From 5580f04fd81870033f46ccea839714a14c823a10 Mon Sep 17 00:00:00 2001
From: Jiawei Duan <jiawei.duan@outlook.com>
Date: Sun, 10 Sep 2023 17:07:37 -0700
Subject: [PATCH] Initial commit

---
 .gitignore                                 |   1 +
 Makefile                                   |  28 ++
 README.md                                  |   2 +
 src/bootstrap.js                           |  37 ++
 src/chrome.manifest                        |   4 +
 src/chrome/content/overlay.js              |   5 +
 src/chrome/content/overlay.xul             |   9 +
 src/chrome/content/test.js                 | 446 +++++++++++++++++++++
 src/chrome/content/threadpool.js           |  60 +++
 src/chrome/content/utilities.js            |  80 ++++
 src/chrome/content/zotmeta.js              | 217 ++++++++++
 src/chrome/locale/en-US/zotmeta.properties |   1 +
 src/defaults/preferences/prefs.js          |   0
 src/install.rdf                            |  33 ++
 src/locale/en-US/zotmeta.ftl               |   2 +
 src/manifest.json                          |  15 +
 updates.json                               |  21 +
 updates.json.tmpl                          |  21 +
 18 files changed, 982 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 Makefile
 create mode 100644 README.md
 create mode 100644 src/bootstrap.js
 create mode 100644 src/chrome.manifest
 create mode 100644 src/chrome/content/overlay.js
 create mode 100644 src/chrome/content/overlay.xul
 create mode 100644 src/chrome/content/test.js
 create mode 100644 src/chrome/content/threadpool.js
 create mode 100644 src/chrome/content/utilities.js
 create mode 100644 src/chrome/content/zotmeta.js
 create mode 100644 src/chrome/locale/en-US/zotmeta.properties
 create mode 100644 src/defaults/preferences/prefs.js
 create mode 100644 src/install.rdf
 create mode 100644 src/locale/en-US/zotmeta.ftl
 create mode 100644 src/manifest.json
 create mode 100644 updates.json
 create mode 100644 updates.json.tmpl

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..c795b05
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+build
\ No newline at end of file
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..9ec2acf
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,28 @@
+# Define variables
+SRC_DIR := src
+BUILD_DIR := build
+VERSION:=$(shell grep em:version src/install.rdf | head -n 1 | sed -e 's/ *<em:version>//' -e 's/<\/em:version>//')
+ZIP_FILE_NAME := zotmeta-$(VERSION).xpi
+ZIP_FILE_PATH := $(BUILD_DIR)/$(ZIP_FILE_NAME)
+JSON_FILE := updates.json
+
+
+# Default target
+all: $(ZIP_FILE_PATH) $(JSON_FILE)
+
+# Target to zip all files in the source folder
+$(ZIP_FILE_PATH): | $(BUILD_DIR)
+	(cd $(SRC_DIR) && zip -r $(abspath $@) .)
+
+# Target to generate a updates.json file
+$(JSON_FILE): | $(BUILD_DIR)
+	jq ".addons[\"zotmeta@roadtodream.tech\"].updates[0].update_hash = \"sha256:`shasum -a 256 $(ZIP_FILE_PATH) | cut -d' ' -f1`\"" updates.json.tmpl | \
+		jq ".addons[\"zotmeta@roadtodream.tech\"].updates[0].update_link = \"https://github.com/RoadToDream/ZotMeta/releases/download/v$(VERSION)/$(ZIP_FILE_NAME)\"" > $@
+
+# Create the build directory if it doesn't exist
+$(BUILD_DIR):
+	mkdir -p $(BUILD_DIR)
+
+# Clean up generated files
+clean:
+	rm -rf $(BUILD_DIR)
\ No newline at end of file
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..21ceb4f
--- /dev/null
+++ b/README.md
@@ -0,0 +1,2 @@
+# ZotMeta: Metadata update tool 
+ZotMeta is a Zotero plugin to update articles metadata. 
