import re
import argparse
import math

# i feel doing this with equations is probably the
# "fast" way.

# we can re-arange stuff so we only need to find the point
# the line crosses the 0 line

# distance is speed * (time less time holding the button (which is equal to speed)):
# -> d = v * (t - v)
# -> v^2 -vt +d = 0

# -> y=0 @ v = t +- sqrt( t^2 - 4d) / 2

def get_cross_points(time:int, distance:int) -> list | None:
    pre_root = time**2 - (4 * distance)
    if pre_root < 0:
        # no solutions
        return None
    if pre_root == 0:
        # one solution
        return [(float(time)/2)]
    sqroot = math.sqrt(pre_root)
    v1 = (float(time) + sqroot)/2
    v2 = (float(time) - sqroot)/2
    return [v1,v2]

def float_pair_to_int_pair(a:float,b:float):
    # if floats are equal to int value, then we need to add one to value
    # as we are looking for values above 0 point
    
    if a > b:
        # lower a and up b
        if a == int(a):
            a -= 1
        if b == int(b):
            b += 1

        return [math.floor(a),math.ceil(b)]
    if a < b:
        if a == int(a):
            a += 1
        if b == int(b):
            b -= 1
        return [math.floor(b),math.ceil(a)]

def main(line_list: list):
    time_section,distance_section = line_list
    if (args.part == 1):
        time_list = filter(None , re.split(' +',time_section.split(':')[1]))
        distance_list = filter(None ,  re.split(' +',distance_section.split(':')[1]))
        games = list(zip(time_list,distance_list))
    if (args.part == 2):
        games = [ [time_section.replace(' ','').split(':')[1],distance_section.replace(' ','').split(':')[1]] ]
    print (games)
    total = 1
    for t,d in games:
        cross = get_cross_points(int(t),int(d))
        cross_int = float_pair_to_int_pair(*cross)
        print (cross_int)
        total *= cross_int[0] - cross_int[1] +1
    
    print(f"total: {total}")

if __name__ == "__main__":
    parser = argparse.ArgumentParser(description="day 6 solver")
    parser.add_argument("-input",type=str)
    parser.add_argument("-part",type=int)
    args = parser.parse_args()
    filename = args.input
    if filename == None:
        parser.print_help()
        exit(1)
    file = open(filename,'r')
    main([line.rstrip('\n') for line in file.readlines()])
    file.close()