# from picamera import PiCamera
import adafruit_dht
import adafruit_tsl2561
import board
import json
import spidev
from picamera import PiCamera
from defines import SENSORDATA


def readDHT22(): 
    """
    Reads DHT22 air temperature and air humidity and return values as float

    Raises:
        Exception: If DHT22 not connected properly

    Returns:
        float: temperature [°C]
        float: humidity [%]
    """
    try:
        dht22 = adafruit_dht.DHT22(board.D4, use_pulseio=False)
    except:
        raise Exception("DHT22 not connected")
    
    # read DHT22
    try:
        temperature = dht22.temperature
        humidity = dht22.humidity
    except:
        raise Exception("DHT22 not connected")

    return temperature, humidity


def readTSL2561():
    """
    Reads TSL2561 brightness in Lux and returns integer value

    Raises:
        Exception: If TSL2561 not connected properly

    Returns:
        int: brightness [Lux]
    """
    try:
        tsl2561 = adafruit_tsl2561.TSL2561(board.I2C())
    except:
        raise Exception("TSL2561 not connected")
    
    # read TSL2561
    brightness = 0
    if type(tsl2561.lux) == type(None):  # Max Value 40.000 -> above error
        brightness = 40000
    else:
        brightness = int(tsl2561.lux)

    return brightness


def readMCP3008():
    """
    Reads YL-69 via MCP3008 ADC soil moisture in percent and returns float value
    
    Raises:
        Exception: If YL-69 not connected properly

    Returns:
        float: soil moisture [%]
    """

    channel = 0                                         # Input channel into MCP3008 ADC
    try:
        spi = spidev.SpiDev()
        spi.open(0,0)
        spi.max_speed_hz = 1000000
    except:
        raise Exception("YL69 not connected")

    val = spi.xfer2([1,(8+channel) << 4, 0])
    data = ((val[1] & 3) << 9) +val[2]
    percentage = data - 680                             # Return values between ~1780 and ~680
    percentage = round(((1100 - percentage) / 1100) *100, 2)   # 680 -> 100% moisture, 1780 -> 0% moisture

    if percentage > 100 or percentage < 0:                # If not connected values above 100% appear  
        percentage = 0
        raise Exception("YL69 not connected")

    return percentage



# TODO Function for all sensors
def readSensors():
    """
    Read DHT22, TSL2561 and Humidity Sensor

    Raises:
        Exception: DHT22 not connected
        Exception: TSL2561 not connected
        Exception: YL69 not connected

    Returns:
        dict: Sensordata
    """
    sensorData = {}
    sensorData |= SENSORDATA
    errorMessage = ""

    # read DHT22
    try:
        sensorData["AirTemperature"], sensorData["AirHumidity"] = readDHT22()   
    except Exception as e:
        sensorData["AirHumidity"] = 0                   # otherwise old value
        sensorData["AirTemperature"] = 0
        errorMessage = str(e) + "\n"

    # read TSL2561
    try:
        sensorData["Brightness"] = readTSL2561()
    except Exception as e:
        sensorData["Brightness"] = 0                   # otherwise old value
        errorMessage = errorMessage + str(e) + "\n"

    # read YL-69
    try:
        sensorData["SoilMoisture"] = readMCP3008()
    except Exception as e:
        sensorData["SoilMoisture"] = 0
        errorMessage = errorMessage + str(e) + "\n"

    # combined error message
    if errorMessage != "":
        raise Exception(errorMessage)

    return sensorData


def takePicture():
    """
    Take picture and return picture
    Returns:
        _type_: _description_
    """
    try:
        camera = PiCamera()
    except:
        raise Exception("Camera not connected")
    
    camera.start_preview()
    camera.capture("picture.png")
    camera.stop_preview()

    return 


# TODO - read position with sensor
def readPosition():
    """
    Read and return Position

    Returns:
        _type_: _description_
     """
    position = ""
    return position


# Testing

def main():
    value = SENSORDATA
    try:
        value |= readSensors()
    except Exception as e:
        print(str(e))

    print(value)

if __name__ == "__main__":
    main()