import math
from pyscript import document

def bereken(event):
	output = document.querySelector("#output")
	try:
		x1 = float(document.querySelector("#x1").value)
		x2 = float(document.querySelector("#x2").value)
		y1 = float(document.querySelector("#y1").value)
		y2 = float(document.querySelector("#y2").value)

		if x1 == x2:
			output.innerText = "x1 en x2 mogen niet gelijk zijn"
			return

		a = (y2 - y1) / (x2 - x1)
		b = y1 - a * x1
		
		if b < 0:
			output.innerText = f"De formule is: y = {round(a,3)}x - {round(abs(b),3)}"
		
		else:
			output.innerText = f"De formule is: y = {round(a,3)}x + {round(b,3)}"

	except ValueError:
		output.innerText = "Fout: Vul geldige getallen in."

def reset(event):
	document.getElementById("x1").value = ""
	document.getElementById("x2").value = ""
	document.getElementById("y1").value = ""
	document.getElementById("y2").value = ""
	document.getElementById("output").innerText = ""