#!/bin/bash

# Syncthing 智能管理脚本 - 安装/卸载二合一
set -e

# 配置变量
SYNCTHING_VERSION="v1.27.7"
INSTALL_DIR="/opt/syncthing"
CONFIG_DIR="$HOME/.config/syncthing"
SERVICE_FILE="/etc/systemd/system/syncthing.service"
BIN_PATH="/usr/local/bin/syncthing"

# 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

# 输出函数
log_info() { echo -e "${BLUE}ℹ️  $1${NC}"; }
log_success() { echo -e "${GREEN}✅ $1${NC}"; }
log_warning() { echo -e "${YELLOW}⚠️  $1${NC}"; }
log_error() { echo -e "${RED}❌ $1${NC}"; }

# 显示使用说明
show_usage() {
    echo -e "${BLUE}"
    echo "================================================"
    echo "          Syncthing 智能管理脚本"
    echo "================================================"
    echo -e "${NC}"
    echo "使用方法: $0 [command]"
    echo ""
    echo "命令:"
    echo "  install    - 安装 Syncthing"
    echo "  uninstall  - 卸载 Syncthing" 
    echo "  reinstall  - 重新安装 Syncthing"
    echo "  status     - 查看服务状态"
    echo "  restart    - 重启服务"
    echo "  不指定命令 - 自动检测并安装或显示状态"
    echo ""
    echo "特性:"
    echo "  ✅ 直接IP访问 (0.0.0.0:8384)"
    echo "  ✅ 系统服务守护"
    echo "  ✅ 完整文件权限"
    echo "  ✅ 一键安装卸载"
    echo -e "${BLUE}================================================"
    echo -e "${NC}"
}

# 检查是否已安装
check_installed() {
    if [ -f "$BIN_PATH" ] || [ -f "$INSTALL_DIR/syncthing" ] || systemctl is-enabled syncthing 2>/dev/null | grep -q enabled; then
        return 0  # 已安装
    else
        return 1  # 未安装
    fi
}

# 获取本机IP
get_ip() {
    hostname -I | awk '{print $1}' 2>/dev/null || echo "127.0.0.1"
}

# 显示状态
show_status() {
    if check_installed; then
        log_success "Syncthing 已安装"
        echo ""
        echo "📁 安装目录: $INSTALL_DIR"
        echo "⚙️  配置目录: $CONFIG_DIR"
        echo "🔧 二进制文件: $BIN_PATH"
        echo ""
        
        # 检查服务状态
        if systemctl is-active --quiet syncthing; then
            log_success "服务状态: 运行中"
            echo "🌐 访问地址: http://$(get_ip):8384"
        else
            log_warning "服务状态: 已停止"
        fi
        
        # 检查端口监听
        if netstat -tuln 2>/dev/null | grep -q ":8384 "; then
            log_success "端口 8384: 正在监听"
        else
            log_warning "端口 8384: 未监听"
        fi
    else
        log_warning "Syncthing 未安装"
    fi
}

# 安装函数
install_syncthing() {
    log_info "开始安装 Syncthing..."
    
    # 检查是否已安装
    if check_installed; then
        log_warning "Syncthing 已安装，如需重新安装请使用: $0 reinstall"
        show_status
        exit 1
    fi

    # 创建安装目录
    log_info "创建安装目录..."
    sudo mkdir -p $INSTALL_DIR
    sudo chown $USER:$USER $INSTALL_DIR

    # 下载并安装
    log_info "下载 Syncthing $SYNCTHING_VERSION..."
    cd /tmp
    wget -q --show-progress https://github.com/syncthing/syncthing/releases/download/$SYNCTHING_VERSION/syncthing-linux-amd64-$SYNCTHING_VERSION.tar.gz

    log_info "解压安装包..."
    tar xzf syncthing-linux-amd64-$SYNCTHING_VERSION.tar.gz
    cd syncthing-linux-amd64-$SYNCTHING_VERSION

