import colors


class WeatherDisplay:
    def __init__(self, characterDisplay, topRow):
        self.characterDisplay = characterDisplay
        self.topRow = topRow
        self.twoDigitStartColumn = 9
        self.oneDigitStartColumn = 13
        self.currentTemperature = [9, 9]
        self.color = colors.GREEN
        self.weatherFile = 'weather.txt'

    def showWeather(self):
        temperature = self.getTemperature()

        if self.isTemperatureMissing(temperature):
            self.characterDisplay.clearRow(self.topRow)
        else:
            self.showTemperature(list(temperature))

    def getTemperature(self):
        try:
            with open(self.weatherFile) as file:
                return file.readline().strip()
        except Exception as e:
            print(e, flush=True)
            return 'error'

    def isTemperatureMissing(self, temperature):
        return temperature == 'error' or temperature == 'init' or temperature == 'halted'

    def showTemperature(self, temperature):
        if temperature != self.currentTemperature:
            self.characterDisplay.clearRow(self.topRow)

            start = self.oneDigitStartColumn if (
                self.isOneDigit(temperature)
            ) else self.twoDigitStartColumn

            for c in temperature:
                if c == '-':
                    self.characterDisplay.displayNegative(
                        start-3, self.topRow, self.color)
                else:
                    self.characterDisplay.displayDigit(
                        start, self.topRow, c, self.color)
                    start = start + 4

            self.currentTemperature = temperature

    def isOneDigit(self, temperature):
        return (len(temperature) == 2 and temperature[0] == '-') or len(temperature) == 1