/*
 *  <Short Description>
 *  Copyright (C) 2025  Brett Terpstra
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */
#include <stdexcept>
#include <blt/std/requests.h>

#ifdef __EMSCRIPTEN__
#include <emscripten.h>
#endif

#if defined(__has_include) && __has_include(<curl/curl.h>)
#include <curl/curl.h>
#define BLT_HAS_CURL
#endif

namespace blt::requests
{
	#ifdef BLT_HAS_CURL
		struct curl_init_t
		{
			curl_init_t()
			{
				const auto version_data = curl_version_info(CURLVERSION_NOW);
				if (!(version_data->features & CURL_VERSION_THREADSAFE))
				{
					thread_safe = false;
				}
				curl_global_init(CURL_GLOBAL_ALL);
			}

			~curl_init_t()
			{
				curl_global_cleanup();
			}

			bool thread_safe = true;
		};

		struct curl_easy_init_t
		{
			curl_easy_init_t(): curl(curl_easy_init())
			{
			}

			~curl_easy_init_t()
			{
				curl_easy_cleanup(curl);
			}

			CURL*  curl;
		};

		void init()
		{
			static curl_init_t curl_init_obj;
		}

		CURL* easy_init()
		{
			thread_local curl_easy_init_t curl_easy_init_obj;
			return curl_easy_init_obj.curl;
		}

		size_t write_to_string_func(const void* data, const size_t size, const size_t nmemb, void* user_data) {
			auto& str = *static_cast<std::string*>(user_data);
			str.append(static_cast<const char*>(data), size * nmemb);
			return size * nmemb;
		};
	#endif

	std::string send_get_request(const std::string& url)
	{
		#ifdef __EMSCRIPTEN__
		auto* str = static_cast<char*>(EM_ASM_PTR(
			{ const v = await fetch('$0', { 'credentials': 'omit', 'headers': { 'User-Agent':
				'Mozilla/5.0 (X11; Linux x86_64; rv:136.0) Gecko/20100101 Firefox/136.0', 'Accept': '/', 'Accept-Language': 'en-US,en;q=0.5',
				'Priority': 'u=4' }, 'method': 'GET', 'mode': 'cors' }); if (!v.ok) { throw v.status; } return stringToNewUTF8(await response.text());
			}, url.c_str()));
		std::string str_obj{str};
		free(str);
		return str_obj;
		#else
		init();
		auto curl = easy_init();
		if (!curl)
			throw std::runtime_error("Failed to initialize curl");
		std::string response_string;

		curl_easy_setopt(curl, CURLOPT_URL, url.c_str());
		curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);
		curl_easy_setopt(curl, CURLOPT_WRITEDATA, static_cast<void*>(&response_string));
		curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, &write_to_string_func);

		const auto res = curl_easy_perform(curl);
		if(res != CURLE_OK)
			throw std::runtime_error(curl_easy_strerror(res));

		return response_string;
		#endif
	}
}