diff --git a/src/bootstrap.js b/src/bootstrap.js
new file mode 100644
index 0000000..7351835
--- /dev/null
+++ b/src/bootstrap.js
@@ -0,0 +1,37 @@
+var ZotMeta;
+
+function log(msg) {
+    Zotero.debug("ZotMeta: " + msg);
+}
+
+function install() {
+    log("Installed");
+}
+
+async function startup({ id, version, rootURI }) {
+    log("Starting");
+    
+    // Load chrome/content file directly via file:/// URL
+    Services.scriptloader.loadSubScript(rootURI + 'chrome/content/utilities.js');
+    Services.scriptloader.loadSubScript(rootURI + 'chrome/content/threadpool.js');
+    Services.scriptloader.loadSubScript(rootURI + 'chrome/content/zotmeta.js');
+    ZotMeta.init({ id, version, rootURI });
+    ZotMeta.addToAllWindows();
+}
+
+function onMainWindowLoad({ window }) {
+    ZotMeta.addToWindow(window);
+}
+
+function onMainWindowUnload({ window }) {
+    ZotMeta.removeFromWindow(window);
+}
+
+function shutdown() {
+    log("Shutting down");
+    ZotMeta.removeFromAllWindows();
+}
+
+function uninstall() {
+    log("Uninstalled");
+}
diff --git a/src/chrome.manifest b/src/chrome.manifest
new file mode 100644
index 0000000..772489c
--- /dev/null
+++ b/src/chrome.manifest
@@ -0,0 +1,4 @@
+content   zotmeta             chrome/content/
+skin      zotmeta   default   chrome/skin/
+locale    zotmeta   en-US     chrome/locale/en-US/
+overlay	chrome://zotero/content/zoteroPane.xul chrome://zotmeta/content/overlay.xul
diff --git a/src/chrome/content/overlay.js b/src/chrome/content/overlay.js
new file mode 100644
index 0000000..8256bc9
--- /dev/null
+++ b/src/chrome/content/overlay.js
@@ -0,0 +1,5 @@
+window.addEventListener('load', async function (event) {
+    await Zotero.initializationPromise;
+    ZotMeta.init();
+    ZotMeta.addToWindow(window);
+});
diff --git a/src/chrome/content/overlay.xul b/src/chrome/content/overlay.xul
new file mode 100644
index 0000000..f9c25c8
--- /dev/null
+++ b/src/chrome/content/overlay.xul
@@ -0,0 +1,9 @@
+<?xml version="1.0"?>
+
+<overlay id="zotmeta-overlay"
+        xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
+    <script src="overlay.js"/>
+    <script src="threadpool.js"/>
+    <script src="utilities.js"/>
+    <script src="zotmeta.js"/>
+</overlay>
diff --git a/src/chrome/content/test.js b/src/chrome/content/test.js
new file mode 100644
index 0000000..fd46dd4
--- /dev/null
+++ b/src/chrome/content/test.js
@@ -0,0 +1,446 @@
+// class ThreadPool {
+//     constructor(numThreads) {
+//         this.numThreads = numThreads;
+//         this.jobs = [];
+//         this.jobsRunning = {
+//             _value: 0, 
+//             onChangeCallback: null,
+
+//             get value() {
+//                 return this._value;
+//             },
+
+//             set value(newValue) {
+//                 var originalValue = this._value;
+//                 if (newValue !== this._value) {
+//                     this._value = newValue;
+//                 }
+//                 if (newValue < originalValue) {
+//                     if (this.onChangeCallback) {
+//                         this.onChangeCallback();
+//                     }
+//                 }
+//             },
+
+//             setOnChangeCallback(callback) {
+//                 this.onChangeCallback = callback;
+//             },
+//         };
+
+//         this.jobsRunning.setOnChangeCallback(async () => {
+//             await this.fill_pool();
+//         });
+//     }
+
+//     submit(job) {
+//         this.jobs.push(job);
+//     }
+
+//     execute() {
+//         this.fill_pool();
+//     }
+
+//     async wait() {
+//         while (this.jobs.length !== 0 || this.jobsRunning.value !== 0) {
+//             await new Promise((resolve) => setTimeout(resolve, 1000));
+//         }
+//     }
+
+//     async fill_pool() {
+//         for (let index = 0; index < this.numThreads - this.jobsRunning.value; index++) {
+//             if (this.jobs.length === 0) {
+//                 break;
+//             }
+//             const selected_job = this.jobs.shift();
+//             this.jobsRunning.value++;
+//             await selected_job();
+//             this.jobsRunning.value--;
+//         }
+//     }
+// }
+
+
+// async function test() {
+//     var pool = new ThreadPool(5);
+//     for (let index = 0; index < 1; index++) {
+//         pool.submit(async () => {
+//             const min = 500;
+//             const max = 1000;
+//             const randomNumber = Math.floor(Math.random() * (max - min + 1)) + min;
+//             await new Promise((resolve) => setTimeout(resolve, randomNumber));
+//             console.log(index + " seconds passed.");
+//         });
+//     }
+//     pool.execute();
+//     await pool.wait();
+//     console.log("Finished");
+// }
+
+// test();
+
+// jobs = [1,2,3];
+// async function wait() {
+//     while (jobs.length !== 0) {
+//         // Wait until the lock is released.
