#!/bin/bash

set -e

if [[ "$(whoami)" != "root" ]]; then
    echo "You need to run this script as root."
    exit 1
fi

TARGETDIR="/opt/fan_control"
if [ ! -z "$1" ]; then
    TARGETDIR="$1"
fi

echo "*** Installing system dependencies..."
if [ -x "$(command -v apt-get)" ]; then
	apt-get update
	apt-get install -y python3-venv python3-pip lm-sensors ipmitool
elif [ -x "$(command -v dnf)" ]; then
	dnf install -y python3-pip lm-sensors ipmitool
else
    echo "Unsupported package manager. Please install: python3-venv, python3-pip, lm-sensors, ipmitool"
    exit 1
fi

echo "*** Creating folder '$TARGETDIR'..."
if [ ! -d "$TARGETDIR" ]; then
    mkdir -p "$TARGETDIR"
fi

echo "*** Creating Python3 virtual environment..."
if [ -d "$TARGETDIR/venv" ]; then
    echo "*** Existing venv found, purging it."
    rm -rf "$TARGETDIR/venv"
fi
python3 -m venv "$TARGETDIR/venv"

echo "*** Installing Python dependencies..."
"$TARGETDIR/venv/bin/pip" install --upgrade pip
"$TARGETDIR/venv/bin/pip" install PyYAML

echo "*** Copying script and configuration..."
if [ -f "$TARGETDIR/fan_control.yaml" ]; then
    echo "*** Backing up existing configuration..."
    cp "$TARGETDIR/fan_control.yaml" "$TARGETDIR/fan_control.yaml.backup.$(date +%Y%m%d_%H%M%S)"
else
    cp fan_control.yaml.example "$TARGETDIR/fan_control.yaml"
    echo "*** Please edit $TARGETDIR/fan_control.yaml to configure your temperature thresholds"
fi

cp fan_control.py "$TARGETDIR/"
chmod +x "$TARGETDIR/fan_control.py"

echo "*** Creating SystemD service..."
cat > /etc/systemd/system/fan-control.service << EOF
[Unit]
Description=Temperature-based fan speed controller
After=multi-user.target
Wants=multi-user.target

[Service]
Type=simple
ExecStart=$TARGETDIR/venv/bin/python3 -u $TARGETDIR/fan_control.py
Restart=always
RestartSec=10
User=root
Group=root

# Ensure fans return to automatic mode on service stop/failure
ExecStopPost=/usr/bin/ipmitool raw 0x30 0x30 0x01 0x01

# Resource limits
MemoryLimit=100M
CPUQuota=10%

# Security hardening
NoNewPrivileges=yes
ProtectSystem=strict
ProtectHome=yes
ReadWritePaths=$TARGETDIR
PrivateTmp=yes

[Install]
WantedBy=multi-user.target
EOF

echo "*** Testing the script..."
if ! "$TARGETDIR/venv/bin/python3" -c "import yaml; print('✓ PyYAML working')"; then
    echo "Error: PyYAML not properly installed"
    exit 1
fi

if ! command -v sensors >/dev/null 2>&1; then
    echo "Error: sensors command not found. Please install lm-sensors"
    exit 1
fi

if ! sensors | grep -q "Core"; then
    echo "Warning: No CPU core temperatures detected. You may need to run 'sensors-detect'"
    echo "Run: sensors-detect and answer YES to safe probes, then reboot"
fi

echo "*** Enabling and starting service..."
systemctl daemon-reload
systemctl enable fan-control
systemctl start fan-control

echo "*** Waiting for service to start..."
sleep 3

echo "*** Installation complete! Service status:"
systemctl status fan-control --no-pager

echo ""
echo "*** Quick checks:"
echo "- Edit configuration: nano $TARGETDIR/fan_control.yaml"
echo "- View logs: journalctl -u fan-control.service -f"
echo "- Test manually: $TARGETDIR/venv/bin/python3 $TARGETDIR/fan_control.py"

set +e