#include <ssl_service_cache.h>
#include <tfe_utils.h>
#include <MESA/MESA_htable.h>
#include <stdlib.h>
#include <string.h>

#define	FAIL_AS_PINNING_COUNT	4
#define	FAIL_TIME_WINDOW		30
#define	FAIL_AS_PROTO_ERR_COUNT	5
struct ssl_svc_client_st
{
	time_t last_update_time;
	unsigned int suspect_pinning_count;	
	unsigned int protocol_error_count;
	char is_mutual_auth;
	struct ssl_service_cache* ref_svc_cache;
};
struct ssl_svc_server_st
{
	char is_ev;
	char is_ct;
	long long ev_st_switched;
	long long ct_st_switched;
	struct ssl_service_cache* ref_svc_cache;
};
struct ssl_service_cache
{
	MESA_htable_handle cli_st_hash;
	MESA_htable_handle srv_st_hash;
	struct ssl_service_cache_statistics stat;
};
struct ssl_service_write_args
{
	struct ssl_service_cache* cache;
	const struct ssl_service_status* status;
};
static void ssl_svc_free_client_st(void * data)
{
	struct ssl_svc_client_st* p = (struct ssl_svc_client_st *) data;
	struct ssl_service_cache* svc_cache=p->ref_svc_cache;
	if(p->is_mutual_auth)
	{
		svc_cache->stat.mutual_auth_cli_cnt--;
	}
	if(p->suspect_pinning_count>=FAIL_AS_PINNING_COUNT)
	{
		svc_cache->stat.pinning_cli_cnt--;
	}
	free(p);
	return;
}
static void ssl_svc_free_server_st(void * data)
{
	struct ssl_svc_server_st* p = (struct ssl_svc_server_st *) data;
	struct ssl_service_cache* svc_cache=p->ref_svc_cache;
	if(p->is_ct)
	{
		svc_cache->stat.ct_srv_cnt--;
	}
	if(p->is_ev)
	{
		svc_cache->stat.ev_srv_cnt--;
	}
	free(p);
	return;
}

static size_t ssl_svc_client_st_mk_key(const struct ssl_chello* chello, char* key_buff, size_t sz)
{
	size_t key_sz=0;
	key_sz=snprintf(key_buff, sz, "%d.%d-%d.%d:%s:%s:%s:%s", chello->min_version.major, chello->min_version.minor,
													chello->max_version.major, chello->max_version.minor,
													chello->sni, chello->alpn, chello->cipher_suites, chello->cipher_suites_tls13);
	return key_sz;
}
static long cli_st_read_cb(void * data, const uchar * key, uint size, void * user_arg)
{
	struct ssl_svc_client_st* cli_st=(struct ssl_svc_client_st*)data;
	struct ssl_service_status* result=(struct ssl_service_status*)user_arg;
	
