import colors


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

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

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

            if self.isTemperatureValid(temperature):
                self.showTemperature(list(temperature))

        self.currentTemperature = 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 isTemperatureValid(self, temperature):
        return not (temperature == 'error' or temperature == 'init' or temperature == 'halted')

    def showTemperature(self, temperature):
        start = self.getStartColumn(temperature)

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

    def getStartColumn(self, temperature):
        return self.oneDigitStartColumn if (self.isOneDigit(temperature)) else self.twoDigitStartColumn

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