+//         await new Promise((resolve) => setTimeout(resolve, 100));
+//     }
+// }
+
+// wait();
+
+// jobs = [1,2,3];
+// async function example() {
+//     while (jobs.length !== 0) {
+//         await new Promise((resolve) => setTimeout(resolve, 1000)); // Sleep for 1 second
+//     }
+        
+// }
+
+// await example();
+
+
+// function fetchWithTimeout(url, timeout) {
+//     // Create a new Promise that will reject if the fetch call doesn't complete within the specified timeout
+//     const timeoutPromise = new Promise((_, reject) => {
+//         setTimeout(() => {
+//             reject(new Error('Request timed out'));
+//         }, timeout);
+//     });
+
+//     // Use Promise.race to race between the fetch call and the timeout promise
+//     return Promise.race([
+//         fetch(url), // The fetch call
+//         timeoutPromise // The timeout promise
+//     ]);
+// }
+
+// // Example usage
+// const url = 'https://www.google.com/';
+// const timeout = 1000; // 5 seconds timeout
+
+// fetchWithTimeout(url, timeout)
+//     .then(response => {
+//         if (!response.ok) {
+//             throw new Error(`HTTP error! Status: ${response.status}`);
+//         }
+//         return response;
+//     })
+//     .then(data => {
+//         console.log(data);
+//     })
+//     .catch(error => {
+//         console.error(error.message);
+//     });
+
+ZotMeta = {
+    id: null,
+    version: null,
+    rootURI: null,
+    initialized: false,
+    addedElementIDs: [],
+
+    init({ id, version, rootURI } = {}) {
+        if (this.initialized) return;
+        this.id = id;
+        this.version = version;
+        this.rootURI = rootURI;
+        this.initialized = true;
+    },
+    
+    log(msg) {
+        Zotero.debug("ZotMeta: " + msg);
+    },
+
+    generateAuthors (author) {
+        var new_author_list = [];
+        if (author) {
+            author.forEach(element => {
+                new_author_list.push(
+                  {
+                    "firstName": element["given"],
+                    "lastName": element["family"],
+                    "creatorType": "author"
+                  }
+                )
+            });
+        }
+        return new_author_list;
+    },
+
+    generateDate (date) {
+        if (!date) {
+            return null;
+        }
+        if (date.length > 0) {
+            return date[0].join("-");
+        }
+        else {
+            return null;
+        }
+    },
+
+    getMetaData (item) {
+        var doi = item.getField('DOI');
+        // if (item.itemTypeID !== Zotero.ItemTypes.getID('journalArticle')) {
+        //     Utilities.publishError("Unsupported Item Type", "Only Journal Article is supported.")
+        //     return;
+        // }
+        // if (!doi) {
+        //     // Utilities.publishError("DOI not found", "DOI is required to retrieve metadata.")
+        //     return;
+        // }
+
+        var url = 'http://dx.doi.org/' + doi;
+        const headers = new Headers({'Accept': 'application/vnd.citationstyles.csl+json'});
+        var requestInfo = { method: 'GET', headers };
+        return Utilities.fetchWithTimeout(url, requestInfo, 3000)
+            .then(response => {
+                if (!response.ok) {
+                    Utilities.publishError("Error retrieving metadata", 
+                        "Please check if DOI is correct and if you have network access to dx.doi.org.");
+                    return null;
+                        
+                }
+                return response.text()
+            })
+            .then(data => {
+                try {
+                    return JSON.parse(data)
+                } catch (error) {
+                    return null;
+                }
+            })
+            .then(data_json => {
+                var Title = Utilities.safeGetFromJson(data_json, ["title"]);
+                var Authors = this.generateAuthors(Utilities.safeGetFromJson(data_json, ["author"]));
+                var Publication = Utilities.safeGetFromJson(data_json, ["container-title"]);
+                var Volume = Utilities.safeGetFromJson(data_json, ["volume"]);
+                var Issue = Utilities.safeGetFromJson(data_json, ["issue"]);
+                var Pages = Utilities.safeGetFromJson(data_json, ["page"]);
+                var PublishDate = this.generateDate(Utilities.safeGetFromJson(data_json, ["published", "date-parts"]));
+                var JournalAbbr = Utilities.safeGetFromJson(data_json, ["container-title-short"]);
+                var Language = Utilities.safeGetFromJson(data_json, ["language"]);
+                return {
+                            "Title": Title ? Title : "",
+                            "Authors": Authors ? Authors : "",
+                            "Publication": Publication ? Publication : "",
+                            "Volume": Volume ? Volume : "",
+                            "Issue": Issue ? Issue : "",
+                            "Pages": Pages ? Pages : "",
+                            "PublishDate": PublishDate ? PublishDate : "",
+                            "JournalAbbr": JournalAbbr ? JournalAbbr : "",
+                            "Language": Language ? Language : ""
+                        };
+            });
+    },
+      
+    async updateMetadata(item) {
+        var metaData = await this.getMetaData(item);
+        if (!metaData) {
+            return 1;
+        }
+        
+        if (!Utilities.isEmpty(metaData["Title"]))       item.setField('title',metaData["Title"]);
+        if (!Utilities.isEmpty(metaData["Authors"]))     item.setCreators(metaData["Authors"]);
+        if (!Utilities.isEmpty(metaData["Publication"])) item.setField('publicationTitle',metaData["Publication"]);
+        if (!Utilities.isEmpty(metaData["Volume"]))      item.setField('volume',metaData["Volume"]);
+        if (!Utilities.isEmpty(metaData["Issue"]))       item.setField('issue',metaData["Issue"]);
+        if (!Utilities.isEmpty(metaData["Pages"]))       item.setField('pages',metaData["Pages"]);
+        if (!Utilities.isEmpty(metaData["PublishDate"])) item.setField('date',metaData["PublishDate"]);
+        if (!Utilities.isEmpty(metaData["JournalAbbr"])) item.setField('journalAbbreviation',metaData["JournalAbbr"]);
+        if (!Utilities.isEmpty(metaData["Language"]))    item.setField('language',metaData["Language"]);
+        await item.saveTx();
+        return 0;
+    },
+
+    async updateSelectedItemsMetadata() {
+        var items = Zotero.getActiveZoteroPane().getSelectedItems();
+        var item_count = items.length;
+        if (item_count === 0) {
+            Utilities.publishSuccess("Finished", "No item is selected.")
