From f3ec6a1ae3813e4a29b6ed90a66f7b169b4d5344 Mon Sep 17 00:00:00 2001
From: RecursiveGreen <recursive.green@gmail.com>
Date: Thu, 6 Jun 2019 15:45:25 -0400
Subject: [PATCH] Create a custom validator for the radio IRI.

---
 savepointradio/core/utils.py      |  3 +-
 savepointradio/core/validators.py | 58 +++++++++++++++++++++++++++++++
 2 files changed, 60 insertions(+), 1 deletion(-)
 create mode 100644 savepointradio/core/validators.py

diff --git a/savepointradio/core/utils.py b/savepointradio/core/utils.py
index f9af9b0..0d904db 100644
--- a/savepointradio/core/utils.py
+++ b/savepointradio/core/utils.py
@@ -17,6 +17,7 @@ from django.db import connection
 from django.utils.encoding import iri_to_uri, uri_to_iri
 
 from .models import Setting
+from .validators import GROUP_NT_DRIVE_LETTER, GROUP_NT_UNC
 
 
 def generate_password(length=32):
@@ -165,7 +166,7 @@ def iri_to_path(iri):
     # Drive letter IRI will have three slashes followed by the drive letter
     # UNC path IRI will have two slashes followed by the UNC path
     uri = iri_to_uri(iri)
-    patt = r'^(?:file:///[A-Za-z]:/|file://[A-Za-z0-9!@#$%^&\'\)\(\.\-_{}~]+/)'
+    patt = r'^(?:' + GROUP_NT_DRIVE_LETTER + r'|' + GROUP_NT_UNC + r')'
     windows = re.match(patt, uri)
     if windows:
         parse = urlparse(uri)
diff --git a/savepointradio/core/validators.py b/savepointradio/core/validators.py
new file mode 100644
index 0000000..6030762
--- /dev/null
+++ b/savepointradio/core/validators.py
@@ -0,0 +1,58 @@
+'''
+Custom Django model/form field validators for the Save Point Radio project.
+'''
+
+import re
+
+from django.core import validators
+from django.core.exceptions import ValidationError
+from django.utils.translation import gettext_lazy as _
+
+
+GROUP_NT_UNC = r'file://[A-Za-z0-9!@#$%^&\'\)\(\.\-_{}~]+/'
+
+GROUP_NT_DRIVE_LETTER = r'file:///[A-Za-z](?:\:|\|)/'
+
+GROUP_NON_AUTH = r'file:///[A-Za-z0-9!@#$%^&\'\)\(\.\-_{}~]+'
+
+FILE_IRI_PATTERN = (
+    r'^(?P<unc>' +
+    GROUP_NT_UNC +
+    r')|(?P<driveletter>' +
+    GROUP_NT_DRIVE_LETTER +
+    r')|(?P<nonauth>' +
+    GROUP_NON_AUTH +
+    r')'
+)
+
+
+class RadioIRIValidator(validators.URLValidator):
+    '''
+    Validates an RFC3987-defined IRI along with RFC8089 for file:// and other
+    custom schemes.
+    '''
+
+    message = _('Enter a valid IRI.')
+    schemes = ['http', 'https', 'file', 'ftp', 'ftps', 's3']
+
+    def __init__(self, schemes=None, **kwargs):
+        super().__init__(**kwargs)
+        if schemes is not None:
+            self.schemes = schemes
+
+    def __call__(self, value):
+        # Check the schemes first
+        scheme = value.split('://')[0].lower()
+        if scheme not in self.schemes:
+            raise ValidationError(self.message, code=self.code)
+
+        # Ignore the non-standard IRI
+        if scheme == 'file':
+            pattern = re.compile(FILE_IRI_PATTERN)
+            if not pattern.match(value):
+                raise ValidationError(self.message, code=self.code)
+        elif scheme == 's3':
+            # Nothing to validate, really. . .
+            return
+        else:
+            super().__call__(value)