	if (cli_st == NULL)
	{
		return 0;
	}
	if(cli_st->suspect_pinning_count==0)
	{		
		result->pinning_status=PINNING_ST_NOT_PINNING;
	}
	else if(cli_st->suspect_pinning_count<FAIL_AS_PINNING_COUNT)
	{
		result->pinning_status=PINNING_ST_MAYBE_PINNING;
	}
	else
	{
		result->pinning_status=PINNING_ST_PINNING;
	}
	if(cli_st->protocol_error_count>=FAIL_AS_PROTO_ERR_COUNT)
	{
		result->has_protocol_errors=1;
	}
	result->is_mutual_auth=cli_st->is_mutual_auth;
	return 1;
}
static long cli_st_write_cb(void * data, const uchar * key, uint size, void * user_arg)
{
	struct ssl_svc_client_st* cli_st=(struct ssl_svc_client_st*)data;
	struct ssl_service_write_args* args=(struct ssl_service_write_args*)user_arg;
	const struct ssl_service_status* status=args->status;
	struct ssl_service_cache* cache=args->cache;
	UNUSED int ret = 0;
	time_t now=time(NULL);
	if(cli_st==NULL)
	{
		cli_st=ALLOC(struct ssl_svc_client_st, 1);
		cli_st->ref_svc_cache=cache;
		ret = MESA_htable_add(cache->cli_st_hash, key, size, cli_st);
		assert(ret >= 0);
	}
	if(cli_st->last_update_time-now>FAIL_TIME_WINDOW)
	{
		if(cli_st->suspect_pinning_count<FAIL_AS_PINNING_COUNT)		cli_st->suspect_pinning_count=0;
		if(cli_st->protocol_error_count<FAIL_AS_PROTO_ERR_COUNT)	cli_st->protocol_error_count=0;
	}
	if(status->pinning_status!=PINNING_ST_NOT_PINNING && cli_st->suspect_pinning_count<FAIL_AS_PINNING_COUNT)
	{
		if(status->pinning_status==PINNING_ST_PINNING)
		{
			cli_st->suspect_pinning_count=FAIL_AS_PINNING_COUNT;
		}
		else
		{
			cli_st->suspect_pinning_count++;
		}
		if(cli_st->suspect_pinning_count==FAIL_AS_PINNING_COUNT)
		{
			cache->stat.pinning_cli_cnt++;
		}
	}
	else if(status->pinning_status==PINNING_ST_PINNING)
	{
		cli_st->suspect_pinning_count=FAIL_AS_PINNING_COUNT;
	}
	if(status->has_protocol_errors)
	{
		cli_st->protocol_error_count++;
		if(cli_st->protocol_error_count==FAIL_AS_PROTO_ERR_COUNT)
		{
			cache->stat.proto_err_cli_cnt++;
		}
	}
	if(status->is_mutual_auth==1&&cli_st->is_mutual_auth==0)
	{
		cache->stat.mutual_auth_cli_cnt++;	
		cli_st->is_mutual_auth=1;
	}
	cli_st->last_update_time=now;	
	return 1;
}

static long srv_st_read_cb(void * data, const uchar * key, uint size, void * user_arg)
{
	struct ssl_svc_server_st* srv_st=(struct ssl_svc_server_st*)data;
	struct ssl_service_status* result=(struct ssl_service_status*)user_arg;
	if (srv_st == NULL)
	{
		return 0;
	}
	result->is_ct=srv_st->is_ct;
	result->is_ev=srv_st->is_ev;
	return 1;
}
static long srv_st_write_cb(void * data, const uchar * key, uint size, void * user_arg)
{
	struct ssl_svc_server_st* srv_st=(struct ssl_svc_server_st*)data;
	struct ssl_service_write_args* args=(struct ssl_service_write_args*)user_arg;
	const struct ssl_service_status* status=args->status;
	struct ssl_service_cache* cache=args->cache;
	UNUSED int ret = 0;
	if(srv_st==NULL)
	{
		srv_st=ALLOC(struct ssl_svc_server_st, 1);
		srv_st->ref_svc_cache=cache;
		ret = MESA_htable_add(cache->srv_st_hash, key, size, srv_st);
		assert(ret >= 0);
	}
	if(status->is_ev==1&&srv_st->is_ev==0)
	{
		srv_st->is_ev=1;
		cache->stat.ev_srv_cnt++;
	}
	if(status->is_ev!=srv_st->is_ev)
	{
		srv_st->ev_st_switched++;
	}
	if(status->is_ct==1&&srv_st->is_ct==0)
	{
		srv_st->is_ct=1;
		cache->stat.ct_srv_cnt++;
	}
	if(status->is_ct!=srv_st->is_ct)
	{
		srv_st->ct_st_switched++;
	}
	assert(srv_st->ev_st_switched<2&&srv_st->ct_st_switched<2);
	return 1;
}

int ssl_service_cache_read(struct ssl_service_cache* svc_cache, const struct ssl_chello* chello, struct ssl_service_status* result)
{
	long cli_st_cb_ret=0, svr_st_cb_ret=0;
	char cli_st_key[2048];
	size_t cli_st_key_sz=0;
	if(chello->sni==NULL)
	{
		return 0;
	}
	cli_st_key_sz=ssl_svc_client_st_mk_key(chello, cli_st_key, sizeof(cli_st_key));
	MESA_htable_search_cb(svc_cache->cli_st_hash, (unsigned char*) cli_st_key, (unsigned int) cli_st_key_sz, cli_st_read_cb, result, &cli_st_cb_ret);	
	MESA_htable_search_cb(svc_cache->srv_st_hash, (unsigned char*) chello->sni, (unsigned int) strlen(chello->sni), srv_st_read_cb, result, &svr_st_cb_ret);
	if(cli_st_cb_ret||svr_st_cb_ret)
	{
		return 1;
	}
	else
	{
		return 0;
	}
}

