#!/bin/bash
# RABBID Chromebook Audio Setup Script for Linux Mint 21.1
# Why Linux mint 21.1? It's the only distro with reports of getting sound to work with these.
# It might work with other ubuntu (and probably debian) distros and kernels but who knows.

# This script configures audio (speakers and microphone) for Asus Chromebook C423N (RABBID)
# with Apollo Lake chipset, DA7219 codec, and MAX98357A amplifier.
# Using the ALSA + pulseaudio software stack with intel-sof audio drivers.

# ** THIS SCRIPT CREATES AND INSTALLS A SERVICE SCRIPT TO RESTART PULSEAUDIO 12s AFTER DESKTOP LOGIN FOR REASONS OF TIMING BEING HARD **
# ** 	~/.config/systemd/user/rabbid-audio-user.service	- calls rabbid-audio-fix.sh restarts pulseaudio
# ** You might not like the unintended consequences of that. 
# ** I personally have no problems beyond the *ding* of new audio devices being found each boot.

# ** The other file it creates are: 
# ** 	/usr/local/bin/rabbid-audio-fix.sh	- bring up the kernel modules in the right order with pauses, unmutes
# **	/etc/systemd/system/rabbid-audio-fix.service - actually calls rabbid-audio-fix.sh
# ** 	/etc/pulse/default.pa.d/rabbid-audio.pa	- sets the RABBID specific audio hardware id paths as pulse input/output devices
# ** 	/lib/firmware/intel/sof-tplg/		- INSTALLS, contents replaced, contains: sof-apl-da7219.tplg topology
# **	/lib/firmware/intel/sof/*		- INSTALLS, contents replaced, contains: sof firmware
# ** 	/etc/modprobe.d/inteldsp.conf		- points kernel snd module at ./intel/sof/ firmware forcing SOF driver for Apollo Lake audio


set -e  # Exit on error

echo "=========================================="
echo "RABBID Chromebook Audio Setup"
echo "For: Asus Chromebook C423N (codename: RABBID)"
echo "OS: Linux Mint 21.1"
echo "=========================================="
echo ""

# Check if running on correct OS
if ! grep -q "Linux Mint 21" /etc/os-release 2>/dev/null; then
    echo "WARNING: This script is designed for Linux Mint 21.1"
    echo "You appear to be running a different distribution."
    read -p "Continue anyway? (y/n) " -n 1 -r
    echo
    if [[ ! $REPLY =~ ^[Yy]$ ]]; then
        exit 1
    fi
fi

# Check if running as root
if [ "$EUID" -eq 0 ]; then
   echo "ERROR: Do not run this script as root/sudo"
   echo "The script will ask for sudo password when needed"
   exit 1
fi

echo "Step 1: Installing required packages..."
sudo apt update
sudo apt install -y alsa-topology-conf alsa-ucm-conf linux-firmware

echo ""
echo "Step 2: Downloading SOF firmware..."
cd /tmp
if [ -d "sof-bin-2024.09.2" ]; then
    rm -rf sof-bin-2024.09.2
fi
wget -q --show-progress https://github.com/thesofproject/sof-bin/releases/download/v2024.09.2/sof-bin-2024.09.2.tar.gz
tar -xzf sof-bin-2024.09.2.tar.gz
cd sof-bin-2024.09.2

echo ""
echo "Step 3: Installing SOF firmware files..."
# Remove any conflicting symlinks/directories
sudo rm -rf /lib/firmware/intel/sof-tplg 2>/dev/null || true
sudo rm -rf /lib/firmware/intel/sof 2>/dev/null || true

# Copy topology files
sudo cp -r sof-tplg /lib/firmware/intel/

# Copy SOF firmware files
sudo cp -r sof /lib/firmware/intel/

# Set proper permissions
sudo chmod -R 644 /lib/firmware/intel/sof*
sudo find /lib/firmware/intel/sof* -type d -exec chmod 755 {} \;

# Verify critical file exists
if [ ! -f "/lib/firmware/intel/sof-tplg/sof-apl-da7219.tplg" ]; then
    echo "ERROR: Critical topology file not found!"
    exit 1
fi
echo "✓ SOF firmware installed successfully"

echo ""
echo "Step 4: Configuring audio driver..."
# Create modprobe configuration
sudo bash -c 'cat > /etc/modprobe.d/inteldsp.conf << EOF
# Force SOF driver for Apollo Lake audio
options snd_intel_dspcfg dsp_driver=3
options snd-sof-pci fw_path=intel/sof/
EOF'

echo "✓ Driver configuration created"

echo ""
echo "Step 5: Creating PulseAudio configuration..."
sudo mkdir -p /etc/pulse/default.pa.d
sudo bash -c 'cat > /etc/pulse/default.pa.d/rabbid-audio.pa << EOF
# RABBID Chromebook audio configuration
# Activate stereo output profile
set-card-profile alsa_card.pci-0000_00_0e.0-platform-bxt_da7219_mx98357a output:stereo-fallback

