#!/bin/sh
# ============================================================
# bench.sh - 内存 & 磁盘 IO 速度检测
# 兼容 BusyBox / POSIX sh，无第三方依赖
# ============================================================

RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
CYAN='\033[0;36m'
BOLD='\033[1m'
NC='\033[0m'

# ── 自动寻找可写磁盘目录 ─────────────────────────────────────
# 排除 tmpfs/ramfs（内存文件系统），找真实存储挂载点
find_disk_dir() {
    # 遍历常见路径，找非 tmpfs 的可写目录
    for dir in /overlay /mnt /data /storage /usb /opt /root /home; do
        [ -d "$dir" ] || continue
        [ -w "$dir" ] || continue
        fstype=$(df -T "$dir" 2>/dev/null | awk 'NR==2{print $2}')
        # 跳过内存文件系统
        case "$fstype" in
            tmpfs|ramfs|devtmpfs|none|"") continue ;;
        esac
        echo "$dir"
        return
    done
    # 再扫一遍 /proc/mounts 找非内存挂载点
    while read -r dev mnt fstype rest; do
        case "$fstype" in
            tmpfs|ramfs|devtmpfs|sysfs|proc|cgroup*|devpts|overlay) continue ;;
        esac
        [ "$mnt" = "/" ] && continue
        [ -w "$mnt" ] || continue
        echo "$mnt"
        return
    done < /proc/mounts
    # 实在没有就用根目录
    echo "/"
}

DISK_DIR="${1:-$(find_disk_dir)}"
MEM_DIR="/dev/shm"
[ ! -d "$MEM_DIR" ] && MEM_DIR="/tmp"

DISK_FILE="$DISK_DIR/bench_$$"
MEM_FILE="$MEM_DIR/bench_mem_$$"

# ── 工具检测 ─────────────────────────────────────────────────
check_tools() {
    for tool in dd awk free df; do
        command -v "$tool" > /dev/null 2>&1 || { printf "${RED}缺少工具: %s${NC}\n" "$tool"; exit 1; }
    done
}

# ── 输出格式 ─────────────────────────────────────────────────
print_header() {
    printf "\n"
    printf "${BOLD}${CYAN}╔══════════════════════════════════════════════╗${NC}\n"
    printf "${BOLD}${CYAN}║         系统性能基准测试                     ║${NC}\n"
    printf "${BOLD}${CYAN}╚══════════════════════════════════════════════╝${NC}\n"
    printf "  测试时间: %s\n" "$(date '+%Y-%m-%d %H:%M:%S')"
    printf "  主机名:   %s\n" "$(cat /proc/sys/kernel/hostname 2>/dev/null || echo unknown)"
    printf "  内核:     %s\n" "$(uname -r)"
    printf "\n"
}

print_section() {
    printf "\n${BOLD}${YELLOW}▶ %s${NC}\n" "$1"
    printf "${YELLOW}──────────────────────────────────────────────────${NC}\n"
}

print_result() {
    printf "  %-18s : ${GREEN}${BOLD}%s${NC} %s\n" "$1" "$2" "$3"
}

# ── 安全水位计算（最多写到 80%）────────────────────────────
# 返回允许写入的 KB 数，0 表示不可用
safe_limit_kb() {
    local dir="$1"
    local total_kb used_kb safe_kb pct_used
    total_kb=$(df -k "$dir" 2>/dev/null | awk 'NR==2{print $2}')
    used_kb=$(df -k  "$dir" 2>/dev/null | awk 'NR==2{print $3}')
    [ -z "$total_kb" ] || [ "$total_kb" -eq 0 ] && { echo 0; return; }
    pct_used=$(( used_kb * 100 / total_kb ))
    safe_kb=$(( total_kb * 80 / 100 - used_kb ))
    if [ "$safe_kb" -le 0 ]; then
        printf "  ${RED}警告: %s 已用 %d%%，超过 80%% 安全水位，跳过！${NC}\n" "$dir" "$pct_used" >&2
        echo 0; return
    fi
    printf "  ${CYAN}%s: 总 %dMB / 已用 %d%% / 本次最多写入 %dMB${NC}\n" \
        "$dir" "$(( total_kb/1024 ))" "$pct_used" "$(( safe_kb/1024 ))" >&2
    echo "$safe_kb"
}

# ── 核心测速函数 ─────────────────────────────────────────────
# 优先用 dd 自身输出的速度；dd 无输出则手动计时
# BusyBox date 只有秒精度 → 强制写入足够大数据保证耗时 >= 2s
timed_dd() {
    local src="$1" dst="$2" bs_kb="$3" count="$4" flags="$5"
    local t0 t1 elapsed dd_out dd_speed total_kb speed_mbs

    total_kb=$(( bs_kb * count ))