void ssl_service_cache_write(struct ssl_service_cache* svc_cache, const struct ssl_chello* chello, const struct ssl_service_status* status)
{
	long cli_st_cb_ret=0, svr_st_cb_ret=0;
	char cli_st_key[2048];
	size_t cli_st_key_sz=0;
	if(chello->sni==NULL)
	{
		return;
	}
	struct ssl_service_write_args write_args={svc_cache, status};
	if(status->is_mutual_auth||status->pinning_status!=PINNING_ST_NOT_PINNING||status->has_protocol_errors)
	{
		cli_st_key_sz=ssl_svc_client_st_mk_key(chello, cli_st_key, sizeof(cli_st_key));
		MESA_htable_search_cb(svc_cache->cli_st_hash, (unsigned char*)cli_st_key, (unsigned int) cli_st_key_sz, cli_st_write_cb, &write_args, &cli_st_cb_ret);	
	}
	if(status->is_ct||status->is_ev)
	{
		MESA_htable_search_cb(svc_cache->srv_st_hash, (unsigned char*)chello->sni, (unsigned int) strlen(chello->sni), srv_st_write_cb, &write_args, &svr_st_cb_ret);
	}
}
struct ssl_service_cache* ssl_service_cache_create(unsigned int slot_size, unsigned int expire_seconds)
{
	struct ssl_service_cache * cache = ALLOC(struct ssl_service_cache, 1);
	unsigned max_num = slot_size * 4;
	UNUSED int ret = 0;
	MESA_htable_handle htable=NULL, saved[2];
	int i=0, opt_val=0;
	void (*free_func[])(void *)={ssl_svc_free_client_st, ssl_svc_free_server_st};
	for(i=0; i<2; i++)
	{
		htable = MESA_htable_born();
		opt_val=0;
		ret = MESA_htable_set_opt(htable, MHO_SCREEN_PRINT_CTRL, &opt_val, sizeof(opt_val));
		opt_val=1;
		ret = MESA_htable_set_opt(htable, MHO_THREAD_SAFE, &opt_val, sizeof(opt_val));
		opt_val=16;
		ret = MESA_htable_set_opt(htable, MHO_MUTEX_NUM, &opt_val, sizeof(opt_val));
		ret = MESA_htable_set_opt(htable, MHO_HASH_SLOT_SIZE, &slot_size, sizeof(slot_size));
		ret = MESA_htable_set_opt(htable, MHO_HASH_MAX_ELEMENT_NUM, &max_num, sizeof(max_num));
		ret = MESA_htable_set_opt(htable, MHO_EXPIRE_TIME, &expire_seconds, sizeof(expire_seconds));
		
		opt_val=HASH_ELIMINATE_ALGO_LRU;
		ret = MESA_htable_set_opt(htable, MHO_ELIMIMINATE_TYPE,
			&opt_val, sizeof(int));
		ret = MESA_htable_set_opt(htable, MHO_CBFUN_DATA_FREE,
			(void*)free_func[i], sizeof(free_func[i]));
		
		ret = MESA_htable_mature(htable);
		assert(ret == 0);
		saved[i]=htable;
	}
	cache->cli_st_hash=saved[0];
	cache->srv_st_hash=saved[1];
	
	return cache;
}
void ssl_service_cache_destroy(struct ssl_service_cache* cache)
{
	MESA_htable_destroy(cache->cli_st_hash, NULL);
	cache->cli_st_hash=NULL;
	MESA_htable_destroy(cache->srv_st_hash, NULL);
	cache->srv_st_hash=NULL;
	free(cache);
	return;
}
void ssl_service_cache_stat(struct ssl_service_cache* svc_cache, struct ssl_service_cache_statistics* result)
{
	*result=svc_cache->stat;
	return;
}