#!/bin/bash

# RTSP网络连接诊断脚本

set -e

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

print_info() {
    echo -e "${GREEN}[INFO]${NC} $1"
}

print_warn() {
    echo -e "${YELLOW}[WARN]${NC} $1"
}

print_error() {
    echo -e "${RED}[ERROR]${NC} $1"
}

# 从配置文件读取RTSP URLs
get_rtsp_urls() {
    if [[ -f "config.json" ]]; then
        # 使用jq解析JSON（如果可用）
        if command -v jq &> /dev/null; then
            jq -r '.streams[].rtsp_url' config.json
        else
            # 简单的grep解析
            grep -o '"rtsp://[^"]*"' config.json | sed 's/"//g'
        fi
    else
        print_error "配置文件 config.json 不存在"
        exit 1
    fi
}

# 测试网络连通性
test_network_connectivity() {
    local url=$1
    print_info "测试RTSP URL: $url"
    
    # 解析URL获取主机和端口
    local host=$(echo $url | sed -n 's|rtsp://\([^:]*\):\([0-9]*\)/.*|\1|p')
    local port=$(echo $url | sed -n 's|rtsp://\([^:]*\):\([0-9]*\)/.*|\2|p')
    
    if [[ -z "$host" || -z "$port" ]]; then
        print_error "无法解析RTSP URL: $url"
        return 1
    fi
    
    print_info "主机: $host, 端口: $port"
    
    # DNS解析测试（改进的检测方法）
    print_info "测试DNS解析..."
    local dns_result=$(nslookup $host 2>/dev/null | grep -A 1 "Name:" | grep "Address:" | awk '{print $2}' | head -1)
    
    if [[ -z "$dns_result" ]]; then
        # 尝试使用dig命令
        dns_result=$(dig +short $host 2>/dev/null | head -1)
    fi
    
    if [[ -z "$dns_result" ]]; then
        # 尝试使用host命令
        dns_result=$(host $host 2>/dev/null | awk '{print $NF}' | head -1)
    fi
    
    if [[ -n "$dns_result" && "$dns_result" =~ ^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+$ ]]; then
        print_info "✅ DNS解析成功"
        print_info "解析IP: $dns_result"
    else
        print_error "❌ DNS解析失败"
        print_info "调试信息: nslookup输出:"
        nslookup $host 2>&1 | sed 's/^/    /'
        return 1
    fi
    
    # 端口连通性测试（增强版）
    print_info "测试端口连通性..."
    
    # 尝试多种连接方法
    local connection_success=false
    
    # 方法1: 使用nc (netcat)
    if command -v nc >/dev/null 2>&1; then
        if timeout 10 nc -z $host $port 2>/dev/null; then
            print_info "✅ 端口 $port 可达 (nc测试)"
            connection_success=true
        fi
    fi
    
    # 方法2: 使用telnet
    if [[ "$connection_success" == "false" ]] && command -v telnet >/dev/null 2>&1; then
        if timeout 10 bash -c "echo '' | telnet $host $port" 2>/dev/null | grep -q "Connected"; then
            print_info "✅ 端口 $port 可达 (telnet测试)"
            connection_success=true
        fi
    fi
    
    # 方法3: 使用/dev/tcp (bash内置)
    if [[ "$connection_success" == "false" ]]; then
        if timeout 10 bash -c "exec 3<>/dev/tcp/$host/$port && exec 3<&-" 2>/dev/null; then
            print_info "✅ 端口 $port 可达 (bash TCP测试)"
            connection_success=true
        fi
    fi
    
    if [[ "$connection_success" == "false" ]]; then
        print_error "❌ 端口 $port 不可达"
        print_info "详细诊断:"
        print_info "  - 尝试ping主机: $(ping -c 1 -W 5 $host >/dev/null 2>&1 && echo '成功' || echo '失败')"
        print_info "  - 尝试traceroute: $(command -v traceroute >/dev/null && echo '可用' || echo '不可用')"
        if command -v traceroute >/dev/null 2>&1; then
            print_info "路由跟踪 (前3跳):"
            timeout 10 traceroute -m 3 $host 2>/dev/null | head -4 | sed 's/^/    /' || echo "    traceroute失败"
        fi
        return 1
    fi
    
