import React, { useMemo } from 'react';
import { useSelector } from 'react-redux';
import PropTypes from 'prop-types';
import { ToolbarButton } from '@ohif/ui';
import { utils } from '@ohif/core';
import { createSelector } from 'reselect';
const { studyMetadataManager } = utils;

const _isDisplaySetReconstructable = (
  displaySetInstanceUID = '',
  StudyInstanceUID = ''
) => {
  if (displaySetInstanceUID == '' || StudyInstanceUID == '') {
    return false;
  }

  const studies = studyMetadataManager.all();

  const study = studies.find(
    study => study.studyInstanceUID === StudyInstanceUID
  );

  if (!study) {
    return false;
  }

  const displaySet = study._displaySets.find(
    set => set.displaySetInstanceUID === displaySetInstanceUID
  );

  if (!displaySet) {
    return false;
  }

  // 2D MPR is not currently available for 4D datasets.

  // Assuming that slices at different time have the same position, here we just check if
  // there are multiple slices for the same ImagePositionPatient and disable MPR.

  // A better heuristic would be checking 4D tags, e.g. the presence of multiple TemporalPositionIdentifier values.
  // However, some studies (e.g. https://github.com/OHIF/Viewers/issues/2113) do not have such tags.

  for (let ii = 0; ii < displaySet.numImageFrames; ++ii) {
    const image = displaySet.images[ii];
    if (!image) continue;

    const imageIdControl = image.getImageId();
    const instanceMetadataControl = cornerstone.metaData.get(
      'instance',
      imageIdControl
    );

    if (
      !instanceMetadataControl ||
      instanceMetadataControl === undefined ||
      !instanceMetadataControl.ImagePositionPatient ||
      instanceMetadataControl.ImagePositionPatient === undefined
    ) {
      // if ImagePositionPatient is missing, skip the 4D datasets check.
      // do not return false, because it could be a 3D dataset.
      continue;
    }

    let xImagePositionPatientControl =
      instanceMetadataControl.ImagePositionPatient[0];
    let yImagePositionPatientControl =
      instanceMetadataControl.ImagePositionPatient[1];
    let zImagePositionPatientControl =
      instanceMetadataControl.ImagePositionPatient[2];

    for (let jj = ii + 1; jj < displaySet.numImageFrames; ++jj) {
      const image = displaySet.images[jj];
      if (!image) continue;

      const imageId = image.getImageId();
      const instanceMetadata = cornerstone.metaData.get('instance', imageId);

      if (
        !instanceMetadata ||
        instanceMetadata === undefined ||
        !instanceMetadata.ImagePositionPatient ||
        instanceMetadata.ImagePositionPatient === undefined
      ) {
        // if ImagePositionPatient is missing, skip the 4D datasets check.
        // do not return false, because it could be a 3D dataset.
        continue;
      }

      let xImagePositionPatient = instanceMetadata.ImagePositionPatient[0];
      let yImagePositionPatient = instanceMetadata.ImagePositionPatient[1];
      let zImagePositionPatient = instanceMetadata.ImagePositionPatient[2];

      // ImagePositionPatient is float
      if (
        Math.abs( xImagePositionPatientControl - xImagePositionPatient ) < 1e-6 &&
        Math.abs( yImagePositionPatientControl - yImagePositionPatient ) < 1e-6 &&
        Math.abs( zImagePositionPatientControl - zImagePositionPatient ) < 1e-6
      ) {
        return false;
      }
    }
  }

  return displaySet.isReconstructable;
};

const selectDisplaySetInstanceUID = state => {
  if (
    state.viewports.viewportSpecificData[state.viewports.activeViewportIndex]
  ) {
    return state.viewports.viewportSpecificData[
      state.viewports.activeViewportIndex
    ].displaySetInstanceUID;
  } else {
    return '';
  }
};

const selectStudyInstanceUID = state => {
  if (
    state.viewports.viewportSpecificData[state.viewports.activeViewportIndex]
  ) {
    return state.viewports.viewportSpecificData[
      state.viewports.activeViewportIndex
    ].StudyInstanceUID;
  } else {
    return '';
  }
};

const stateSelector = createSelector(
  [selectDisplaySetInstanceUID, selectStudyInstanceUID],
  (displaySetInstanceUID, StudyInstanceUID) => {
    return {
      displaySetInstanceUID,
      StudyInstanceUID,
    };
  }
);

function VTKMPRToolbarButton({ toolbarClickCallback, button, isActive }) {
  const { id, label, icon } = button;
  const { displaySetInstanceUID, StudyInstanceUID } = useSelector(
    stateSelector
  );

  const isVisible = useMemo(() => {
    return _isDisplaySetReconstructable(
      displaySetInstanceUID,
      StudyInstanceUID
    );
  }, [displaySetInstanceUID, StudyInstanceUID]);

  return (
    <React.Fragment>
      {isVisible && (
        <ToolbarButton
          key={id}
          label={label}
          icon={icon}
          onClick={evt => toolbarClickCallback(button, evt)}
          isActive={isActive}
        />
      )}
    </React.Fragment>
  );
}

VTKMPRToolbarButton.propTypes = {
  parentContext: PropTypes.object.isRequired,
  toolbarClickCallback: PropTypes.func.isRequired,
  button: PropTypes.object.isRequired,
  activeButtons: PropTypes.array.isRequired,
  isActive: PropTypes.bool,
  className: PropTypes.string,
};

export default VTKMPRToolbarButton;