import Rhino
import Grasshopper as gh
import clr
clr.AddReferenceToFile("KangarooSolver.dll")
import KangarooSolver as ks
from System import Array
import subprocess

class Interrupter(ks.GoalObject):
    def __init__(self, on_id):
        self.PPos = Array.CreateInstance(Rhino.Geometry.Point3d, 0)
        self.on_id = on_id
        self.cmd = None

    def Calculate(self, p):
        if self.cmd is None: # no window - open one
            self.cmd = subprocess.Popen(["cmd.exe", "/c", "echo Press any key to interrupt & pause>nul"])
        if self.cmd.poll() is not None: # window was triggered (closed)
            for obj in ghenv.Component.OnPingDocument().Objects:
                if type(obj) == gh.Kernel.Special.GH_BooleanToggle and str(obj.InstanceGuid) in self.on_id:
                    obj.Value = 0
                    obj.ExpireSolution(True)
            raise KeyboardInterrupt("User requested interrupt")

    def Terminate(self): # close window
        if self.cmd is not None:
            self.cmd.terminate()

# find guid of 'On' bool
on_id = []
for input in ghenv.Component.Params.Input:
    if input.NickName == "On":
        for s in input.Sources:
            attr = s.Attributes
            component = attr.GetTopLevel.DocObject
            on_id.append(str(component.InstanceGuid))

try: # clean up unwanted window from previous instance
    interrupter.Terminate()
except NameError: # instance doesn't exist yet
    pass

interrupter = Interrupter(on_id)
I = interrupter # roundabout variable naming because gh will reset I each time