    # 安装二进制文件
    log_info "安装二进制文件..."
    sudo cp syncthing $INSTALL_DIR/
    sudo chmod +x $INSTALL_DIR/syncthing
    sudo ln -sf $INSTALL_DIR/syncthing $BIN_PATH

    # 创建配置目录
    log_info "创建配置目录..."
    mkdir -p $CONFIG_DIR

    # 创建 systemd 服务文件
    log_info "创建系统服务..."
    sudo tee $SERVICE_FILE > /dev/null <<EOF
[Unit]
Description=Syncthing - Open Source Continuous File Synchronization
Documentation=man:syncthing(1)
After=network.target

[Service]
Type=simple
User=$USER
ExecStart=$BIN_PATH -no-browser -gui-address="0.0.0.0:8384" -no-restart
Restart=on-failure
RestartSec=5
SuccessExitStatus=3 4
RestartForceExitStatus=3 4

[Install]
WantedBy=multi-user.target
EOF

    # 重新加载 systemd
    sudo systemctl daemon-reload

    # 启动服务
    log_info "启动 Syncthing 服务..."
    sudo systemctl enable syncthing
    sudo systemctl start syncthing

    # 等待服务启动
    log_info "等待服务启动..."
    for i in {1..10}; do
        if systemctl is-active --quiet syncthing; then
            break
        fi
        sleep 2
    done

    # 检查服务状态
    if systemctl is-active --quiet syncthing; then
        log_success "Syncthing 安装成功！"
        log_success "访问地址: http://$(get_ip):8384"
        log_success "配置目录: $CONFIG_DIR"
    else
        log_error "服务启动失败，检查日志: journalctl -u syncthing -f"
        exit 1
    fi

    # 清理临时文件
    rm -rf /tmp/syncthing-linux-amd64*
}

# 卸载函数
uninstall_syncthing() {
    log_info "开始卸载 Syncthing..."
    
    if ! check_installed; then
        log_warning "Syncthing 未安装，无需卸载"
        exit 1
    fi

    # 停止服务
    log_info "停止服务..."
    sudo systemctl stop syncthing 2>/dev/null || true
    sudo systemctl disable syncthing 2>/dev/null || true

    # 删除服务文件
    log_info "删除服务文件..."
    sudo rm -f $SERVICE_FILE
    sudo systemctl daemon-reload

    # 删除安装文件
    log_info "删除安装文件..."
    sudo rm -rf $INSTALL_DIR

    # 删除符号链接
    log_info "删除符号链接..."
    sudo rm -f $BIN_PATH

    # 询问是否删除配置
    echo ""
    read -p "❓ 是否删除配置文件和数据? [y/N]: " -n 1 -r
    echo
    if [[ $REPLY =~ ^[Yy]$ ]]; then
        log_info "删除配置文件..."
        rm -rf $CONFIG_DIR
        log_success "配置已删除"
    else
        log_info "配置保留在: $CONFIG_DIR"
    fi

    log_success "Syncthing 卸载完成！"
}

# 重新安装函数
reinstall_syncthing() {
    log_info "开始重新安装 Syncthing..."
    $0 uninstall
    sleep 2
    $0 install
}

# 重启服务
restart_service() {
    if check_installed; then
        log_info "重启 Syncthing 服务..."
        sudo systemctl restart syncthing
        sleep 3
        show_status
    else
        log_error "Syncthing 未安装，请先安装"
        exit 1
    fi
}

# 主程序
case "${1:-}" in
    "install")
        install_syncthing
        ;;
    "uninstall")
        uninstall_syncthing
        ;;
    "reinstall")
        reinstall_syncthing
        ;;
    "status")
        show_status
        ;;
    "restart")
        restart_service
        ;;
    "")
        # 无参数时自动判断
        if check_installed; then
            show_status
        else
            log_info "未检测到 Syncthing，开始安装..."
            install_syncthing
        fi
        ;;
    "help"|"-h"|"--help")
        show_usage
        ;;
    *)
        log_error "未知命令: $1"
        show_usage
        exit 1
        ;;
esac