1 files changed, 94 insertions, 0 deletions
diff --git a/src/Validator.php b/src/Validator.php
new file mode 100644
index 0000000..33cdf34
--- /dev/null
+++ b/src/Validator.php
@@ -0,0 +1,94 @@
+<?php
+
+namespace FlatFileForms;
+
+class Validator
+{
+  public function __construct(
+    private string $formPath
+  )
+  {}
+
+  public function validateRequest(array $fields): array
+  {
+    /**@var Utilities $utilities*/
+    global $utilities;
+
+    $result = [];
+    $hasInvalidFields = false;
+
+    $fields = $this->validateFields($fields);
+
+    if ($utilities->isPagedFieldSet($fields)) {
+      // remove surplus field values from response
+      $fields = array_map(function ($page) {
+        return array_map(function ($field) {
+          return array_intersect_key($field, array_flip([
+            'is_valid',
+          ]));
+        }, $page);
+      }, $fields);
+
+      $flattened = array_merge(...array_values($fields));
+      $hasInvalidFields = in_array(false, array_column($flattened, 'is_valid'));
+    } else {
+      // remove surplus field values from response
+      $fields = array_map(function ($field) {
+        return array_intersect_key($field, array_flip([
+          'is_valid',
+        ]));
+      }, $fields);
+
+      $hasInvalidFields = in_array(false, array_column($fields, 'is_valid'));
+    }
+
+    $result['fields'] = $fields;
+
+    if ($hasInvalidFields) {
+      $result['error'] = 'invalid fields';
+    }
+
+    return $result;
+  }
+
+  public function validateFields(array $fields): array
+  {
+    /**@var Utilities $utilities*/
+    global $utilities;
+
+    if ($utilities->isPagedFieldSet($fields)) {
+      foreach ($fields as $pageKey => &$pageFields) {
+        foreach ($pageFields as $key => &$field) {
+          $field = $this->validateSingleField($field);
+        }
+      }
+    } else {
+      foreach ($fields as $key => &$field) {
+        $field = $this->validateSingleField($field);
+      }
+    }
+
+    return $fields;
+  }
+
+  public function validateSingleField(array $field): array
+  {
+    $value = $_POST[$field['name']] ?? '';
+    $field['is_valid'] = true;
+
+    if (isset($field['required']) && empty($value)) {
+      $field['is_valid'] = false;
+    }
+
+    if (isset($field['validation']['pattern']) && preg_match_all('/' . $field['validation']['pattern'] . '/', $value) === 0) {
+      $field['is_valid'] = false;
+    }
+
+    $validationFunctionName = 'validate_' . basename($this->formPath) . '_' . $field['name'];
+    if (function_exists($validationFunctionName)) {
+      $field = call_user_func($validationFunctionName, $field, $value);
+    }
+
+    return $field;
+  }
+}