+        }
+        var progress_handle = Utilities.initializeProgress("Updating metadata for " + item_count + " items...")
+
+        var pool = new ThreadPool(5);
+        var progress = 0;
+        var success_count = 0;
+        var failed_count = 0;
+        for (let i = 0; i < item_count; i++) {
+            pool.submit(async () => { 
+                var status = await this.updateMetadata(items[i]);
+                if (status === 0) {
+                    success_count++;
+                } else if(status === 1) {
+                    failed_count++;
+                }
+                progress++;
+                var progress_mapped = Math.round(progress / item_count * 100);
+                await Utilities.publishProgress(progress_handle, progress_mapped, progress + " out of " + item_count + " finished updating.");
+            });
+        }
+
+        pool.execute();
+        await pool.wait();
+        await Utilities.publishSuccess("Finished", success_count + " items updated, " + failed_count + " items failed.");
+    },
+
+    addToWindow(window) {
+        let doc = window.document;
+        
+        // createElementNS() necessary in Zotero 6; createElement() defaults to HTML in Zotero 7
+        let XUL_NS = "http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul";
+        
+        // Add menu option
+        let menuitem = doc.createElementNS(XUL_NS, 'menuitem');
+        menuitem.id = 'update-metadata';
+        menuitem.setAttribute('type', 'button');
+        menuitem.setAttribute('data-l10n-id', 'update-metadata');
+        menuitem.addEventListener('command', () => {
+            this.updateSelectedItemsMetadata();
+        });
+        doc.getElementById('zotero-itemmenu').appendChild(menuitem);
+        this.storeAddedElement(menuitem);
+        
+        // Use strings from zotmeta.ftl (Fluent) in Zotero 7
+        if (Zotero.platformMajorVersion >= 102) {
+            window.MozXULElement.insertFTLIfNeeded("zotmeta.ftl");
+        }
+        // Use strings from zotmeta.properties (legacy properties format) in Zotero 6
+        else {
+            let stringBundle = Services.strings.createBundle(
+                'chrome://zotmeta/locale/zotmeta.properties'
+            );
+            doc.getElementById('update-metadata')
+                .setAttribute('label', stringBundle.GetStringFromName('update-metadata.label'));
+        }
+    },
+    
+    addToAllWindows() {
+        var windows = Zotero.getMainWindows();
+        for (let win of windows) {
+            if (!win.ZoteroPane) continue;
+            this.addToWindow(win);
+        }
+    },
+    
+    storeAddedElement(elem) {
+        if (!elem.id) {
+            throw new Error("Element must have an id");
+        }
+        this.addedElementIDs.push(elem.id);
+    },
+    
+    removeFromWindow(window) {
+        var doc = window.document;
+        // Remove all elements added to DOM
+        for (let id of this.addedElementIDs) {
+            // ?. (null coalescing operator) not available in Zotero 6
+            let elem = doc.getElementById(id);
+            if (elem) elem.remove();
+        }
+        doc.querySelector('[href="zotmeta.ftl"]').remove();
+    },
+    
+    removeFromAllWindows() {
+        var windows = Zotero.getMainWindows();
+        for (let win of windows) {
+            if (!win.ZoteroPane) continue;
+            this.removeFromWindow(win);
+        }
+    },
+};
+
+Utilities = {
+    publishError(title, message) {
+        var progressWindowError = new Zotero.ProgressWindow({closeOnClick:true});
+        var errorIcon = "chrome://zotero/skin/cross.png";
+        progressWindowError.changeHeadline(title);
+        progressWindowError.progress = new progressWindowError.ItemProgress(errorIcon, message);
+        progressWindowError.progress.setError();
+        progressWindowError.show();
+        progressWindowError.startCloseTimer(3000);
+    },
+    publishSuccess(title, message) {
+        var progressWindowSuccess = new Zotero.ProgressWindow({closeOnClick:true});
+        var successIcon = "chrome://zotero/skin/tick.png";
+        progressWindowSuccess.changeHeadline(title);
+        progressWindowSuccess.progress = new progressWindowSuccess.ItemProgress(successIcon, message);
+        progressWindowSuccess.show();
+        progressWindowSuccess.startCloseTimer(3000);
+    },
+    initializeProgress(title, message) {
+        var progressWindowProgress = new Zotero.ProgressWindow({closeOnClick:true});
+        var loadingIcon = "chrome://zotero/skin/spinner-16px.png";
+        progressWindowProgress.changeHeadline(title);
+        progressWindowProgress.progress = new progressWindowProgress.ItemProgress(loadingIcon, message);
+        progressWindowProgress.progress.setProgress(0);
+        progressWindowProgress.progress.setText(message);
+        progressWindowProgress.show();
+        return progressWindowProgress;
+        
+    },
