.graphResult = null;
      rightState.logsResult = null;
      rightState.tableResult = null;
      rightState.queryKeys = [];
      urlState.queries = [];
      rightState.urlState = urlState;
      if (options.range) {
        urlState.range = options.range.raw;
        // This is super hacky. In traces to logs we want to create a link but also internally open split window.
        // We use the same range object but the raw part is treated differently because it's parsed differently during
        // init depending on whether we open split or new window.
        rightState.range = {
          ...options.range,
          raw: {
            from: options.range.from.utc().toISOString(),
            to: options.range.to.utc().toISOString(),
          },
        };
      }

      dispatch(splitOpenAction({ itemState: rightState }));

      const queries = [
        {
          ...options.query,
          refId: 'A',
        } as DataQuery,
      ];

      const dataSourceSettings = getDatasourceSrv().getInstanceSettings(options.datasourceUid);

      await dispatch(changeDatasource(ExploreId.right, dataSourceSettings!.name));
      await dispatch(setQueriesAction({ exploreId: ExploreId.right, queries }));
      await dispatch(runQueries(ExploreId.right));
    } else {
      rightState.queries = leftState.queries.slice();
      rightState.urlState = urlState;
      dispatch(splitOpenAction({ itemState: rightState }));
    }

    dispatch(stateSave());
  };
}

/**
 * Close the split view and save URL state.
 */
export function splitClose(itemId: ExploreId): ThunkResult<void> {
  return dispatch => {
    dispatch(splitCloseAction({ itemId }));
    dispatch(stateSave());
  };
}

export interface NavigateToExploreDependencies {
  getDataSourceSrv: () => DataSourceSrv;
  getTimeSrv: () => TimeSrv;
  getExploreUrl: (args: GetExploreUrlArguments) => Promise<string | undefined>;
  openInNewWindow?: (url: string) => void;
}

export const navigateToExplore = (
  panel: PanelModel,
  dependencies: NavigateToExploreDependencies
): ThunkResult<void> => {
  return async dispatch => {
    const { getDataSourceSrv, getTimeSrv, getExploreUrl, openInNewWindow } = dependencies;
    const datasourceSrv = getDataSourceSrv();
    const datasource = await datasourceSrv.get(panel.datasource);
    const path = await getExploreUrl({
      panel,
      panelTargets: panel.targets,
      panelDatasource: datasource,
      datasourceSrv,
      timeSrv: getTimeSrv(),
    });

    if (openInNewWindow && path) {
      openInNewWindow(path);
      return;
    }

    const query = {}; // strips any angular query param
    dispatch(updateLocation({ path, query }));
  };
};

/**
 * Global Explore state that handles multiple Explore areas and the split state
 */
const initialExploreItemState = makeExplorePaneState();
export const initialExploreState: ExploreState = {
  split: false,
  syncedTimes: false,
  left: initialExploreItemState,
  right: initialExploreItemState,
  richHistory: [],
};

/**
 * Global Explore reducer that handles multiple Explore areas (left and right).
 * Actions that have an `exploreId` get routed to the ExploreItemReducer.
 */
export const exploreReducer = (state = initialExploreState, action: AnyAction): ExploreState => {
  if (splitCloseAction.match(action)) {
    const { itemId } = action.payload as SplitCloseActionPayload;
    const targetSplit = {
      left: itemId === ExploreId.left ? state.right : state.left,
      right: initialExploreState.right,
    };
    return {
      ...state,
      ...targetSplit,
      split: false,
    };
  }

  if (splitOpenAction.match(action)) {
    return { ...state, split: true, right: { ...action.payload.itemState } };
  }

  if (syncTimesAction.match(action)) {
    return { ...state, syncedTimes: action.payload.syncedTimes };
  }

  if (richHistoryUpdatedAction.match(action)) {
    return {
      ...state,
      richHistory: action.payload.richHistory,
    };
  }

  if (resetExploreAction.match(action)) {
    const payload: ResetExplorePayload = action.payload;
    const leftState = state[ExploreId.left];
    const rightState = state[ExploreId.right];
    stopQueryState(leftState.querySubscription);
    stopQueryState(rightState.querySubscription);

    if (payload.force || !Number.isInteger(state.left.originPanelId)) {
      return initialExploreState;
    }

    return {
      ...initialExploreState,
      left: {
        ...initialExploreItemState,
        queries: state.left.queries,
        originPanelId: state.left.originPanelId,
      },
    };
  }

  if (updateLocation.match(action)) {
    const payload: LocationUpdate = action.payload;
    const { query } = payload;
    if (!query || !query[ExploreId.left]) {
      return state;
    }

    const split = query[ExploreId.right] ? true : false;
    const leftState = state[ExploreId.left];
    const rightState = state[ExploreId.right];

    return {
      ...state,
      split,
      [ExploreId.left]: updatePaneRefreshState(leftState, payload, ExploreId.left),
      [ExploreId.right]: updatePaneRefreshState(rightState, payload, ExploreId.right),
    };
  }

  if (action.payload) {
    const { exploreId } = action.payload;
    if (exploreId !== undefined) {
      // @ts-ignore
      const explorePaneState = state[exploreId];
      return { ...state, [exploreId]: paneReducer(explorePaneState, action as any) };
    }
  }

  return state;
};

export default {
  explore: exploreReducer,
};

export const updatePaneRefreshState = (
  state: Readonly<ExploreItemState>,
  payload: LocationUpdate,
  exploreId: ExploreId
): ExploreItemState => {
  const path = payload.path || '';
  if (!payload.query) {
    return state;
  }

  const queryState = payload.query[exploreId] as string;
  if (!queryState) {
    return state;
  }

  const urlState = parseUrlState(queryState);
  if (!state.urlState || path !== '/explore') {
    // we only want to refresh when browser back/forward
    return {
      ...state,
      urlState,
      update: { datasource: false, queries: false, range: false, mode: false },
    };
  }

  const datasource = _.isEqual(urlState ? urlState.datasource : '', state.urlState.datasource) === false;
  const queries = _.isEqual(urlState ? urlState.queries : [], state.urlState.queries) === false;
  const range = _.isEqual(urlState ? urlState.range : DEFAULT_RANGE, state.urlState.range) === false;

  return {
    ...state,
    urlState,
    update: {
      ...state.update,
      datasource,
      queries,
      range,
    },
  };
};