#!/bin/bash
# RDtop Installer — RustDesk headless display setup (dummy driver)
# Usage: bash -c "$(curl -fsSL https://git.softuniq.eu/NW/RDtop/raw/branch/main/install.sh)"
set -euo pipefail

echo "=== RDtop Installer ==="
echo "Installing RustDesk headless display fallback..."

# Config paths
REPO_URL="https://git.softuniq.eu/NW/RDtop"
X11_CONF="/etc/X11/xorg.conf.d/20-dummy-headless.conf"
BIN_DST="$HOME/.local/bin/hdmi-fallback.sh"
SYSTEMD_DST="$HOME/.config/systemd/user/hdmi-fallback.service"
EDID_DST="/lib/firmware/edid/samsung.bin"
LOG="$HOME/.local/logs/rdtop-install.log"

mkdir -p "$(dirname "$LOG")"
log() { echo "$(date '+%F %T') $1" | tee -a "$LOG"; }

log "Start install"

# --- Check prerequisites ---
if [ "$EUID" -eq 0 ]; then
    log "ERROR: Do not run as root. Run as regular user with sudo access."
    exit 1
fi

# --- Check sudo works ---
if ! sudo -n true 2>/dev/null; then
    echo "This script requires sudo privileges. Please enter your password when prompted."
fi

# --- Install dummy driver ---
if [ -f /usr/lib/xorg/modules/drivers/dummy_drv.so ]; then
    log "Dummy driver already present"
else
    log "Installing xserver-xorg-video-dummy..."
    if command -v apt-get >/dev/null 2>&1; then
        sudo apt-get update -qq && sudo apt-get install -y -qq xserver-xorg-video-dummy || true
    else
        log "WARNING: apt-get not found, cannot install dummy driver"
        exit 1
    fi
fi

# --- Remove old conflicting configs ---
log "Removing old Intel X11 configs"
sudo rm -f /etc/X11/xorg.conf.d/20-intel-virtual.conf
sudo rm -f /etc/X11/xorg.conf.d/90-fallback.conf

# --- Copy EDID firmware ---
log "Saving EDID firmware"
if [ -f /sys/class/drm/card0-HDMI-A-1/edid ]; then
    sudo mkdir -p /lib/firmware/edid
    sudo cp /sys/class/drm/card0-HDMI-A-1/edid "$EDID_DST"
    sudo chmod 644 "$EDID_DST"
    log "EDID saved to $EDID_DST"
else
    log "WARNING: No EDID found at /sys/class/drm/card0-HDMI-A-1/edid"
fi

# --- Create dummy headless X11 config ---
log "Creating dummy headless X11 config at $X11_CONF"
cat <<'XORG' | sudo tee "$X11_CONF" >/dev/null
Section "Device"
    Identifier "DummyHeadless"
    Driver "dummy"
    Option "ConstantDPI" "true"
    VideoRam 256000
EndSection

Section "Monitor"
    Identifier "DummyMonitor"
    HorizSync 28-80
    VertRefresh 48-75
EndSection

Section "Screen"
    Identifier "DummyScreen"
    Device "DummyHeadless"
    Monitor "DummyMonitor"
    DefaultDepth 24
    SubSection "Display"
        Depth 24
        Modes "1920x1080" "1280x720"
    EndSubSection
EndSection
XORG
sudo chmod 644 "$X11_CONF"
log "X11 config installed"

# --- Update GRUB for kernel EDID fallback ---
log "Updating GRUB cmdline for EDID fallback"
if [ -f /etc/default/grub ]; then
    sudo sed -i 's|GRUB_CMDLINE_LINUX_DEFAULT=".*"|GRUB_CMDLINE_LINUX_DEFAULT="quiet splash video=HDMI-A-1:1920x1080@60 drm.edid_firmware=HDMI-A-1:edid/samsung.bin"|' /etc/default/grub
    sudo update-grub >/dev/null 2>&1 || log "WARNING: update-grub failed"
    log "GRUB updated"
else
    log "WARNING: /etc/default/grub not found"
fi

# --- Install fallback script ---
log "Installing hdmi-fallback.sh to ~/.local/bin/"
mkdir -p "$HOME/.local/bin"
cat > "$BIN_DST" <<'SCRIPT'
#!/bin/bash
# Universal HDMI Fallback: DUMMY0 (dummy driver) or VIRTUAL1 (intel)
# Works both with HDMI connected and disconnected at boot

LOG="$HOME/.local/logs/drm-hotplug.log"
mkdir -p "$HOME/.local/logs"
export DISPLAY=:0

log() {
    echo "$(date '+%Y-%m-%d %H:%M:%S') $1" | tee -a "$LOG" >/dev/null
}

# Find available primary output (DUMMY0 or VIRTUAL1)
find_primary_output() {
    if xrandr 2>/dev/null | grep -q "^DUMMY0"; then
        echo "DUMMY0"
    elif xrandr 2>/dev/null | grep -q "^VIRTUAL1"; then
        echo "VIRTUAL1"
    else
        echo ""
    fi
}

# Find HDMI output name (HDMI-1, HDMI1, etc)
find_hdmi_output() {
    xrandr 2>/dev/null | grep -E "^HDMI-[0-9] connected" | awk '{print $1}' | head -1
}

