#!/bin/bash
# VPN 专线管理平台 启动脚本 // Logan.Li
# 单二进制内嵌前端交付：构建前端 → 编译 Go → 启动单二进制
# 用法: ./run.sh [build-frontend|build|run|dev|stop|restart|status|help]
#
# 与 opsx-web-lite 的区别：
# - opsx-web-lite 是前后端分离 dev 模式（backend + frontend 独立进程）
# - 本项目把前端构建产物 embed 进 Go 二进制，最终 ./opsx-vpn 单文件运行

set -e

# ============================================================
# 配置区
# ============================================================
PROJECT_NAME="VPN 管理平台"
BACKEND_PORT=8080
FRONTEND_PORT=5173
BINARY_NAME="opsx-vpn"
FRONTEND_DIR="frontend"
BACKEND_DIR="backend"

# 日志配置
MAX_LOG_FILES=3
MAX_LOG_SIZE=$((50 * 1024 * 1024))  # 50MB

# ============================================================
# 通用函数
# ============================================================
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
NC='\033[0m'

info()    { echo -e "${BLUE}[INFO]${NC} $1"; }
success() { echo -e "${GREEN}[SUCCESS]${NC} $1"; }
warning() { echo -e "${YELLOW}[WARNING]${NC} $1"; }
error()   { echo -e "${RED}[ERROR]${NC} $1"; }

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
cd "$SCRIPT_DIR"

# PID 文件
PID_FILE="$SCRIPT_DIR/.vpn.pid"

# 检查端口是否被占用
check_port() {
    lsof -ti:$1 2>/dev/null | head -1
}

# 释放端口
kill_port() {
    local pids=$(lsof -ti:$1 2>/dev/null || echo "")
    if [ -n "$pids" ]; then
        info "释放端口 $1..."
        echo "$pids" | xargs kill -9 2>/dev/null || true
        sleep 1
    fi
}

# 日志轮转（仅启动时调用）
rotate_log() {
    local log_file=$1
    [ ! -f "$log_file" ] && return 0

    local file_size=$(stat -f%z "$log_file" 2>/dev/null || stat -c%s "$log_file" 2>/dev/null || echo "0")
    if [ "$file_size" -gt "$MAX_LOG_SIZE" ]; then
        [ -f "${log_file}.${MAX_LOG_FILES}" ] && rm -f "${log_file}.${MAX_LOG_FILES}"
        for i in $(seq $((MAX_LOG_FILES - 1)) -1 1); do
            [ -f "${log_file}.${i}" ] && mv "${log_file}.${i}" "${log_file}.$((i + 1))"
        done
        mv "$log_file" "${log_file}.1"
        info "日志已轮转: $log_file"
    fi
}

# ============================================================
# 构建前端
# ============================================================
build_frontend() {
    info "========== 构建前端 =========="
    cd "$SCRIPT_DIR/$FRONTEND_DIR"

    if [ ! -d "node_modules" ]; then
        warning "node_modules 不存在，正在安装依赖..."
        npm install
    fi

    info "执行 vite build（产物输出到 ../$BACKEND_DIR/dist）..."
    npm run build

    cd "$SCRIPT_DIR"
    success "前端构建完成"
}

# ============================================================
# 编译单二进制
# ============================================================
build_binary() {
    info "========== 编译 Go 单二进制 =========="
    cd "$SCRIPT_DIR"

    # dist 必须存在（embed 需要至少一个文件）
    if [ ! -d "$BACKEND_DIR/dist" ]; then
        mkdir -p "$BACKEND_DIR/dist"
        echo "<!doctype html><html><body>请先构建前端</body></html>" > "$BACKEND_DIR/dist/index.html"
    fi

    info "go build -ldflags='-s -w' -o $BINARY_NAME ./$BACKEND_DIR"
    go build -ldflags="-s -w" -o "$BINARY_NAME" "./$BACKEND_DIR"
    success "二进制编译完成: $BINARY_NAME"
}

# ============================================================
# 全量构建（前端 + 后端）
# ============================================================
build_all() {
    build_frontend
    build_binary
}

# ============================================================
# 运行单二进制
# ============================================================
start_binary() {
    info "========== 启动 $PROJECT_NAME =========="
    cd "$SCRIPT_DIR"
    mkdir -p logs data
    rotate_log "logs/vpn.log"

    # 每次启动前都将最新前端与后端合并为单一二进制
    build_all

    kill_port $BACKEND_PORT

    export VPN_LISTEN_ADDR=":${BACKEND_PORT}"

    nohup ./"$BINARY_NAME" >> logs/vpn.log 2>&1 &
    echo $! > "$PID_FILE"

    # 等待服务启动
    local retries=0
    while ! curl -s "http://localhost:$BACKEND_PORT/api/health" > /dev/null 2>&1; do
        retries=$((retries + 1))
        if [ $retries -ge 30 ]; then
            error "服务启动超时，请检查日志: logs/vpn.log"
            return 1
        fi
        sleep 1
    done

    success "服务已启动 (PID: $(cat "$PID_FILE"), 端口: $BACKEND_PORT)"
    info "访问地址: http://localhost:$BACKEND_PORT"
    info "默认账号: admin / admin123"
    return 0
}