    # 判断 date 是否支持纳秒
    local use_ns=0
    local ts
    ts=$(date +%s%N 2>/dev/null)
    echo "$ts" | grep -vq 'N' && use_ns=1

    if [ "$use_ns" = "1" ]; then
        t0=$(date +%s%N)
        dd_out=$(dd if="$src" of="$dst" bs="${bs_kb}k" count="$count" $flags 2>&1)
        sync
        t1=$(date +%s%N)
        elapsed=$(( (t1 - t0) / 1000000 ))   # ms
    else
        t0=$(date +%s)
        dd_out=$(dd if="$src" of="$dst" bs="${bs_kb}k" count="$count" $flags 2>&1)
        sync
        t1=$(date +%s)
        elapsed=$(( (t1 - t0) * 1000 ))       # ms
    fi

    # 尝试从 dd 输出提取速度（GNU dd / 部分 BusyBox dd）
    dd_speed=$(echo "$dd_out" | awk '{
        for(i=1;i<=NF;i++){
            if($i~/^[0-9.]+$/ && $(i+1)~/^[MmGgKk][Ii]?B\/s$/){
                spd=$i; unit=$(i+1)
            }
        }
    } END { if(spd) printf "%s %s", spd, unit }')

    if [ -n "$dd_speed" ]; then
        printf "%s ${YELLOW}(dd)${NC}" "$dd_speed"
        return
    fi

    # 手动计时兜底
    if [ "$elapsed" -le 0 ]; then
        # 耗时为 0，说明操作极快（内存缓存），给个提示
        printf "${YELLOW}< 1s，数据可能来自缓存，仅供参考${NC}"
        return
    fi

    # total_kb * 1000 / elapsed = KB/s，再转 MB/s
    speed_mbs=$(awk "BEGIN{printf \"%.1f\", $total_kb / $elapsed }")
    printf "%s MB/s ${YELLOW}(计时 %dms)${NC}" "$speed_mbs" "$elapsed"
}

# ── 系统信息 ─────────────────────────────────────────────────
show_sysinfo() {
    print_section "系统信息"
    local cpu cores mem_gb fstype
    cpu=$(grep -m1 'model name\|Hardware\|cpu model' /proc/cpuinfo 2>/dev/null | awk -F': ' '{print $2}')
    [ -z "$cpu" ] && cpu=$(uname -m)
    cores=$(grep -c '^processor' /proc/cpuinfo 2>/dev/null || echo "?")
    mem_gb=$(awk '/MemTotal/{printf "%.1f GB", $2/1024/1024}' /proc/meminfo)
    fstype=$(df -T "$DISK_DIR" 2>/dev/null | awk 'NR==2{print $2}')
    print_result "CPU" "$cpu" "($cores 核)"
    print_result "内存" "$mem_gb" ""
    print_result "内存测试目录" "$MEM_DIR" "($(df -T "$MEM_DIR" 2>/dev/null | awk 'NR==2{print $2}'))"
    print_result "磁盘测试目录" "$DISK_DIR" "($fstype)"
}

# ── 内存使用情况 ─────────────────────────────────────────────
show_memory_info() {
    print_section "内存使用情况"
    free | awk '
        NR==1 {printf "  %-10s %10s %10s %10s\n", "",    $1,  $2,  $3}
        NR==2 {printf "  %-10s %10s %10s %10s\n", "内存(KB):", $2, $3, $4}
        NR==3 {printf "  %-10s %10s %10s %10s\n", "Swap(KB):", $2, $3, $4}
    '
}

# ── 内存读写测试（写到 /dev/shm 或 /tmp）────────────────────
test_memory() {
    print_section "内存读写速度 ($MEM_DIR)"

    local safe_kb
    safe_kb=$(safe_limit_kb "$MEM_DIR")
    [ "$safe_kb" -le 0 ] && { printf "  ${RED}跳过：空间不足${NC}\n"; return; }

    # 限制最大 256MB，最小 16MB
    local max_kb=$(( 256 * 1024 ))
    local test_kb=$(( safe_kb < max_kb ? safe_kb : max_kb ))
    [ "$test_kb" -lt $(( 16 * 1024 )) ] && { printf "  ${RED}跳过：安全可用空间不足 16MB${NC}\n"; return; }

