#!/usr/bin/env bash
# ============================================================================
# MAX SysInfo — 服务器系统信息概览
# 原创脚本，专为纯文本 SSH 服务端环境优化，聚焦关键指标
# 灵感源于 neofetch / screenfetch 的系统信息展示功能
#
# 风险等级: 🟢 只读 — 不修改任何系统设置
# 用法: bash <(curl -fsSL https://dl.unvmax.com/linux/scripts/max-tools/max-sysinfo.sh)
# ============================================================================

set -e

R='\033[1;31m' G='\033[1;32m' Y='\033[1;33m' B='\033[1;34m'
C='\033[1;36m' M='\033[1;35m' W='\033[1;37m' N='\033[0m'
GR='\033[90m'

echo -e "${B}┌─────────────────────────────────────────────┐${N}"
echo -e "${B}│${N}  ${G}MAX 系统信息概览${N}  ${GR}(只读诊断)${N}"
echo -e "${B}└─────────────────────────────────────────────┘${N}"
echo

hostname=$(hostname 2>/dev/null || echo "unknown")
os=$(grep -E '^PRETTY_NAME=' /etc/os-release 2>/dev/null | cut -d'"' -f2 || echo "unknown")
kernel=$(uname -r 2>/dev/null || echo "unknown")
arch=$(uname -m 2>/dev/null || echo "unknown")
uptime_sec=$(awk '{print $1}' /proc/uptime 2>/dev/null | cut -d. -f1)
up_d=$((uptime_sec/86400)) up_h=$(((uptime_sec%86400)/3600)) up_m=$(((uptime_sec%3600)/60))

echo -e "  ${C}主机名:${N}     ${W}$hostname${N}"
echo -e "  ${C}系统版本:${N}   ${W}$os${N}"
echo -e "  ${C}内核版本:${N}   ${W}$kernel${N}  ${GR}$arch${N}"
echo -e "  ${C}运行时间:${N}   ${W}${up_d}d ${up_h}h ${up_m}m${N}"

cpu_model=$(grep -m1 'model name' /proc/cpuinfo 2>/dev/null | sed 's/.*: //' | sed 's/\s\+/ /g')
cpu_cores=$(grep -c '^processor' /proc/cpuinfo 2>/dev/null || echo "?")
cpu_load=$(awk '{printf "%.1f %.1f %.1f", $1,$2,$3}' /proc/loadavg 2>/dev/null || echo "? ? ?")
echo -e "  ${C}CPU 型号:${N}    ${W}$cpu_model${N}"
echo -e "  ${C}CPU 核心:${N}    ${W}${cpu_cores}${N}"
echo -e "  ${C}系统负载:${N}    ${W}${cpu_load}${N}"

if [ -f /proc/meminfo ]; then
    mem_total=$(awk '/^MemTotal:/{printf "%.0f", $2/1024}' /proc/meminfo)
    mem_avail=$(awk '/^MemAvailable:/{printf "%.0f", $2/1024}' /proc/meminfo)
    mem_used=$((mem_total - mem_avail))
    mem_pct=$((mem_used * 100 / mem_total))
    swap_total=$(awk '/^SwapTotal:/{printf "%.0f", $2/1024}' /proc/meminfo)
    swap_free=$(awk '/^SwapFree:/{printf "%.0f", $2/1024}' /proc/meminfo)
    swap_used=$((swap_total - swap_free))

    [ "$mem_pct" -gt 80 ] && mem_color=$R
    [ "$mem_pct" -gt 60 ] && [ "$mem_pct" -le 80 ] && mem_color=$Y
    [ "$mem_pct" -le 60 ] && mem_color=$G

    echo -e "  ${C}物理内存:${N}   ${mem_color}${mem_used}MB / ${mem_total}MB ($mem_pct%)${N}"
    if [ "$swap_total" -gt 0 ]; then
        swap_pct=$((swap_used * 100 / swap_total))
        [ "$swap_pct" -gt 50 ] && swp_c=$R || swp_c=$G
        echo -e "  ${C}交换分区:${N}   ${swp_c}${swap_used}MB / ${swap_total}MB ($swap_pct%)${N}"
    fi
fi

echo -e "\n  ${M}── 磁盘使用率 TOP5 ──${N}"
df -h 2>/dev/null | grep '^/' | sort -rn -k5 | head -5 | while read -r line; do
    fs=$(echo "$line" | awk '{print $1}')
    size=$(echo "$line" | awk '{print $2}')
    used=$(echo "$line" | awk '{print $3}')
    pct=$(echo "$line" | awk '{print $5}' | tr -d '%')
    mount=$(echo "$line" | awk '{print $6}')
    [ "$pct" -gt 85 ] && c=$R
    [ "$pct" -gt 70 ] && [ "$pct" -le 85 ] && c=$Y
    [ "$pct" -le 70 ] && c=$G
    echo -e "    ${c}${used}/${size} ($pct%)${N}  ${GR}$fs → $mount${N}"
done

echo -e "\n  ${M}── 监听端口 ──${N}"
ss -tlnp 2>/dev/null | awk 'NR>1 {
    split($4, a, ":")
    port=a[length(a)]
    printf "    %s :%s\n", $1, port
}' | sort -t: -k2 -n | uniq | head -10

echo -e "\n  ${M}── 最近登录 ${GR}(last 3)${N}"
last -n 3 2>/dev/null | head -3 | while read -r line; do
    echo -e "    ${GR}$line${N}"
done

echo
echo -e "${GR}👉 查看完整报告: max-diskreport.sh | 网络分析: max-netstat.sh${N}"
echo -e "${GR}👉 一键执行: bash <(curl -fsSL https://dl.unvmax.com/linux/scripts/max-tools/max-sysinfo.sh)${N}"