#pragma once

 /*
 * http client for anet implementation
 * anet ��http �ͻ���
 * Copyright (C) 2019 - 2023 gavingqf(gavingqf@126.com)
 *
 *    Distributed under the Boost Software License, Version 1.0.
 *    (See accompanying file LICENSE_1_0.txt or copy at
 *    http://www.boost.org/LICENSE_1_0.txt)
 */

#include <functional>
#include <utility>
#include "event_loop.hpp"
#include "client.hpp"
#include "log.h"
#include "http_info.hpp"
#include "anet.hpp"
#include "asio/detail/noncopyable.hpp"
#include "semaphore.hpp"


namespace anet {
	namespace http {
		// http require callback typedef.
		typedef std::function<void (const std::string &res,httpStatus status)> httpReqCallback;

		// http require struct
		struct HttpReq {
			// method
			std::string method{ "" };

			// path
			std::string path{ "" };

			// version
			std::string version{ "" };

			// content type
			std::string contentType{ "" };

			// content
			std::string content{ "" };

			// connection mode
			std::string connectionMode{ "" };

			// http status
			httpStatus  status{ httpStatus::NOT_FIND };

			// parse http content.
			bool parse(const std::string &content) {
				// == post parse == //
				auto pos = content.find(gHttpSpaceLine);
				assert(pos != gHttpStrFindInvalid && "invalid content");
				if (pos == gHttpStrFindInvalid) {
					return false;
				}

				// req content.
				this->content = std::move(std::string(&content[pos + gHttpSpaceLineLen]));

				// try to parse method and body
				std::vector<std::string> vecContents;
				strSplits(content, gHttpCRLF, vecContents);

				{// parse content type.
					auto find = false;
					for (size_t i = 0; i < vecContents.size(); i++) {
						auto p = vecContents[i].find(gHttpContentTypeLine);
						if (gHttpStrFindInvalid != p) {
							this->contentType = std::move(std::string(&vecContents[i][p + strlen(gHttpContentTypeLine)]));
							find = true;
							break;
						}
					}
					if (!find) {
						this->contentType = gHttpContentTypeJson;
					}
				}

				{// parse Connection flag.
					auto find = false;
					for (size_t i = 0; i < vecContents.size(); i++) {
						auto p = vecContents[i].find(gHttpConnectionLine);
						if (gHttpStrFindInvalid != p) {
							this->connectionMode = std::move(std::string(&vecContents[i][p + strlen(gHttpConnectionLine)]));
							find = true;
							break;
						}
					}
					if (!find) {
						this->connectionMode = gHttpConnectionClose;
					}
				}

				// parse the first data.
				std::vector<std::string> vec;
				strSplits(vecContents[0], " ", vec);

				// build http parameter.
				assert(vec.size() >= 3 && "parse http info error");
				if (vec.size() < 3) {
					return false;
				}

				// get version and status.
				this->version = std::move(vec[0]);
				this->status = httpStatus(std::atoi(vec[1].c_str()));
				return true;
			}
		};

		// http client response define.
		typedef std::pair<httpStatus, std::string> response;

		// http req vector.
		typedef std::vector<std::pair<HttpReq, httpReqCallback>> VecHttpReq;

		// http client codec.
		class CHttpClientCodec final: public anet::tcp::ICodec {
		public:
			CHttpClientCodec() = default;
			virtual ~CHttpClientCodec() = default;

		public:
			virtual int parsePacket(const char *data, int len) override {
				std::string strData(data, len);
				auto pos = strData.find(gHttpSpaceLine);
				if (pos == gHttpStrFindInvalid) {
					return anet::tcp::retNotComplete;
				}

				auto lenPos = strData.find(gHttpContentLenLine);
				if (lenPos == gHttpStrFindInvalid) {
					return anet::tcp::retError; // just close it.
				}

				// content len flag string.
				std::string conLenString(&data[lenPos + gHttpContentLenLineLen]);
				auto contentLen = std::atoi(conLenString.c_str());
				if (len >= int(pos + gHttpSpaceLineLen + contentLen)) {
					return int(pos + gHttpSpaceLineLen + contentLen);
				} else {
					return anet::tcp::retNotComplete;
				}
			}
		};

