// Copyright Epic Games, Inc. All Rights Reserved.

#include <zenhttp/httpclientauth.h>

#include <zenhttp/auth/authmgr.h>

ZEN_THIRD_PARTY_INCLUDES_START
#include <cpr/cpr.h>
#include <fmt/format.h>
#include <json11.hpp>
ZEN_THIRD_PARTY_INCLUDES_END

namespace zen { namespace httpclientauth {

	using namespace std::literals;

	std::function<HttpClientAccessToken()> CreateFromStaticToken(HttpClientAccessToken Token)
	{
		return [Token]() { return Token; };
	}

	std::function<HttpClientAccessToken()> CreateFromStaticToken(std::string_view Token)
	{
		return CreateFromStaticToken(
			HttpClientAccessToken{.Value = fmt::format("Bearer {}"sv, Token), .ExpireTime = HttpClientAccessToken::TimePoint::max()});
	}

	std::function<HttpClientAccessToken()> CreateFromOAuthClientCredentials(const OAuthClientCredentialsParams& Params)
	{
		OAuthClientCredentialsParams OAuthParams(Params);
		return [OAuthParams]() {
			using namespace std::chrono;

			std::string Body = fmt::format("client_id={}&scope=cache_access&grant_type=client_credentials&client_secret={}"sv,
										   OAuthParams.ClientId,
										   OAuthParams.ClientSecret);

			cpr::Response Response = cpr::Post(cpr::Url{OAuthParams.Url},
											   cpr::Header{{"Content-Type", "application/x-www-form-urlencoded"}},
											   cpr::Body{std::move(Body)});

			if (Response.error || Response.status_code != 200)
			{
				return HttpClientAccessToken{};
			}

			std::string	 JsonError;
			json11::Json Json = json11::Json::parse(Response.text, JsonError);

			if (JsonError.empty() == false)
			{
				return HttpClientAccessToken{};
			}

			std::string						 Token			  = Json["access_token"].string_value();
			int64_t							 ExpiresInSeconds = static_cast<int64_t>(Json["expires_in"].int_value());
			HttpClientAccessToken::TimePoint ExpireTime		  = HttpClientAccessToken::Clock::now() + seconds(ExpiresInSeconds);

			return HttpClientAccessToken{.Value = fmt::format("Bearer {}"sv, Token), .ExpireTime = ExpireTime};
		};
	}

	std::function<HttpClientAccessToken()> CreateFromOpenIdProvider(AuthMgr& AuthManager, std::string_view OpenIdProvider)
	{
		return [&AuthManager = AuthManager, OpenIdProvider = std::string(OpenIdProvider)]() {
			AuthMgr::OpenIdAccessToken Token = AuthManager.GetOpenIdAccessToken(OpenIdProvider);
			return HttpClientAccessToken{.Value = Token.AccessToken, .ExpireTime = Token.ExpireTime};
		};
	}

	std::function<HttpClientAccessToken()> CreateFromDefaultOpenIdProvider(AuthMgr& AuthManager)
	{
		return CreateFromOpenIdProvider(AuthManager, "Default"sv);
	}

}}	// namespace zen::httpclientauth