    # RTSP协议测试（简化版）
    print_info "测试RTSP协议响应..."
    if command -v nc >/dev/null 2>&1; then
        local rtsp_response=$(timeout 5 bash -c "echo -e 'OPTIONS $url RTSP/1.0\r\nCSeq: 1\r\nUser-Agent: Network-Test\r\n\r\n' | nc $host $port 2>/dev/null" || echo "")
        
        if [[ "$rtsp_response" == *"RTSP/1.0"* ]]; then
            print_info "✅ RTSP服务器响应正常"
            print_info "服务器响应: $(echo "$rtsp_response" | head -1 | tr -d '\r\n')"
            return 0
        else
            print_warn "⚠️  端口可达但RTSP服务可能异常"
            print_info "尝试的RTSP请求无响应，可能是:"
            print_info "  1. RTSP服务器需要认证"
            print_info "  2. 服务器配置了特殊的连接要求"
            print_info "  3. 端口上运行的不是RTSP服务"
            return 0  # 端口可达就认为基本连接正常
        fi
    else
        print_info "✅ 基本连接测试通过（无法进行RTSP协议测试）"
        return 0
    fi
}

# 主函数
main() {
    echo ""
    print_info "=========================================="
    print_info "RTSP网络连接诊断工具"
    print_info "=========================================="
    echo ""
    
    # 检查必要工具
    for tool in nc nslookup timeout; do
        if ! command -v $tool &> /dev/null; then
            print_error "缺少必要工具: $tool"
            print_info "请安装: apt-get install netcat-openbsd dnsutils coreutils"
            exit 1
        fi
    done
    
    # 显示网络环境信息
    print_info "网络环境信息："
    echo "  主机名: $(hostname)"
    echo "  网络接口: $(ip route get 8.8.8.8 | awk '{print $5; exit}')"
    echo "  外网IP检测: $(timeout 5 curl -s ifconfig.me || echo "无法获取")"
    echo "  DNS配置:"
    cat /etc/resolv.conf | grep nameserver | head -3 | sed 's/^/    /'
    echo ""
    
    # 获取RTSP URLs
    print_info "从配置文件读取RTSP流地址..."
    local urls=($(get_rtsp_urls))
    
    if [[ ${#urls[@]} -eq 0 ]]; then
        print_error "配置文件中未找到RTSP URL"
        exit 1
    fi
    
    print_info "找到 ${#urls[@]} 个RTSP流地址"
    echo ""
    
    # 测试每个URL
    local success_count=0
    local total_count=${#urls[@]}
    
    for url in "${urls[@]}"; do
        print_info "========== 测试流 $((success_count + 1))/$total_count =========="
        if test_network_connectivity "$url"; then
            ((success_count++))
            print_info "✅ 测试通过"
        else
            print_error "❌ 测试失败"
        fi
        echo ""
    done
    
    # 显示总结
    print_info "=========================================="
    print_info "测试完成"
    print_info "=========================================="
    print_info "成功: $success_count/$total_count"
    
    if [[ $success_count -eq $total_count ]]; then
        print_info "🎉 所有RTSP流连接测试通过！"
        print_info "如果Docker中仍无法连接，请检查:"
        print_info "  1. Docker网络模式是否为host"
        print_info "  2. 容器内DNS配置是否正确"
        print_info "  3. 防火墙设置是否阻止连接"
    else
        print_warn "⚠️  部分RTSP流连接失败"
        print_info "建议检查:"
        print_info "  1. 网络连接状态"
        print_info "  2. RTSP服务器状态" 
        print_info "  3. 防火墙配置"
    fi
    
    echo ""
}

# 执行主函数
main