		// http client session.
		class CHttpClientSession final: public anet::tcp::ISession {
		public:
			explicit CHttpClientSession(const VecHttpReq &req) :
				m_vecReq(req), m_index(0), m_close(true) {
			}
			virtual ~CHttpClientSession() = default;

		public:
			virtual void onConnected(anet::tcp::connSharePtr conn) override {
				m_close = false;
				m_conn = conn;

				// host name
				auto &&host = std::string(conn->getRemoteAddr());
				host += ":";
				host += std::to_string(conn->getRemotePort());
				for (size_t i = 0; i < m_vecReq.size(); i++) {
					this->sendHttpReq(m_vecReq[i].first, host);
				}
			}

			virtual void onRecv(const char *data, int len) override {
				HttpReq httpReq;
				auto ret = httpReq.parse(std::string(data, data + len));
				assert(ret && "parse http content error");
				if (!ret) {
					return;
				}

				auto &&reqCallback = m_vecReq[m_index].second;
				reqCallback(httpReq.content, httpReq.status);
			}

			virtual void onTerminate() override {
				m_close = true;
			}

			virtual void release() override {
				delete this;
			}

			bool isClose() const {
				return m_close;
			}

		private:
			// send http response.
			void sendHttpReq(const HttpReq &httpReq,const std::string &host) {
				std::string req;
				req.reserve(m_sendBuffSize);

				if (0 == stricmp(httpReq.method.c_str(), gHttpGetMethod)) {
					req = gHttpGetMethod;
					req += " ";
					req += httpReq.path;
					// content 
					if (!httpReq.content.empty()) {
						req += "?";
						req += httpReq.content;
					}
					req += " ";
					req += httpReq.version;
				} else if (0 == stricmp(httpReq.method.c_str(), gHttpPostMethod)) {
					req = gHttpPostMethod;
					req += " ";
					req += httpReq.path;
					req += " ";
					req += httpReq.version;
				}
				req.append(gHttpCRLF, gHttpCRLFLen);

				// Content type
				if (!httpReq.contentType.empty()) {
					req.append(gHttpContentTypeLine, strlen(gHttpContentTypeLine));
					req.append(httpReq.contentType);
					req.append(";");
					req.append(gHttpCharsetUtf8);
					req.append(gHttpCRLF, gHttpCRLFLen);
				} else {
					req.append(gHttpContentTypeLine, strlen(gHttpContentTypeLine));
					req.append(gHttpContentTypeUrlEncoded);
					req.append(gHttpCRLF, gHttpCRLFLen);
				}

				// connection close flag.
				req.append(gHttpConnectionLine, strlen(gHttpConnectionLine));
				req.append(gHttpConnectionClose, strlen(gHttpConnectionClose));
				req.append(gHttpCRLF, gHttpCRLFLen);
				
				// !! above http/1.1 must add "host" command.
				if (0 == stricmp(httpReq.version.c_str(), gHttpVersion11) ||
					0 == stricmp(httpReq.version.c_str(), gHttpVersion20)) {
					req.append("Host:" + host);
					req.append(gHttpCRLF, gHttpCRLFLen);
				}

				// for POST
				if (0 == stricmp(httpReq.method.c_str(), gHttpPostMethod)) {
					// content len
					std::string dataLen(gHttpContentLenLine);
					dataLen += std::to_string(httpReq.content.size());
					req += dataLen;
					req.append(gHttpSpaceLine, gHttpSpaceLineLen);

					// content.
					req += httpReq.content;
				} else {
					// space line
					req.append(gHttpSpaceLine, gHttpSpaceLineLen);
				}

				this->send(req);
			}

		protected:
			void send(const std::string &req) {
				if (isClose()) return;
				m_conn->send(req);
			}

		private:
			anet::tcp::connSharePtr m_conn{nullptr};
			VecHttpReq       m_vecReq;
			size_t           m_index;
			std::atomic_bool m_close{ true };
			static const int m_sendBuffSize{ 1024 };
		};

