1 files changed, 96 insertions, 0 deletions
diff --git a/day9/task5_vue/backend/database/validators.py b/day9/task5_vue/backend/database/validators.py
new file mode 100644
index 0000000..e4b7310
--- /dev/null
+++ b/day9/task5_vue/backend/database/validators.py
@@ -0,0 +1,96 @@
+from abc import ABC, abstractmethod
+import re
+
+
+class ValidationError(Exception):
+    pass
+
+
+class Validator(ABC):
+    @staticmethod
+    @abstractmethod
+    def validate(value, field_object):
+        pass
+
+
+class ValidateNull(Validator):
+    @staticmethod
+    def validate(value, field_object):
+        if value is None and not field_object.nullable:
+            raise ValidationError('Value cannot be NULL')
+
+
+class ValidateType(Validator):
+    @staticmethod
+    def validate(value, field_object):
+        if field_object.nullable and value is None:
+            return
+        if not isinstance(value, field_object.data_type):
+            raise ValidationError('Value is of wrong type')
+
+
+class ValidateLength(Validator):
+    @staticmethod
+    def validate(value, field_object):
+        if len(str(value)) > field_object.max_length:
+            raise ValidationError('Value has too many digits')
+
+
+class ValidateTime(Validator):
+    @staticmethod
+    def validate(value, field_object):
+        match = re.fullmatch(r'(\d\d):(\d\d):(\d\d)', value)
+        if not match:
+            raise ValidationError('Wrong time format')
+        else:
+            hour, minute, second = map(int, match.groups())
+            if hour not in range(0, 24):
+                raise ValidationError('Wrong hour value')
+
+            if minute not in range(0, 60):
+                raise ValidationError('Wrong minute value')
+
+            if second not in range(0, 60):
+                raise ValidationError('Wrong second value')
+
+
+class ValidateDate(Validator):
+    @staticmethod
+    def validate(value, field_object):
+        match = re.fullmatch(r'(\d\d\d\d)-(\d\d)-(\d\d)', value)
+        if not match:
+            raise ValidationError('Wrong date format')
+        else:
+            year, month, day = map(int, match.groups())
+            if year < 0:
+                raise ValidationError('Wrong year value')
+
+            if month not in range(1, 12):
+                raise ValidationError('Wrong month value')
+
+            if month == 2:
+                if year % 4 == 0 and year % 100 != 0 or year % 400 == 0:
+                    febr_range = range(1, 29)
+                else:
+                    febr_range = range(1, 28)
+                if day not in febr_range:
+                    raise ValidationError('Wrong day value')
+            else:
+                days_count = {
+                    1: 31, 3: 31, 4: 30, 5: 31,
+                    6: 30, 7: 31, 8: 31, 9: 30,
+                    10: 31, 11: 30, 12: 31
+                }.get(month)
+                if day not in range(1, days_count):
+                    raise ValidationError('Wrong day value')
+
+
+class ValidateDatetime(Validator):
+    @staticmethod
+    def validate(value, field_object):
+        datetime = value.split()
+        if len(datetime) != 2:
+            raise ValidationError('Wrong datetime format')
+        else:
+            ValidateDate.validate(datetime[0], {})
+            ValidateTime.validate(datetime[1], {})
+\ No newline at end of file