Download from API (#593)

* fix duplicated download screen in nav stack

* fix: reset to Installation tab's root when app is reopened

* init add contracts and update query nouns

* "Noun annotation: update queryNounForm based on gender contract"

* Restore DACommandVariables.swift

* Plural command: update query for plural command and add plural annotation

* Noun annotation: fix multiple annotation case

* Preposition annotation: update queryPrepForm and add conversion preposition to abbreviation

* Conjugate: use dynamic conjugation and declension

* Declension: move declension contract to main contract file

* Conjugation and declension: add function documentation and fix comments

* Add YAML version of data contracts

* Minor fix in comment in contracts

* feat: change to using YAML contract

* feat: API call and write into sqlite db

* feat: initialize download button state

* feat: All languages button download state and handle click

* feat: initialize button states on "Check for new data"

* feat: remove built in database and read from new downloaded one

* add comments for new functions

---------

Co-authored-by: Andrew Tavis McAllister <andrew.t.mcallister@gmail.com>

Author: catreedle

Keyboards/Data/DELanguageData.sqlite

@@ -16,7 +16,7 @@ class LanguageDBManager {
     if translate {
       database = openDBQueue("TranslationData")
     } else {
-      database = openDBQueue("\(getControllerLanguageAbbr().uppercased())LanguageData")
+      database = openDownloadedDBQueue("\(getControllerLanguageAbbr().uppercased())LanguageData")
     }
   }
 
@@ -42,6 +42,21 @@ class LanguageDBManager {
     }
   }
 
+  /// Opens a connection to the downloaded language database for the current language.
+  private func openDownloadedDBQueue(_ dbName: String) -> DatabaseQueue? {
+    let fileManager = FileManager.default
+    guard let containerURL = fileManager.containerURL(forSecurityApplicationGroupIdentifier: "group.be.scri.userDefaultsContainer") else {
+        print("App group container not found")
+        return nil
+    }
+    let dbPath = containerURL.appendingPathComponent("\(dbName).sqlite").path
+    guard fileManager.fileExists(atPath: dbPath) else {
+        print("\(dbName).sqlite not found in app group container")
+        return nil
+    }
+    return try? DatabaseQueue(path: dbPath)
+}
+
   /// Loads a JSON file that contains grammatical information into a dictionary.
   ///
   /// - Parameters

Keyboards/Data/ENLanguageData.sqlite

@@ -457,7 +457,7 @@ class KeyboardViewController: UIInputViewController {
         // Get options for completion that start with the current prefix and are not just one letter.
         let completionOptions = LanguageDBManager.shared.queryAutocompletions(word: currentPrefix)
 
-        if !completionOptions[0].isEmpty {
+        if !completionOptions.isEmpty && !completionOptions[0].isEmpty {
           if completionOptions.count <= 3 {
             for i in 0 ..< completionOptions.count {
               if shiftButtonState == .shift {