# Load internal DMIC (digital microphone)
load-module module-alsa-source device=hw:0,99

# Load headset microphone
load-module module-alsa-source device=hw:0,1

# Set internal DMIC as default microphone
set-default-source alsa_input.hw_0_99
EOF'

echo "✓ PulseAudio configuration created"

echo ""
echo "Step 6: Updating initramfs..."
sudo update-initramfs -u

echo ""
echo "Step 7: Creating boot-time audio fix service..."
# Create the fix script
sudo bash -c 'cat > /usr/local/bin/rabbid-audio-fix.sh << '\''EOF'\''
#!/bin/bash
# Wait for system to fully boot
sleep 5

# Reload the SOF audio module to work around boot-time race condition
modprobe -r snd_soc_sst_bxt_da7219_max98357a
modprobe -r snd_sof_pci_intel_apl
sleep 1
modprobe snd_sof_pci_intel_apl

# Wait for module to initialize
sleep 3

# Unmute microphone controls
amixer -c 0 cset numid=2 on 2>/dev/null    # Main mic
amixer -c 0 cset numid=8 on 2>/dev/null    # Capture digital
amixer -c 0 cset numid=69 on 2>/dev/null   # Headset mic
amixer -c 0 cset numid=7 127 2>/dev/null   # Capture volume

# Save ALSA state
alsactl store

exit 0
EOF'

# Make script executable
sudo chmod +x /usr/local/bin/rabbid-audio-fix.sh

# Create systemd service
sudo bash -c 'cat > /etc/systemd/system/rabbid-audio-fix.service << '\''EOF'\''
[Unit]
Description=RABBID Chromebook Audio Fix
After=sound.target systemd-user-sessions.service
Wants=sound.target

[Service]
Type=oneshot
ExecStart=/usr/local/bin/rabbid-audio-fix.sh
RemainAfterExit=yes

[Install]
WantedBy=multi-user.target
EOF'

# Enable the service
sudo systemctl daemon-reload
sudo systemctl enable rabbid-audio-fix.service

echo "✓ Boot-time audio fix service created and enabled"

echo ""
echo "Step 8: Creating user-level PulseAudio restart service..."
# Create user service directory
mkdir -p ~/.config/systemd/user/

# Create user service
cat > ~/.config/systemd/user/rabbid-audio-user.service << 'EOF'
[Unit]
Description=RABBID Audio User Fix
After=rabbid-audio-fix.service
Requires=sound.target

[Service]
Type=oneshot
ExecStartPre=/bin/sleep 2
ExecStart=/bin/bash -c 'systemctl --user restart pulseaudio.service'
RemainAfterExit=yes

[Install]
WantedBy=default.target
EOF

# Enable user service
systemctl --user daemon-reload
systemctl --user enable rabbid-audio-user.service

echo "✓ User-level audio restart service created and enabled"

echo ""
echo "Step 9: Installing pasystray (optional audio tray icon)..."
sudo apt install -y pasystray

echo ""
echo "=========================================="
echo "Setup Complete!"
echo "=========================================="
echo ""
echo "IMPORTANT: You must REBOOT for changes to take effect."
echo ""
echo "After reboot:"
echo "  - Audio will automatically reload ~10 seconds after boot"
echo "  - Speakers should work automatically"
echo "  - Internal microphone (DMIC) should work"
echo "  - Headset microphone should work when plugged in"
echo ""
echo "To test after reboot:"
echo "  Speaker test: paplay /usr/share/sounds/alsa/Front_Center.wav"
echo "  Mic test:     parec -d alsa_input.hw_0_99 --format=s32le | paplay --format=s32le"
echo ""
echo "Optional: Add pasystray to startup applications for a system tray volume icon"
echo ""
echo "To check service status:"
echo "  System service: sudo systemctl status rabbid-audio-fix.service"
echo "  User service:   systemctl --user status rabbid-audio-user.service"
echo ""
read -p "Reboot now? (y/n) " -n 1 -r
echo
if [[ $REPLY =~ ^[Yy]$ ]]; then
    sudo reboot
fi