from django.urls import reverse

from boards.utils import cached_result

TRIPCODE_VIEW = '<a href="{url}?tripcode={full_text}"' \
    'class="tripcode" title="{full_text}"' \
    'style="border: solid 2px #{color}; border-left: solid 1ex #{color};">' \
    '{short_text}</a>'

SHORT_TEXT_CHARS = 8
COLOR_CHARS = 6


class Tripcode:
    def __init__(self, code_str):
        self.tripcode = code_str

    def get_color(self):
        return self.tripcode[:COLOR_CHARS]

    def get_background(self):
        code = self.get_color()
        result = ''

        for i in range(0, len(code), 2):
            p = code[i:i+2]
            background = hex(255 - int(p, 16))[2:]
            if len(background) < 2:
                background = '0' + background
            result += background

        return result

    def get_short_text(self):
        return self.tripcode[:SHORT_TEXT_CHARS]

    def get_full_text(self):
        return self.tripcode

    def _get_cache_key(self):
        return [self.tripcode]

    @cached_result(key_method=_get_cache_key)
    def get_view(self):
        return TRIPCODE_VIEW.format(url=reverse('feed'),
                                    short_text=self.get_short_text(),
                                    full_text=self.get_full_text(),
                                    color=self.get_color())