		//
		// http client for asynchronous mode.
		//
		class CHttpClient final: asio::noncopyable {
		public:
			explicit CHttpClient(anet::tcp::CEventLoop &loop) : m_client(loop) {}
			virtual ~CHttpClient() = default;

		public:
			bool connect(const std::string &addr, unsigned short port) {
				auto sess = new CHttpClientSession(m_vecHttpReq);
				m_client.setSession(sess);
				m_client.setPacketParser(new CHttpClientCodec());
				return m_client.syncConnect(addr, port);
			}

			// async post.
			bool async_post(const std::string &path,
				const std::string &req, httpReqCallback &&call
			) {
				if (!checkPath(path)) {
					return false;
				}
				HttpReq httpReq;
				httpReq.content = req;
				httpReq.method = gHttpPostMethod;
				httpReq.contentType = gHttpContentTypeJson;
				httpReq.version = gHttpVersion11;
				httpReq.connectionMode = gHttpConnectionClose;
				httpReq.path = path;
				m_vecHttpReq.push_back({ httpReq,call });
				return true;
			}
			bool async_post(const std::string &path, const std::string &req, 
				const std::string &contentType, const std::string &httpVersion,
				httpReqCallback &&call
			) {
				if (!checkPath(path)) {
					return false;
				}
				HttpReq httpReq;
				httpReq.content = req;
				httpReq.method = gHttpPostMethod;
				httpReq.contentType = contentType;
				httpReq.version = httpVersion;
				httpReq.connectionMode = gHttpConnectionClose;
				httpReq.path = path;
				m_vecHttpReq.push_back({ httpReq,call });
				return true;
			}

			// async get.
			bool async_get(const std::string &path,
				const std::string &req, httpReqCallback &&call
			) {
				if (!checkPath(path)) {
					return false;
				}

				HttpReq httpReq;
				httpReq.content = req;
				httpReq.path = path;
				httpReq.method = gHttpGetMethod;
				httpReq.contentType = gHttpContentTypeUrlEncoded;
				httpReq.version = gHttpVersion11;
				httpReq.connectionMode = gHttpConnectionClose;
				m_vecHttpReq.push_back({ httpReq,call });
				return true;
			}
			bool async_get(const std::string &path, const std::string &req, 
				const std::string &contentType, const std::string &httpVersion, 
				httpReqCallback &&call
			) {
				if (!checkPath(path)) {
					return false;
				}

				HttpReq httpReq;
				httpReq.content = req;
				httpReq.path = path;
				httpReq.method = gHttpGetMethod;
				httpReq.contentType = contentType;
				httpReq.version = httpVersion;
				httpReq.connectionMode = gHttpConnectionClose;
				m_vecHttpReq.push_back({ httpReq,call });
				return true;
			}

		protected:
			bool checkPath(const std::string& path) {
				for (size_t i = 0; i < m_vecHttpReq.size(); i++) {
					if (m_vecHttpReq[i].first.path == path) {
						return false;
					}
				}
				return true;
			}

		private:
			// TCP client
			anet::tcp::CClient m_client;

			// http req vector
			VecHttpReq m_vecHttpReq;
		};


		// http synchronous session factory.
		template<typename session>
		class CHttpSyncSessionFactory final {
		public:
			CHttpSyncSessionFactory() : m_nextId(1) {}
			~CHttpSyncSessionFactory() = default;
			CHttpSyncSessionFactory(const CHttpSyncSessionFactory &rhs) = delete;
			CHttpSyncSessionFactory operator=(const CHttpSyncSessionFactory &rhs) = delete;

			typedef std::shared_ptr<session> sessionSharePtr;
			typedef std::map<unsigned int, sessionSharePtr> Id2SessionPtr;

		public:
			// return share_ptr<session> object.
			sessionSharePtr createSession() {
				std::lock_guard<std::mutex> mu(m_lock);

				// create session's share pointer.
				unsigned int sessionId = m_nextId++;
				auto sessSharePtr = std::make_shared<session>();

				// set id.
				sessSharePtr->setId(sessionId);

				sessSharePtr->SetFactory(this);

