Flag duplicate clients/leads when using the client_add modal

agent/ajax.php

@@ -675,3 +675,27 @@ if (isset($_POST['update_recurring_invoice_items_order'])) {
     echo json_encode(['status' => 'success']);
     exit;
 }
+
+if (isset($_GET['client_duplicate_check'])) {
+    enforceUserPermission('module_client', 2);
+
+    $name = sanitizeInput($_GET['name']);
+
+    $response['message'] = ""; // default
+
+    if (strlen($name) >= 5) {
+        $sql_clients = mysqli_query($mysqli, "SELECT client_name FROM clients
+        WHERE client_archived_at IS NULL
+        AND client_name LIKE '%$name%'
+        ORDER BY client_id DESC LIMIT 1"
+        );
+
+        if (mysqli_num_rows($sql_clients) > 0) {
+            while ($row = mysqli_fetch_array($sql_clients)) {
+                $response['message'] = "<i class='fas fa-fw fa-copy mr-2'></i> Potential duplicate: <i>" . nullable_htmlentities($row['client_name']) . "</i> already exists.";
+            }
+        }
+    }
+
+    echo json_encode($response);
+}

agent/modals/client/client_add.php

@@ -55,13 +55,16 @@ ob_start();
                         <div class="input-group-prepend">
                             <span class="input-group-text"><i class="fa fa-fw fa-user"></i></span>
                         </div>
-                        <input type="text" class="form-control" name="name" placeholder="Name or Company" maxlength="200" required autofocus>
+                        <input type="text" class="form-control" name="name" id="client_name" placeholder="Name or Company" maxlength="200" onfocusout="client_duplicate_check()" required autofocus>
                         <div class="input-group-append">
                             <div class="input-group-text">
                                 <input type="checkbox" name="lead" value="1" <?php if($leads_filter == 1){ echo "checked"; } ?>>
                             </div>
                         </div>
                     </div>
+                    <div class="mt-2">
+                        <span class="text-info" id="client_duplicate_info"></span>
+                    </div>
                 </div>
 
                 <div class="form-group">
@@ -392,5 +395,22 @@ ob_start();
     }
 </script>
 
+<script>
+    // Checks for duplicate clients
+    function client_duplicate_check() {
+        var name = document.getElementById("client_name").value;
+        //Send a GET request to ajax.php as ajax.php?client_duplicate_check=true&name=NAME
+        jQuery.get(
+            "ajax.php",
+            {client_duplicate_check: 'true', name: name},
+            function(data) {
+                //If we get a response from ajax.php, parse it as JSON
+                const client_duplicate_data = JSON.parse(data);
+                document.getElementById("client_duplicate_info").innerHTML = client_duplicate_data.message;
+            }
+        );
+    }
+</script>
+
 <?php
 require_once '../../../includes/modal_footer.php';