+    publishProgress(handle, progress, message) {
+        var validated_progress = Math.min(Math.max(progress, 0), 100);
+        handle.progress.setProgress(validated_progress);
+        handle.progress.setText(message);
+        if (progress === 100) {
+            var successIcon = "chrome://zotero/skin/tick.png";
+            handle.progress.setIcon(successIcon);
+        }
+        handle.show();
+    },
+
+    fetchWithTimeout(url, requestInfo, timeout) {
+        const timeoutPromise = new Promise((_, reject) => {
+            setTimeout(() => {
+                reject(new Error('Request timed out'));
+            }, timeout);
+        });
+    
+        return Promise.race([
+            fetch(url, requestInfo),
+            timeoutPromise
+        ]);
+    },
+
+    safeGetFromJson(json, key_array) {
+        if (!json) {
+            return null;
+        }
+        var json_loc = json;
+        for (const key of key_array) {
+            if (key in json_loc) {
+                json_loc = json_loc[key];
+            } else {
+                return null;
+            }
+        }
+        return json_loc;
+    },
+    
+    isEmpty(value) {
+        if (typeof value === 'string') {
+            return value.trim() === '';
+        } else if (Array.isArray(value)) {
+            return value.length === 0;
+        } else if (typeof value === 'object' && value !== null) {
+            return Object.keys(value).length === 0;
+        } else {
+            return false;
+        }
+    }
+};
+
+class Item {
+    getField(key) {
+        return "10.13334/j.0258-8013.pcsee.2012.36.020";
+    }
+}
+
+async function test() {
+    var item = new Item();
+    var metadata = await ZotMeta.getMetaData(item);
+    return metadata;
+}
+
+test();
\ No newline at end of file
diff --git a/src/chrome/content/threadpool.js b/src/chrome/content/threadpool.js
new file mode 100644
index 0000000..b7b2fcf
--- /dev/null
+++ b/src/chrome/content/threadpool.js
@@ -0,0 +1,60 @@
+class ThreadPool {
+    constructor(numThreads) {
+        this.numThreads = numThreads;
+        this.jobs = [];
+        this.jobsRunning = {
+            _value: 0, 
+            onChangeCallback: null,
+
+            get value() {
+                return this._value;
+            },
+
+            set value(newValue) {
+                var originalValue = this._value;
+                if (newValue !== this._value) {
+                    this._value = newValue;
+                }
+                if (newValue < originalValue) {
+                    if (this.onChangeCallback) {
+                        this.onChangeCallback();
+                    }
+                }
+            },
+
+            setOnChangeCallback(callback) {
+                this.onChangeCallback = callback;
+            },
+        };
+
+        this.jobsRunning.setOnChangeCallback(async () => {
+            await this.fill_pool();
+        });
+    }
+
+    submit(job) {
+        this.jobs.push(job);
+    }
+
+    execute() {
+        this.fill_pool();
+    }
+
+    async wait() {
+        while (this.jobs.length !== 0 || this.jobsRunning.value !== 0) {
+            await new Promise((resolve) => setTimeout(resolve, 1000));
+        }
+    }
+
+    async fill_pool() {
+        for (let index = 0; index < this.numThreads - this.jobsRunning.value; index++) {
+            if (this.jobs.length === 0) {
+                break;
+            }
+            const selected_job = this.jobs.shift();
+            this.jobsRunning.value++;
+            await selected_job();
+            this.jobsRunning.value--;
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/chrome/content/utilities.js b/src/chrome/content/utilities.js
new file mode 100644
index 0000000..72b361a
--- /dev/null
+++ b/src/chrome/content/utilities.js
@@ -0,0 +1,80 @@
+Utilities = {
+    publishError(title, message) {
+        var progressWindowError = new Zotero.ProgressWindow({closeOnClick:true});
+        var errorIcon = "chrome://zotero/skin/cross.png";
+        progressWindowError.changeHeadline(title);
+        progressWindowError.progress = new progressWindowError.ItemProgress(errorIcon, message);
+        progressWindowError.progress.setError();
+        progressWindowError.show();
+        progressWindowError.startCloseTimer(3000);
+    },
+    publishSuccess(title, message) {
+        var progressWindowSuccess = new Zotero.ProgressWindow({closeOnClick:true});
+        var successIcon = "chrome://zotero/skin/tick.png";
+        progressWindowSuccess.changeHeadline(title);
+        progressWindowSuccess.progress = new progressWindowSuccess.ItemProgress(successIcon, message);
+        progressWindowSuccess.show();
+        progressWindowSuccess.startCloseTimer(3000);
+    },
+    initializeProgress(title, message) {
+        var progressWindowProgress = new Zotero.ProgressWindow({closeOnClick:true});
+        var loadingIcon = "chrome://zotero/skin/spinner-16px.png";
+        progressWindowProgress.changeHeadline(title);