    # BusyBox date 秒精度：确保数据量足够大让耗时 >= 2s
    # 假设内存 >= 500MB/s，2s 需要 >= 1000MB，但内存有限所以取实际值
    local count=$(( test_kb / 1024 ))   # 单位: 1MB块
    [ "$count" -lt 1 ] && count=1

    printf "  ${CYAN}写入测试 (%dMB)...${NC}\n" "$count"
    local w
    w=$(timed_dd /dev/zero "$MEM_FILE" 1024 "$count")
    print_result "内存写入" "$w" ""

    printf "  ${CYAN}读取测试 (%dMB)...${NC}\n" "$count"
    local r
    r=$(timed_dd "$MEM_FILE" /dev/null 1024 "$count")
    print_result "内存读取" "$r" ""

    rm -f "$MEM_FILE"
}

# ── 磁盘读写测试 ─────────────────────────────────────────────
test_disk() {
    print_section "磁盘 IO 速度 ($DISK_DIR)"

    local safe_kb
    safe_kb=$(safe_limit_kb "$DISK_DIR")
    [ "$safe_kb" -le 0 ] && { printf "  ${RED}跳过：空间不足${NC}\n"; return; }

    local max_kb=$(( 512 * 1024 ))
    local test_kb=$(( safe_kb < max_kb ? safe_kb : max_kb ))
    [ "$test_kb" -lt $(( 16 * 1024 )) ] && { printf "  ${RED}跳过：安全可用空间不足 16MB${NC}\n"; return; }

    local count=$(( test_kb / 1024 ))
    [ "$count" -lt 1 ] && count=1

    # ── 顺序写入
    printf "  ${CYAN}顺序写入 (%dMB, 含 sync)...${NC}\n" "$count"
    local sw
    sw=$(timed_dd /dev/zero "$DISK_FILE" 1024 "$count" "conv=fsync")
    print_result "顺序写入" "$sw" ""

    # ── 顺序读取
    printf "  ${CYAN}顺序读取 (%dMB)...${NC}\n" "$count"
    sync; echo 3 > /proc/sys/vm/drop_caches 2>/dev/null
    local sr
    sr=$(timed_dd "$DISK_FILE" /dev/null 1024 "$count")
    print_result "顺序读取" "$sr" ""

    # ── 随机 4K 写入
    printf "  ${CYAN}随机 4K 写入 (200次)...${NC}\n"
    local t0 t1 elapsed iops i=0
    t0=$(date +%s)
    while [ $i -lt 200 ]; do
        offset=$(( (i * 7919 + 12345) % 9973 ))
        dd if=/dev/urandom of="$DISK_FILE" bs=4k count=1 seek=$offset conv=notrunc 2>/dev/null
        i=$(( i + 1 ))
    done
    sync
    t1=$(date +%s)
    elapsed=$(( t1 - t0 ))
    if [ "$elapsed" -gt 0 ]; then
        iops=$(( 200 / elapsed ))
        print_result "随机4K写入" "${iops} IOPS" "(${elapsed}s)"
    else
        print_result "随机4K写入" ">200 IOPS" "(<1s)"
    fi

    # ── 随机 4K 读取
    printf "  ${CYAN}随机 4K 读取 (200次)...${NC}\n"
    sync; echo 3 > /proc/sys/vm/drop_caches 2>/dev/null
    t0=$(date +%s); i=0
    while [ $i -lt 200 ]; do
        offset=$(( (i * 7919 + 12345) % 9973 ))
        dd if="$DISK_FILE" of=/dev/null bs=4k count=1 skip=$offset 2>/dev/null
        i=$(( i + 1 ))
    done
    t1=$(date +%s)
    elapsed=$(( t1 - t0 ))
    if [ "$elapsed" -gt 0 ]; then
        iops=$(( 200 / elapsed ))
        print_result "随机4K读取" "${iops} IOPS" "(${elapsed}s)"
    else
        print_result "随机4K读取" ">200 IOPS" "(<1s)"
    fi

    rm -f "$DISK_FILE"
}

# ── 清理 ─────────────────────────────────────────────────────
cleanup() { rm -f "$DISK_FILE" "$MEM_FILE" 2>/dev/null; }
trap cleanup EXIT INT TERM

# ── 主流程 ───────────────────────────────────────────────────
main() {
    check_tools
    print_header
    show_sysinfo
    show_memory_info
    test_memory
    test_disk
    printf "\n"
    printf "${BOLD}${CYAN}╔══════════════════════════════════════════════╗${NC}\n"
    printf "${BOLD}${CYAN}║              测试完成                        ║${NC}\n"
    printf "${BOLD}${CYAN}╚══════════════════════════════════════════════╝${NC}\n"
    printf "\n"
}

main