From b5359d2468a2760df599d54d379ac261e9cfef3c Mon Sep 17 00:00:00 2001
From: robyngit <thiessenbock@nceas.ucsb.edu>
Date: Mon, 14 Oct 2024 14:26:37 -0400
Subject: [PATCH] Add a model for querying CrossRef

Issue #2541
---
 src/js/models/CrossRefModel.js                | 114 ++++++++++++++++++
 test/config/tests.json                        |   1 +
 .../specs/unit/models/CrossRefModel.spec.js   |  37 ++++++
 3 files changed, 152 insertions(+)
 create mode 100644 src/js/models/CrossRefModel.js
 create mode 100644 test/js/specs/unit/models/CrossRefModel.spec.js

diff --git a/src/js/models/CrossRefModel.js b/src/js/models/CrossRefModel.js
new file mode 100644
index 000000000..fc4d2141e
--- /dev/null
+++ b/src/js/models/CrossRefModel.js
@@ -0,0 +1,114 @@
+define(["backbone"], (Backbone) => {
+  const CACHE_PREFIX = "crossref_";
+  /**
+   * @class CrossRef
+   * @classdesc Handles querying CrossRef API for metadata about a DOI.
+   * @classcategory Models
+   * @augments Backbone.Model
+   * @constructs
+   * @augments Backbone.Model
+   * @since 0.0.0
+   */
+  const CrossRef = Backbone.Model.extend(
+    /** @lends CrossRef.prototype */
+    {
+      /** @inheritdoc */
+      type: "CrossRef",
+
+      /**
+       * Defaults for the CrossRef model.
+       * @type {object}
+       * @property {string} baseURL - The base URL for the CrossRef API.
+       * @property {string} email - The email address to use for "polite"
+       * requests. See https://github.com/CrossRef/rest-api-doc#good-manners--more-reliable-service).
+       */
+      defaults() {
+        return {
+          baseURL:
+            MetacatUI.appModel.get("crossRefAPI") ||
+            "https://api.crossref.org/works/",
+          email: MetacatUI.appModel.get("emailContact") || "",
+        };
+      },
+
+      /** @inheritdoc */
+      url() {
+        let doi = this.get("doi");
+        if (!doi) return null;
+        // Make sure the DOI is formatted correctly
+        doi = MetacatUI.appModel.removeAllDOIPrefixes(doi);
+        this.set("doi", doi);
+        const doiStr = encodeURIComponent(doi);
+        const email = this.get("email");
+        const emailStr = email ? `?mailto:${email}` : "";
+        const baseURL = this.get("baseURL");
+        const url = `${baseURL}${doiStr}${emailStr}`;
+        return url;
+      },
+
+      /** @inheritdoc */
+      fetch() {
+        // first check if there's a cached response
+        const doi = this.get("doi");
+        const cachedResponse = this.getCachedResponse(doi);
+        if (cachedResponse) {
+          this.set(cachedResponse);
+          return;
+        }
+
+        const url = this.url();
+        if (!url) return;
+        const model = this;
+        // Make the request using native fetch
+        fetch(url)
+          .then((response) => {
+            if (!response.ok) {
+              throw new Error("Network response was not ok");
+            }
+            return response.json();
+          })
+          .then((responseJSON) => {
+            const parsedData = responseJSON.message;
+            model.cacheResponse(doi, parsedData);
+            model.set(parsedData);
+            model.trigger("sync");
+          })
+          .catch((error) => {
+            model.trigger("error", error);
+            model.set("error", "fetchError");
+            model.set("errorMessage", error.message);
+          });
+      },
+
+      /**
+       * Cache the response from the CrossRef API
+       * @param {string} doi The DOI for the response
+       * @param {object} response The response from the CrossRef API
+       */
+      cacheResponse(doi, response) {
+        localStorage.setItem(`${CACHE_PREFIX}${doi}`, JSON.stringify(response));
+      },
+
+      /**
+       * Get the cached response for a DOI
+       * @param {string} doi The DOI to get the cached response for
+       * @returns {object|null} The cached response or null if there is no cached response
+       */
+      getCachedResponse(doi) {
+        const cachedResponse = localStorage.getItem(`${CACHE_PREFIX}${doi}`);
+        if (!cachedResponse) return null;
+        return JSON.parse(cachedResponse);
+      },
+
+      /** Clear the cache of CrossRef responses */
+      clearCache() {
+        const keysToRemove = Object.keys(localStorage).filter((key) =>
+          key.startsWith(CACHE_PREFIX),
+        );
+        keysToRemove.forEach((key) => localStorage.removeItem(key));
+      },
+    },
+  );
+
+  return CrossRef;
+});
diff --git a/test/config/tests.json b/test/config/tests.json
index 6eef2b901..88fe3b759 100644
--- a/test/config/tests.json
+++ b/test/config/tests.json
@@ -18,6 +18,7 @@
     "./js/specs/unit/models/filters/Filter.spec.js",
     "./js/specs/unit/models/filters/NumericFilter.spec.js",
     "./js/specs/unit/models/CitationModel.spec.js",
+    "./js/specs/unit/models/CrossRefModel.spec.js",
     "./js/specs/unit/collections/ProjectList.spec.js",
     "./js/specs/unit/collections/DataPackage.spec.js",
     "./js/specs/unit/models/project/Project.spec.js",
diff --git a/test/js/specs/unit/models/CrossRefModel.spec.js b/test/js/specs/unit/models/CrossRefModel.spec.js
new file mode 100644
index 000000000..b226ddaa8
--- /dev/null
+++ b/test/js/specs/unit/models/CrossRefModel.spec.js
@@ -0,0 +1,37 @@
+"use strict";
+
+define(["/test/js/specs/shared/clean-state.js", "models/CrossRefModel"], (
+  cleanState,
+  CrossRef,
+) => {
+  const should = chai.should();
+  const expect = chai.expect;
+
+  describe("CrossRef Test Suite", () => {
+    const state = cleanState(() => {
+      // Example DOI from:
+
+      // Jerrentrup, A., Mueller, T., Glowalla, U., Herder, M., Henrichs, N.,
+      // Neubauer, A., & Schaefer, J. R. (2018). Teaching medicine with the
+      // help of “Dr. House.” PLoS ONE, 13(3), Article e0193972.
+      // https://doi.org/10.1371/journal.pone.0193972
+      const crossRef = new CrossRef({
+        doi: "https://doi.org/10.1371/journal.pone.0193972",
+      });
+      return { crossRef };
+    }, beforeEach);
+
+    it("creates a CrossRef instance", () => {
+      state.crossRef.should.be.instanceof(CrossRef);
+    });
+
+    it("forms valid fetch URLs", () => {
+      const url = state.crossRef.url();
+
+      url.should.be.a("string");
+      url.should.include("https://api.crossref.org/works/");
+      url.should.include("10.1371%2Fjournal.pone.0193972");
+      url.should.include("?mailto:knb-help@nceas.ucsb.edu");
+    });
+  });
+});