+        progressWindowProgress.progress = new progressWindowProgress.ItemProgress(loadingIcon, message);
+        progressWindowProgress.progress.setProgress(0);
+        progressWindowProgress.progress.setText(message);
+        progressWindowProgress.show();
+        return progressWindowProgress;
+        
+    },
+    publishProgress(handle, progress, message) {
+        var validated_progress = Math.min(Math.max(progress, 0), 100);
+        handle.progress.setProgress(validated_progress);
+        handle.progress.setText(message);
+        if (progress === 100) {
+            var successIcon = "chrome://zotero/skin/tick.png";
+            handle.progress.setIcon(successIcon);
+        }
+        handle.show();
+    },
+
+    fetchWithTimeout(url, requestInfo, timeout) {
+        const timeoutPromise = new Promise((_, reject) => {
+            setTimeout(() => {
+                reject(new Error('Request timed out'));
+            }, timeout);
+        });
+    
+        return Promise.race([
+            fetch(url, requestInfo),
+            timeoutPromise
+        ]);
+    },
+
+    safeGetFromJson(json, key_array) {
+        if (!json) {
+            return null;
+        }
+        var json_loc = json;
+        for (const key of key_array) {
+            if (key in json_loc) {
+                json_loc = json_loc[key];
+            } else {
+                return null;
+            }
+        }
+        return json_loc;
+    },
+    
+    isEmpty(value) {
+        if (typeof value === 'string') {
+            return value.trim() === '';
+        } else if (Array.isArray(value)) {
+            return value.length === 0;
+        } else if (typeof value === 'object' && value !== null) {
+            return Object.keys(value).length === 0;
+        } else {
+            return false;
+        }
+    }
+};
\ No newline at end of file
diff --git a/src/chrome/content/zotmeta.js b/src/chrome/content/zotmeta.js
new file mode 100644
index 0000000..66a6d22
--- /dev/null
+++ b/src/chrome/content/zotmeta.js
@@ -0,0 +1,217 @@
+ZotMeta = {
+    id: null,
+    version: null,
+    rootURI: null,
+    initialized: false,
+    addedElementIDs: [],
+
+    init({ id, version, rootURI } = {}) {
+        if (this.initialized) return;
+        this.id = id;
+        this.version = version;
+        this.rootURI = rootURI;
+        this.initialized = true;
+    },
+    
+    log(msg) {
+        Zotero.debug("ZotMeta: " + msg);
+    },
+
+    generateAuthors (author) {
+        var new_author_list = [];
+        if (author) {
+            author.forEach(element => {
+                new_author_list.push(
+                  {
+                    "firstName": element["given"],
+                    "lastName": element["family"],
+                    "creatorType": "author"
+                  }
+                )
+            });
+        }
+        return new_author_list;
+    },
+
+    generateDate (date) {
+        if (!date) {
+            return null;
+        }
+        if (date.length > 0) {
+            return date[0].join("-");
+        }
+        else {
+            return null;
+        }
+    },
+
+    getMetaData (item) {
+        var doi = item.getField('DOI');
+        if (item.itemTypeID !== Zotero.ItemTypes.getID('journalArticle')) {
+            Utilities.publishError("Unsupported Item Type", "Only Journal Article is supported.")
+            return;
+        }
+        if (!doi) {
+            // Utilities.publishError("DOI not found", "DOI is required to retrieve metadata.")
+            return;
+        }
+
+        var url = 'http://dx.doi.org/' + doi;
+        const headers = new Headers({'Accept': 'application/vnd.citationstyles.csl+json'});
+        var requestInfo = { method: 'GET', headers };
+        return Utilities.fetchWithTimeout(url, requestInfo, 3000)
+            .then(response => {
+                if (!response.ok) {
+                    Utilities.publishError("Error retrieving metadata", 
+                        "Please check if DOI is correct and if you have network access to dx.doi.org.");
+                    return null;
+                        
+                }
+                return response.text()
+            })
+            .then(data => {
+                try {
+                    return JSON.parse(data)
+                } catch (error) {
+                    return null;
+                }
+            })
+            .then(data_json => {
+                var Title = Utilities.safeGetFromJson(data_json, ["title"]);
+                var Authors = this.generateAuthors(Utilities.safeGetFromJson(data_json, ["author"]));
+                var Publication = Utilities.safeGetFromJson(data_json, ["container-title"]);
+                var Volume = Utilities.safeGetFromJson(data_json, ["volume"]);
+                var Issue = Utilities.safeGetFromJson(data_json, ["issue"]);
+                var Pages = Utilities.safeGetFromJson(data_json, ["page"]);
