import {
  actionChannel,
  call,
  fork,
  put,
  select,
  take,
} from "redux-saga/effects";

import {
  EvaluationReduxAction,
  ReduxAction,
  ReduxActionTypes,
  ReduxActionWithoutPayload,
} from "constants/ReduxActionConstants";
import {
  getDataTree,
  getUnevaluatedDataTree,
} from "selectors/dataTreeSelectors";
import WidgetFactory, { WidgetTypeConfigMap } from "../utils/WidgetFactory";
import { GracefulWorkerService } from "utils/WorkerUtil";
import Worker from "worker-loader!../workers/evaluation.worker";
import { EVAL_WORKER_ACTIONS } from "utils/DynamicBindingUtils";
import log from "loglevel";
import { WidgetProps } from "widgets/BaseWidget";
import PerformanceTracker, {
  PerformanceTransactionName,
} from "../utils/PerformanceTracker";
import * as Sentry from "@sentry/react";
import { Action } from "redux";
import {
  EVALUATE_REDUX_ACTIONS,
  FIRST_EVAL_REDUX_ACTIONS,
  setDependencyMap,
  setEvaluatedTree,
  shouldProcessBatchedAction,
} from "actions/evaluationActions";
import {
  evalErrorHandler,
  logSuccessfulBindings,
  postEvalActionDispatcher,
  updateTernDefinitions,
} from "./PostEvaluationSagas";
import { getAppMode } from "selectors/applicationSelectors";
import { APP_MODE } from "entities/App";
import { diff } from "deep-diff";

let widgetTypeConfigMap: WidgetTypeConfigMap;

const worker = new GracefulWorkerService(Worker);

function* evaluateTreeSaga(
  postEvalActions?: Array<ReduxAction<unknown> | ReduxActionWithoutPayload>,
) {
  const unevalTree = yield select(getUnevaluatedDataTree);
  log.debug({ unevalTree });
  PerformanceTracker.startAsyncTracking(
    PerformanceTransactionName.DATA_TREE_EVALUATION,
  );
  const workerResponse = yield call(
    worker.request,
    EVAL_WORKER_ACTIONS.EVAL_TREE,
    {
      unevalTree,
      widgetTypeConfigMap,
    },
  );
  const {
    dataTree,
    dependencies,
    errors,
    evaluationOrder,
    logs,
    unEvalUpdates,
  } = workerResponse;
  PerformanceTracker.stopAsyncTracking(
    PerformanceTransactionName.DATA_TREE_EVALUATION,
  );
  PerformanceTracker.startAsyncTracking(
    PerformanceTransactionName.SET_EVALUATED_TREE,
  );
  const oldDataTree = yield select(getDataTree);

  const updates = diff(oldDataTree, dataTree) || [];

  yield put(setEvaluatedTree(dataTree, updates));
  PerformanceTracker.stopAsyncTracking(
    PerformanceTransactionName.SET_EVALUATED_TREE,
  );

  const updatedDataTree = yield select(getDataTree);

  log.debug({ dataTree: updatedDataTree });
  logs.forEach((evalLog: any) => log.debug(evalLog));
  yield call(evalErrorHandler, errors, updatedDataTree, evaluationOrder);
  const appMode = yield select(getAppMode);
  if (appMode !== APP_MODE.PUBLISHED) {
    yield fork(
      logSuccessfulBindings,
      unevalTree,
      updatedDataTree,
      evaluationOrder,
    );

    yield fork(updateTernDefinitions, updatedDataTree, unEvalUpdates);
  }

  yield put(setDependencyMap(dependencies));
  if (postEvalActions && postEvalActions.length) {
    yield call(postEvalActionDispatcher, postEvalActions);
  }
}

export function* evaluateActionBindings(
  bindings: string[],
  executionParams: Record<string, any> | string = {},
) {
  const workerResponse = yield call(
    worker.request,
    EVAL_WORKER_ACTIONS.EVAL_ACTION_BINDINGS,
    {
      bindings,
      executionParams,
    },
  );

  const { errors, values } = workerResponse;

  yield call(evalErrorHandler, errors);
  return values;
}

export function* evaluateDynamicTrigger(
  dynamicTrigger: string,
  callbackData?: Array<any>,
) {
  const unEvalTree = yield select(getUnevaluatedDataTree);

  const workerResponse = yield call(
    worker.request,
    EVAL_WORKER_ACTIONS.EVAL_TRIGGER,
    { dataTree: unEvalTree, dynamicTrigger, callbackData },
  );

  const { errors, triggers } = workerResponse;
  yield call(evalErrorHandler, errors);
  return triggers;
}

export function* clearEvalCache() {
  yield call(worker.request, EVAL_WORKER_ACTIONS.CLEAR_CACHE);

  return true;
}

export function* clearEvalPropertyCache(propertyPath: string) {
  yield call(worker.request, EVAL_WORKER_ACTIONS.CLEAR_PROPERTY_CACHE, {
    propertyPath,
  });
}

/**
 * clears all cache keys of a widget
 *
 * @param widgetName
 */
export function* clearEvalPropertyCacheOfWidget(widgetName: string) {
  yield call(
    worker.request,
    EVAL_WORKER_ACTIONS.CLEAR_PROPERTY_CACHE_OF_WIDGET,
    {
      widgetName,
    },
  );
}

export function* validateProperty(
  property: string,
  value: any,
  props: WidgetProps,
) {
  const unevalTree = yield select(getUnevaluatedDataTree);
  const validation = unevalTree[props.widgetName].validationPaths[property];
  return yield call(worker.request, EVAL_WORKER_ACTIONS.VALIDATE_PROPERTY, {
    property,
    value,
    props,
    validation,
  });
}

function evalQueueBuffer() {
  let canTake = false;
  let postEvalActions: any = [];
  const take = () => {
    if (canTake) {
      const resp = postEvalActions;
      postEvalActions = [];
      canTake = false;
      return { postEvalActions: resp, type: "BUFFERED_ACTION" };
    }
  };
  const flush = () => {
    if (canTake) {
      return [take() as Action];
    }

    return [];
  };

  const put = (action: EvaluationReduxAction<unknown | unknown[]>) => {
    if (!shouldProcessBatchedAction(action)) {
      return;
    }
    canTake = true;

    // TODO: If the action is the same as before, we can send only one and ignore duplicates.
    if (action.postEvalActions) {
      postEvalActions.push(...action.postEvalActions);
    }
  };

  return {
    take,
    put,
    isEmpty: () => {
      return !canTake;
    },
    flush,
  };
}

function* evaluationChangeListenerSaga() {
  // Explicitly shutdown old worker if present
  yield call(worker.shutdown);
  yield call(worker.start);
  widgetTypeConfigMap = WidgetFactory.getWidgetTypeConfigMap();
  const initAction = yield take(FIRST_EVAL_REDUX_ACTIONS);
  yield fork(evaluateTreeSaga, initAction.postEvalActions);
  const evtActionChannel = yield actionChannel(
    EVALUATE_REDUX_ACTIONS,
    evalQueueBuffer(),
  );
  while (true) {
    const action: EvaluationReduxAction<unknown | unknown[]> = yield take(
      evtActionChannel,
    );
    if (shouldProcessBatchedAction(action)) {
      yield call(evaluateTreeSaga, action.postEvalActions);
    }
  }
}

export default function* evaluationSagaListeners() {
  yield take(ReduxActionTypes.START_EVALUATION);
  while (true) {
    try {
      yield call(evaluationChangeListenerSaga);
    } catch (e) {
      log.error(e);
      Sentry.captureException(e);
    }
  }
}