#include <pthread.h>
#include <signal.h>
#ifdef USE_OPENSSL
#include <openssl/ssl.h>
#include <openssl/err.h>
#endif
#include <unistd.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/socket.h>
#include <sys/select.h>
#include <errno.h>
#include <time.h>
#include "http_server.h"
#include "lib/ini.h"
#include "lib/scheduler.h"
#include "plugin_manager.h"
#include "lib/utils.h"

#define SEND_STAT(fd, buff, ret, ...)       \
	snprintf(buff, BUFFLEN, ##__VA_ARGS__); \
	ret = write(fd, buff, strlen(buff));

static antd_scheduler_t* scheduler;

#ifdef USE_OPENSSL

// define the cipher suit used
// dirty hack, this should be configured by the configuration file
#define CIPHER_SUIT "HIGH"

static int ssl_session_ctx_id = 1;
SSL_CTX *ctx;
static void init_openssl()
{
	SSL_load_error_strings();
	OpenSSL_add_ssl_algorithms();
}

static SSL_CTX *create_context()
{
	const SSL_METHOD *method;
	SSL_CTX *ctx;

	method = SSLv23_server_method();

	ctx = SSL_CTX_new(method);
	if (!ctx)
	{
		ERROR("Unable to create SSL context");
		ERR_print_errors_fp(stderr);
		exit(EXIT_FAILURE);
	}

	return ctx;
}
#if OPENSSL_VERSION_NUMBER >= 0x10002000L
static unsigned char antd_protocols[] = {
	//TODO: add support to HTTP/2 protocol: 2,'h', '2',
	8, 'h', 't', 't', 'p', '/', '1', '.', '1'};
static int alpn_advertise_protos_cb(SSL *ssl, const unsigned char **out, unsigned int *outlen, void *arg)
{
	UNUSED(ssl);
	UNUSED(arg);
	*out = antd_protocols;
	*outlen = sizeof(antd_protocols);
	return SSL_TLSEXT_ERR_OK;
}
static int alpn_select_cb(SSL *ssl, const unsigned char **out, unsigned char *outlen, const unsigned char *in, unsigned int inlen, void *arg)
{
	UNUSED(ssl);
	UNUSED(arg);
	if (SSL_select_next_proto((unsigned char **)out, outlen, antd_protocols, sizeof(antd_protocols), in, inlen) == OPENSSL_NPN_NEGOTIATED)
	{
		return SSL_TLSEXT_ERR_OK;
	}
	else
	{
		ERROR("No protocol support overlap found between client and server\n");
		return SSL_TLSEXT_ERR_ALERT_FATAL;
	}
}
#endif
static void configure_context(SSL_CTX *ctx)
{
#if defined(SSL_CTX_set_ecdh_auto)
	SSL_CTX_set_ecdh_auto(ctx, 1);
#else
	SSL_CTX_set_tmp_ecdh(ctx, EC_KEY_new_by_curve_name(NID_X9_62_prime256v1));
#endif
	//SSL_CTX_set_ecdh_auto(ctx, 1);
	/* Set some options and the session id.
     * SSL_OP_NO_SSLv2: SSLv2 is insecure, disable it.
     * SSL_OP_NO_TICKET: We don't want TLS tickets used because this is an SSL server caching example.
     *                   It should be fine to use tickets in addition to server side caching.
     */
	SSL_CTX_set_options(ctx, SSL_OP_NO_TLSv1 | SSL_OP_NO_TLSv1_1 | SSL_OP_NO_SSLv2 | SSL_OP_NO_TICKET);
	SSL_CTX_set_session_id_context(ctx, (void *)&ssl_session_ctx_id, sizeof(ssl_session_ctx_id));
	// set the cipher suit
	config_t *cnf = config();
	const char *suit = cnf->ssl_cipher ? cnf->ssl_cipher : CIPHER_SUIT;
	LOG("Cirpher suit used: %s", suit);
	if (SSL_CTX_set_cipher_list(ctx, suit) != 1)
	{
		ERROR("Fail to set ssl cirpher suit: %s", suit);
		ERR_print_errors_fp(stderr);
		exit(EXIT_FAILURE);
	}
	/* Set the key and cert */
	/* use the full chain bundle of certificate */
	//if (SSL_CTX_use_certificate_file(ctx, server_config->sslcert, SSL_FILETYPE_PEM) <= 0) {
	if (SSL_CTX_use_certificate_chain_file(ctx, cnf->sslcert) <= 0)
	{
		ERROR("Fail to read SSL certificate chain file: %s", cnf->sslcert);
		ERR_print_errors_fp(stderr);
		exit(EXIT_FAILURE);
	}

	if (SSL_CTX_use_PrivateKey_file(ctx, cnf->sslkey, SSL_FILETYPE_PEM) <= 0)
	{
		ERROR("Fail to read SSL private file: %s", cnf->sslkey);
		ERR_print_errors_fp(stderr);
		exit(EXIT_FAILURE);
	}
	if (!SSL_CTX_check_private_key(ctx))
	{
		ERROR("Failed to validate SSL certificate");
		ERR_print_errors_fp(stderr);
		exit(EXIT_FAILURE);
	}
#if OPENSSL_VERSION_NUMBER >= 0x10002000L
	SSL_CTX_set_alpn_select_cb(ctx, alpn_select_cb, NULL);
	SSL_CTX_set_next_protos_advertised_cb(ctx, alpn_advertise_protos_cb, NULL);
#endif
}