+                var PublishDate = this.generateDate(Utilities.safeGetFromJson(data_json, ["published", "date-parts"]));
+                var JournalAbbr = Utilities.safeGetFromJson(data_json, ["container-title-short"]);
+                var Language = Utilities.safeGetFromJson(data_json, ["language"]);
+                return {
+                            "Title": Title ? Title : "",
+                            "Authors": Authors ? Authors : "",
+                            "Publication": Publication ? Publication : "",
+                            "Volume": Volume ? Volume : "",
+                            "Issue": Issue ? Issue : "",
+                            "Pages": Pages ? Pages : "",
+                            "PublishDate": PublishDate ? PublishDate : "",
+                            "JournalAbbr": JournalAbbr ? JournalAbbr : "",
+                            "Language": Language ? Language : ""
+                        };
+            });
+    },
+      
+    async updateMetadata(item) {
+        var metaData = await this.getMetaData(item);
+        if (!metaData) {
+            return 1;
+        }
+        
+        if (!Utilities.isEmpty(metaData["Title"]))       item.setField('title',metaData["Title"]);
+        if (!Utilities.isEmpty(metaData["Authors"]))     item.setCreators(metaData["Authors"]);
+        if (!Utilities.isEmpty(metaData["Publication"])) item.setField('publicationTitle',metaData["Publication"]);
+        if (!Utilities.isEmpty(metaData["Volume"]))      item.setField('volume',metaData["Volume"]);
+        if (!Utilities.isEmpty(metaData["Issue"]))       item.setField('issue',metaData["Issue"]);
+        if (!Utilities.isEmpty(metaData["Pages"]))       item.setField('pages',metaData["Pages"]);
+        if (!Utilities.isEmpty(metaData["PublishDate"])) item.setField('date',metaData["PublishDate"]);
+        if (!Utilities.isEmpty(metaData["JournalAbbr"])) item.setField('journalAbbreviation',metaData["JournalAbbr"]);
+        if (!Utilities.isEmpty(metaData["Language"]))    item.setField('language',metaData["Language"]);
+        await item.saveTx();
+        return 0;
+    },
+
+    async updateSelectedItemsMetadata() {
+        var items = Zotero.getActiveZoteroPane().getSelectedItems();
+        var item_count = items.length;
+        if (item_count === 0) {
+            Utilities.publishSuccess("Finished", "No item is selected.")
+        }
+        var progress_handle = Utilities.initializeProgress("Updating metadata for " + item_count + " items...")
+
+        var pool = new ThreadPool(5);
+        var progress = 0;
+        var success_count = 0;
+        var failed_count = 0;
+        for (let i = 0; i < item_count; i++) {
+            pool.submit(async () => { 
+                var status = await this.updateMetadata(items[i]);
+                if (status === 0) {
+                    success_count++;
+                } else if(status === 1) {
+                    failed_count++;
+                }
+                progress++;
+                var progress_mapped = Math.round(progress / item_count * 100);
+                await Utilities.publishProgress(progress_handle, progress_mapped, progress + " out of " + item_count + " finished updating.");
+            });
+        }
+
+        pool.execute();
+        await pool.wait();
+        await Utilities.publishSuccess("Finished", success_count + " items updated, " + failed_count + " items failed.");
+    },
+
+    addToWindow(window) {
+        let doc = window.document;
+        
+        // createElementNS() necessary in Zotero 6; createElement() defaults to HTML in Zotero 7
+        let XUL_NS = "http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul";
+        
+        // Add menu option
+        let menuitem = doc.createElementNS(XUL_NS, 'menuitem');
+        menuitem.id = 'update-metadata';
+        menuitem.setAttribute('type', 'button');
+        menuitem.setAttribute('data-l10n-id', 'update-metadata');
+        menuitem.addEventListener('command', () => {
+            this.updateSelectedItemsMetadata();
+        });
+        doc.getElementById('zotero-itemmenu').appendChild(menuitem);
+        this.storeAddedElement(menuitem);
+        
+        // Use strings from zotmeta.ftl (Fluent) in Zotero 7
+        if (Zotero.platformMajorVersion >= 102) {
+            window.MozXULElement.insertFTLIfNeeded("zotmeta.ftl");
+        }
+        // Use strings from zotmeta.properties (legacy properties format) in Zotero 6
+        else {
+            let stringBundle = Services.strings.createBundle(
+                'chrome://zotmeta/locale/zotmeta.properties'
+            );
+            doc.getElementById('update-metadata')
+                .setAttribute('label', stringBundle.GetStringFromName('update-metadata.label'));
+        }
+    },
+    
+    addToAllWindows() {
+        var windows = Zotero.getMainWindows();
+        for (let win of windows) {