				// save it to map to keep the life.
				m_sessions[sessSharePtr->getId()] = sessSharePtr;

				return sessSharePtr;
			}

			// release session.
			void ReleaseSession(const session *pSession) {
				if (pSession == nullptr) {
					return;
				}
				std::lock_guard<std::mutex> mu(m_lock);
				m_sessions.erase(pSession->getId());
			}

		protected:
			mutable std::mutex m_lock;
			Id2SessionPtr m_sessions;
			unsigned int m_nextId{ 1 };
		};

		// http synchronous session and its factory.
		class CHttpClientSyncSession;
		typedef CHttpSyncSessionFactory<CHttpClientSyncSession> httSyncSessionFactory;

		//
		// http client session for synchronous mode.
		//
		class CHttpClientSyncSession final : public anet::tcp::ISession,
			public std::enable_shared_from_this<CHttpClientSyncSession> {
		public:
			CHttpClientSyncSession() = default;
			virtual ~CHttpClientSyncSession() = default;

		public:
			// connected callback
			virtual void onConnected(anet::tcp::connSharePtr conn) {
				m_close = false;
				m_conn = conn;
			}

			// recv data callback: data and its length.
			virtual void onRecv(const char *data, int len) {
				HttpReq httpReq;
				auto ret = httpReq.parse(std::string(data, data + len));
				if (ret) {
					m_res.first = httpReq.status;
					m_res.second = httpReq.content;
				} else {
					m_res.first = httpStatus::NOT_FIND;
					m_res.second = "";
				}
				m_sem.signal();
				m_signaled = true;
			}

			// connection terminate callback
			virtual void onTerminate() {
				if (!m_signaled) {
					m_sem.signal();
					m_signaled = true;
				}
				m_close = true;
			}

			// release callback
			virtual void release() {
				assert(m_factory != nullptr);
				m_factory->ReleaseSession(this);
			}
			void SetFactory(httSyncSessionFactory *factory) {
				assert(factory != nullptr && "invalid session factory.");
				m_factory = factory;
			}

			// send http response.
			void sendHttpReq(const HttpReq &httpReq, const std::string &host) {
				std::string req;
				req.reserve(m_sendBuffSize);

				if (0 == stricmp(httpReq.method.c_str(), gHttpGetMethod)) {
					req = gHttpGetMethod;
					req += " ";
					req += httpReq.path;
					// content 
					if (!httpReq.content.empty()) {
						req += "?";
						req += httpReq.content;
					}
					req += " ";
					req += httpReq.version;
				} else if (0 == stricmp(httpReq.method.c_str(), gHttpPostMethod)) {
					req = gHttpPostMethod;
					req += " ";
					req += httpReq.path;
					req += " ";
					req += httpReq.version;
				}
				req.append(gHttpCRLF, gHttpCRLFLen);

				// Content type
				if (!httpReq.contentType.empty()) {
					req.append(gHttpContentTypeLine, strlen(gHttpContentTypeLine));
					req.append(httpReq.contentType);
					req.append(gHttpCRLF, gHttpCRLFLen);
				} else {
					req.append(gHttpContentTypeLine, strlen(gHttpContentTypeLine));
					req.append(gHttpContentTypeUrlEncoded);
					req.append(gHttpCRLF, gHttpCRLFLen);
				}

				// connection close flag.
				req.append(gHttpConnectionLine, strlen(gHttpConnectionLine));
				req.append(gHttpConnectionClose, strlen(gHttpConnectionClose));
				req.append(gHttpCRLF, gHttpCRLFLen);

				// !! above http/1.1 must add host command.
				if (0 == stricmp(httpReq.version.c_str(), gHttpVersion11) ||
					0 == stricmp(httpReq.version.c_str(), gHttpVersion20)) {
					req.append("Host:" + host);
					req.append(gHttpCRLF, gHttpCRLFLen);
				}

				// for POST
				if (0 == stricmp(httpReq.method.c_str(), gHttpPostMethod)) {
					// content len
					std::string dataLen(gHttpContentLenLine);
					dataLen += std::to_string(httpReq.content.size());
					req += dataLen;

					// space line
					req.append(gHttpSpaceLine, gHttpSpaceLineLen);

