Source: src/js/models/CollectionModel.js

define([
  "jquery",
  "underscore",
  "backbone",
  "uuid",
  "collections/Filters",
  "collections/SolrResults",
  "models/DataONEObject",
  "models/filters/Filter",
  "models/filters/FilterGroup",
  "models/Search",
], function (
  $,
  _,
  Backbone,
  uuid,
  Filters,
  SolrResults,
  DataONEObject,
  Filter,
  FilterGroup,
  Search,
) {
  /**
   * @class CollectionModel
   * @classdesc A collection of datasets, defined by one or more search filters
   * @classcategory Models
   * @name CollectionModel
   * @extends DataONEObject
   * @constructor
   */
  var CollectionModel = DataONEObject.extend(
    /** @lends CollectionModel.prototype */ {
      /**
       * The name of this Model
       * @type {string}
       * @readonly
       */
      type: "Collection",

      /**
       * Default attributes for CollectionModels
       * @type {Object}
       * @property {string[]} ignoreQueryGroups - Deprecated
       * @property {FilterGroup} definition - The parent-level Filter Group model that represents the collection definition.
       * @property {Filters} definitionFilters - A Filters collection that stores definition filters that have been serialized to the Collection. The same filters that are stored in the definition.
       * @property {Search} searchModel - A Search model with a Filters collection that contains the filters associated with this collection
       * @property {SolrResults} searchResults - A SolrResults collection that contains the filtered search results of datasets in this collection
       * @property {SolrResults} allSearchResults - A SolrResults collection that contains the unfiltered search results of all datasets in this collection
       */
      defaults: function () {
        return _.extend(DataONEObject.prototype.defaults(), {
          name: null,
          label: null,
          originalLabel: null,
          labelBlockList: ["new"],
          description: null,
          formatId: "https://purl.dataone.org/collections-1.1.0",
          formatType: "METADATA",
          type: "collection",
          definition: null,
          definitionFilters: null,
          searchModel: null,
          searchResults: new SolrResults(),
          allSearchResults: null,
        });
      },

      /**
       * The default Backbone.Model.initialize() function
       */
      initialize: function (options) {
        //Call the super class initialize function
        DataONEObject.prototype.initialize.call(this, options);

        this.listenToOnce(
          this.get("searchResults"),
          "sync",
          this.cacheSearchResults,
        );

        //If the searchResults collection is replaced at any time, reset the listener
        this.off("change:searchResults");
        this.on("change:searchResults", function (searchResults) {
          this.listenToOnce(
            this.get("searchResults"),
            "sync",
            this.cacheSearchResults,
          );
        });

        // Update the search model when the definition filters are updated.
        // Definition filters may be updated by the user in the Query Builder,
        // or they may be updated automatically by this model (e.g. when adding
        // an isPartOf filter).
        this.off("change:definition");
        this.on(
          "change:definition",
          function () {
            this.stopListening(this.get("definition"), "update change");
            this.listenTo(
              this.get("definition"),
              "update change",
              this.updateSearchModel,
            );
          },
          this,
        );

        //Create a search model
        this.set("searchModel", this.createSearchModel());

        // Create a Filters collection to store the definition filters. Add the catalog
        // search query fragment to the definition Filter Group model.
        this.set(
          "definition",
          new FilterGroup({ catalogSearch: true, nodeName: "definition" }),
        );
        this.set("definitionFilters", this.get("definition").get("filters"));

        // Update the blocklist with the node/repository labels
        var nodeBlockList = MetacatUI.appModel.get("portalLabelBlockList");
        if (nodeBlockList !== undefined && Array.isArray(nodeBlockList)) {
          this.set(
            "labelBlockList",
            this.get("labelBlockList").concat(nodeBlockList),
          );
        }
      },

      /**
       * updateSearchModel - This function is called when any changes are made to
       * the definition filters. The function adds, removes, or updates models
       * in the Search Model filters when models are changed in the collection
       * Definition Filters.
       *
       * @param  {Filter|Filters} model The model or collection that has been
       * changed (filter models) or updated (filters collection). This is ignored.
       * @param  {object} record     The data passed by backbone that indicates
       * which models have been added, removed, or updated. If the only change was
       * to a pre-existing model attribute, then the object will be empty.
       */
      updateSearchModel: function (model, record) {
        try {
          var model = this;

          // Merge the updated definition Filter Group model with the Search Model collection.
          this.get("searchModel")
            .get("filters")
            .add(model.get("definition"), { merge: true });
        } catch (e) {
          console.log(
            "Failed to update the Search Model collection when the " +
              "Definition Model collection changed, error message: " +
              e,
          );
        }
      },