+            if (!win.ZoteroPane) continue;
+            this.addToWindow(win);
+        }
+    },
+    
+    storeAddedElement(elem) {
+        if (!elem.id) {
+            throw new Error("Element must have an id");
+        }
+        this.addedElementIDs.push(elem.id);
+    },
+    
+    removeFromWindow(window) {
+        var doc = window.document;
+        // Remove all elements added to DOM
+        for (let id of this.addedElementIDs) {
+            // ?. (null coalescing operator) not available in Zotero 6
+            let elem = doc.getElementById(id);
+            if (elem) elem.remove();
+        }
+        doc.querySelector('[href="zotmeta.ftl"]').remove();
+    },
+    
+    removeFromAllWindows() {
+        var windows = Zotero.getMainWindows();
+        for (let win of windows) {
+            if (!win.ZoteroPane) continue;
+            this.removeFromWindow(win);
+        }
+    },
+};
diff --git a/src/chrome/locale/en-US/zotmeta.properties b/src/chrome/locale/en-US/zotmeta.properties
new file mode 100644
index 0000000..97ec7ca
--- /dev/null
+++ b/src/chrome/locale/en-US/zotmeta.properties
@@ -0,0 +1 @@
+update-metadata.label = Update Metadata
diff --git a/src/defaults/preferences/prefs.js b/src/defaults/preferences/prefs.js
new file mode 100644
index 0000000..e69de29
diff --git a/src/install.rdf b/src/install.rdf
new file mode 100644
index 0000000..f35a02a
--- /dev/null
+++ b/src/install.rdf
@@ -0,0 +1,33 @@
+<?xml version="1.0"?>
+<RDF xmlns="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
+        xmlns:em="http://www.mozilla.org/2004/em-rdf#">
+
+    <Description about="urn:mozilla:install-manifest">
+        <em:id>zotmeta@roadtodream.tech</em:id>
+        <em:name>ZotMeta</em:name>
+        <em:version>1.0</em:version>
+        <em:multiprocessCompatible>true</em:multiprocessCompatible>
+        <em:updateURL>https://raw.githubusercontent.com/RoadToDream/ZotMeta/master/updates.json</em:updateURL>
+        <em:homepageURL>https://github.com/RoadToDream/ZotMeta</em:homepageURL>
+        <em:localized>
+            <Description>
+                <em:locale>en-US</em:locale>
+                <em:name>ZotMeta</em:name>
+                <em:description>Retrieve metadata for articles.</em:description>
+            </Description>
+        </em:localized>
+
+        <em:creator>Zotero</em:creator>
+        <em:type>2</em:type> <!-- type=extension -->
+        <em:iconURL>chrome://zotmeta/skin/icon.png</em:iconURL>
+        <em:icon64URL>chrome://zotmeta/skin/icon64.png</em:icon64URL>
+
+        <em:targetApplication>
+            <Description>
+                <em:id>zotero@chnm.gmu.edu</em:id>
+                <em:minVersion>6.0</em:minVersion>
+                <em:maxVersion>*</em:maxVersion>
+            </Description>
+        </em:targetApplication>
+    </Description>
+</RDF>
diff --git a/src/locale/en-US/zotmeta.ftl b/src/locale/en-US/zotmeta.ftl
new file mode 100644
index 0000000..7e6b98b
--- /dev/null
+++ b/src/locale/en-US/zotmeta.ftl
@@ -0,0 +1,2 @@
+update-metadata =
+    .label = Update Metadata
diff --git a/src/manifest.json b/src/manifest.json
new file mode 100644
index 0000000..0b83d9f
--- /dev/null
+++ b/src/manifest.json
@@ -0,0 +1,15 @@
+{
+    "manifest_version": 2,
+    "name": "ZotMeta",
+    "version": "1.0",
+    "description": "ZotMeta",
+    "homepage_url": "https://github.com/RoadToDream/ZotMeta",
+    "applications": {
+        "zotero": {
+            "id": "zotmeta@roadtodream.tech",
+            "update_url": "https://raw.githubusercontent.com/RoadToDream/ZotMeta/master/updates.json",
+            "strict_min_version": "6.999",
+            "strict_max_version": "7.0.*"
+        }
+    }
+}
diff --git a/updates.json b/updates.json
new file mode 100644
index 0000000..6f9519b
--- /dev/null
+++ b/updates.json
@@ -0,0 +1,21 @@
+{
+  "addons": {
+    "zotmeta@roadtodream.tech": {
+      "updates": [
+        {
+          "version": "1.0",
+          "update_link": "https://github.com/RoadToDream/ZotMeta/releases/download/v1.0/zotmeta-1.0.xpi",
+          "update_hash": "sha256:06d19b3c13b663c806f9ed3dad4a18a005eb04d2094533d452299d22f62e0ae3",
+          "applications": {
+            "gecko": {
+              "strict_min_version": "60.0"
+            },
+            "zotero": {
+              "strict_min_version": "6.999"
+            }
+          }
+        }
+      ]
+    }
+  }
+}
diff --git a/updates.json.tmpl b/updates.json.tmpl
new file mode 100644
index 0000000..a88c28f
--- /dev/null
+++ b/updates.json.tmpl
@@ -0,0 +1,21 @@
+{
+  "addons": {
+    "zotmeta@roadtodream.tech": {
+      "updates": [
+        {
+          "version": "1.0",
+          "update_link": "",
+          "update_hash": "",
+          "applications": {
+            "gecko": {
+              "strict_min_version": "60.0"
+            },
+            "zotero": {
+              "strict_min_version": "6.999"
+            }
+          }
+        }
+      ]
+    }
+  }
+}