import type { ActionPattern } from "redux-saga/effects";
import { call, take, select, put, actionChannel } from "redux-saga/effects";
import type { ReduxAction } from "@appsmith/constants/ReduxActionConstants";
import { ReduxActionTypes } from "@appsmith/constants/ReduxActionConstants";
import log from "loglevel";
import * as Sentry from "@sentry/react";
import { getFormEvaluationState } from "selectors/formSelectors";
import { evalFormConfig } from "./EvaluationsSaga";
import type {
  ConditionalOutput,
  DynamicValues,
  FormEvaluationState,
} from "reducers/evaluationReducers/formEvaluationReducer";
import { FORM_EVALUATION_REDUX_ACTIONS } from "@appsmith/actions/evaluationActions";
import type { Action, ActionConfig } from "entities/Action";
import type { FormConfigType } from "components/formControls/BaseControl";
import PluginsApi from "api/PluginApi";
import type { ApiResponse } from "api/ApiResponses";
import { getAction } from "@appsmith/selectors/entitiesSelector";
import { getDataTreeActionConfigPath } from "entities/Action/actionProperties";
import { getDataTree } from "selectors/dataTreeSelectors";
import { getDynamicBindings, isDynamicValue } from "utils/DynamicBindingUtils";
import get from "lodash/get";
import { klona } from "klona/lite";
import type { DataTree } from "@appsmith/entities/DataTree/types";
import {
  extractFetchDynamicValueFormConfigs,
  extractQueueOfValuesToBeFetched,
} from "./helper";
import type { DatasourceConfiguration } from "entities/Datasource";
import { buffers } from "redux-saga";

export type FormEvalActionPayload = {
  formId: string;
  datasourceId?: string;
  pluginId?: string;
  actionConfiguration?: ActionConfig;
  editorConfig?: FormConfigType[];
  settingConfig?: FormConfigType[];
  actionDiffPath?: string;
  hasRouteChanged?: boolean;
  datasourceConfiguration?: DatasourceConfiguration;
};

// This value holds an array of values that needs to be dynamically fetched
// when we run form evaluations we store dynamic values to be fetched in this array
// and when evaluations are finally done, we pick the last dynamic values and call it.

function* setFormEvaluationSagaAsync(
  action: ReduxAction<FormEvalActionPayload>,
): any {
  try {
    // Get current state from redux
    const currentEvalState: FormEvaluationState = yield select(
      getFormEvaluationState,
    );
    // Trigger the worker to compute the new eval state
    const workerResponse = yield call(evalFormConfig, {
      ...action,
      currentEvalState,
    });

    if (action?.type === ReduxActionTypes.INIT_FORM_EVALUATION) {
      const fetchDynamicValueFormConfigs = extractFetchDynamicValueFormConfigs(
        workerResponse[action?.payload?.formId],
      );
      yield put({
        type: ReduxActionTypes.INIT_TRIGGER_VALUES,
        payload: {
          [action?.payload?.formId]: klona(fetchDynamicValueFormConfigs),
        },
      });
    }
    // RUN_FORM_EVALUATION shouldn't be called before INIT_FORM_EVALUATION has been called with
    // the same `formId` else `extractQueueOfValuesToBeFetched` will be sent an undefined value.
    let queueOfValuesToBeFetched;
    if (
      action?.type === ReduxActionTypes.RUN_FORM_EVALUATION &&
      workerResponse[action?.payload?.formId]
    ) {
      queueOfValuesToBeFetched = extractQueueOfValuesToBeFetched(
        workerResponse[action?.payload?.formId],
      );
    }

    // Update the eval state in redux only if it is not empty
    if (workerResponse) {
      yield put({
        type: ReduxActionTypes.SET_FORM_EVALUATION,
        payload: workerResponse,
      });
    }
    // If there are any actions in the queue, run them
    // Once all the actions are done, extract the actions that need to be fetched dynamically
    const formId = action.payload.formId;
    const evalOutput = workerResponse[formId];
    if (evalOutput && typeof evalOutput === "object") {
      if (queueOfValuesToBeFetched) {
        yield put({
          type: ReduxActionTypes.FETCH_TRIGGER_VALUES_INIT,
          payload: {
            formId,
            values: queueOfValuesToBeFetched,
          },
        });

        // Pass the queue to the saga to fetch the dynamic values
        yield call(
          fetchDynamicValuesSaga,
          queueOfValuesToBeFetched,
          formId,
          action.payload.datasourceId ? action.payload.datasourceId : "",
          action.payload.pluginId ? action.payload.pluginId : "",
        );
      }
    }
  } catch (e) {
    log.error(e);
  }
}

// Function to fetch the dynamic values one by one from the queue
export function* fetchDynamicValuesSaga(
  queueOfValuesToBeFetched: Record<string, ConditionalOutput>,
  formId: string,
  datasourceId: string,
  pluginId: string,
) {
  for (const key of Object.keys(queueOfValuesToBeFetched)) {
    queueOfValuesToBeFetched[key].fetchDynamicValues = yield call(
      fetchDynamicValueSaga,
      queueOfValuesToBeFetched[key],
      Object.assign(
        {},
        queueOfValuesToBeFetched[key].fetchDynamicValues as DynamicValues,
      ),
      formId,
      datasourceId,
      pluginId,
      key,
    );
  }

