#!/bin/bash
# Gather system information from a remote server
# Output format: [section] headers followed by key=value pairs

echo "[system]"
echo "hostname=$(hostname)"
if [ -f /etc/os-release ]; then
    . /etc/os-release
    echo "os_name=$NAME"
    echo "os_version=$VERSION_ID"
    echo "os_pretty=$PRETTY_NAME"
fi
echo "kernel=$(uname -r)"
echo "arch=$(uname -m)"
echo "uptime_seconds=$(cut -d' ' -f1 /proc/uptime 2>/dev/null | cut -d. -f1)"

# Motherboard (readable without root on most systems)
echo "board_vendor=$(cat /sys/class/dmi/id/board_vendor 2>/dev/null || echo 'Unknown')"
echo "board_name=$(cat /sys/class/dmi/id/board_name 2>/dev/null || echo 'Unknown')"
echo "board_version=$(cat /sys/class/dmi/id/board_version 2>/dev/null || echo 'Unknown')"
echo "bios_version=$(cat /sys/class/dmi/id/bios_version 2>/dev/null || echo 'Unknown')"
echo "bios_date=$(cat /sys/class/dmi/id/bios_date 2>/dev/null || echo 'Unknown')"

echo "[cpu]"
echo "model=$(lscpu 2>/dev/null | grep 'Model name' | sed 's/Model name:[[:space:]]*//')"
echo "cores=$(nproc 2>/dev/null || echo 0)"
echo "sockets=$(lscpu 2>/dev/null | grep 'Socket(s)' | awk '{print $2}')"
echo "threads_per_core=$(lscpu 2>/dev/null | grep 'Thread(s) per core' | awk '{print $2}')"

# CPU usage - sample /proc/stat with 1 second interval
read -r label user1 nice1 system1 idle1 iowait1 irq1 softirq1 steal1 < /proc/stat
sleep 1
read -r label user2 nice2 system2 idle2 iowait2 irq2 softirq2 steal2 < /proc/stat

total1=$((user1 + nice1 + system1 + idle1 + iowait1 + irq1 + softirq1 + steal1))
total2=$((user2 + nice2 + system2 + idle2 + iowait2 + irq2 + softirq2 + steal2))
diff_total=$((total2 - total1))
diff_idle=$((idle2 - idle1))
if [ $diff_total -gt 0 ]; then
    usage_x10=$(( (diff_total - diff_idle) * 1000 / diff_total ))
    whole=$((usage_x10 / 10))
    frac=$((usage_x10 % 10))
    echo "usage_percent=${whole}.${frac}"
else
    echo "usage_percent=0.0"
fi

echo "[memory]"
total_kb=$(grep MemTotal /proc/meminfo 2>/dev/null | awk '{print $2}')
available_kb=$(grep MemAvailable /proc/meminfo 2>/dev/null | awk '{print $2}')
if [ -n "$total_kb" ] && [ -n "$available_kb" ]; then
    used_kb=$((total_kb - available_kb))
    total_mb=$((total_kb / 1024))
    used_mb=$((used_kb / 1024))
    available_mb=$((available_kb / 1024))
    if [ "$total_kb" -gt 0 ]; then
        usage_x10=$((used_kb * 1000 / total_kb))
        whole=$((usage_x10 / 10))
        frac=$((usage_x10 % 10))
        echo "usage_percent=${whole}.${frac}"
    else
        echo "usage_percent=0.0"
    fi
    echo "total_mb=$total_mb"
    echo "used_mb=$used_mb"
    echo "available_mb=$available_mb"
fi

# Physical disks
lsblk -b -n -o NAME,SIZE,TYPE 2>/dev/null | while read -r name size type; do
    if [ "$type" = "disk" ]; then
        echo "[disk:$name]"
        echo "name=$name"
        echo "size_bytes=$size"
    fi
done

# Mounted filesystem usage
df -B1 --output=target,size,used,avail,pcent 2>/dev/null | tail -n +2 | while read -r mount total used avail percent; do
    case "$mount" in
        /|/home|/var|/tmp|/boot|/data*|/mnt*|/srv*|/opt*)
            safename=$(echo "$mount" | tr '/' '_')
            echo "[disk_usage:${safename}]"
            echo "mount=$mount"
            echo "total_bytes=$total"
            echo "used_bytes=$used"
            echo "available_bytes=$avail"
            echo "usage_percent=${percent%\%}"
            ;;
    esac
done

# GPUs
gpu_idx=0
while read -r line; do
    echo "[gpu:$gpu_idx]"
    echo "description=$line"
    gpu_idx=$((gpu_idx + 1))
done < <(lspci 2>/dev/null | grep -iE 'vga|3d|display')

# Network interfaces
for iface in $(ls /sys/class/net/ 2>/dev/null); do
    [ "$iface" = "lo" ] && continue

    echo "[net:$iface]"
    echo "name=$iface"
    echo "mac=$(cat /sys/class/net/$iface/address 2>/dev/null)"
    echo "ipv4=$(ip -4 addr show "$iface" 2>/dev/null | grep -oP 'inet \K[0-9.]+' | head -1)"
    echo "ipv6=$(ip -6 addr show "$iface" 2>/dev/null | grep -oP 'inet6 \K[0-9a-f:]+' | grep -v '^fe80' | head -1)"
    echo "state=$(cat /sys/class/net/$iface/operstate 2>/dev/null)"

    speed=$(cat /sys/class/net/$iface/speed 2>/dev/null)
    [ -n "$speed" ] && [ "$speed" != "-1" ] && echo "speed_mbps=$speed"

    driver=$(readlink /sys/class/net/$iface/device/driver 2>/dev/null | xargs basename 2>/dev/null)
    [ -n "$driver" ] && echo "driver=$driver"
done

echo "[routing]"
default_line=$(ip route 2>/dev/null | grep default | head -1)
echo "gateway=$(echo "$default_line" | awk '{print $3}')"
echo "interface=$(echo "$default_line" | awk '{print $5}')"

echo "[dns]"
grep -E '^nameserver' /etc/resolv.conf 2>/dev/null | awk '{print "server=" $2}'

echo "[tailscale]"
if command -v tailscale &>/dev/null; then
    echo "installed=true"
    echo "ipv4=$(tailscale ip -4 2>/dev/null)"
    echo "hostname=$(tailscale status --self --json 2>/dev/null | grep -o '"DNSName":"[^"]*"' | head -1 | cut -d'"' -f4)"
else
    echo "installed=false"
fi

echo "[end]"