      /**
       *
       *
       */
      url: function () {
        return (
          MetacatUI.appModel.get("objectServiceUrl") +
          encodeURIComponent(this.get("id"))
        );
      },

      /**
       * Overrides the default Backbone.Model.fetch() function to provide some custom
       * fetch options
       *
       */
      fetch: function () {
        var model = this;

        var requestSettings = {
          dataType: "xml",
          error: function () {
            model.trigger("error");
          },
        };

        //Add the authorization header and other AJAX settings
        requestSettings = _.extend(
          requestSettings,
          MetacatUI.appUserModel.createAjaxSettings(),
        );
        return Backbone.Model.prototype.fetch.call(this, requestSettings);
      },

      /**
       * Sends an AJAX request to fetch the system metadata for this object.
       * Will not trigger a sync event since it does not use Backbone.Model.fetch
       */
      fetchSystemMetadata: function (options) {
        if (!options) var options = {};
        else options = _.clone(options);

        //Get the active alternative repository, if one is configured
        var activeAltRepo = MetacatUI.appModel.getActiveAltRepo();

        if (activeAltRepo) {
          baseUrl = activeAltRepo.metaServiceUrl;
        } else {
          baseUrl = MetacatUI.appModel.get("metaServiceUrl");
        }

        //Exit if no base URL was found
        if (!baseUrl) {
          return;
        }

        var model = this,
          fetchOptions = _.extend(
            {
              url:
                baseUrl +
                encodeURIComponent(this.get("id") || this.get("seriesId")),
              dataType: "text",
              success: function (response) {
                model.set(DataONEObject.prototype.parse.call(model, response));
                model.trigger("systemMetadataSync");
              },
              error: function () {
                model.trigger("error");
              },
            },
            options,
          );

        //Add the authorization header and other AJAX settings
        _.extend(fetchOptions, MetacatUI.appUserModel.createAjaxSettings());

        $.ajax(fetchOptions);
      },

      /**
       * Overrides the default Backbone.Model.parse() function to parse the custom
       * collection XML document
       *
       * @param {XMLDocument} response - The XMLDocument returned from the fetch() AJAX call
       * @return {JSON} The result of the parsed XML, in JSON. To be set directly on the model.
       */
      parse: function (json) {
        //Start the empty JSON object
        var modelJSON = {},
          collectionNode;

        //Iterate over each root XML node to find the collection node
        $(response)
          .children()
          .each(function (i, el) {
            if (el.tagName.indexOf("collection") > -1) {
              collectionNode = el;
              return false;
            }
          });

        //If a collection XML node wasn't found, return an empty JSON object
        if (typeof collectionNode == "undefined" || !collectionNode) return {};

        //Parse the collection XML and return it
        return this.parseCollectionXML(collectionNode);
      },

      /**
       * Parses the collection XML into a JSON object
       *
       * @param {Element} rootNode - The XML Element that contains all the collection nodes
       * @return {JSON} The result of the parsed XML, in JSON. To be set directly on the model.
       */
      parseCollectionXML: function (rootNode) {
        // Get and save the namespace version number. It should be 1.0.0 or 1.1.0. Version
        // 1.0.0 portals will be updated to 1.1.0 on save. We need to know which version
        // while parsing to keep rendering of the old versions of collections/portals
        // consistent with how they were rendered before MetacatUI was updated to handle
        // 1.1.0 collections/portals - e.g. the fieldsOperator attribute in filters.
        var namespace = rootNode.namespaceURI,
          versionRegex = /\d\.\d\.\d$/g,
          version = namespace.match(versionRegex);
        if (version && version.length && version[0] != "") {
          this.set("originalVersion", version[0]);
        }

        var modelJSON = {};

        //Parse the simple text nodes
        modelJSON.name = this.parseTextNode(rootNode, "name");
        modelJSON.label = this.parseTextNode(rootNode, "label");
        modelJSON.description = this.parseTextNode(rootNode, "description");

        //Create a Filters collection to contain the collection definition Filters
        var definitionXML = rootNode.getElementsByTagName("definition")[0];
        // Add the catalog search query fragment to the definition Filter Group model
        modelJSON.definition = new FilterGroup({
          objectDOM: definitionXML,
          catalogSearch: true,
        });
        modelJSON.definitionFilters = modelJSON.definition.get("filters");

        //Create a Search model for this collection's filters
        modelJSON.searchModel = this.createSearchModel();
        // Add all the filters from the Collection definition to the search model as a single
        // Filter Group model.
        modelJSON.searchModel.get("filters").add(modelJSON.definition);

