#!/bin/bash

set -e

NQPTP_VERSION="1.2.4"
SHAIRPORT_SYNC_VERSION="4.3.2"
TMP_DIR=""

cleanup() {
    if [ -d "${TMP_DIR}" ]; then
        rm -rf "${TMP_DIR}"
    fi
}

verify_os() {
    MSG="Unsupported OS: Raspberry Pi OS 12 (bookworm) is required."

    if [ ! -f /etc/os-release ]; then
        echo $MSG
        exit 1
    fi

    . /etc/os-release

    if [[ ("$ID" != "debian" && "$ID" != "raspbian") || "$VERSION_ID" != "12" ]]; then
        echo $MSG
        exit 1
    fi
}

set_hostname() {
    CURRENT_PRETTY_HOSTNAME=$(hostnamectl status --pretty)

    read -p "Hostname [$(hostname)]: " HOSTNAME
    sudo raspi-config nonint do_hostname ${HOSTNAME:-$(hostname)}

    read -p "Pretty hostname [${CURRENT_PRETTY_HOSTNAME:-Raspberry Pi}]: " PRETTY_HOSTNAME
    PRETTY_HOSTNAME="${PRETTY_HOSTNAME:-${CURRENT_PRETTY_HOSTNAME:-Raspberry Pi}}"
    sudo hostnamectl set-hostname --pretty "$PRETTY_HOSTNAME"
}

install_bluetooth() {
    read -p "Do you want to install Bluetooth Audio (ALSA)? [y/N] " REPLY
    if [[ ! "$REPLY" =~ ^(yes|y|Y)$ ]]; then return; fi

    # Bluetooth Audio ALSA Backend (bluez-alsa-utils)
    sudo apt update
    sudo apt install -y --no-install-recommends bluez-tools bluez-alsa-utils

    # Bluetooth settings
    sudo tee /etc/bluetooth/main.conf >/dev/null <<'EOF'
[General]
Class = 0x200414
DiscoverableTimeout = 0
JustWorksRepairing=always

[Policy]
AutoEnable=true
EOF

    # Bluetooth Agent
    sudo tee /etc/systemd/system/bt-agent@.service >/dev/null <<'EOF'
[Unit]
Description=Bluetooth Agent
Requires=bluetooth.service
After=bluetooth.service

[Service]
ExecStartPre=/usr/bin/bluetoothctl discoverable on
ExecStartPre=/bin/hciconfig %I piscan
ExecStartPre=/bin/hciconfig %I sspmode 1
ExecStart=/usr/bin/bt-agent --capability=NoInputNoOutput
RestartSec=5
Restart=always
KillSignal=SIGUSR1

[Install]
WantedBy=multi-user.target
EOF
    sudo systemctl daemon-reload
    sudo systemctl enable bt-agent@hci0.service

    # Bluetooth udev script
    sudo tee /usr/local/bin/bluetooth-udev >/dev/null <<'EOF'
#!/bin/bash
if [[ ! $NAME =~ ^\"([0-9A-F]{2}[:-]){5}([0-9A-F]{2})\"$ ]]; then exit 0; fi

action=$(expr "$ACTION" : "\([a-zA-Z]\+\).*")

if [ "$action" = "add" ]; then
    bluetoothctl discoverable off
    # disconnect wifi to prevent dropouts
    #ifconfig wlan0 down &
fi

if [ "$action" = "remove" ]; then
    # reenable wifi
    #ifconfig wlan0 up &
    bluetoothctl discoverable on
fi
EOF
    sudo chmod 755 /usr/local/bin/bluetooth-udev

    sudo tee /etc/udev/rules.d/99-bluetooth-udev.rules >/dev/null <<'EOF'
SUBSYSTEM=="input", GROUP="input", MODE="0660"
KERNEL=="input[0-9]*", RUN+="/usr/local/bin/bluetooth-udev"
EOF
}

install_shairport() {
    read -p "Do you want to install Shairport Sync (AirPlay 2 audio player)? [y/N] " REPLY
    if [[ ! "$REPLY" =~ ^(yes|y|Y)$ ]]; then return; fi

