#!/bin/bash

# ============================================================
#  TikTok 真实可访问性检测脚本 v1.0
#  检测原理: 先通过美国 VPS DNS 解析 TikTok 域名，
#            再用解析到的 IP 发起实际 HTTP 请求，
#            模拟手机/设备的真实访问行为
# ============================================================

Font_Red="\033[31m"
Font_Green="\033[32m"
Font_Yellow="\033[33m"
Font_SkyBlue="\033[36m"
Font_Suffix="\033[0m"
Font_Bold="\033[1m"

# 美国 VPS DNS 服务器
US_DNS="142.171.202.195"

UA_Browser="Mozilla/5.0 (iPhone; CPU iPhone OS 17_0 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.0 Mobile/15E148 Safari/604.1"

print_banner() {
    echo ""
    echo -e "${Font_SkyBlue}${Font_Bold}╔══════════════════════════════════════════════╗${Font_Suffix}"
    echo -e "${Font_SkyBlue}${Font_Bold}║    TikTok 真实访问检测脚本 v1.0             ║${Font_Suffix}"
    echo -e "${Font_SkyBlue}${Font_Bold}╚══════════════════════════════════════════════╝${Font_Suffix}"
    echo -e "  测试时间: $(date)"
    echo ""
}

get_ip_info() {
    local ip
    ip=$(curl -4 -s --max-time 8 https://api64.ipify.org 2>/dev/null)
    local ip_mask
    ip_mask=$(awk -F"." '{print $1"."$2".*.*"}' <<<"${ip}")
    local isp
    isp=$(curl -s -4 --max-time 8 "https://api.ip.sb/geoip/${ip}" 2>/dev/null | grep '"organization"' | cut -f4 -d'"')
    echo -e "  ${Font_SkyBlue}本机出口: ${isp:-未知} (${ip_mask})${Font_Suffix}"
    echo -e "  ${Font_SkyBlue}使用 DNS:  ${US_DNS} (美国 VPS)${Font_Suffix}"
    echo ""
}

check_dns_resolution() {
    echo -n -e "  [1/3] DNS 解析测试..."
    local resolved_ip
    resolved_ip=$(dig +short @"$US_DNS" www.tiktok.com A 2>/dev/null | grep -E '^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+$' | head -1)

    if [ -n "$resolved_ip" ]; then
        echo -e "\r  [1/3] DNS 解析测试    ${Font_Green}✅ 成功${Font_Suffix} → ${Font_SkyBlue}${resolved_ip}${Font_Suffix}"
        echo "$resolved_ip"
        return 0
    else
        echo -e "\r  [1/3] DNS 解析测试    ${Font_Red}❌ 失败（无法通过美国 DNS 解析）${Font_Suffix}"
        return 1
    fi
}

check_tcp_connect() {
    local ip=$1
    echo -n -e "  [2/3] TCP 连接测试..."
    if timeout 8 bash -c "echo >/dev/tcp/${ip}/443" 2>/dev/null; then
        echo -e "\r  [2/3] TCP 连接测试    ${Font_Green}✅ 成功${Font_Suffix} → ${Font_SkyBlue}${ip}:443 可达${Font_Suffix}"
        return 0
    else
        echo -e "\r  [2/3] TCP 连接测试    ${Font_Red}❌ 失败（${ip}:443 不可达）${Font_Suffix}"
        return 1
    fi
}

check_http_access() {
    local ip=$1
    echo -n -e "  [3/3] HTTP 访问测试..."

    # 用解析到的 IP 直接请求，通过 Host 头指定域名（模拟设备真实访问）
    local result
    result=$(curl \
        --resolve "www.tiktok.com:443:${ip}" \
        --user-agent "${UA_Browser}" \
        -sL --max-time 15 \
        -H "Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8" \
        -H "Accept-Encoding: gzip" \
        -H "Accept-Language: en-US,en;q=0.9" \
        "https://www.tiktok.com/" 2>/dev/null | gunzip 2>/dev/null)

    local region
    region=$(echo "$result" | grep -o '"region":"[^"]*"' | head -1 | cut -f4 -d'"')

    if [ -n "$region" ]; then
        echo -e "\r  [3/3] HTTP 访问测试   ${Font_Green}✅ 成功${Font_Suffix} → TikTok Region: ${Font_Green}【${region}】${Font_Suffix}"
        return 0
    fi

    # 尝试不带 gzip
    local result2
    result2=$(curl \
        --resolve "www.tiktok.com:443:${ip}" \
        --user-agent "${UA_Browser}" \
        -s --max-time 15 \
        -H "Accept-Language: en-US,en;q=0.9" \
        "https://www.tiktok.com/" 2>/dev/null)

    local region2
    region2=$(echo "$result2" | grep -o '"region":"[^"]*"' | head -1 | cut -f4 -d'"')

    if [ -n "$region2" ]; then
        echo -e "\r  [3/3] HTTP 访问测试   ${Font_Green}✅ 成功${Font_Suffix} → TikTok Region: ${Font_Green}【${region2}】${Font_Suffix}"
        return 0
    fi

    local http_code
    http_code=$(curl \
        --resolve "www.tiktok.com:443:${ip}" \
        --user-agent "${UA_Browser}" \
        -s -o /dev/null -w "%{http_code}" \
        --max-time 10 \
        "https://www.tiktok.com/" 2>/dev/null)

    if [[ "$http_code" =~ ^(200|301|302)$ ]]; then
        echo -e "\r  [3/3] HTTP 访问测试   ${Font_Yellow}⚠️  可连接${Font_Suffix}（HTTP ${http_code}，未获取到 region，可能为 IDC IP）"
        return 0
    else
        echo -e "\r  [3/3] HTTP 访问测试   ${Font_Red}❌ 失败${Font_Suffix}（HTTP ${http_code:-超时}）"
        return 1
    fi
}

print_summary() {
    local result=$1
    echo ""
    if [ "$result" -eq 0 ]; then
        echo -e "  ${Font_Green}${Font_Bold}══════════════════════════════════════════${Font_Suffix}"
        echo -e "  ${Font_Green}${Font_Bold}  ✅ 结论：设备通过此 DNS 可正常访问 TikTok${Font_Suffix}"
        echo -e "  ${Font_Green}${Font_Bold}══════════════════════════════════════════${Font_Suffix}"
    else
        echo -e "  ${Font_Red}${Font_Bold}══════════════════════════════════════════${Font_Suffix}"
        echo -e "  ${Font_Red}${Font_Bold}  ❌ 结论：设备通过此 DNS 无法访问 TikTok${Font_Suffix}"
        echo -e "  ${Font_Red}${Font_Bold}══════════════════════════════════════════${Font_Suffix}"
    fi
    echo ""
}

# ── 主流程 ──────────────────────────────────────
print_banner
get_ip_info

resolved_ip=$(check_dns_resolution)
dns_ok=$?

if [ $dns_ok -ne 0 ]; then
    print_summary 1
    exit 1
fi

check_tcp_connect "$resolved_ip"
tcp_ok=$?

if [ $tcp_ok -ne 0 ]; then
    print_summary 1
    exit 1
fi

check_http_access "$resolved_ip"
http_ok=$?

print_summary $http_ok