#!/bin/bash
# This script is called by udev when you link a bluetooth device with your comp$
# It's called to add or remove the device from pulseaudio
#
#

# Output to this file
LOGFILE="/var/log/bluetooth_dev"

# Name of the local sink in this computer
# You can get it by calling : pactl list short sinks
# AUDIOSINK="alsa_output.platform-bcm2835_AUD0.0.analog-stereo"
AUDIOSINK="alsa_output.0.analog-stereo"

# User used to execute pulseaudio, an active session must be open to avoid erro$
USER="pi"

# Audio Output for raspberry-pi
# 0=auto, 1=headphones, 2=hdmi.
AUDIO_OUTPUT=1

# If on, this computer is not discovearable when an audio device is connected
# 0=off, 1=on
ENABLE_BT_DISCOVER=1

echo "For output see $LOGFILE"

## This function add the pulseaudio loopback interface from source to sink
## The source is set by the bluetooth mac address using XX_XX_XX_XX_XX_XX forma$
## param: XX_XX_XX_XX_XX_XX
## return 0 on success
add_from_mac(){
  if [ -z "$1" ] # zero params
    then
        echo "Mac not found" >> $LOGFILE
    else
        mac=$1 # Mac is parameter-1

        # Setting source name
        bluez_dev=bluez_source.$mac
        echo "bluez source: $mac"  >> $LOGFILE

        # This script is called early, we just wait to be sure that pulseaudio $
        sleep 1
        # Very that the source is present
        CONFIRM=`sudo -u pi pactl list short | grep $bluez_dev`
        if [ ! -z "$CONFIRM" ]
        then
            echo "Adding the loopback interface:  $bluez_dev"  >> $LOGFILE
            echo "sudo -u $USER pactl load-module module-loopback source=$bluez$

            # This command route audio from bluetooth source to the local sink..
            # it's the main goal of this script
            sudo -u $USER pactl load-module module-loopback source=$bluez_dev s$
            return $?
        else
            echo "Unable to find a bluetooth device compatible with pulsaudio u$
            return -1
        fi
    fi
}

## This function will detect the bluetooth mac address from input device and co$
## Lots of devices are seen as input devices. But Mac OS X is not detected as i$
## return 0 on success
detect_mac_from_input(){
    ERRORCODE=-1

    echo "Detecting mac from input devices" >> $LOGFILE
    for dev in $(find /sys/devices/virtual/input/ -name input*)
    do
        if [ -f "$dev/name" ]
        then
            mac=$(cat "$dev/name" | sed 's/:/_/g')
            add_from_mac $mac

            # Endfor if the command is successfull
            ERRORCODE=$?
            if [ $ERRORCODE -eq 0]; then
                return 0
            fi
        fi
    done
    # Error
    return $ERRORCODE
}

## This function will detect the bt mac address from dev-path and configure it.
## Devpath is set by udev on device link
## return 0 on success
detect_mac_from_devpath(){
    ERRORCODE=-1
    if [ ! -z "$DEVPATH" ]; then
        echo "Detecting mac from DEVPATH"  >> $LOGFILE
        for dev in $(find /sys$DEVPATH -name address)
        do
            mac=$(cat "$dev" | sed 's/:/_/g')
            add_from_mac $mac

            # Endfor if the command is successfull
            ERRORCODE=$?
            if [ $ERRORCODE -eq 0]; then
                return 0
            fi

        done
        return $ERRORCODE;
    else
        echo "DEVPATH not set, wrong bluetooth device? " >> $LOGFILE
        return -2
    fi
    return $ERRORCODE
}

## Detecting if an action is set
if [ -z "$ACTION" ]; then
    echo "The script must be called from udev." >> $LOGFILE
    exit -1;
fi
## Getting the action
ACTION=$(expr "$ACTION" : "\([a-zA-Z]\+\).*")

# Switch case
case "$ACTION" in
"add")

        # Turn off bluetooth discovery before connecting existing BT device to $
        if [ $ENABLE_BT_DISCOVER == 1 ]
        then
                echo "Set computer as hidden" >> $LOGFILE
                hciconfig hci0 noscan
        else
            echo "Not setting computer as hidden" >> $LOGFILE
        fi


    # Turn volume to max
    volume_max

    # Detect BT Mac Address from input devices
    detect_mac_from_input
    OK=$?

    # Detect BT Mac address from device path on a bluetooth event
    if [ $OK != 0 ]; then
        if [ "$SUBSYSTEM" == "bluetooth" ]; then
            detect_mac_from_devpath
            OK=$?
        fi
    fi

    # Check if the add was successfull, otherwise display all available sources
    if [ $OK != 0 ]; then
        echo "Your bluetooth device is not detected !" >> $LOGFILE
        echo "Available sources are:" >> $LOGFILE
        sudo -u $USER pactl list short sources >> $LOGFILE
    else
        echo "Device successfully added " >> $LOGFILE
    fi
    ;;

"remove")

        # Turn off bluetooth discovery before connecting existing BT device to $
        if [ $ENABLE_BT_DISCOVER == 1 ]
        then
                echo "Set computer as visable" >> $LOGFILE
                sudo hciconfig hci0 piscan
        else
            echo "Not setting computer as visible" >> $LOGFILE
        fi

    echo "Removed Audio Device" >> $LOGFILE
    ;;

#
*)
    echo "Unsuported action $action" >> $LOGFILE
    ;;
esac
echo "--" >> $LOGFILE