    sudo apt update
    sudo apt install -y --no-install-recommends wget unzip autoconf automake build-essential libtool git autoconf automake libpopt-dev libconfig-dev libasound2-dev avahi-daemon libavahi-client-dev libssl-dev libsoxr-dev libplist-dev libsodium-dev libavutil-dev libavcodec-dev libavformat-dev uuid-dev libgcrypt20-dev xxd

    if [[ -z "$TMP_DIR" ]]; then
        TMP_DIR=$(mktemp -d)
    fi

    cd $TMP_DIR

    # Install ALAC
    wget -O alac-master.zip https://github.com/mikebrady/alac/archive/refs/heads/master.zip
    unzip alac-master.zip
    cd alac-master
    autoreconf -fi
    ./configure
    make -j $(nproc)
    sudo make install
    sudo ldconfig
    cd ..
    rm -rf alac-master

    # Install NQPTP
    wget -O nqptp-${NQPTP_VERSION}.zip https://github.com/mikebrady/nqptp/archive/refs/tags/${NQPTP_VERSION}.zip
    unzip nqptp-${NQPTP_VERSION}.zip
    cd nqptp-${NQPTP_VERSION}
    autoreconf -fi
    ./configure --with-systemd-startup
    make -j $(nproc)
    sudo make install
    cd ..
    rm -rf nqptp-${NQPTP_VERSION}

    # Install Shairport Sync
    wget -O shairport-sync-${SHAIRPORT_SYNC_VERSION}.zip https://github.com/mikebrady/shairport-sync/archive/refs/tags/${SHAIRPORT_SYNC_VERSION}.zip
    unzip shairport-sync-${SHAIRPORT_SYNC_VERSION}.zip
    cd shairport-sync-${SHAIRPORT_SYNC_VERSION}
    autoreconf -fi
    ./configure --sysconfdir=/etc --with-alsa --with-soxr --with-avahi --with-ssl=openssl --with-systemd --with-airplay-2 --with-apple-alac
    make -j $(nproc)
    sudo make install
    cd ..
    rm -rf shairport-sync-${SHAIRPORT_SYNC_VERSION}

    # Configure Shairport Sync
    sudo tee /etc/shairport-sync.conf >/dev/null <<EOF
general = {
  name = "${PRETTY_HOSTNAME:-$(hostname)}";
  output_backend = "alsa";
}

sessioncontrol = {
  session_timeout = 20;
};
EOF

    sudo usermod -a -G gpio shairport-sync
    sudo systemctl enable --now nqptp
    sudo systemctl enable --now shairport-sync
}

install_raspotify() {
    read -p "Do you want to install Raspotify (Spotify Connect)? [y/N] " REPLY
    if [[ ! "$REPLY" =~ ^(yes|y|Y)$ ]]; then return; fi

    # Install Raspotify
    curl -sL https://dtcooper.github.io/raspotify/install.sh | sh

    # Configure Raspotify
    LIBRESPOT_NAME="${PRETTY_HOSTNAME// /-}"
    LIBRESPOT_NAME=${LIBRESPOT_NAME:-$(hostname)}

    sudo tee /etc/raspotify/conf >/dev/null <<EOF
LIBRESPOT_QUIET=on
LIBRESPOT_AUTOPLAY=on
LIBRESPOT_DISABLE_AUDIO_CACHE=on
LIBRESPOT_DISABLE_CREDENTIAL_CACHE=on
LIBRESPOT_ENABLE_VOLUME_NORMALISATION=on
LIBRESPOT_NAME="${LIBRESPOT_NAME}"
LIBRESPOT_DEVICE_TYPE="avr"
LIBRESPOT_BITRATE="320"
LIBRESPOT_INITIAL_VOLUME="100"
EOF

    sudo systemctl daemon-reload
    sudo systemctl enable raspotify
}

trap cleanup EXIT

echo "Raspberry Pi Audio Receiver"

verify_os
set_hostname
install_bluetooth
install_shairport
install_raspotify