moving hsla color computation into the model

src/viralhostrange/viralhostrangedb/models.py

@@ -59,6 +59,33 @@ class GlobalViralHostResponseValue(models.Model):
         )
         return h * 360, s * 100, v * 50
 
+    @classmethod
+    def get_hsv_color_for(cls, value):
+        lower = cls.objects_mappable().filter(value__lte=value).order_by("-value").first()
+        upper = cls.objects_mappable().filter(value__gte=value).order_by("value").first()
+        lower_hsv = lower.to_hsv()
+        upper_hsv = upper.to_hsv()
+        if lower.value == upper.value:
+            percentage = 0
+        else:
+            percentage = (value - lower.value) / (upper.value - lower.value)
+
+        hue = lower_hsv[0] * percentage + upper_hsv[0] * (1 - percentage)
+        sat = lower_hsv[1] * percentage + upper_hsv[1] * (1 - percentage)
+        lgt = lower_hsv[2] * percentage + upper_hsv[2] * (1 - percentage)
+        return hue, sat, lgt
+
+    @classmethod
+    def get_rgb_color_for(cls, value):
+        hue, sat, lgt = cls.get_hsv_color_for(value=value)
+        r, g, b = colorsys.hsv_to_rgb(hue / 360, sat / 100, lgt / 50)
+        return int(r * 255), int(g * 255), int(b * 255)
+
+    @classmethod
+    def get_html_color_for(cls, value):
+        r, g, b = cls.get_rgb_color_for(value)
+        return '#%02x%02x%02x' % (r, g, b)
+
     @staticmethod
     def get_not_mapped_yet_keyword():
         return 'NOT MAPPED YET'

src/viralhostrange/viralhostrangedb/views.py

@@ -597,18 +597,7 @@ def custom_css(request, slug):
     slug = slug.replace(".", "-")
     value = float(value)
 
-    lower = models.GlobalViralHostResponseValue.objects_mappable().filter(value__lte=value).order_by("-value").first()
-    upper = models.GlobalViralHostResponseValue.objects_mappable().filter(value__gte=value).order_by("value").first()
-    lower_hsv = lower.to_hsv()
-    upper_hsv = upper.to_hsv()
-    if lower.value == upper.value:
-        percentage = 0
-    else:
-        percentage = (value - lower.value) / (upper.value - lower.value)
-
-    hue = lower_hsv[0] * percentage + upper_hsv[0] * (1 - percentage)
-    sat = lower_hsv[1] * percentage + upper_hsv[1] * (1 - percentage)
-    lgt = lower_hsv[2] * percentage + upper_hsv[2] * (1 - percentage)
+    hue, sat, lgt = models.GlobalViralHostResponseValue.get_hsv_color_for(value)
 
     # default color
     s = 0.6