#!/bin/bash
# 每日健康报告 — 发送格式化摘要邮件到管理员
# 部署：cp 到服务器 /root/rust/scripts/daily-report.sh，cron 每日执行

set -e

TO="m943790568@163.com"
DATE=$(date "+%Y-%m-%d")
HOST=$(hostname)

# ---------- 采集数据 ----------

UPTIME=$(uptime -p | sed 's/up //')
LOAD=$(uptime | awk -F'load average:' '{print $2}' | xargs)
DISK_USED=$(df -h / | awk 'NR==2{print $3}')
DISK_TOTAL=$(df -h / | awk 'NR==2{print $2}')
DISK_PCT=$(df -h / | awk 'NR==2{print $5}')
MEM_USED=$(free -h | awk '/Mem/{print $3}')
MEM_TOTAL=$(free -h | awk '/Mem/{print $2}')
MEM_PCT=$(free | awk '/Mem/{printf "%.0f", $3/$2 * 100}')
CPU_TEMP=$(cat /sys/class/thermal/thermal_zone0/temp 2>/dev/null | awk '{printf "%.1f°C", $1/1000}' || echo "N/A")

# Docker
DOCKER_STATUS=$(docker ps --format '{{.Names}}  {{.Status}}' 2>/dev/null || echo "Docker 不可用")

# SSL 证书
SSL_EXPIRY=$(echo "" | openssl s_client -connect xmclassmate.top:443 -servername xmclassmate.top 2>&1 | openssl x509 -noout -enddate 2>/dev/null | cut -d= -f2 || echo "检测失败")
SSL_DAYS=$(( ($(date -d "$SSL_EXPIRY" +%s 2>/dev/null) - $(date +%s)) / 86400 )) || SSL_DAYS="?"

# 服务状态
GREEN_STATUS=$(systemctl is-active rust-backend-green.service 2>/dev/null || echo "unknown")
BLUE_STATUS=$(systemctl is-active rust-backend-blue.service 2>/dev/null || echo "unknown")
NGINX_STATUS=$(systemctl is-active nginx 2>/dev/null || echo "unknown")

# 最近备份
LAST_BACKUP=$(ls -1t /root/rust/backups/milkydata/ 2>/dev/null | head -1)
BACKUP_AGE="未知"
if [ -n "$LAST_BACKUP" ]; then
    BACKUP_TIME=$(stat -c %Y "/root/rust/backups/milkydata/$LAST_BACKUP" 2>/dev/null)
    NOW=$(date +%s)
    AGE_HOURS=$(( (NOW - BACKUP_TIME) / 3600 ))
    if [ "$AGE_HOURS" -lt 24 ]; then
        BACKUP_AGE="✅ ${AGE_HOURS}小时前"
    elif [ "$AGE_HOURS" -lt 48 ]; then
        BACKUP_AGE="⚠️ ${AGE_HOURS}小时前"
    else
        BACKUP_AGE="❌ ${AGE_HOURS}小时前"
    fi
fi

# Fail2Ban 封禁统计
SSH_BANS=$(sudo fail2ban-client status sshd 2>/dev/null | grep "Currently banned" | awk '{print $NF}' || echo "0")
NGINX_BANS=$(sudo fail2ban-client status nginx-botsearch 2>/dev/null | grep "Currently banned" | awk '{print $NF}' || echo "0")

# 近期错误数（昨天 journalctl）
YESTERDAY_ERRORS=$(journalctl -u rust-backend-green.service --since "1 day ago" --priority err --no-pager 2>/dev/null | wc -l)
YESTERDAY_WARNS=$(journalctl -u rust-backend-green.service --since "1 day ago" --priority warning --no-pager 2>/dev/null | wc -l)

# 应用统计（昨天活跃用户）
ACTIVE_USERS=$(journalctl -u rust-backend-green.service --since "1 day ago" --no-pager 2>/dev/null | grep -c "user_id=\|登录成功\|上传成功" || echo "0")
API_COUNT=$(journalctl -u rust-backend-green.service --since "1 day ago" --no-pager 2>/dev/null | grep -c "INFO\|WARN\|ERROR" || echo "0")

# ---------- 构建邮件正文 ----------

SUBJECT="[ASD 服务器报告] ${DATE} — ${HOST}"

MAIL=$(cat <<EOF
===========================================
  ASD 服务器健康报告
  ${DATE}
  主机: ${HOST}
===========================================

🖥  系统状态
  - 运行时长: ${UPTIME}
  - 负载: ${LOAD}
  - 磁盘: ${DISK_USED} / ${DISK_TOTAL} (${DISK_PCT})
  - 内存: ${MEM_USED} / ${MEM_TOTAL} (${MEM_PCT})
  - CPU 温度: ${CPU_TEMP}

📦 容器
$(echo "$DOCKER_STATUS" | sed 's/^/  /')

🔐 SSL 证书
  域名: xmclassmate.top
  到期: ${SSL_EXPIRY}
  剩余: ${SSL_DAYS} 天

🔄 服务状态
  - 后端 (green): ${GREEN_STATUS}
  - 后端 (blue):  ${BLUE_STATUS}
  - nginx:        ${NGINX_STATUS}

🛡  安全
  - SSH 封禁: ${SSH_BANS} 个 IP
  - nginx 封禁: ${NGINX_BANS} 个 IP
  - 昨日错误: ${YESTERDAY_ERRORS}
  - 昨日警告: ${YESTERDAY_WARNS}

📊 应用概况（昨日）
  - 日志事件数: ${API_COUNT}
  - 活跃用户操作: ${ACTIVE_USERS}

💾 备份
  - 最新备份: ${LAST_BACKUP:-无}
  - 备份时效: ${BACKUP_AGE}

---
ASD 自动监控 | $(date "+%Y-%m-%d %H:%M")
EOF
)

# ---------- 发送邮件 ----------

echo "$MAIL" | msmtp -a default "$TO"
echo "✅ 健康报告已发送到 ${TO}"