CRM-19151: Add the ability to merge memberships without data loss

CRM/Dedupe/Merger.php

@@ -322,6 +322,7 @@ public static function cpTables() {
         // Empty array == do nothing - this table is handled by mergeGroupContact
         'civicrm_subscription_history' => array(),
         'civicrm_relationship' => array('CRM_Contact_BAO_Relationship' => 'mergeRelationships'),
+        'civicrm_membership' => array('CRM_Member_BAO_Membership' => 'mergeMemberships'),
       );
     }
     return $tables;
@@ -518,7 +519,7 @@ public static function moveContactBelongings($mainId, $otherId, $tables = FALSE,
       // Call custom processing function for objects that require it
       if (isset($cpTables[$table])) {
         foreach ($cpTables[$table] as $className => $fnName) {
-          $className::$fnName($mainId, $otherId, $sqls);
+          $className::$fnName($mainId, $otherId, $sqls, $tables, $tableOperations);
         }
         // Skip normal processing
         continue;

CRM/Member/BAO/Membership.php

@@ -2570,4 +2570,131 @@ public static function getContactsCancelledMembership($contactID, $isTest = FALS
     return $cancelledMembershipIds;
   }
 
+  /**
+   * Merges the memberships from otherContactID to mainContactID.
+   *
+   * General idea is to merge memberships in regards to their type. We
+   * move the other contact’s contributions to the main contact’s
+   * membership which has the same type (if any) and then we update
+   * membership to avoid loosing `join_date`, `end_date`, and
+   * `status_id`. In this function, we don’t touch the contributions
+   * directly (CRM_Dedupe_Merger::moveContactBelongings() takes care
+   * of it).
+   *
+   * This function adds new SQL queries to the $sqlQueries parameter.
+   *
+   * @param int $mainContactID
+   *   Contact id of main contact record.
+   * @param int $otherContactID
+   *   Contact id of record which is going to merge.
+   * @param array $sqlQueries
+   *   (reference) array of SQL queries to be executed.
+   * @param array $tables
+   *   List of tables that have to be merged.
+   * @param array $tableOperations
+   *   Special options/params for some tables to be merged.
+   *
+   * @see CRM_Dedupe_Merger::cpTables()
+   */
+  public static function mergeMemberships($mainContactID, $otherContactID, &$sqlQueries, $tables, $tableOperations) {
+    /*
+     * If the user requests not to merge memberships but to add them,
+     * just attribute the `civicrm_membership` to the
+     * `$mainContactID`. We have to do this here since the general
+     * merge process is bypassed by this function.
+     */
+    if (array_key_exists("civicrm_membership", $tableOperations) && $tableOperations['civicrm_membership']['add']) {
+      $sqlQueries[] = "UPDATE IGNORE civicrm_membership SET contact_id = $mainContactID WHERE contact_id = $otherContactID";
+      return;
+    }
+
+    /*
+     * Retrieve all memberships that belongs to each contacts and
+     * keep track of each membership type.
+     */
+    $mainContactMemberships = array();
+    $otherContactMemberships = array();
+
+    $sql = "SELECT id, membership_type_id FROM civicrm_membership membership WHERE contact_id = %1";
+    $dao = CRM_Core_DAO::executeQuery($sql, array(1 => array($mainContactID, "Integer")));
+    while ($dao->fetch()) {
+      $mainContactMemberships[$dao->id] = $dao->membership_type_id;
+    }
+
+    $dao = CRM_Core_DAO::executeQuery($sql, array(1 => array($otherContactID, "Integer")));
+    while ($dao->fetch()) {
+      $otherContactMemberships[$dao->id] = $dao->membership_type_id;
+    }
+
+    /*
+     * For each membership, move related contributions to the main
+     * contact’s membership (by updating `membership_payments`). Then,
+     * update membership’s `join_date` (if the other membership’s
+     * join_date is older) and `end_date` (if the other membership’s
+     * `end_date` is newer) and `status_id` (if the newly calculated
+     * status is different).
+     *
+     * FIXME: what should we do if we have multiple memberships with
+     * the same type (currently we only take the first one)?
+     */
+    $newSql = array();
+    foreach ($otherContactMemberships as $otherMembershipId => $otherMembershipTypeId) {
+      if ($newMembershipId = array_search($otherMembershipTypeId, $mainContactMemberships)) {
+
+        /*
+         * Move other membership’s contributions to the main one only
+         * if user requested to merge contributions.
+         */
+        if (!empty($tables) && in_array('civicrm_contribution', $tables)) {
+          $newSql[] = "UPDATE civicrm_membership_payment SET membership_id=$newMembershipId WHERE membership_id=$otherMembershipId";
+        }
+
+        $sql = "SELECT * FROM civicrm_membership membership WHERE id = %1";
+
+        $newMembership = CRM_Member_DAO_Membership::findById($newMembershipId);
+        $otherMembership = CRM_Member_DAO_Membership::findById($otherMembershipId);
+
+        $updates = array();
+        if (new DateTime($otherMembership->join_date) < new DateTime($newMembership->join_date)) {
+          $updates["join_date"] = $otherMembership->join_date;
+        }
+
+        if (new DateTime($otherMembership->end_date) > new DateTime($newMembership->end_date)) {
+          $updates["end_date"] = $otherMembership->end_date;
+        }
+
+        if (count($updates)) {
+
+          /*
+           * Update status
+           */
+          $status = CRM_Member_BAO_MembershipStatus::getMembershipStatusByDate(
+            isset($updates["start_date"]) ? $updates["start_date"] : $newMembership->start_date,
+            isset($updates["end_date"]) ? $updates["end_date"] : $newMembership->end_date,
+            isset($updates["join_date"]) ? $updates["join_date"] : $newMembership->join_date,
+            'today',
+            FALSE,
+            $newMembershipId,
+            $newMembership
+          );
+
+          if (!empty($status['id']) and $status['id'] != $newMembership->status_id) {
+            $updates['status_id'] = $status['id'];
+          }
+
+          $updates_sql = [];
+          foreach ($updates as $k => $v) {
+            $updates_sql[] = "$k = '{$v}'";
+          }
+
+          $newSql[] = sprintf("UPDATE civicrm_membership SET %s WHERE id=%s", implode(", ", $updates_sql), $newMembershipId);
+          $newSql[] = sprintf("DELETE FROM civicrm_membership WHERE id=%s", $otherMembershipId);
+        }
+
+      }
+    }
+
+    $sqlQueries = array_merge($sqlQueries, $newSql);
+  }
+
 }