#include <string.h>
#include <assert.h>
#include "user_data.h"
#include "util.h"


struct user_data{
	i64 userid;

	int *fds;
	i64 *last_active;
	i64 cap,len;
};

struct hash_item{
	struct user_data data;
	struct hash_item *next;
};

#define USER_HASH_SIZE (16)
static struct hash_item *user_hash[USER_HASH_SIZE];


static struct hash_item* find_userdata(i64 userid){
	struct hash_item *item=user_hash[userid%USER_HASH_SIZE];
	while(item&&item->data.userid!=userid)item=item->next;
	return item;
}

static void remove_userdata(i64 userid){
	struct hash_item *item=user_hash[userid%USER_HASH_SIZE];
	assert(item);
	if(item->data.userid==userid){
		user_hash[userid%USER_HASH_SIZE]=item->next;
		free(item->data.fds);
		free(item);
		return;
	}
	struct hash_item *parent=NULL;
	while(item->data.userid!=userid){
		parent=item;
		item=item->next;
		assert(item);
	}
	parent->next=item->next;
	free(item->data.fds);
	free(item);
}

void userdata_register(i64 userid,int fd){
	struct hash_item *item=find_userdata(userid);
	if(item){
		for(i64 i=0;i<item->data.len;i++){
			if(item->data.fds[i]==fd){
				die("userdata_register(%" PRIi64 ", %d) while pair already existed",userid,fd);
			}
		}
		if(item->data.len==item->data.cap){
			item->data.cap*=2;
			item->data.fds=realloc(item->data.fds,item->data.cap,int);
			item->data.last_active=realloc(item->data.last_active,item->data.cap,i64);
		}
		item->data.fds[item->data.len]=fd;
		item->data.last_active[item->data.len]=make_timestamp();
		item->data.len++;
	} else {
		item=malloc(1,struct hash_item);
		item->data.userid=userid;
		item->data.cap=2;
		item->data.len=1;
		item->data.fds=malloc(item->data.cap,int);
		item->data.fds[0]=fd;
		item->data.last_active=malloc(item->data.cap,i64);
		item->data.last_active[0]=make_timestamp();
		item->next=user_hash[userid%USER_HASH_SIZE];
		user_hash[userid%USER_HASH_SIZE]=item;
	}
}

void userdata_unregister(i64 userid,int fd){
	struct hash_item *item=find_userdata(userid);
	if(!item){
		die("userdata_unregister(%" PRIi64 ", %d) while nonexistent",userid,fd);
	}
	i64 i;
	for(i=0;i<item->data.len;i++){
		if(item->data.fds[i]==fd)break;
	}
	if(i==item->data.len){
		die("userdata_unregister(%" PRIi64 ", %d) while nonexistent",userid,fd);
	}
	memmove(item->data.fds+i,item->data.fds+i+1,item->data.len-i-1);
	memmove(item->data.last_active+i,item->data.last_active+i+1,item->data.len-i-1);
	item->data.len--;
	if(item->data.len==0){
		remove_userdata(userid);
	}
}

void userdata_mark_active(i64 userid,int fd,bool active){
	struct hash_item *item=find_userdata(userid);
	if(!item){
		die("userdata_mark_active(%" PRIi64 ", %d, %d) with nonexistent userid",userid,fd,active);
	}
	i64 i;
	for(i=0;i<item->data.len;i++){
		if(item->data.fds[i]==fd)break;
	}
	if(i==item->data.len){
		die("userdata_mark_active(%" PRIi64 ", %d, %d) while nonexistent",userid,fd,active);
	}

	item->data.last_active[i]=active?make_timestamp():-1;
}

bool userdata_is_active(i64 userid){
	struct hash_item *item=find_userdata(userid);
	if(!item)return false;
	i64 last=0;
	for(i64 i=0;i<item->data.len;i++){
		if(item->data.last_active[i]>last)last=item->data.last_active[i];
	}
	return make_timestamp()-last<2*60*1000*1000;
}

const int* userdata_online(i64 userid,i64 *nfds){
	struct hash_item *item=find_userdata(userid);
	if(!item){
		if(nfds)*nfds=0;
		return NULL;
	}
	assert(item->data.len!=0);
	if(nfds)*nfds=item->data.len;
	return item->data.fds;
}