epub converter: fix color to all in hex

src/util/color_reader.py

@@ -1,4 +1,7 @@
-from webcolors import html4_hex_to_names, hex_to_rgb, rgb_to_name
+import re
+
+from webcolors import html4_hex_to_names, hex_to_rgb, rgb_to_name, rgb_percent_to_hex, rgb_to_hex, css3_names_to_hex
+from colorsys import hls_to_rgb
 
 
 def closest_colour_rgb(requested_color):
@@ -42,7 +45,7 @@ def get_hex_color_name(color):
         return closest_name
 
 
-def str2color_name(s: str):
+def str2closest_html_color_name(s: str):
     if 'rgb' in s:
         rgb_str = 'rgba' if ('rgba' in s) else 'rgb'
         s = s.replace(rgb_str, '').replace('(', '').replace(')', '')
@@ -75,6 +78,45 @@ def str2color_name(s: str):
         return ''
 
 
+def str2hex(s: str):
+    if '#' in s:
+        return s
+
+    if ('rgb' in s) and ('%' in s):
+        rgb_str = 'rgba' if ('rgba' in s) else 'rgb'
+        s = s.replace(rgb_str, '').replace('(', '').replace(')', '')
+        rgb_percent = s.split(',')[:3]
+        hex_color = rgb_percent_to_hex(rgb_percent)
+        return hex_color
+
+    if 'rgb' in s:
+        rgb_str = 'rgba' if ('rgba' in s) else 'rgb'
+        s = s.replace(rgb_str, '').replace('(', '').replace(')', '')
+        try:
+            rgb = [int(x) for x in s.split(',')[:3]]
+            rgb = tuple(rgb)
+        except ValueError:
+            return ''
+        hex_color = rgb_to_hex(rgb)
+        return hex_color
+
+    if 'hsl' in s:
+        # hsl(hue in {0,360}, saturation [0, 100%], lightness [0, 100%])
+        match = re.search(r'hsla*\(((\d+), *(\d+)%, *(\d+)%(, \d\.\d)*)\)', s)
+        if match:
+            h, s, l = match.group(2), match.group(3), match.group(4)
+            h /= 360
+            s /= 10
+            l /= 100
+            rgb = tuple(hls_to_rgb(h, s, l))
+            return rgb_to_hex(rgb)
+
+    if s.lower() in css3_names_to_hex:
+        return css3_names_to_hex[s.lower()]
+
+    return ''
+
+
 if __name__ == '__main__':
 
     str2color_name('rgb(139, 0, 0)')