#!/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://8.134.128.173/relayx/node_exporter-1.10.2.linux-amd64.tar.gz"
GLOBAL_URL="https://github.com/prometheus/mysqld_exporter/releases/download/v0.18.0/mysqld_exporter-0.18.0.linux-amd64.tar.gz"
TARGET="/tmp/mysqld_exporter-0.18.0.linux-amd64.tar.gz"

is_cn=false

echo "Detecting geographic location..."

COUNTRY=$(curl -s --max-time 3 https://ipinfo.io/country || true)
if [ "$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"


sudo mkdir -p /etc/mysqld_exporter


# Extract
echo "Extracting Node Exporter..."
tar -zxvf /tmp/mysqld_exporter-0.18.0.linux-amd64.tar.gz -C /tmp

# Copy to /node_exporter
echo "Copying Node Exporter to /node_exporter..."
sudo cp -r /tmp/mysqld_exporter-0.18.0.linux-amd64/mysqld_exporter /usr/bin/mysqld_exporter

# Create mysqld_exporter config
sudo tee "/etc/mysqld_exporter/my.cnf" > /dev/null <<EOF

[client]
user=exporter
password=exporter_password
host=127.0.0.1
port=3306

EOF

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

echo "Creating systemd service file..."
sudo tee "$SERVICE_FILE" > /dev/null <<EOF

[Unit]
Description=Prometheus MySQL Exporter
Documentation=https://github.com/prometheus/mysqld_exporter
Wants=network-online.target
After=network-online.target

[Service]
Type=simple
User=root
Group=root
ExecStart=/usr/bin/mysqld_exporter \
  --config.my-cnf=/etc/mysqld_exporter/my.cnf \
  --web.listen-address=0.0.0.0:9104
Restart=always
RestartSec=5
NoNewPrivileges=true
PrivateTmp=true
ProtectSystem=full
ProtectHome=true

[Install]
WantedBy=multi-user.target

EOF

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

echo "MySQL Exporter installation completed, listening on port 9104"