# ============================================================
# 开发模式（前后端分离）
# ============================================================
start_dev() {
    info "========== $PROJECT_NAME 开发模式 =========="
    cd "$SCRIPT_DIR"

    if ! command -v go &> /dev/null; then
        error "Go 未安装，请先安装 Go"
        exit 1
    fi
    if ! command -v npm &> /dev/null; then
        error "npm 未安装，请先安装 Node.js"
        exit 1
    fi

    mkdir -p logs data

    # 后端：go run（前台 / 后台均可，这里后台以便同时跑前端）
    kill_port $BACKEND_PORT
    export VPN_LISTEN_ADDR=":${BACKEND_PORT}"
    export GIN_MODE=debug
    nohup go run "./$BACKEND_DIR" >> logs/vpn-dev.log 2>&1 &
    echo $! > "$PID_FILE.dev"
    info "后端已启动 (go run, 端口: $BACKEND_PORT)"

    # 前端：vite dev server
    cd "$FRONTEND_DIR"
    if [ ! -d "node_modules" ]; then
        warning "node_modules 不存在，正在安装依赖..."
        npm install
    fi
    kill_port $FRONTEND_PORT
    nohup npm run dev >> ../logs/frontend-dev.log 2>&1 &
    echo $! > "../.frontend.pid"
    cd "$SCRIPT_DIR"

    # 等待前端就绪
    local retries=0
    while ! curl -s "http://localhost:$FRONTEND_PORT" > /dev/null 2>&1; do
        retries=$((retries + 1))
        if [ $retries -ge 40 ]; then
            error "前端启动超时，请检查日志: logs/frontend-dev.log"
            return 1
        fi
        sleep 1
    done

    success "开发模式已启动"
    info "前端地址: http://localhost:$FRONTEND_PORT（代理 /api 到 $BACKEND_PORT）"
    info "后端地址: http://localhost:$BACKEND_PORT"
}

# ============================================================
# 停止服务
# ============================================================
stop_all() {
    info "正在停止服务..."

    # 单二进制
    if [ -f "$PID_FILE" ]; then
        local pid=$(cat "$PID_FILE" 2>/dev/null || echo "")
        if [ -n "$pid" ] && kill -0 "$pid" 2>/dev/null; then
            kill "$pid" 2>/dev/null || true
            success "单二进制服务已停止"
        fi
        rm -f "$PID_FILE"
    fi
    kill_port $BACKEND_PORT

    # 开发模式后端
    if [ -f "$PID_FILE.dev" ]; then
        local devpid=$(cat "$PID_FILE.dev" 2>/dev/null || echo "")
        if [ -n "$devpid" ] && kill -0 "$devpid" 2>/dev/null; then
            kill "$devpid" 2>/dev/null || true
            success "后端 dev 进程已停止"
        fi
        rm -f "$PID_FILE.dev"
    fi

    # 开发模式前端
    if [ -f "$SCRIPT_DIR/.frontend.pid" ]; then
        local fpid=$(cat "$SCRIPT_DIR/.frontend.pid" 2>/dev/null || echo "")
        if [ -n "$fpid" ] && kill -0 "$fpid" 2>/dev/null; then
            kill "$fpid" 2>/dev/null || true
            success "前端 dev 进程已停止"
        fi
        rm -f "$SCRIPT_DIR/.frontend.pid"
    fi
    kill_port $FRONTEND_PORT

    info "所有服务已停止"
}

# ============================================================
# 状态查看
# ============================================================
show_status() {
    info "服务状态:"
    if [ -n "$(check_port $BACKEND_PORT)" ]; then
        local pid=$(check_port $BACKEND_PORT)
        success "后端服务: 运行中 (PID: $pid, 端口: $BACKEND_PORT)"
    else
        warning "后端服务: 未运行"
    fi

    if [ -n "$(check_port $FRONTEND_PORT)" ]; then
        local fpid=$(lsof -ti:$FRONTEND_PORT 2>/dev/null | grep -v Chrome | head -1)
        if [ -n "$fpid" ]; then
            success "前端 dev : 运行中 (PID: $fpid, 端口: $FRONTEND_PORT)"
        fi
    else
        info "前端 dev : 未运行（生产模式由后端内嵌提供）"
    fi
}

# ============================================================
# 帮助
# ============================================================
show_help() {
    echo "$PROJECT_NAME 启动脚本"
    echo ""
    echo "用法: ./run.sh [命令]"
    echo ""
    echo "命令:"
    echo "  run              构建并后台运行单二进制（默认）"
    echo "  build            全量构建（前端 + 后端二进制）"
    echo "  build-frontend   仅构建前端（输出到 backend/dist）"
    echo "  build-binary     仅编译 Go 二进制"
    echo "  dev              开发模式（前后端分离，vite 代理到后端）"
    echo "  stop             停止所有服务"
    echo "  restart          重启服务"
    echo "  status           查看服务状态"
    echo "  help             显示帮助信息"
    echo ""
    echo "环境变量:"
    echo "  VPN_LISTEN_ADDR  监听地址（默认 :8080）"
    echo "  VPN_DATA_DIR     数据目录（默认 ./data）"
    echo ""
    echo "示例:"
    echo "  ./run.sh                     # 构建并运行"
    echo "  ./run.sh build               # 仅构建"
    echo "  ./run.sh dev                 # 开发模式"
    echo "  ./run.sh stop                # 停止服务"
}

# ============================================================
# 主入口
# ============================================================
main() {
    local command=${1:-run}

    case "$command" in
        run)
            start_binary
            ;;
        build)
            build_all
            ;;
        build-frontend)
            build_frontend
            ;;
        build-binary)
            build_binary
            ;;
        dev)
            start_dev
            ;;
        stop)
            stop_all
            ;;
        restart)
            stop_all
            sleep 2
            start_binary
            ;;
        status)
            show_status
            ;;
        help|--help|-h)
            show_help
            ;;
        *)
            error "未知命令: $command"
            show_help
            exit 1
            ;;
    esac
}

main "$@"