					// content.
					req += httpReq.content;
				} else {
					// space line
					req.append(gHttpSpaceLine, gHttpSpaceLineLen);
				}
				this->send(req);
			}

			// tcp connection.
			auto getConn() {
				return m_conn;
			}

			void close() {
				if (m_close) return;
				m_conn->close();
			}

			// wait for result.
			response waitFor() {
				auto timeOut = std::chrono::milliseconds{3000};
				if (!m_sem.wait_for(timeOut)) {
					return { httpStatus::NOT_FIND,"" };
				} else {
					return m_res;
				}
			}

			void setId(unsigned int id) {
				m_id = id;
			}
			unsigned int getId() const {
				return m_id;
			}

		protected:
			void send(const std::string &req) {
				if (m_close) return;
				m_conn->send(req);	
			}

		private:
			anet::tcp::connSharePtr m_conn{ nullptr };
			std::atomic_bool m_close{ true };
			std::atomic_bool m_signaled{ false };

			// session factory.
			httSyncSessionFactory *m_factory{ nullptr };

			// sync semaphore.
			anet::utils::CSemaphore m_sem{0};

			// session id.
			unsigned int m_id{ 0 };

			// response pair.
			response m_res{ httpStatus::NOT_FIND, "" };
			static const int m_sendBuffSize{ 1024 };
		};

		// http client for synchronous mode.
		// this class must set a httSyncSessionFactory to manager session.
		class CHttpSyncClient final : asio::noncopyable {
		public:
			explicit CHttpSyncClient(httSyncSessionFactory *factory) : 
				m_sessionFactory(factory) {	
			}
			virtual ~CHttpSyncClient() = default;

		public:
			// return post {Status, content} synchronously.
			response post(const std::string &addr, const std::string &path, const std::string &req) {
				// connect to remote server.
				if (!syncConnect(addr)) {
					return { httpStatus::NOT_FIND,"" };
				}

				// send requirement.
				this->sendReq(path, req, gHttpPostMethod);

				// wait for response return.
				return m_session->waitFor();
			}

			// return get {Status, content} synchronously.
			response get(const std::string &addr, const std::string &path, const std::string &req) {
				// connect to remote server.
				if (!syncConnect(addr)) {
					return { httpStatus::NOT_FIND,"" };
				}

				// send requirement.
				this->sendReq(path, req, gHttpGetMethod);

				// wait for result.
				return m_session->waitFor();
			}

			void close() {
				if (m_session != nullptr) {
					m_session->close();
					m_session = nullptr;
				}
			}

		private:
			void sendReq(const std::string &path, const std::string &req, const char *method) {
				HttpReq httpReq;
				httpReq.content = req;
				httpReq.method = method;
				httpReq.contentType = gHttpContentTypeUrlEncoded;
				httpReq.version = gHttpVersion11;
				httpReq.connectionMode = gHttpConnectionClose;
				httpReq.path = path;

				// host command.
				auto &&host = std::string(m_session->getConn()->getRemoteAddr());
				host += ":";
				host += std::to_string(m_session->getConn()->getRemotePort());
				m_session->sendHttpReq(httpReq, host);
			}

			bool syncConnect(const std::string &addr) {
				this->close(); // try to close before connection.

				std::vector<std::string> vec;
				strSplits(addr, ":", vec);
				if (vec.size() < 2) {
					return false;
				}

				// initialize client's codec and session.
				m_client.setPacketParser(&m_codec);
				m_session = m_sessionFactory->createSession();
				m_client.setSession(m_session.get());

				// try to connect remote server.
				auto port = (unsigned short)std::atoi(vec[1].c_str());
				return m_client.syncConnect(vec[0], port);
			}

		private:
			// TCP client
			anet::tcp::CClient     m_client{ m_loop };
			
			// Event loop.
			anet::tcp::CEventLoop  m_loop{ 1 };

			// Client codec.
			CHttpClientCodec       m_codec;

			// client session.
			using httpSyncSessionPtr = std::shared_ptr<CHttpClientSyncSession>;
			httpSyncSessionPtr m_session{ nullptr };

			// session factory.
			httSyncSessionFactory *m_sessionFactory{ nullptr };
		};
	}
}