#include "CORSConfig.h"
#include <map>
#include <vector>
#include <sstream>
#include "Global.h"

CORSConfig GlobalCORSConfig;

CORSConfig::CORSConfig()
{
	max_age = 86400;
	allow_cookie = false;
	validate_urls = {};
	validate_hosts = {};
	validate_methods = { "GET", "POST", "OPTIONS" };
	validate_headers = 
	{
		"Accept",
		"Accept-Language",
		"Content-Language",
		"Content-Type",
		"Authorization",
		"X-Requested-With",
		"X-CSRF-Token",
		"X-Client-Version",
		"X-App-Id",
		"X-Request-ID"
	};
}

int CORSConfig::GetMaxAge() const
{
	return max_age;
}

bool CORSConfig::AllowCookie() const
{
	return allow_cookie;
}

std::string CORSConfig::GetValidateMethods() const
{
	if (validate_methods.empty())
		return std::string();
	std::ostringstream oss;
	size_t index = 0;
	for (const auto& method : validate_methods)
	{
		if (index++ > 0)
			oss << ", ";
		oss << uns::tools::ToUpper(method); // 统一大写方法名
	}
	return oss.str();
}

bool CORSConfig::UrlValidate(const std::string& url) const
{
	return (validate_urls.find(url) != validate_urls.end());
}

bool CORSConfig::HostValidate(const std::string& host) const
{
	return (validate_hosts.find(host) != validate_hosts.end());
}

bool CORSConfig::IsMethodAllowed(const std::string method) const
{
	return (validate_methods.find(method) != validate_methods.end());
}

std::string CORSConfig::GetValidateHeaders(const std::set<std::string>& headers) const
{
	// build map from lowercase(validate_headers) => original form (preserve casing)
	std::map<std::string, std::string> lowerToOriginal;
	for (const auto& h : validate_headers)
		lowerToOriginal[uns::tools::ToLower(h)] = h;
	std::vector<std::string> allowedOut;
	if (headers.empty())
	{
		// 返回服务端全部允许的头（保持 validate_headers 中的原始展示形式）
		for (const auto& kv : lowerToOriginal)
			allowedOut.push_back(kv.second);
	}
	else
	{
		// 交集比较（headers 已经是小写的—为了健壮性，再转换一次）
		for (const auto& reqLower : headers)
		{
			std::string reqNorm = uns::tools::ToLower(reqLower);
			auto it = lowerToOriginal.find(reqNorm);
			if (it != lowerToOriginal.end())
				allowedOut.push_back(it->second); // 使用原始展示形式
		}
		// 如果客户端请求了头（headers 非空）但交集为空，返回空字符串
	}
	if (allowedOut.empty())
		return std::string();
	// join with ", "
	std::ostringstream oss;
	for (size_t i = 0; i < allowedOut.size(); ++i)
	{
		if (i)
			oss << ", ";
		oss << allowedOut[i];
	}
	return oss.str();
}

void CORSConfig::SetMaxAge(int max_age)
{
	this->max_age = max_age;
}

void CORSConfig::SetAllowCookie(bool allow)
{
	allow_cookie = allow;
}

void CORSConfig::ClearValidateUrls()
{
	validate_urls.clear();
}

void CORSConfig::ClearValidateHosts()
{
	validate_hosts.clear();
}

void CORSConfig::ClearValidateMethods()
{
	validate_methods.clear();
}

void CORSConfig::ClearValidateHeaders()
{
	validate_headers.clear();
}

void CORSConfig::AddValidateUrl(const std::string& url)
{
	validate_urls.insert(url);
}

void CORSConfig::AddValidateHost(const std::string& host)
{
	validate_hosts.insert(host);
}

void CORSConfig::AddValidateMethod(const std::string& method)
{
	validate_methods.insert(uns::tools::ToUpper(method));
}

void CORSConfig::AddValidateHeader(const std::string& header)
{
	validate_headers.insert(header);
}

void CORSConfig::AddValidateUrls(const std::set<std::string>& urls)
{
	for(const auto& url : urls)
		validate_urls.insert(url);
}

void CORSConfig::AddValidateHosts(const std::set<std::string>& hosts)
{
	for(const auto& host : hosts)
		validate_hosts.insert(host);
}

void CORSConfig::AddValidateMethods(const std::set<std::string>& methods)
{
	for(const auto& method : methods)
		validate_methods.insert(method);
}

void CORSConfig::AddValidateHeaders(const std::set<std::string>& headers)
{
	for(const auto& header : headers)
		validate_headers.insert(header);
}