#!/bin/bash
set -e

#Detect Operation System

if command -v apt >/dev/null 2>&1; then
    echo "Detected apt-based system"
    sudo apt update
    sudo apt install -y wget curl tar 

elif command -v dnf >/dev/null 2>&1; then
    echo "Detected dnf-based system"
    sudo dnf install -y wget curl tar 

else
    echo "Unsupported package manager"
    exit 1
fi


# Download Node Exporter

CN_URL="https://s3.cloudyun.top/downloads/node_exporter-1.10.2.linux-amd64.tar.gz"
GLOBAL_URL="https://github.com/prometheus/node_exporter/releases/download/v1.10.2/node_exporter-1.10.2.linux-amd64.tar.gz"
TARGET="/tmp/node_exporter.tar.gz"

is_cn=false

echo "Detecting geographic location..."

COUNTRY=$(curl -s --max-time 5 https://ipinfo.littlediary.cn/info | grep -o '"countryName":"[^"]*"' | cut -d'"' -f4)

if [ "$COUNTRY" = "China" ]; then
    is_cn=true
fi
if [ "$is_cn" = true ]; then
    echo "Geolocation: China mainland detected"
    DOWNLOAD_URL="$CN_URL"
else
    echo "Geolocation: non-China region detected"
    DOWNLOAD_URL="$GLOBAL_URL"
fi

echo "Downloading from: $DOWNLOAD_URL"
curl -fL -o "$TARGET" "$DOWNLOAD_URL"




# Extract
echo "Extracting Node Exporter..."
tar -zxvf /tmp/node_exporter.tar.gz -C /tmp

# Copy to /node_exporter
echo "Copying Node Exporter to /node_exporter..."
sudo cp -r /tmp/node_exporter-1.10.2.linux-amd64 /node_exporter

# Create systemd service file
SERVICE_FILE="/etc/systemd/system/node_exporter.service"

echo "Creating systemd service file..."
sudo tee "$SERVICE_FILE" > /dev/null <<EOF
[Unit]
Description=Node Exporter
Wants=network-online.target
After=network-online.target

[Service]
User=root
ExecStart=/node_exporter/node_exporter --web.listen-address=":9100"
Restart=always

[Install]
WantedBy=multi-user.target
EOF

# Reload systemd, enable and start service
echo "Enabling and starting node_exporter service..."
sudo systemctl daemon-reload
sudo systemctl enable --now node_exporter.service

echo "Node Exporter installation completed, listening on port 9100"