#!/bin/bash
# RDtop Installer — RustDesk headless display setup
# 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/90-fallback.conf"
BIN_DST="$HOME/.local/bin/hdmi-fallback.sh"
SYSTEMD_DST="$HOME/.config/systemd/user/hdmi-fallback.service"
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

if ! xset q >/dev/null 2>&1; then
    log "WARNING: No X11 display found. You need to run this from a graphical session."
fi

# --- Check if dummy driver exists or can be installed ---
if [ -f /usr/lib/xorg/modules/drivers/dummy_drv.so ]; then
    log "Dummy driver already present"
else
    log "Dummy driver not found. Will try to install 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 || log "WARNING: apt failed, dummy not installed (VIRTUAL1 should still work)"
    else
        log "WARNING: apt-get not found, skipping dummy driver install"
    fi
fi

# --- Create X11 fallback config ---
log "Creating X11 fallback config at $X11_CONF"
echo "retrowest" | sudo -S bash -c 'cat > /etc/X11/xorg.conf.d/90-fallback.conf' <<'EOF'
# Fallback Xorg config: guarantee a framebuffer even without HDMI
Section "Device"
    Identifier "AutoDevice"
    Driver "modesetting"
EndSection

Section "Monitor"
    Identifier "AutoMonitor"
    Option "DPMS" "false"
EndSection

Section "Screen"
    Identifier "AutoScreen"
    Device "AutoDevice"
    Monitor "AutoMonitor"
    DefaultDepth 24
    SubSection "Display"
        Depth 24
        Virtual 1920 1080
        Modes "1920x1080"
    EndSubSection
EndSection
EOF

sudo chmod 644 /etc/X11/xorg.conf.d/90-fallback.conf
log "X11 config installed"

# --- Install fallback script ---
log "Installing hdmi-fallback.sh to ~/.local/bin/"
mkdir -p "$HOME/.local/bin"
cat > "$BIN_DST" <<'SCRIPT'
#!/bin/bash
LOG="$HOME/.local/logs/drm-hotplug.log"
mkdir -p "$(dirname "$LOG")"
export DISPLAY=:0

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

log "=== Starting VIRTUAL1-primary fallback monitor ==="

MODE="1920x1080_60.00"
if ! xrandr 2>/dev/null | grep -q "$MODE"; then
    xrandr --newmode "$MODE" 173.00 1920 2048 2248 2576 1080 1083 1088 1120 2>/dev/null || true
fi
xrandr --addmode VIRTUAL1 "$MODE" 2>/dev/null || true

setup_virtual_primary() {
    log "Setting up VIRTUAL1 as primary..."
    xrandr --output VIRTUAL1 --mode "$MODE" --primary 2>&1 && log "VIRTUAL1 primary OK" || log "VIRTUAL1 primary failed"
}

enable_hdmi_clone() {
    log "Enabling HDMI1 as clone of VIRTUAL1"
    xrandr --output HDMI1 --auto --same-as VIRTUAL1 2>&1 && log "HDMI1 cloned OK" || log "HDMI1 clone failed"
}

disable_hdmi() {
    log "HDMI1 disconnected, keeping VIRTUAL1 primary"
    xrandr --output HDMI1 --off 2>&1 && log "HDMI1 off OK" || true
}

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 "ERROR: No HDMI-A-1 found"
    setup_virtual_primary
    exit 1
fi

log "Monitoring: $CONNECTOR"

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

if [ "$HDMI_STATE" = "connected" ]; then
    enable_hdmi_clone
else
    disable_hdmi
fi

log "Initial setup complete. Monitors:"
xrandr --listmonitors 2>&1 | while read line; do log "  $line"; done

LAST_STATE="$HDMI_STATE"

while true; do
    CURRENT=$(cat "$CONNECTOR/status" 2>/dev/null || echo "unknown")
    if [ "$CURRENT" != "$LAST_STATE" ]; then
        log "HDMI changed: $LAST_STATE -> $CURRENT"
        setup_virtual_primary
        if [ "$CURRENT" = "connected" ]; then
            enable_hdmi_clone
        else
            disable_hdmi
        fi
        log "Monitor layout after change:"
        xrandr --listmonitors 2>&1 | while read line; do log "  $line"; done
        LAST_STATE="$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 VIRTUAL1 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
log "Systemd unit enabled and started"

# --- Summary ---
echo ""
echo "============================================"
echo "RDtop installation complete!"
echo "============================================"
echo ""
echo "Next steps:"
echo "1. Reboot or re-login to apply X11 config"
echo "   sudo systemctl restart gdm"
echo ""
echo "2. After reboot, verify VIRTUAL1 is primary:"
echo "   xrandr --listmonitors"
echo ""
echo "3. Check service status:"
echo "   systemctl --user status hdmi-fallback.service"
echo ""
echo "4. To verify: unplug HDMI cable, VIRTUAL1 will stay active"
echo ""
log "Install complete"