OrderQueue.py

from CustomPizza import *
from SpecialtyPizza import *
from Pizza import *
from PizzaOrder import * 


class OrderQueue:
    def __init__(self):
        self.heapList = [0]
        self.currentSize = 0
        
    def percUp(self, i):
        while i // 2 > 0:
            if self.heapList[i].getTime() < self.heapList[i // 2].getTime():
                tmp = self.heapList[i // 2]
                self.heapList[i // 2] = self.heapList[i] 
                self.heapList[i] = tmp 
            i = i // 2

    def addOrder(self, pizzaOrder):
        self.heapList.append(pizzaOrder)
        self.currentSize = self.currentSize + 1
        self.percUp(self.currentSize)

    def percDown(self, i):
        while (i * 2) <= self.currentSize: 
            mc = self.minChild(i) 
            if self.heapList[i].getTime() > self.heapList[mc].getTime(): 
                tmp = self.heapList[i]
                self.heapList[i] = self.heapList[mc] 
                self.heapList[mc] = tmp 
            i = mc

    def minChild(self, i):
        if (i * 2 + 1) > self.currentSize:
            return i * 2
        else:
            if self.heapList[i * 2].getTime() < self.heapList[i*2+1].getTime():
                return i*2
            else:
                return i*2+1

    def processNextOrder(self):
        if self.heapList == [0]:
            raise QueueEmptyException()
    
        retval = self.heapList[1].getOrderDescription() #retval
        self.heapList[1] = self.heapList[self.currentSize] 
        self.currentSize = self.currentSize - 1
        self.heapList.pop() 
        self.percDown(1) 
        return retval

class QueueEmptyException(Exception):
    pass