import sys

from matplotlib import pyplot as plt
from numint.RiemannSum import numint
from numint.input_parser import parse_function, parse_value


def plot_cli(function_expr:str, start:str, end:str, epsilon: str):
    f = parse_function(function_expr)

    (a, b) = (parse_value(start), parse_value(end))
    eps = parse_value(epsilon)
    (x, y, l, r, n) = numint(f, a, b, eps)
    # print(l, r, n)
    plt.step(x, y, label="x^3")
    plt.step(x, y, where="post", label="x^3")
    plt.plot(x, y, color="gray", alpha=0.3)
    plt.show()
    pass


def main():
    function_expr = sys.argv[1]
    start = sys.argv[2]
    end = sys.argv[3]
    eps = sys.argv[4]
    plot_cli(function_expr, start, end, eps)


if __name__ == "__main__":
    main()