  // Set the values to the state once all values are fetched
  yield put({
    type: ReduxActionTypes.FETCH_TRIGGER_VALUES_SUCCESS,
    payload: {
      formId,
      values: queueOfValuesToBeFetched,
    },
  });
}

function* fetchDynamicValueSaga(
  value: ConditionalOutput,
  dynamicFetchedValues: DynamicValues,
  actionId: string,
  datasourceId: string,
  pluginId: string,
  configProperty: string,
) {
  try {
    const { config, evaluatedConfig } =
      value.fetchDynamicValues as DynamicValues;
    const { params } = evaluatedConfig;

    dynamicFetchedValues.hasStarted = true;

    let url = PluginsApi.defaultDynamicTriggerURL(datasourceId);

    if (
      "url" in evaluatedConfig &&
      !!evaluatedConfig.url &&
      evaluatedConfig.url.length > 0
    )
      url = evaluatedConfig.url;

    // Eval Action is the current action as it is stored in the dataTree
    let evalAction: any;
    // Evaluated params is the object that will hold the evaluated values of the parameters as computed in the dataTree
    let evaluatedParams;
    // this is a temporary variable, used to derive the evaluated value of the current parameters before being stored in the evaluated params
    let substitutedParameters = {};

    const action: Action = yield select(getAction, actionId);
    const dataTree: DataTree = yield select(getDataTree);

    if (!!action) {
      evalAction = dataTree[action.name];
    }

    // we use the config parameters to get the action diff path value of the parameters i.e. {{actionConfiguration.formData.sheetUrl.data}. Note that it is enclosed within dynamic bindings
    if ("parameters" in config?.params && !!evalAction) {
      Object.entries(config?.params.parameters).forEach(([key, value]) => {
        // we extract the action diff path of the param value from the dynamic binding i.e. actionConfiguration.formData.sheetUrl.data
        const dynamicBindingValue = getDynamicBindings(value as string)
          ?.jsSnippets[0];
        // we convert this action Diff path into the same format as it is stored in the dataTree i.e. config.formData.sheetUrl.data
        const dataTreeActionConfigPath =
          getDataTreeActionConfigPath(dynamicBindingValue);
        // then we get the value of the current parameter from the evaluatedValues in the action object stored in the dataTree.
        const evaluatedValue = get(
          evalAction?.__evaluation__?.evaluatedValues,
          dataTreeActionConfigPath,
        );
        // if it exists, we store it in the substituted params object.
        // we check if that value is enclosed in dynamic bindings i.e the value has not been evaluated or somehow still contains a js expression
        // if it is, we return an empty string since we don't want to send dynamic bindings to the server.
        // if it contains a value, we send the value to the server
        if (!!evaluatedValue) {
          substitutedParameters = {
            ...substitutedParameters,
            [key]: isDynamicValue(evaluatedValue) ? "" : evaluatedValue,
          };
        }
      });
    }

    // we destructure the values back to the appropriate places.
    if ("parameters" in params) {
      evaluatedParams = {
        ...params,
        parameters: {
          ...params.parameters,
          ...substitutedParameters,
        },
      };
    } else {
      evaluatedParams = {
        ...params,
      };
    }

    // Call the API to fetch the dynamic values
    const response: ApiResponse<{ trigger?: unknown }> = yield call(
      PluginsApi.fetchDynamicFormValues,
      url,
      {
        actionId,
        configProperty,
        datasourceId,
        pluginId,
        ...evaluatedParams,
      },
    );
    dynamicFetchedValues.isLoading = false;
    if (response.responseMeta.status === 200 && "trigger" in response.data) {
      dynamicFetchedValues.data = response.data.trigger;
      dynamicFetchedValues.hasFetchFailed = false;
    } else {
      dynamicFetchedValues.hasFetchFailed = true;
      dynamicFetchedValues.data = [];
    }
  } catch (e) {
    log.error(e);
    dynamicFetchedValues.hasFetchFailed = true;
    dynamicFetchedValues.isLoading = false;
    dynamicFetchedValues.data = [];
  }
  return dynamicFetchedValues;
}

function* formEvaluationChangeListenerSaga() {
  const buffer = buffers.fixed();
  const formEvalChannel: ActionPattern<ReduxAction<FormEvalActionPayload>> =
    yield actionChannel(FORM_EVALUATION_REDUX_ACTIONS, buffer as any);
  while (true) {
    if (buffer.isEmpty()) {
      yield put({
        type: ReduxActionTypes.FORM_EVALUATION_EMPTY_BUFFER,
      });
    }
    const action: ReduxAction<FormEvalActionPayload> = yield take(
      formEvalChannel,
    );
    yield call(setFormEvaluationSagaAsync, action);
  }
}

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