import machine
import time

uart_port = 1
uart_default_baud = 115200
uart_timeout = 28
default_responce_timeout = 8000

status_pin = Pin(6, Pin.IN)
ringer_pin = Pin(8, Pin.IN)
pwr_key_pin = Pin(23, Pin.OUT)

# Open the UART
uart = machine.UART(uart_port, uart_default_baud, mode=UART.BINARY, timeout=uart_timeout)
dirtybuffer = False # Flag if the buffer could have residual end of responces line in it?

# Check if the SIM800 is powered up
def ison():
    return status_pin.value()==1

# Check if the SIM800 is ringing
def isringing():
    return ringer_pin.value()==0

# Identify if this was a positive responce
def ispositive(responce):
    return (responce=="OK") or responce.startswith("CONNECT")

# Identify if this was a negative responce
def isnegative(responce):
    return (responce=="NO CARRIER") or (responce=="ERROR") or (responce=="NO DIALTONE") or (responce=="BUSY") or (responce=="NO ANSWER")

# Extract the [first] parameter from a responce 
def extractval(parameter, responce, default=""):
    for entry in responce:
        if entry.startswith(parameter):
            return (entry[len(parameter):]).strip()
    return default

# Read a lines of responce from the UART
def readline():
    stringin = ""
    while (True):
        charin = uart.read(1)
        # If we time out we are at the end of a line
        if charin is None:
            return stringin
        # Look for all EOL chars just in case settigns were changed
        elif (charin == b'\n') or (charin == b'\r'):
            if (stringin!=""):
                return stringin
        # This will be part of the string then
        else:
            stringin += str(charin, "ASCII")

# Execute a command on the module
# command is the AT command without the AT or CR/LF, responce_timeout (in ms) is how long to wait for completion, custom_endofdata is to wait for a non standard bit of 
def command(command="", responce_timeout=default_responce_timeout, custom_endofdata=None):
    # Empty the buffer
    uart.read()
    # Send the command
    uart.write("AT" + command + "\r\n")
    # Read the results
    result = []
    complete = False
    customcomplete = custom_endofdata is None
    timeouttime = time.time()+(responce_timeout/1000)
    while (time.time()<timeouttime):
        line = readline()
        # Remember the line if not empty
        if (len(line)>0):
            result.append(line)
        # Check if we have a standard end of responce
        if (ispositive(line)) or (isnegative(line)):
            complete = True
        # Check if we have the data we are looking for
        if (custom_endofdata is not None) and (line.startswith(custom_endofdata)):
            customcomplete = True
        # Check if we are done
        if complete and customcomplete:
            return result
    # We ran out of time
    # set the dirty buffer flag is an out of date end of responcs cound end up in the buffer
    if custom_endofdata is None:
        global dirtybuffer
        dirtybuffer = True
    result.append("TIMEOUT")
    return result

# Power on the SIN800
def poweron():
	# Only power on if we are off
    if not ison():
		# Check that the power pin has not beel left high
        if (pwr_key_pin.value()):
            pwr_key_pin.off()
            time.sleep(1)
        pwr_key_pin.on()
        time.sleep(3)
        pwr_key_pin.off()
		# Send a command to autonigotiate UART speed        
        command()
        time.sleep(2)
        uart.read() # Empty the buffer

# Power off the SIN800
def poweroff():
	# Only power off if we are on
    if (status_pin.value()):
		# Check that the power pin has not beel left high
        if (pwr_key_pin.value()):
            pwr_key_pin.off()
            time.sleep(1)
        pwr_key_pin.on()
        time.sleep(3)
        pwr_key_pin.off()
        uart.read() # Empty the buffer
        dirtybuffer = False

# Change the speed on the communication
def uartspeed(newbaud):
    global uart
    command("+IPR=" + str(newbaud))
    uart.deinit()
    if (newbaud==0):
        uart = machine.UART(uart_port, uart_default_baud, mode=UART.BINARY, timeout=uart_timeout)
    else:
        uart = machine.UART(uart_port, newbaud, mode=UART.BINARY, timeout=uart_timeout)

# Make a voice call
def call(number):
    command("D" + str(newbaud) + ";")

# Answer a voice call
def answer(number):
    command("A")

# End a voice call
def handup():
    command("H")

# Get/Set ringer volume (0-100)
def ringervolume(level=None):
    # Set the new leve if we have one to set
    if level is not None:
        command("+CRSL=" + str(level))
    # Retieve the set level to report back
    responce = command("+CRSL?")
    return int(extractval("+CRSL:", responce, 0))

# Get/Set speaker volume (0-100)
def speakervolume(level=None):
    # Set the new leve if we have one to set
    if level is not None:
        command("+CLVL=" + str(level))
    # Retieve the set level to report back
    responce = command("+CLVL?")
    return int(extractval("+CLVL:", responce, 0))

# Is the battery charging (0=no, 1=yes, 2=full)
def batterycharging():
    responce = command("+CBC")
    vals = extractval("+CBC:", responce, "0,0,0").split(",")
    return int(vals[0])

# How full is the battery (1-100)
def batterycharge():
    responce = command("+CBC")
    vals = extractval("+CBC:", responce, "0,0,0").split(",")
    return int(vals[1])

# List the available operator (returns list of [0=?,1=available,2=current,3=forbidden], 0=long name, 1=short name, 2=GSMLAI )
def listoperators(available_only=True):
    delim = "||||"
    responce = command("+COPS=?", 45000)
    responcedata = extractval("+COPS:", responce, "").split(",,")[0]
    responcelist = responcedata.replace("),(",delim)[1:-1].split(delim)
    results = []
    for entry in responcelist:
        subresults = []
        for subentry in entry.split(","):
            subresults.append(subentry.strip("\""))
        if (not available_only) or (subresults[0]=="1") or (subresults[0]=="2"):
            results.append(subresults)
    return results

# Get the current operator (format 0=long name, 1=short name, 2=GSMLAI)
def currentoperator(format=0):
    command("+COPS=3," + str(format))
    responce = command("+COPS?")
    responcedata = extractval("+COPS:", responce, "").split(",")
    if (len(responcedata)>=3):
        return responcedata[2].strip("\"")
    else:
        return ""

# Set the operator selection ([0=automatic,2=deregister])
def soperator(mode, format=None, operator=None):
    params = ""
    if format is not None:
        params += "," + str(format)
        if operator is not None:
            params += "," + str(operator)
    command("+COPS=" + str(mode) + params, 120000)

# Get the activity status (returns 0=ready, 2=unknown, 3=ringing, 4=call in progress)
def getstatus():
    responce = command("+CPAS")
    vals = extractval("+CPAS:", responce, "2")
    return int(extractval("+CPAS:", responce, "2"))

# Get my number
def getmynumber():
    responce = command("+CUSD=1,\"*#100#\"", 8000, "+CUSD:")
    responcedata = extractval("+CUSD:", responce, "").split(",")
    if (len(responcedata)>=2):
        return responcedata[1].strip().strip("\"")
    else:
        return ""


# Turn on the SIM800
poweron()