[ADD] CSS compression on save

allianceauth/custom_css/models.py

@@ -2,10 +2,15 @@
 Models for the custom_css app
 """
 
+import hashlib
+import re
+import sys
+
 # Alliance Auth Framework
 from allianceauth.framework.models import SingletonModel
 
 # Django
+from django.conf import settings
 from django.db import models
 from django.utils.translation import gettext_lazy as _
 
@@ -21,6 +26,7 @@ class CustomCSS(SingletonModel):
         verbose_name=_("Your custom CSS"),
         help_text=_("This CSS will be added to the site after the default CSS."),
     )
+    timestamp = models.DateTimeField(auto_now=True)
 
     class Meta:
         """
@@ -32,4 +38,99 @@ class CustomCSS(SingletonModel):
         verbose_name_plural = _("Custom CSS")
 
     def __str__(self) -> str:
+        """
+        String representation of CustomCSS
+
+        :return:
+        :rtype:
+        """
+
         return str(_("Custom CSS"))
+
+    def save(self, *args, **kwargs):
+        """
+        Save method for CustomCSS
+
+        :param args:
+        :type args:
+        :param kwargs:
+        :type kwargs:
+        :return:
+        :rtype:
+        """
+
+        self.pk = 1
+
+        custom_css_file = open(
+            f"{settings.STATIC_ROOT}allianceauth/custom-styles.css", "w+"
+        )
+        custom_css_file.write(self.compress_css())
+        custom_css_file.close()
+
+        super().save(*args, **kwargs)
+
+    def compress_css(self) -> str:
+        """
+        Compress CSS
+
+        :return:
+        :rtype:
+        """
+
+        css = self.css
+        new_css = ""
+
+        # Remove comments
+        css = re.sub(pattern=r"\s*/\*\s*\*/", repl="$$HACK1$$", string=css)
+        css = re.sub(pattern=r"/\*[\s\S]*?\*/", repl="", string=css)
+        css = css.replace("$$HACK1$$", "/**/")
+
+        # url() doesn't need quotes
+        css = re.sub(pattern=r'url\((["\'])([^)]*)\1\)', repl=r"url(\2)", string=css)
+
+        # Spaces may be safely collapsed as generated content will collapse them anyway.
+        css = re.sub(pattern=r"\s+", repl=" ", string=css)
+
+        # Shorten collapsable colors: #aabbcc to #abc
+        css = re.sub(
+            pattern=r"#([0-9a-f])\1([0-9a-f])\2([0-9a-f])\3(\s|;)",
+            repl=r"#\1\2\3\4",
+            string=css,
+        )
+
+        # Fragment values can loose zeros
+        css = re.sub(
+            pattern=r":\s*0(\.\d+([cm]m|e[mx]|in|p[ctx]))\s*;", repl=r":\1;", string=css
+        )
+
+        for rule in re.findall(pattern=r"([^{]+){([^}]*)}", string=css):
+            # We don't need spaces around operators
+            selectors = [
+                re.sub(
+                    pattern=r"(?<=[\[\(>+=])\s+|\s+(?=[=~^$*|>+\]\)])",
+                    repl=r"",
+                    string=selector.strip(),
+                )
+                for selector in rule[0].split(",")
+            ]
+
+            # Order is important, but we still want to discard repetitions
+            properties = {}
+            porder = []
+
+            for prop in re.findall(pattern="(.*?):(.*?)(;|$)", string=rule[1]):
+                key = prop[0].strip().lower()
+
+                if key not in porder:
+                    porder.append(key)
+
+                properties[key] = prop[1].strip()
+
+            # output rule if it contains any declarations
+            if properties:
+                new_css += "{}{{{}}}".format(
+                    ",".join(selectors),
+                    "".join([f"{key}:{properties[key]};" for key in porder])[:-1],
+                )
+
+        return new_css