        // If we are parsing the first version of a collection or portal
        if (this.get("originalVersion") === "1.0.0") {
          modelJSON = this.updateTo110(modelJSON);
        }

        return modelJSON;
      },

      /**
       * Takes parsed Collections 1.0.0 XML in JSON format and makes any changes required so
       * that collections are still represented in MetacatUI as they were before MetacatUI
       * was updated to support 1.1.0 Collections.
       * @param {JSON} modelJSON Parsed 1.0.0 Collections XML, in JSON
       * @return {JSON} The updated JSON, compatible with 1.1.0 changes
       */
      updateTo110: function (modelJSON) {
        try {
          // For version 1.0.0 filters, MetacatUI used the "operator" attribute to set the
          // operator between both fields and values. In 1.1.0, we now have the
          // "fieldsOperator" attribute. (Since "AND" was the default, only the "OR"
          // operator is ever serialized). Therefore, if a version 1.0.0 filter has "OR" as
          // the operator, we should also set the "fieldOperator" to "OR".
          modelJSON.definitionFilters.each(function (filterModel) {
            if (filterModel.get("operator") === "OR") {
              filterModel.set("fieldsOperator", "OR");
            }
          }, this);
          return modelJSON;
        } catch (error) {
          console.log(
            "Error trying to update a 1.0.0 Collection to 1.1.0 " +
              "returning the JSON unchanged. Error details: " +
              error,
          );
          return modelJSON;
        }
      },

      /**
       * Generate a UUID, reserve it using the DataOne API, and set it on the model
       */
      reserveSeriesId: function () {
        // Create a new series ID
        var seriesId = "urn:uuid:" + uuid.v4();

        // Set the seriesId on the portal model right away, since reserving takes
        // time. This will be updated in the rare case that the first seriesId was
        // already taken.
        this.set("seriesId", seriesId);

        // Reserve a series ID for the new portal
        var model = this;
        var options = {
          url: MetacatUI.appModel.get("reserveServiceUrl"),
          type: "POST",
          data: { pid: seriesId },
          tryCount: 0,
          // If a generated seriesId is already reserved, how many times to retry
          retryLimit: 5,
          success: function (xhr) {
            // If the first seriesId was taken, then update the model with the
            // successfully reserved seriesId.
            if (this.tryCount > 0) {
              model.set("seriesId", $(xhr).find("identifier").text());
            }
          },
          error: function (xhr) {
            // If the seriesId was already reserved, try again
            if (xhr.status == 409) {
              this.tryCount++;
              if (this.tryCount <= this.retryLimit) {
                // Generate another seriesId
                this.data = { pid: "urn:uuid:" + uuid.v4() };
                // Send the reserve request again
                $.ajax(this);
                return;
              }
              return;
              // If the user isn't logged in, or doesn't have write access
            } else if ((xhr.status = 401)) {
              model.set("isAuthorized", false);
            } else {
              parsedResponse = $(xhr.responseText).not("style, title").text();
              model.set("errorMessage", parsedResponse);
            }
          },
        };
        _.extend(options, MetacatUI.appUserModel.createAjaxSettings());
        $.ajax(options);
      },

      /**
       * Creates a FilterModel with isPartOf as the field and this collection's
       * seriesId as the value, then adds it to the definitionFilters collection.
       * (which will also add it to the searchFilters collection)
       * @param {string} [seriesId] - the seriesId of the collection or portal
       * @return {Filter} The new isPartOf filter that was created
       */
      addIsPartOfFilter: function (seriesId) {
        try {
          // If no seriesId is given
          if (!seriesId) {
            // Use the seriesId set on the model
            if (this.get("seriesId")) {
              seriesId = this.get("seriesId");
              // If there's no seriesId on the model, make and reserve one
            } else {
              //Create and reserve a new seriesId
              this.reserveSeriesId();
              seriesId = this.get("seriesId");

              // Set a listener to create an isPartOf filter using the seriesId once
              // the series Id is set. Just in case the first seriesId generated was
              // already reserved, update the isPartOf filters on the subsequent
              // attempts to create and resere an ID.
              this.on("change:seriesId", function (seriesId) {
                this.addIsPartOfFilter();
              });
            }
          }

          // Create the new isPartOf filter attributes object
          // NOTE: All other attributes are set in Filter.initialize();
          var isPartOfAttributes = {
            fields: ["isPartOf"],
            values: [seriesId],
            matchSubstring: false,
            operator: "OR",
          };

