pacificclimate/climate-explorer-frontend

import _ from "lodash";
import {
  assignColoursByGroup,
  fadeSeriesByRank,
  hideSeriesInLegend,
  sortSeriesByRank,
} from "../../core/chart-formatters";
import { caseInsensitiveStringSearch } from "../../core/util";

function areAllPropsValid({ meta, model_id, variable_id, experiment }) {
  console.log("areAllPropsValid", { meta, model_id, variable_id, experiment });
  const propValues = _.values({ meta, model_id, variable_id, experiment });
  return propValues.length > 0 && propValues.every(Boolean);
}

function multiYearMeanSelected({ model_id, variable_id, experiment, meta }) {
  // Indicates whether the currently selected dataset is a multi-year-mean
  if (meta && meta.length === 0) {
    return undefined;
  }
  var selectedMetadata = _.find(meta, { model_id, variable_id, experiment });
  return selectedMetadata.multi_year_mean;
}

function hasComparand(props) {
  return !_.isUndefined(props.comparandMeta);
}

function isVariableMYM(props) {
  // Indicates whether the currently selected dataset for the (primary)
  // variable is a multi-year-mean
  return multiYearMeanSelected(props);
}

function isComparandMYM({ model_id, comparand_id, experiment, comparandMeta }) {
  // Indicates whether the currently selected dataset for the (secondary)
  // comparand is a multi-year-mean
  return multiYearMeanSelected({
    model_id,
    variable_id: comparand_id,
    experiment,
    meta: comparandMeta,
  });
}

function isEnsembleLoading(props) {
  // When switching ensembles, DualDataController is sometimes rendered when
  // the primary variable has been updated to reflect the new ensemble,
  // but the comparand hasn't yet.
  // This function evaluates that condition.
  // False when there is no comparand to load!
  return (
    hasComparand(props) &&
    props.meta.length > 0 &&
    props.comparandMeta.length < 1
  );
}

function findMatchingMetadata(example, difference, meta) {
  // Given a dataset's metadata and a "difference" listing of attribute values pairs,
  // returns metadata for another dataset that:
  // - matches all attribute/value pairs in the "difference object"
  // - matches the original dataset for any attributes not in "difference"
  // (Unique_id is ignored for purposes of matching datasets.)
  //
  // Example: findMatchingMetadata(monthlyDataset, {timescale: "annual"})
  // would return the annual-resolution dataset that corresponds to a monthly one.
  // Returns only one dataset's metadata even if multiple qualify.
  var template = {};
  for (var att in example) {
    // TODO: !==
    if (att !== "unique_id" && att !== "variable_name") {
      template[att] = difference[att] ? difference[att] : example[att];
    }
  }
  return _.find(meta, template);
}

export function errorMessage(error) {
  // Create an error message for any error generated in the
  // process of showing a graph or table. Handles networking
  // errors thrown by axios calls and errors thrown by validators
  // and parsers, which have different formats.
  if (error.response) {
    // axios error: data server sent a non-200 response
    return "Error: " + error.response.status + " received from data server.";
  }

  if (error.request) {
    // axios error: data server didn't respond
    return "Error: no response received from data server.";
  }

  // either an error thrown by a data validation function,
  // an error thrown by the DataGraph or DataTable parsers,
  // or the generic and somewhat unhelpful 'Network Error' from axios
  // Testing turned up 'Network Error' in two cases:
  // the server is down, or the server has a 500 error.
  // Other http error statuses tested were reflected in
  // error.response.status as expected
  // (see https://github.com/mzabriskie/axios/issues/383)
  return error.message;
}

function displayError(error, displayMethod) {
  // Used to display any error (via `displayMethod`)
  displayMethod(errorMessage(error));
}

function noDataMessageGraphSpec(message) {
  return {
    data: {
      columns: [],
      empty: {
        label: {
          text: message,
        },
      },
    },
    axis: {},
  };
}

const blankGraphSpec = {
  data: {
    columns: [],
  },
  axis: {},
};

export const loadingDataGraphSpec = noDataMessageGraphSpec("Loading data...");

function shouldLoadData(props, displayMessage) {
  // Return true iff the current state, evaluated based on `props`, indicates
  // that data should be loaded.
  // As a side effect, display the appropriate data loading message via
  // `displayMessage`.
  const tests = [
    {
      failCondition: (p) => !areAllPropsValid(p),
      message: "Preparing to load data...",
    },
    { failCondition: isEnsembleLoading, message: "Loading ensemble..." },
    {
      failCondition: (p) =>
        hasComparand(p) && isVariableMYM(p) !== isComparandMYM(p),
      message:
        "Error: Cannot compare climatologies to nominal time value datasets.",
    },
  ];
  for (const test of tests) {
    if (test.failCondition(props)) {
      displayMessage(test.message);
      return false;
    }
  }
  displayMessage("Loading data...");
  return true;
}

function emphasizeSeries(graph, seriesName) {
  // De-emphasizes all non-selected series in a graph specification.
  // Every data series that does not have seriesName in its name will
  // be assigned the same low-saturation colour, removed from the legend,
  // and placed on a lower z-axis.
  // Used by graphs that whose purpose is to provide context for a
  // particular dataset: (SingleTimeSliceGraph, SingleContextGraph).
  // Classify data series by which model generated them
  const makeSegmentor = function (selectedOutput, otherOutput) {
    return function (dataseries) {
      return caseInsensitiveStringSearch(dataseries[0], seriesName)
        ? selectedOutput
        : otherOutput;
    };
  };

  graph = assignColoursByGroup(graph, makeSegmentor(1, 0));
  graph = fadeSeriesByRank(graph, makeSegmentor(1, 0.35));
  graph = hideSeriesInLegend(graph, makeSegmentor(false, true));
  graph = sortSeriesByRank(graph, makeSegmentor(1, 0));

  return graph;
}

export {
  multiYearMeanSelected,
  isVariableMYM,
  isComparandMYM,
  isEnsembleLoading,
  findMatchingMetadata,
  displayError,
  noDataMessageGraphSpec,
  blankGraphSpec,
  shouldLoadData,
  emphasizeSeries,
};