#endif

static void stop_serve(int dummy)
{
	UNUSED(dummy);
	// close log server
	closelog();
	sigset_t mask;
	sigemptyset(&mask);
	//Blocks the SIG_IGN signal (by adding SIG_IGN to newMask)
	sigaddset(&mask, SIGINT);
	sigaddset(&mask, SIGPIPE);
	sigaddset(&mask, SIGABRT);
	sigprocmask(SIG_BLOCK, &mask, NULL);
	antd_scheduler_destroy(scheduler);
	unload_all_plugin();
#ifdef USE_OPENSSL
	FIPS_mode_set(0);
	SSL_CTX_free(ctx);
	FIPS_mode_set(0);
	// DEPRECATED: CONF_modules_unload(1);
	EVP_cleanup();
	EVP_PBE_cleanup();
	// DEPRECATED:ENGINE_cleanup();
	CRYPTO_cleanup_all_ex_data();
	// DEPRECATED: ERR_remove_state(0);
	ERR_free_strings();
#endif
	destroy_config();
	sigprocmask(SIG_UNBLOCK, &mask, NULL);
}

static void antd_monitor(port_config_t *pcnf)
{
	antd_task_t *task = NULL;
	int client_sock = -1;
	struct sockaddr_in client_name;
	socklen_t client_name_len = sizeof(client_name);
	char *client_ip = NULL;
	config_t *conf = config();
	if (pcnf->sock > 0)
	{
		client_sock = accept(pcnf->sock, (struct sockaddr *)&client_name, &client_name_len);
		if (client_sock > 0)
		{
			// just dump the scheduler when we have a connection
			antd_client_t *client = (antd_client_t *)malloc(sizeof(antd_client_t));
			antd_request_t *request = (antd_request_t *)malloc(sizeof(*request));
			request->client = client;
			request->request = dict();
			client->zstream = NULL;
			client->z_level = ANTD_CNONE;

			dictionary_t xheader = dict();
			dput(request->request, "REQUEST_HEADER", xheader);
			dput(request->request, "REQUEST_DATA", dict());
			dput(request->request, "SERVER_PORT", (void *)__s("%d", pcnf->port));
			dput(request->request, "SERVER_WWW_ROOT", (void *)strdup(pcnf->htdocs));
			/*
					get the remote IP
				*/
			if (client_name.sin_family == AF_INET)
			{
				client_ip = inet_ntoa(client_name.sin_addr);
				LOG("Connect to client IP: %s on port:%d (%d)", client_ip, pcnf->port, client_sock);
				// ip address
				dput(request->request, "REMOTE_ADDR", (void *)strdup(client_ip));
				//LOG("socket: %d\n", client_sock);
			}

			// set timeout to socket
			set_nonblock(client_sock);

			client->sock = client_sock;
			time(&client->last_io);
			client->ssl = NULL;
			client->state = ANTD_CLIENT_ACCEPT;
			client->z_status = 0;
#ifdef USE_OPENSSL
			if (pcnf->usessl == 1)
			{
				client->ssl = (void *)SSL_new(ctx);
				if (!client->ssl)
				{
					finish_request(request);
					return;
				}
				SSL_set_fd((SSL *)client->ssl, client->sock);
				// this can be used in the protocol select callback to
				// set the protocol selected by the server
				if (!SSL_set_ex_data((SSL *)client->ssl, client->sock, client))
				{
					ERROR("Cannot set ex data to ssl client:%d", client->sock);
				}
				/*if (SSL_accept((SSL*)client->ssl) <= 0) {
						LOG("EROOR accept\n");
						ERR_print_errors_fp(stderr);
						antd_close(client);
						continue;
					}*/
			}
#endif
			antd_scheduler_lock(scheduler);
			conf->connection++;
			antd_scheduler_unlock(scheduler);
			// create callback for the server
			task = antd_create_task(accept_request, (void *)request, finish_request, client->last_io);
			antd_task_bind_event(task,client->sock,0, TASK_EVT_ON_WRITABLE| TASK_EVT_ON_READABLE);
			antd_scheduler_add_task(scheduler, task);
		}
	}
}

