from PyQt5 import QtGui
from typing import Optional
import math
import re

import todo.gui.color

def format(minutes: int):
    if minutes >= 60 * 24:
        return "" + format_decimal(minutes / 60 / 24) + "d"
    elif minutes >= 60:
        return "" + format_decimal(minutes / 60) + "h"
    elif minutes > 0:
        return "" + str(minutes) + "m"
    else:
        return ""

def format_decimal(d: float) -> str:
    return "{0:.2g}".format(d)

def parse(duration: str) -> Optional[int]:
    duration = duration.strip()
    if duration:
        result = re.match("^(\d+)(\.(\d+))?([mhd])$", duration.strip())
        if result:
            n = int(result.group(1))
            if result.group(3):
                d = int(result.group(3)) * pow(10, -1 * len(result.group(3)))
            else:
                d = 0
            num = n + d
            unit = result.group(4)
            if unit == "m":
                return math.floor(num)
            elif unit == "h":
                return math.floor(num * 60)
            elif unit == "d":
                return math.floor(num * 60 * 24)
        else:
            return None
    else:
        return 0

def color(minutes: int):
    if minutes <= 15:
        return todo.gui.color.short_duration
    elif minutes < 60:
        return todo.gui.color.medium_duration
    else:
        return todo.gui.color.long_duration