"""
    An inbound application that prompts the user to enter a 4-digit pin that represents a 
    conference room, to which they are then transferred. Please read the documentation about
    conference rooms.

    The application uses TTS to communicate with the caller.

    This application requires 1 extra channel.

    Actions:
        - wait for anbound call
        - wait for four DTMF digits
        - create a tone player
        - transfer the call to the conference room
        - wait for the caller to hang up

"""

from prosody.uas import Hangup, Error, ToneManager

__uas_identify__ = "application"
__uas_version__  = "1.0b1"

def main(channel, application_instance_id, file_man, my_log, application_parameters):

    return_code = 0

    try:
        if channel.state() == channel.State.CALL_INCOMING:
            channel.ring()   # this can raise a Hangup exception
            channel.answer() # this can raise a Hangup exception
        else:
            raise Hangup('No inbound call')

        # get the extra channel
        try:
            out_channel = channel.ExtraChannel[0]
        except:
            raise Error("You need to register an extra channel for this application")

        channel.FilePlayer.say("Please enter a four digit conference i d.", barge_in = True)

        digits = channel.DTMFDetector.get_digits(count=4, seconds_predigits_timeout = 10)

        if channel.DTMFDetector.cause() == channel.DTMFDetector.Cause.COUNT:
            channel.FilePlayer.say("Adding you to conference {0}".format(", ".join(digits)))

            # because this is a transfer, we need to create the tone player
            tone_manager = ToneManager(my_log)
            channel.create_tone_player(tone_manager)
                                    
            if channel.transfer_to_conference_room(out_channel, digits) is False:
                my_log.error("Transfer to conference. Hanging up")
                channel.FilePlayer.say ("Sorry, I could not connect you to your conference. Good bye")
                return_code = -104
            else:
                my_log.info ("Transfer to conference {0} succeeded. Waiting for idle".format (digits))
                channel.wait_for_idle(seconds_timeout=None)
        else:
            channel.FilePlayer.say ("I did not receive four digits. Hanging up.")
            return_code = -103
            
    except Hangup as exc:
        my_log.info("Got Hangup")
        return_code = -100

    except Error as exc:
        my_log.error("Got Error {0}".format(exc))
        return_code = -102

    except Exception as exc:
        my_log.exception("Got unexpected exception {0}".format(exc))
        return_code = -101

    finally:
        if channel.state() != channel.State.IDLE:
            channel.hang_up()
    return return_code