Created Friends List database helper

.idea/misc.xml

@@ -55,7 +55,7 @@
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     <ConfirmationsSetting value="0" id="Remove" />
   </component>
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_1_8" default="true" assert-keyword="true" jdk-15="true" project-jdk-name="1.8" project-jdk-type="JavaSDK">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_1_7" default="true" assert-keyword="true" jdk-15="true" project-jdk-name="1.8" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/build/classes" />
   </component>
   <component name="ProjectType">

app/src/main/java/org/communiquons/android/comunic/client/data/friendsList/FriendsListDbHelper.java

@@ -0,0 +1,178 @@
+package org.communiquons.android.comunic.client.data.friendsList;
+
+import android.content.ContentValues;
+import android.database.Cursor;
+import android.database.sqlite.SQLiteDatabase;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+
+import org.communiquons.android.comunic.client.data.DatabaseHelper;
+import org.communiquons.android.comunic.client.data.DatabaseContract.FriendsListSchema;
+
+import java.util.ArrayList;
+
+/**
+ * Friends list helper
+ *
+ * This file makes the interface between the application and the database.
+ *
+ * @author Pierre HUBERT
+ * Created by pierre on 11/18/17.
+ */
+
+public class FriendsListDbHelper {
+
+    /**
+     * Database helper
+     */
+    private DatabaseHelper dbHelper;
+
+    /**
+     * Public constructor
+     *
+     * @param dbHelper Database helper, required to etablish the connexion with the database
+     */
+    public FriendsListDbHelper(DatabaseHelper dbHelper){
+        this.dbHelper = dbHelper;
+    }
+
+    /**
+     * Retrieve the list of friends
+     *
+     * @return The list of friends of the user or null in case of failure
+     */
+    @Nullable
+    ArrayList<Friend> get_list(){
+
+        //Get read access to the database
+        SQLiteDatabase db = dbHelper.getReadableDatabase();
+
+        //Prepare the request on the database
+        String table_name = FriendsListSchema.TABLE_NAME;
+        String[] columns = {
+                FriendsListSchema.COLUMN_NAME_FRIEND_ID,
+                FriendsListSchema.COLUMN_NAME_FRIEND_ACCEPTED,
+                FriendsListSchema.COLUMN_NAME_FRIEND_FOLLOWING,
+                FriendsListSchema.COLUMN_NAME_FRIEND_LAST_ACTIVITY
+        };
+        String order = FriendsListSchema._ID;
+
+        //Perform the request
+        Cursor c = db.query(table_name, columns, null, null, null, null, order);
+
+        //Check if the request echoed
+        if(c == null)
+            return null; //An error occurred
+
+        ArrayList<Friend> friendsList = new ArrayList<>();
+
+        //Process the list of responses
+        c.moveToFirst();
+        for(int i = 0; i < c.getCount(); i++){
+
+            //Get information about the friend
+            Friend friend = new Friend();
+
+            friend.setId(c.getInt(c.getColumnIndexOrThrow(
+                    FriendsListSchema.COLUMN_NAME_FRIEND_ID)));
+
+            friend.setAccepted(c.getInt(c.getColumnIndexOrThrow(
+                    FriendsListSchema.COLUMN_NAME_FRIEND_ACCEPTED)) == 1);
+
+            friend.setFollowing(c.getInt(c.getColumnIndexOrThrow(
+                    FriendsListSchema.COLUMN_NAME_FRIEND_FOLLOWING)) == 1);
+
+            friend.setLast_activity(c.getInt(c.getColumnIndexOrThrow(
+                    FriendsListSchema.COLUMN_NAME_FRIEND_LAST_ACTIVITY)));
+
+            //Add the friend to the list
+            friendsList.add(friend);
+
+            //Move to the next friend
+            if(!c.moveToNext())
+                break;
+        }
+
+        //Close cursor
+        c.close();
+
+        //Close the access to the database
+        db.close();
+
+        return friendsList;
+    }
+
+    /**
+     * Update the entire list of friends
+     *
+     * @param friendsList The new list of friend to insert in the database
+     * @return The result of the operation
+     */
+    public boolean update_list(@NonNull ArrayList<Friend> friendsList){
+
+        //First, remove all entries from the database
+        remove_all();
+
+        //Get writable access to the database
+        SQLiteDatabase db = dbHelper.getWritableDatabase();
+
+        //Process the list of user
+        boolean success = true;
+        for(Friend friend : friendsList){
+            success = insert_user(db, friend) && success;
+        }
+
+        //Close the database
+        db.close();
+
+        return success;
+    }
+
+
+    /**
+     * Insert a single user in the database
+     *
+     * @param db Access to the database
+     * @param friend The friend to insert
+     * @return True in case of success / false else
+     */
+    private boolean insert_user(SQLiteDatabase db, Friend friend){
+
+        //Prepare the query
+        String table_name = FriendsListSchema.TABLE_NAME;
+        String nullColumnHack = null;
+
+        //Set the values
+        ContentValues values = new ContentValues();
+        values.put(FriendsListSchema.COLUMN_NAME_FRIEND_ID, friend.getId());
+        values.put(FriendsListSchema.COLUMN_NAME_FRIEND_ACCEPTED, friend.isAccepted() ? 1 : 0);
+        values.put(FriendsListSchema.COLUMN_NAME_FRIEND_FOLLOWING, friend.isFollowing() ? 1 : 0);
+        values.put(FriendsListSchema.COLUMN_NAME_FRIEND_LAST_ACTIVITY, friend.getLast_activity());
+
+        //Perform the query
+        return db.insert(table_name, nullColumnHack, values) > -1;
+    }
+
+    /**
+     * Remove all the friend entries from the database
+     *
+     * @return The number of affected rows
+     */
+    public int remove_all(){
+
+        //Get writable database access
+        SQLiteDatabase db = dbHelper.getWritableDatabase();
+
+        //Prepare the request
+        String table_name = FriendsListSchema.TABLE_NAME;
+        String whereClause = FriendsListSchema._ID + " > 0";
+        String[] whereArgs = new String[0];
+
+        int result = db.delete(table_name, whereClause, whereArgs);
+
+        //Close the database
+        db.close();
+
+        return result;
+    }
+}