#!/bin/bash
#

primary=$(xrandr --current | grep primary | awk  '{print $1}')
hdmi_output="HDMI2"

function get_state
{
    state=$(xrandr --listactivemonitors | tail -n +2)
    nb_screen=$(echo "$state" | wc -l)

    if [[ $nb_screen -eq 1 ]]; then
        if echo "$state" | grep -q $primary; then
            echo hdmi_off
        else
            echo hdmi_only
        fi
    elif [[ $nb_screen -eq 2 ]]; then
        if echo "$state" | grep -Pq "\+0\+0\s+$hdmi_output"; then
            echo hdmi_mirror
        else
            echo hdmi_right
        fi
    fi
}

function hdmi_switch_mode
{
    state=$(get_state)
    [[ $state == "hdmi_mirror" ]] && hdmi_right && exit
    [[ $state == "hdmi_right" ]] && hdmi_only && exit
    [[ $state == "hdmi_only" ]] && hdmi_mirror && exit
}

function hdmi_toggle
{
    state=$(get_state)
    [[ $state == "hdmi_off" ]] && hdmi_mirror && exit
    [[ $state != "hdmi_off" ]] && hdmi_off && exit
}

function hdmi_mirror
{
    primary_on
    xrandr --output $hdmi_output --auto --same-as $primary
    sound_to_hdmi
}

function hdmi_right
{
    primary_on
    xrandr --output $hdmi_output --auto --right-of $primary
    sound_to_hdmi
}

function hdmi_only
{
    hdmi_mirror
    primary_off
    sound_to_hdmi
}

function hdmi_off
{
    primary_on
    xrandr --output $hdmi_output --off
    reset_sound
}

function primary_off
{
    xrandr --output $primary --off
}

function primary_on
{
    xrandr --output $primary --auto
}

function sound_to_hdmi
{
    hdmi_sound_card=$(pacmd list-cards | grep 'output:' | grep $hdmi_output | head -1 | awk  '{print $1}')
    pactl set-card-profile 0 $hdmi_sound_card
    pulseaudio --kill
}

function reset_sound
{
    pactl set-card-profile 0 output:analog-stereo
    pulseaudio --kill
}

function print_help ()
{
    [[ $# -ne 0 ]] && echo "[HELP ] $*"

    echo "
    $0 [--toggle|--switch_mode|--mirror|--right|--hdmi_only]

    # Require:
     - xrandr
     - pulseaudio
     - configure hdmi output name (xrandr -q)
    "

    exit
}

function main ()
{
    [[ $# -eq 0 ]] && print_help

    while [[ $# -ne 0 ]]; do
        arg="$1"; shift
        case "$arg" in
            --toggle) hdmi_toggle ;;
            --switch_mode) hdmi_switch_mode ;;
            --off)       hdmi_off ;;
            --mirror)    hdmi_mirror ;;
            --right)     hdmi_right ;;
            --hdmi_only) hdmi_only;;
            --help)      print_help ;;
            * ) [[ $arg =~ \-+.* ]] && print_help "$arg unknown"
        esac
    done
}

main "$@"