# Set up mode for virtual output
setup_mode() {
    local OUTPUT="$1"
    local MODE_NAME="1920x1080"

    if [ "$OUTPUT" = "VIRTUAL1" ]; then
        local MODELINE="1920x1080_60.00"
        if ! xrandr 2>/dev/null | grep -q "$MODELINE"; then
            xrandr --newmode "$MODELINE" 173.00 1920 2048 2248 2576 1080 1083 1088 1120 2>/dev/null || true
        fi
        xrandr --addmode VIRTUAL1 "$MODELINE" 2>/dev/null || true
        MODE_NAME="$MODELINE"
    fi
    echo "$MODE_NAME"
}

log "Start monitor (user=$USER, display=$DISPLAY)"

CONNECTOR=""
for p in /sys/class/drm/card1-HDMI-A-1 /sys/class/drm/card0-HDMI-A-1; do
    [ -e "$p/status" ] && { CONNECTOR="$p"; break; }
done
[ -z "$CONNECTOR" ] && CONNECTOR=$(find /sys/class/drm -maxdepth 1 -name "*HDMI-A-1" -type d | head -1)

if [ -z "$CONNECTOR" ] || [ ! -e "$CONNECTOR/status" ]; then
    log "WARNING: No HDMI-A-1 connector found, running headless only"
fi

# Initial state
LAST_STATE=$(cat "$CONNECTOR/status" 2>/dev/null || echo unknown)
log "Initial HDMI: $LAST_STATE"

# Detect outputs
PRIMARY=$(find_primary_output)
HDMI=$(find_hdmi_output)

if [ -z "$PRIMARY" ]; then
    log "ERROR: No virtual output found (DUMMY0 or VIRTUAL1)"
    exit 1
fi

log "Primary: $PRIMARY, HDMI: ${HDMI:-none}"

MODE=$(setup_mode "$PRIMARY")

# Initial setup
if [ "$LAST_STATE" = "connected" ] && [ -n "$HDMI" ]; then
    log "HDMI connected, setting clone: $PRIMARY primary + $HDMI same-as"
    xrandr --output "$PRIMARY" --mode "$MODE" --primary 2>/dev/null || true
    xrandr --output "$HDMI" --auto --same-as "$PRIMARY" 2>/dev/null || true
else
    log "HDMI disconnected or not found, keeping $PRIMARY primary"
    xrandr --output "$PRIMARY" --mode "$MODE" --primary 2>/dev/null || true
    [ -n "$HDMI" ] && xrandr --output "$HDMI" --off 2>/dev/null || true
fi

log "Setup complete. Monitors:"
xrandr --listmonitors 2>/dev/null | while read -r line; do log "  $line"; done

# Main loop
while true; do
    CURRENT=$(cat "$CONNECTOR/status" 2>/dev/null || echo unknown)

    if [ "$CURRENT" != "$LAST_STATE" ]; then
        log "HDMI changed: $LAST_STATE -> $CURRENT"

        # Re-detect
        PRIMARY=$(find_primary_output)
        HDMI=$(find_hdmi_output)
        MODE=$(setup_mode "$PRIMARY")

        if [ -z "$PRIMARY" ]; then
            log "ERROR: No virtual output detected after HDMI change"
            sleep 5
            continue
        fi

        # Always make PRIMARY primary
        xrandr --output "$PRIMARY" --mode "$MODE" --primary 2>/dev/null || true

        if [ "$CURRENT" = "connected" ] && [ -n "$HDMI" ]; then
            log "HDMI connected, cloning $HDMI to $PRIMARY"
            xrandr --output "$HDMI" --auto --same-as "$PRIMARY" 2>/dev/null || true
        else
            log "HDMI disconnected, keeping $PRIMARY primary"
            [ -n "$HDMI" ] && xrandr --output "$HDMI" --off 2>/dev/null || true
        fi

        LAST_STATE="$CURRENT"
    fi

    sleep 2
done
SCRIPT

chmod +x "$BIN_DST"
log "Script installed"

# --- Install systemd unit ---
log "Installing systemd user unit"
mkdir -p "$HOME/.config/systemd/user"
cat > "$SYSTEMD_DST" <<'UNIT'
[Unit]
Description=HDMI to Virtual Fallback Monitor
After=graphical-session.target

[Service]
Type=simple
ExecStart=%h/.local/bin/hdmi-fallback.sh
Restart=always
RestartSec=5
Environment="DISPLAY=:0"

[Install]
WantedBy=graphical-session.target
UNIT

systemctl --user daemon-reload
systemctl --user enable --now hdmi-fallback.service 2>/dev/null || true
log "Systemd unit enabled"

# --- Summary ---
echo ""
echo "============================================"
echo "RDtop installation complete!"
echo "============================================"
echo ""
echo "Next steps:"
echo "1. REBOOT now for changes to take effect:"
echo "   sudo reboot"
echo ""
echo "2. After reboot without HDMI, check:"
echo "   xrandr --listmonitors"
echo ""
echo "3. Service status:"
echo "   systemctl --user status hdmi-fallback.service"
echo ""
echo "4. View logs:"
echo "   cat ~/.local/logs/drm-hotplug.log"
echo ""
log "Install complete"