from Wheel import Wheel
import wiringpi

class Tank:
    # 初始速度为0
    __speed=0
    # 记录小车状态
    __status='stop'
    # 转向PWM增益
    __turningPWMIncrease=1.4
    def __init__(self):
        wiringpi.wiringPiSetup()
        self.__left=Wheel(pin1=23,pin2=22,pwm=25)
        self.__right=Wheel(pin1=28,pin2=29,pwm=26)
    def forward(self):
        self.__status='forward'
        self.setSpeed(self.__speed)
        self.__left.forward()
        self.__right.forward()
    def backward(self):
        self.__status='backward'
        self.setSpeed(self.__speed)
        self.__left.backward()
        self.__right.backward()
    def left(self):
        self.__status='left'
        self.setSpeed(self.__speed)
        self.__left.backward()
        self.__right.forward()
    def right(self):
        self.__status='right'
        self.setSpeed(self.__speed)
        self.__left.forward()
        self.__right.backward()        
    def stop(self):
        self.__status='stop'
        self.__left.stop()
        self.__right.stop()
    def speedUp(self):
        self.__speed=self.__speed+5
        if self.__speed>50:
            self.__speed=50
        self.setSpeed(self.__speed)
    def speedDown(self):
        self.__speed=self.__speed-5
        if self.__speed<15:
            self.__speed=15
        self.__left.setSpeed(self.__speed)
    def setSpeed(self,speed):
        self.__speed=speed
        self.__setRunSpeed(self.__speed)
    def __setRunSpeed(self,speed):
        if self.__status=='left' or self.__status=='right':
            # 如果是转弯，要给加大速度，才能用同样的速度转动
            turnSpeed = int(self.__speed*self.__turningPWMIncrease)
            print("转向速度："+str(turnSpeed))
            self.__left.setSpeed(turnSpeed)
            self.__right.setSpeed(turnSpeed)
        else:
            self.__left.setSpeed(self.__speed)
            self.__right.setSpeed(self.__speed)