          // Remove any existing isPartOf filters, and add the new isPartOf filter

          // NOTE:
          // 1. Changes to the definition filters will automatically update the
          // Search Model filters because of the listener set in initialize().
          // 2. Add the new Filter model by passing a list of attributes to the
          // Filters collection, instead of by passing a new Filter, in order
          // to trigger 'update' and 'change' events for other models and views.

          this.get("definitionFilters").removeFiltersByField("isPartOf");
          var filterModel =
            this.get("definitionFilters").add(isPartOfAttributes);

          return filterModel;
        } catch (e) {
          console.log(
            "Failed to create and add a new isPartOf Filter, error message: " +
              e,
          );
        }
      },

      /**
       * Gets the text content of the XML node matching the given node name
       *
       * @param {Element} parentNode - The parent node to select from
       * @param {string} nodeName - The name of the XML node to parse
       * @param {boolean} isMultiple - If true, parses the nodes into an array
       * @return {(string|Array)} - Returns a string or array of strings of the text content
       */
      parseTextNode: function (parentNode, nodeName, isMultiple) {
        var node = $(parentNode).children(nodeName);

        //If no matching nodes were found, return falsey values
        if (!node || !node.length) {
          //Return an empty array if the isMultiple flag is true
          if (isMultiple) return [];
          //Return null if the isMultiple flag is false
          else return null;
        }
        //If exactly one node is found and we are only expecting one, return the text content
        else if (node.length == 1 && !isMultiple) {
          return node[0].textContent.trim();
        }
        //If more than one node is found, parse into an array
        else {
          return _.map(node, function (node) {
            return node.textContent.trim() || null;
          });
        }
      },

      /**
       * Updates collection XML with values in the collection model
       *
       * @param {XMLDocument} objectDOM the XML element to be updated
       * @return {XMLElement} An updated XML element
       */
      updateCollectionDOM: function (objectDOM) {
        // Get or make objectDOM
        if (!objectDOM) {
          if (this.get("objectDOM")) {
            var objectDOM = this.get("objectDOM").cloneNode(true);
            $(objectDOM).empty();
          } else {
            // create an XML collection element from scratch
            var objectDOM = $(this.createXML()).children()[0];
          }
        }

        // Set schema version. May need to be updated from 1.0.0 to 1.1.0.
        // The formatId is the same as the namespace URI.
        var currentNamespace = this.defaults().formatId;

        // The NS attribute name could be xmlns:por or xmlns:col
        objectDOM.attributes.forEach(function (attr) {
          if (attr.name.match(/^xmlns/)) {
            if (attr.value !== currentNamespace) {
              var newObjectDOM = this.createXML().documentElement;
              while (objectDOM.firstChild) {
                newObjectDOM.appendChild(objectDOM.firstChild);
              }
              objectDOM = newObjectDOM;
            }
          }
        }, this);

        // Remove definition node if it exists in XML already
        $(objectDOM).find("definition").remove();

        // Get the filters that are currently applied to the search.
        var definitionSerialized = this.get("definition").updateDOM();
        objectDOM.ownerDocument.adoptNode(definitionSerialized);

        //If at least one filter was serialized, add the <definition> node
        if (definitionSerialized.childNodes.length) {
          $(objectDOM).prepend(definitionSerialized);
        }

        // Get and update the simple text strings (everything but definition)
        // in reverse order because we prepend them consecutively to objectDOM
        var collectionTextData = {
          description: this.get("description"),
          name: this.get("name"),
          label: this.get("label"),
        };

        _.map(collectionTextData, function (value, nodeName) {
          // Remove the node if it exists
          // Use children() and not find() as there are sub-children named label
          $(objectDOM).children(nodeName).remove();

          // Don't serialize falsey values
          if (value && typeof value == "string" && value.trim().length) {
            // Make new sub-node
            var collectionSubnodeSerialized =
              objectDOM.ownerDocument.createElement(nodeName);
            $(collectionSubnodeSerialized).text(value);
            // Append new sub-node to the start of the objectDOM
            $(objectDOM).prepend(collectionSubnodeSerialized);
          }
        });

        return objectDOM;
      },

      /**
       * Initialize the object XML for a brand spankin' new collection
       * @return {Element}
       */
      createXML: function () {
        var xmlString =
            '<col:collection xmlns:col="https://purl.dataone.org/collections-1.1.0"></col:collection>',
          xmlNew = $.parseXML(xmlString),
          colNode = xmlNew.getElementsByTagName("col:collections")[0];

