class Process(object):
    """docstring for Process"""
    def __init__(self, name, exec_time, exec_order, priority, pages):
        super(Process, self).__init__()
        self.name = name
        self.exec_time = exec_time
        self.exec_order = exec_order
        self.priority = priority
        self.pages = pages
        self.finished = False

    def __str__(self):
        return self.name

def isProcessDone(processes):
    for p in processes:
        if not p.finished:
            return False
    return True

def seconde_chance(process, pagesHistory, oldestPageIndex, clock):
    pagesToAdd = process.pages
    pagingErrors = 0
    for page in pagesToAdd:
        if len(pagesHistory) == 0:
            pagesHistory.append([page])
            pagingErrors += 1
            clock[0]['page'] = page
        elif len(pagesHistory[-1]) == 1:
            if not page in pagesHistory[-1]:
                pagesHistory.append([pagesHistory[0][0], page])
                pagingErrors += 1
                clock[1]['page'] = page
            else:
                pagesHistory.append(pagesHistory[-1])
        elif len(pagesHistory[-1]) == 2:
            if not page in pagesHistory[-1]:
                pagesHistory.append([pagesHistory[0][0], pagesHistory[1][1], page])
                pagingErrors += 1
                clock[2]['page'] = page
            else:
                pagesHistory.append(pagesHistory[-1])
        else:
            if not page in pagesHistory[-1]:
                while clock[oldestPageIndex]['bits'] == 1:
                    clock[oldestPageIndex]['bits'] = 0
                    oldestPageIndex += 1
                    oldestPageIndex %= 3

                clock[oldestPageIndex]['page'] = page
                clock[oldestPageIndex]['bits'] = 1
                pagingErrors += 1

            else:
                pagesHistory.append(pagesHistory[-1])

        process.priority += pagingErrors

    return pagesHistory, oldestPageIndex, clock

def execution_queue(processes, quantum, currentExecQueue, execQueueHistory, pagesHistory, oldestPageIndex, clock):
    if currentExecQueue == [[]] * 10:
        for p in processes:
            currentExecQueue[p.priority].append(p)
    else:
        for case in currentExecQueue:
            if not case == []:
                for i in range(quantum):
                    if case[0].exec_time - 1 >= 0:
                        case[0].exec_time -= 1
                        execQueueHistory.append(case[0].name)
                    else:
                        execQueueHistory.append("X")

                if case[0].exec_time == 0:
                    case[0].finished = True
                    print(case[0].name + " is finished!")
                else:
                    seconde_chance(case[0], pagesHistory, oldestPageIndex, clock)
                    case[0].priority += quantum
                    if case[0].priority > 9:
                        case[0].priority = 9
                    currentExecQueue[case[0].priority].append(case[0])


                case.remove(case[0])

    return {
        "currentExecQueue": currentExecQueue,
        "execQueueHistory": execQueueHistory,
        "pagesHistory": pagesHistory,
        "oldestPageIndex": oldestPageIndex,
        "clock": clock
    }

def main():
    quantum = 3
    t1 = Process("T1", 10, 0, 1, [1,5])
    t2 = Process("T2", 8, 1, 1, [2,5])
    t3 = Process("T3", 4, 2, 1, [2,3,6])
    t4 = Process("T4", 4, 3, 1, [4])
    processes = [t1, t2, t3, t4]
    pagesHistory = []
    oldestPageIndex = 0
    executionQueue = [[]] * 10
    execQueueHistory = []
    clock = [
        {
            'page': 0,
            'bits': 0
        }
    ] * quantum

    while not isProcessDone(processes):
        returnDict = (execution_queue(processes, quantum, executionQueue, execQueueHistory, pagesHistory, oldestPageIndex, clock))
        executionQueue = returnDict['currentExecQueue']
        execQueueHistory = returnDict['execQueueHistory']
        pagesHistory = returnDict['pagesHistory']
        oldestPageIndex = returnDict['oldestPageIndex']
        clock = returnDict["clock"]

    for pageOrder in pagesHistory:
        print(pageOrder)

if __name__ == '__main__':
    main()