#!/bin/bash

# ========================================
# 安装 systemd 服务脚本
# 用途：配置 Go API 为 systemd 服务
# ========================================

set -e

# 颜色定义
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
NC='\033[0m' # No Color

# 配置
SERVICE_NAME="go-api"
SERVICE_FILE="/etc/systemd/system/${SERVICE_NAME}.service"
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
SERVICE_TEMPLATE="${SCRIPT_DIR}/${SERVICE_NAME}.service"
WORK_DIR="/www/wwwroot/api.yunzer.cn"
MAIN_FILE="${WORK_DIR}/main.go"

echo -e "${BLUE}========================================${NC}"
echo -e "${BLUE}安装 Go API systemd 服务${NC}"
echo -e "${BLUE}========================================${NC}"
echo ""

# 检查是否为 root
if [ "$EUID" -ne 0 ]; then 
    echo -e "${RED}错误：请使用 root 用户运行此脚本${NC}"
    echo "使用方法: sudo bash $0"
    exit 1
fi

# 检查工作目录
if [ ! -d "$WORK_DIR" ]; then
    echo -e "${RED}错误：工作目录不存在: $WORK_DIR${NC}"
    exit 1
fi

# 检查 main.go
if [ ! -f "$MAIN_FILE" ]; then
    echo -e "${RED}错误：找不到 main.go: $MAIN_FILE${NC}"
    exit 1
fi

# 检查 Go 是否安装
if ! command -v go &> /dev/null; then
    echo -e "${RED}错误：Go 未安装或不在 PATH 中${NC}"
    exit 1
fi

GO_PATH=$(which go)
echo -e "${GREEN}✓ Go 路径: $GO_PATH${NC}"

# 停止现有服务
echo -e "${YELLOW}1. 停止现有服务...${NC}"
if systemctl is-active --quiet "$SERVICE_NAME"; then
    systemctl stop "$SERVICE_NAME"
    echo -e "${GREEN}   ✓ 已停止现有服务${NC}"
else
    echo -e "${YELLOW}   - 服务未运行${NC}"
fi

# 停止可能的手动启动进程
echo -e "${YELLOW}2. 清理手动启动的进程...${NC}"
if pgrep -f "go run main.go" > /dev/null; then
    pkill -f "go run main.go"
    echo -e "${GREEN}   ✓ 已清理手动启动的进程${NC}"
else
    echo -e "${YELLOW}   - 无手动启动的进程${NC}"
fi

# 创建服务文件
echo -e "${YELLOW}3. 创建 systemd 服务文件...${NC}"

cat > "$SERVICE_FILE" << EOF
[Unit]
Description=Go API Server
After=network.target mysql.service
Wants=mysql.service

[Service]
Type=simple
User=root
Group=root
WorkingDirectory=$WORK_DIR
ExecStart=$GO_PATH run main.go
Restart=always
RestartSec=5
StandardOutput=append:$WORK_DIR/go.log
StandardError=append:$WORK_DIR/go.log

# 环境变量
Environment="PATH=$GO_PATH:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"

# 资源限制
LimitNOFILE=65535
LimitNPROC=65535

# 安全设置
PrivateTmp=true
NoNewPrivileges=false

[Install]
WantedBy=multi-user.target
EOF

echo -e "${GREEN}   ✓ 服务文件已创建: $SERVICE_FILE${NC}"

# 重载 systemd
echo -e "${YELLOW}4. 重载 systemd 配置...${NC}"
systemctl daemon-reload
echo -e "${GREEN}   ✓ systemd 配置已重载${NC}"

# 启动服务
echo -e "${YELLOW}5. 启动服务...${NC}"
systemctl start "$SERVICE_NAME"
sleep 2

# 检查服务状态
if systemctl is-active --quiet "$SERVICE_NAME"; then
    echo -e "${GREEN}   ✓ 服务启动成功${NC}"
else
    echo -e "${RED}   ✗ 服务启动失败${NC}"
    echo ""
    echo -e "${YELLOW}查看错误日志：${NC}"
    journalctl -u "$SERVICE_NAME" -n 20 --no-pager
    exit 1
fi

# 启用开机自启
echo -e "${YELLOW}6. 启用开机自启...${NC}"
systemctl enable "$SERVICE_NAME"
echo -e "${GREEN}   ✓ 已启用开机自启${NC}"

# 显示服务状态
echo ""
echo -e "${BLUE}========================================${NC}"
echo -e "${BLUE}安装完成！${NC}"
echo -e "${BLUE}========================================${NC}"
echo ""
echo -e "${GREEN}服务信息：${NC}"
echo -e "  服务名称: $SERVICE_NAME"
echo -e "  工作目录: $WORK_DIR"
echo -e "  日志文件: $WORK_DIR/go.log"
echo -e "  配置文件: $SERVICE_FILE"
echo ""
echo -e "${GREEN}常用命令：${NC}"
echo -e "  启动服务: systemctl start $SERVICE_NAME"
echo -e "  停止服务: systemctl stop $SERVICE_NAME"
echo -e "  重启服务: systemctl restart $SERVICE_NAME"
echo -e "  查看状态: systemctl status $SERVICE_NAME"
echo -e "  查看日志: journalctl -u $SERVICE_NAME -f"
echo -e "  查看文件日志: tail -f $WORK_DIR/go.log"
echo ""
echo -e "${YELLOW}当前服务状态：${NC}"
systemctl status "$SERVICE_NAME" --no-pager -l
echo ""
echo -e "${YELLOW}最近日志（最后 10 行）：${NC}"
if [ -f "$WORK_DIR/go.log" ]; then
    tail -n 10 "$WORK_DIR/go.log"
else
    echo "  日志文件尚未创建"
fi
echo ""