        // set attributes
        colNode.setAttribute(
          "xmlns:xsi",
          "http://www.w3.org/2001/XMLSchema-instance",
        );
        colNode.setAttribute(
          "xsi:schemaLocation",
          "https://purl.dataone.org/collections-1.1.0",
        );

        this.set("ownerDocument", colNode.ownerDocument);

        return xmlNew;
      },

      /**
       * Creates a new instance of a Search model with a Filters collection.
       * The Search model is created and returned and NOT set directly on the model in
       * this function, because this function is called during parse(), when we're not ready
       * to set attributes directly on the model yet.
       * @return {Search}
       */
      createSearchModel: function () {
        var search = new Search();
        // Do not set "catalogSearch" to true, even though the search model is specifically
        // created in order to do a catalog search. Instead, we set the definition
        // filterGroup model catalogSearch = true. This allows us to append the query
        // fragment with ID fields AFTER the catalog query fragment.
        search.set("filters", new Filters());
        return search;
      },

      /**
       * This is a shortcut function that returns the query for the datasets in this portal,
       *  using the Search model for this portal. This is the full query that includes the filters not
       *  serialized to the portal XML, such as the filters used for the DataCatalogView.
       *
       */
      getQuery: function () {
        return this.get("definition").getQuery();
      },

      /**
       * Creates a copy of the SolrResults collection and saves it in this
       * model so that there is always access to the unfiltered list of datasets
       *
       * @param {SolrResults} searchResults - The SolrResults collection to cache
       */
      cacheSearchResults: function (searchResults) {
        //Save a copy of the SolrResults so that we always have a copy of
        // the unfiltered list of datasets
        this.set("allSearchResults", searchResults.clone());

        //Make a copy of the facetCounts object
        var allSearchResults = this.get("allSearchResults");
        allSearchResults.facetCounts = Object.assign(
          {},
          searchResults.facetCounts,
        );
      },

      /**
       * Overrides the default Backbone.Model.validate.function() to
       * check if this portal model has all the required values necessary
       * to save to the server.
       *
       * @param {Object} [attrs] - A literal object of model attributes to validate.
       * @param {Object} [options] - A literal object of options for this validation process
       * @return {Object} If there are errors, an object comprising error
       *                   messages. If no errors, returns nothing.
       */
      validate: function (attrs, options) {
        try {
          var errors = {};

          // Validate label
          var labelError = this.validateLabel(this.get("label"));
          if (labelError) {
            errors.label = labelError;
          }

          // Validate the definition
          var definitionError = this.get("definition").validate(attrs, options);

          if (definitionError) {
            if (definitionError.noFilters) {
              type = this.type.toLowerCase();
              errors.definition =
                "Your dataset collection hasn't been created. Add at " +
                "least one query rule below to find datasets for this " +
                type +
                ". For example, to create a " +
                type +
                " for datasets from a specific " +
                "research project, try using the project name field.";
            } else {
              // Just show the first error for now.
              errors.definition = Object.values(definitionError)[0];
            }
          }

          if (Object.keys(errors).length) {
            console.log(errors);
            return errors;
          } else {
            return;
          }
        } catch (e) {
          console.error(e);
        }
      },

      /**
       * Checks that a label does not equal a restricted value
       * (e.g. new temporary name), and that it's encoded properly
       * for use as part of a url
       *
       * @param {string} label - The label to be validated
       * @return {string} - If the label is invalid, an error message string is returned
       */
      validateLabel: function (label) {
        try {
          //Validate the label set on the model if one isn't given
          if (typeof label != "string") {
            var label = this.get("label");
          }

          //If the label is not a string or is an empty string
          if (typeof label != "string" || !label.trim().length) {
            //Convert numbers to strings
            if (typeof label == "number") {
              label = label.toString();
            } else {
              var type = this.type.toLowerCase();
              return (
                "Please choose a name for this " + type + " to use in the URL."
              );
            }
          }

          // If the label is a restricted string
          var blockList = this.get("labelBlockList");
          if (blockList && Array.isArray(blockList)) {
            if (blockList.includes(label)) {
              return "This URL is already taken, please try something else";
            }
          }

          // If the label includes illegal characters
          // (Only allow letters, numbers, underscores and dashes)
          if (label.match(/[^A-Za-z0-9_-]/g)) {
            return "URLs may only contain letters, numbers, underscores (_), and dashes (-).";
          }
        } catch (e) {
          //Trigger an error event
          this.trigger("errorValidatingLabel");
          console.error(e);
        }
      },
    },
  );

  return CollectionModel;
});