1 files changed, 78 insertions, 0 deletions
diff --git a/web-server/opendc/util/parameter_checker.py b/web-server/opendc/util/parameter_checker.py
new file mode 100644
index 00000000..f55e780e
--- /dev/null
+++ b/web-server/opendc/util/parameter_checker.py
@@ -0,0 +1,78 @@
+from opendc.util import database, exceptions
+
+
+def _missing_parameter(params_required, params_actual, parent=''):
+    """Recursively search for the first missing parameter."""
+
+    for param_name in params_required:
+
+        if param_name not in params_actual:
+            return '{}.{}'.format(parent, param_name)
+
+        param_required = params_required.get(param_name)
+        param_actual = params_actual.get(param_name)
+
+        if isinstance(param_required, dict):
+
+            param_missing = _missing_parameter(param_required, param_actual, param_name)
+
+            if param_missing is not None:
+                return '{}.{}'.format(parent, param_missing)
+
+    return None
+
+
+def _incorrect_parameter(params_required, params_actual, parent=''):
+    """Recursively make sure each parameter is of the correct type."""
+
+    for param_name in params_required:
+
+        param_required = params_required.get(param_name)
+        param_actual = params_actual.get(param_name)
+
+        if isinstance(param_required, dict):
+
+            param_incorrect = _incorrect_parameter(param_required, param_actual, param_name)
+
+            if param_incorrect is not None:
+                return '{}.{}'.format(parent, param_incorrect)
+
+        else:
+
+            if param_required == 'datetime':
+                try:
+                    database.string_to_datetime(param_actual)
+                except:
+                    return '{}.{}'.format(parent, param_name)
+
+            if param_required == 'int' and not isinstance(param_actual, int):
+                return '{}.{}'.format(parent, param_name)
+
+            if param_required == 'string' and not isinstance(param_actual, str) and not isinstance(param_actual, int):
+                return '{}.{}'.format(parent, param_name)
+
+            if param_required.startswith('list') and not isinstance(param_actual, list):
+                return '{}.{}'.format(parent, param_name)
+
+
+def _format_parameter(parameter):
+    """Format the output of a parameter check."""
+
+    parts = parameter.split('.')
+    inner = ['["{}"]'.format(x) for x in parts[2:]]
+    return parts[1] + ''.join(inner)
+
+
+def check(request, **kwargs):
+    """Return True if all required parameters are there."""
+
+    for location, params_required in kwargs.items():
+        params_actual = getattr(request, 'params_{}'.format(location))
+
+        missing_parameter = _missing_parameter(params_required, params_actual)
+        if missing_parameter is not None:
+            raise exceptions.MissingParameterError(_format_parameter(missing_parameter), location)
+
+        incorrect_parameter = _incorrect_parameter(params_required, params_actual)
+        if incorrect_parameter is not None:
+            raise exceptions.IncorrectParameterError(_format_parameter(incorrect_parameter), location)