import time
import sys
import errno

GPIO_IFACE_MISSING = -1
GPIO_PIN_EXP_FAIL = -2
GPIO_DIR_CONT_FAIL = -3
GPIO_SWITCH_FAIL = -4
GPIO_PIN_UNX_NF = -5
GPIO_PIN_UNX_FAIL = -6

PINLISTMISS = -1
PINLISTTOKFAIL = -2

def preparePin(pinno):
    try: x = open('/sys/class/gpio/export', 'w')
    except:
        return GPIO_IFACE_MISSING
    else:
        try:
            x.write(f'{pinno}')
            x.close()
        except OSError as e:
            if (e.errno != errno.EBUSY): # Busy devices are already exported
                return GPIO_PIN_EXP_FAIL
            return
        for i in range(0,5):
            try: g = open(f'/sys/class/gpio/gpio{pinno}/direction', 'w')
            except:
                if (i == 4):
                    return GPIO_DIR_CONT_FAIL
                else: time.sleep(1)
            else:
                try: g.write('out')
                except:
                    g.close()
                    return GPIO_SWITCH_FAIL
                else:
                    g.close()
                    break

def closePin(pinno):
    try: x = open('/sys/class/gpio/unexport', 'w')
    except: return GPIO_PIN_UNX_NF
    else:
        try: x.write(pinno)
        except: return GPIO_PIN_UNX_FAIL
    finally: x.close()

try: preparePin(sys.argv[1])
except GPIO_SWITCH_FAIL: print(f'GPIO Pin direction couldn\'t be switched to out. {sys.argv[1]}')
except GPIO_DIR_CONT_FAIL: print(f'GPIO Pin control couldn\'t be opened. {sys.argv[1]}')
except GPIO_PIN_EXP_FAIL:  print(f'GPIO Pin couldn\'t be exported. P: {sys.argv[1]}')
except GPIO_IFACE_MISSING: print(f'GPIO Export interface couldn\'t be opened. {sys.argv[1]}')

with open(f'/sys/class/gpio/gpio{sys.argv[1]}/value', 'w') as x:
    if (len(sys.argv) == 3): x.write(sys.argv[2])
    else: x.write('0')