void antd_scheduler_ext_statistic(int fd, void *user_data)
{
	antd_request_t *request = (antd_request_t *)user_data;
	chain_t it, it1;
	dictionary_t tmp;
	int ret;
	char buff[BUFFLEN];
	if (request == NULL)
	{
		SEND_STAT(fd, buff, ret, "Data is null\n");
		return;
	}
	// send client general infomation
	SEND_STAT(fd, buff, ret, "Client id: %d\n", request->client->sock);
	SEND_STAT(fd, buff, ret, "Last IO: %lu\n", (unsigned long)request->client->last_io);
	SEND_STAT(fd, buff, ret, "Current state: %d\n", request->client->state);
	SEND_STAT(fd, buff, ret, "z_level: %d\n", request->client->z_level);
	if (request->client->ssl)
	{
		SEND_STAT(fd, buff, ret, "SSL is enabled\n");
	}
	// send client request detail
	if (request->request)
	{
		for_each_assoc(it, request->request)
		{
			if (strcmp(it->key, "REQUEST_HEADER") == 0 ||
				strcmp(it->key, "REQUEST_DATA") == 0 ||
				strcmp(it->key, "COOKIE") == 0)
			{
				tmp = (dictionary_t)it->value;
				if (tmp)
				{
					for_each_assoc(it1, tmp)
					{
						SEND_STAT(fd, buff, ret, "%s: %s\n", it1->key, (char *)it1->value);
					}
				}
			}
			else
			{
				SEND_STAT(fd, buff, ret, "%s: %s\n", it->key, (char *)it->value);
			}
		}
	}
	UNUSED(ret);
}

void antd_scheduler_destroy_data(void *data)
{
	antd_request_t *rq = (antd_request_t *)data;
	antd_client_t *proxy = (antd_client_t *)dvalue(rq->request, "PROXY_HANDLE");
	if(proxy)
	{
		close(proxy->sock);
	}
	finish_request(data);
}

int antd_task_data_id(void *data)
{
	antd_request_t *rq = (antd_request_t *)data;
	if(!rq)
		return 0; 
	return antd_scheduler_next_id(scheduler,rq->client->sock);
	/*UNUSED(data);
	return antd_scheduler_next_id(scheduler,0);*/
}

int main(int argc, char *argv[])
{
	pthread_t sched_th;
	// startup port
	chain_t it;
	struct timeval timeout;
	port_config_t *pcnf;
	fd_set master_set, working_set;
	int status, maxfd = 0;
	int nlisten = 0;
	// load the config first
	if (argc == 1)
		load_config(CONFIG_FILE);
	else
		load_config(argv[1]);
	// ignore the broken PIPE error when writing
	//or reading to/from a closed socked connection
	signal(SIGPIPE, SIG_IGN);
	signal(SIGABRT, SIG_IGN);
	signal(SIGINT, stop_serve);

	config_t *conf = config();
	// start syslog
	if(conf->debug_enable == 1)
	{
		setlogmask(LOG_UPTO(LOG_NOTICE));
	}
	else
	{
		setlogmask(LOG_UPTO(LOG_ERR));
	}
	openlog(SERVER_NAME, LOG_CONS | LOG_PID | LOG_NDELAY, LOG_DAEMON);

#ifdef USE_OPENSSL
	if (conf->enable_ssl == 1)
	{
		init_openssl();
		ctx = create_context();

		configure_context(ctx);
	}

#endif
	// enable scheduler
	// default to 4 workers
	scheduler = antd_scheduler_init( conf->n_workers, conf->stat_fifo_path);
	if (scheduler == NULL)
	{
		ERROR("Unable to initialise scheduler. Exit");
		stop_serve(0);
		exit(1);
	}
	FD_ZERO(&master_set);
	for_each_assoc(it, conf->ports)
	{
		pcnf = (port_config_t *)it->value;
		if (pcnf)
		{
			pcnf->sock = startup(&pcnf->port);
			if (pcnf->sock > 0)
			{
				set_nonblock(pcnf->sock);
				FD_SET(pcnf->sock, &master_set);
				LOG("Listening on port %d", pcnf->port);
				maxfd = pcnf->sock > maxfd ? pcnf->sock : maxfd;
				nlisten++;
			}
			else
			{
				ERROR("Port %d is disabled", pcnf->port);
			}
		}
	}
	if (nlisten == 0)
	{
		ERROR("No port is listenned, quit!!");
		stop_serve(0);
		exit(1);
	}
	// Start scheduler
	if (pthread_create(&sched_th, NULL, (void *(*)(void *))antd_scheduler_wait, (void *)scheduler) != 0)
	{
		ERROR("pthread_create: cannot start scheduler thread");
		stop_serve(0);
		exit(1);
	}
	else
	{
		// reclaim data when exit
		pthread_detach(sched_th);
	}

	while (antd_scheduler_ok(scheduler))
	{
		if (conf->connection > conf->maxcon)
		{
			//ERROR("Reach max connection %d", conf->connection);
			timeout.tv_sec = 0;
			timeout.tv_usec = 10000; // 5 ms
			select(0, NULL, NULL, NULL, &timeout);
			continue;
		}
		FD_ZERO(&working_set);
		memcpy(&working_set, &master_set, sizeof(master_set));
		// blocking select
		status = select(maxfd + 1, &working_set, NULL, NULL, NULL);
		if (status < 0)
		{
			ERROR("select() error: %s", strerror(errno));
			break;
		}
		if (status == 0)
		{
			continue;
		}
		for_each_assoc(it, conf->ports)
		{
			pcnf = (port_config_t *)it->value;
			if (pcnf && pcnf->sock > 0 && FD_ISSET(pcnf->sock, &working_set))
			{
				antd_monitor(pcnf);
			}
		}
	}
	stop_serve(0);
	return (0);
}