from js import document
import math
from fractions import Fraction

def bereken(event=None):
    # Ophalen van waarden uit de HTML
    rule = document.querySelector("#rule_select").value
    a_val = document.querySelector("#a_input").value
    b_val = document.querySelector("#b_input").value

    # Omzetten naar floats
    A = float(a_val) if a_val else 0
    B = float(b_val) if b_val else 0

    # Berekening volgens de gekozen vorm
    if rule == "1":  # A² + B² = C²
        C = math.sqrt(A**2 + B**2)
        onbekende = "C"
        berekening = (
            f"A² + B² = C²<br>"
            f"{A}² + {B}² = {A**2} + {B**2} = {A**2 + B**2}<br>"
            f"C = √{A**2 + B**2} = {C:.4f}"
        )

    elif rule == "2":  # C² - B² = A²
        C = A  # hier is A eigenlijk C
        A = math.sqrt(C**2 - B**2)
        onbekende = "A"
        berekening = (
            f"C² - B² = A²<br>"
            f"{C}² - {B}² = {C**2} - {B**2} = {C**2 - B**2}<br>"
            f"A = √{C**2 - B**2} = {A:.4f}"
        )
        C = A

    elif rule == "3":  # C² - A² = B²
        C = A  # hier is A eigenlijk C
        B = math.sqrt(C**2 - B**2)
        onbekende = "B"
        berekening = (
            f"C² - A² = B²<br>"
            f"{C}² - {A}² = {C**2} - {A**2} = {C**2 - A**2}<br>"
            f"B = √{C**2 - A**2} = {B:.4f}"
        )
        C = B

    # Afronden naar gemengde vorm
    ph1 = math.floor(C)
    ph2 = C - ph1
    ph3 = Fraction(ph2).limit_denominator(100)

    # Output
    document.querySelector("#c_output").value = f"{ph1} + {ph3}"
    document.querySelector("#formula").innerHTML = f"De lengte van zijde {onbekende} is {C:.4f}"

    # Berekening tonen in het vak
    document.querySelector("#output").innerHTML = berekening