#!/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/prometheus-3.9.1.linux-amd64.tar.gz"
GLOBAL_URL="https://github.com/prometheus/prometheus/releases/download/v3.9.1/prometheus-3.9.1.linux-amd64.tar.gz"
TARGET="/tmp/prometheus-3.9.1.linux-amd64.tar.gz"

is_cn=false

echo "Detecting geographic location..."
COUNTRY=$(curl -s --max-time 3 https://ipinfo.littlediary.cn/country || true)
if [ "$COUNTRY" = "CN" ]; 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 Prometheus..."
tar -zxvf /tmp/prometheus-3.9.1.linux-amd64.tar.gz -C /tmp
#Create Config Floder
mkdir -p /etc/prometheus/prometheus_data
echo "Copying Prometheus to /usr/bin/prometheus ..."
sudo cp -r /tmp/prometheus-3.9.1.linux-amd64/prometheus /usr/bin/prometheus

# Create Blank Prometheus Config File

sudo tee "/etc/prometheus/prometheus.yml" > /dev/null <<EOF

global:
  scrape_interval: 5s
scrape_configs:
  - job_name: 'SIMPLE'
    static_configs:
      - targets: ['8.8.8.8:9100']

EOF

# Create systemd service file

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

[Service]
User=root
Group=root
Type=simple
ExecStart=/usr/bin/prometheus \
  --config.file=/etc/prometheus/prometheus.yml \
  --storage.tsdb.path=/etc/prometheus/prometheus_data \
  --storage.tsdb.retention.time=15d \
  --web.listen-address=0.0.0.0:9090
Restart=always

[Install]
WantedBy=multi-user.target

EOF

# Create systemd service restart file
echo "Create systemd service restart file..."
sudo tee "/usr/bin/restart_prometheus" > /dev/null <<EOF

#!/bin/bash
systemctl daemon-reload
systemctl restart prometheus.service
systemctl status prometheus.service

EOF
sudo chmod 755 /usr/bin/restart_prometheus
# Reload systemd, enable and start service
echo "Enabling and starting Prometheus service..."
sudo systemctl daemon-reload
sudo systemctl enable --now prometheus.service

echo "Prometheus installation completed, listening on port 9090"