ppm.py

def ppm():
    REQUIRED_PH = 5.9

    solution_volume = int(input('Type solution volume (0-20): '))
    desired_solution_volume = int(input('Type desired volume (0-20):'))
    required_volume = desired_solution_volume - solution_volume

    print(f"Required volume is {required_volume} liters")

    current_ppm = int(input('Type current ppm: '))
    desired_ppm = int(input('Type desired ppm: '))

    current_mg = current_ppm * solution_volume
    print(f"Current mg is {current_mg}")

    required_mg = ((desired_ppm * desired_solution_volume) - current_mg)
    if required_mg < 0:
        required_mg = 0
    print(f"Required mg is {required_mg}")

    try:
        required_ppm = required_mg / required_volume
    except ZeroDivisionError:
        required_ppm = 0

    print(
        'Solution needed: '
        f'volume {required_volume} liters, '
        f'eletrocond. {required_ppm:.1f} ppm, '
        f'ph {REQUIRED_PH:.1f}'
    )

    def get_ml_per_liter(required_ppm):
        if required_ppm < 100:
            ml_gallon = 0
        elif required_ppm < 200:
            ml_gallon = 5
        elif required_ppm < 400:
            ml_gallon = 8
        elif required_ppm < 600:
            ml_gallon = 12
        elif required_ppm < 800:
            ml_gallon = 14
        elif required_ppm < 1000:
            ml_gallon = 16
        elif required_ppm < 1100:
            ml_gallon = 17.5
        elif required_ppm < 1200:
            ml_gallon = 19
        elif required_ppm < 1300:
            ml_gallon = 21
        else:
            ml_gallon = 23

        gallon_as_liter = 3.79
        return ml_gallon / gallon_as_liter

    ml_per_liter = get_ml_per_liter(required_ppm)
    total_ml = (required_volume * ml_per_liter)

    print(f'ml/l => {ml_per_liter:.1f} , so total for {required_volume} l is {total_ml:.1f} ml')

    def get_propotion_by_purpose():
        PURPOSES_PROPORTIONS = {
            1: (1, 1, 1),
            2: (3, 2, 1),
            3: (1, 2, 3)
        }

        print(
            '[Please set the purpose to define ratio]\n'
            '1. General (cutting, seedling, mild veg., transition)\n'
            '2. Vegetative\n'
            '3. Bloom\n'
        )

        purpose = None
        while purpose is None:
            try:
                purpose = int(input('Type purpose: '))
                assert purpose in (1, 2, 3)
            except (AssertionError, ValueError):
                purpose = None
                print('Invalid purpose, try again!')

        return PURPOSES_PROPORTIONS[purpose]

    grow_proportion, micro_proportion, bloom_proportion = get_propotion_by_purpose()
    max_proportion = grow_proportion + micro_proportion + bloom_proportion

    ml_of_grow = total_ml * (grow_proportion / max_proportion)
    ml_of_micro = total_ml * (micro_proportion / max_proportion)
    ml_of_bloom = total_ml * (bloom_proportion / max_proportion)
    print(
        f'Proportion of Grow: {ml_of_grow:.1f} ml or {(ml_of_grow/12.):.1f} "mddrs"\n'
        f'Proportion of Micro: {ml_of_micro:.1f} ml or {(ml_of_micro/12.):.1f} "mddrs"\n'
        f'Proportion of Bloom: {ml_of_bloom:.1f} ml or {(ml_of_bloom/12.):.1f} "mddrs"\n'
    )

    print(f"... or adjust the ppm to: {required_ppm:.1f}")

if __name__ == '__main__':
    try:
        ppm()
    except KeyboardInterrupt:
        print("\n2Bye!")