#include "db.h"
#include "cache.h"
#include "db_access.h"


off_t _db_index_year(db_t* db, db_date_t d)
{
	db_metadata_t* md = db->index.years;
	int max = db->index.nyears, min=0;
	int i = max/2;
	
	while(1)
	{
		if(md[i].date.year==d.year)
			return md[i].index;
		else if(d.year>md[i].date.year)
		{
			if( max!=min )
			{
				min=i+1;
				i=(max-i)/2+i;
			}
			else if(max==db->index.nyears) return db->index.nmonthes;
			else return 0xffffffff;
		}
		else
		{
			if( max!=min )
			{
				max=i;
				i=(i-min)/2+min;
			}
			else if(!min) return 0;
			else return 0xffffffff;
		}
	}
}

off_t _db_index_month(db_t* db, db_date_t d, off_t start, off_t len)
{
	db_metadata_t* md = db->index.monthes;
	int max = len, min = 0;
	int i = max/2;
	if(min==max) return min;
	while(1)
	{
		if(md[i+start].date.month==d.month)
			return md[i+start].index;
		else if(d.month>md[i+start].date.month)
		{
			if( max!=min )
			{
				min=i+1;
				i=(max-i)/2+i;
			}
			else if(max==len && len+start<db->index.nmonthes) return md[len+start].index;
			else if(max==len && len+start>=db->index.nmonthes) return db->index.ndays;
			else return 0xffffffff;
		}
		else
		{
			if( max!=min )
			{
				max=i;
				i=(i-min)/2+min;
			}
			else if(!min) return 0;
			else return 0xffffffff;
		}
	}
}


off_t _db_index_day(db_t* db, db_date_t d, off_t start, off_t len)
{
	db_metadata_t* md = db->index.days;
	int max = len, min=0;
	int i = max/2;
	
	if(min==max) return min;
	while(1)
	{
		if(md[i+start].date.day==d.day)
			return md[i+start].index;
		else if(d.day>md[i+start].date.day)
		{
			if( max!=min ) 
			{
				min=i+1;
				i=(max-i)/2+i;
			}
			else if(max==len && len+start<db->index.ndays) return md[len+start].index;
			else if(max==len && len+start>=db->index.ndays) return db->index.data_count;
			else return 0xffffffff;
		}
		else
		{
			if( max!=min) 
			{
				max=i;
				i=(i-min)/2+min;
			}
			else if(!min) return 0;
			else return 0xffffffff;
		}
	}
}


db_interval_t db_inter_get(db_t* db, db_date_t d)
{
	db_interval_t inter;
	db_date_t d2;
	off_t ys, yl, ms, ml;
	inter.start=0xFFFFFFFF;
	inter.len=0xFFFFFFFF;
	
	d2=d; 
	ys=_db_index_year(db, d2);
	if(ys==0XFFFFFFFF) return inter;
	d2.year++;
	yl=_db_index_year(db, d2);
	if(yl==0XFFFFFFFF) return inter;
	
	d2=d; 
	ms=_db_index_month(db, d2, ys, yl-ys);
	if(ms==0XFFFFFFFF) return inter;
	d2.month++;
	ml=_db_index_month(db, d2, ys, yl-ys);
	if(ml==0XFFFFFFFF) return inter;
	
	d2=d;
	inter.start=_db_index_day(db, d2, ms, ml-ms);
	if(inter.start==0XFFFFFFFF) return inter;
	d2.day++;
	inter.len=_db_index_day(db, d2, ms, ml-ms)-inter.start;
	return inter;
}


int  db_init(db_t* db)
{
	if(!db) return -1;

	if(db_index_load(&db->index));
	return 0;
}

void db_free(db_t* db)
{
	if(!db) return;
	db_index_release(&db->index);
}

int db_time_cmp( db_time_t* a, db_time_t* b)
{
	if(a->date.year > b->date.year) return 1;
	if(a->date.year < b->date.year) return -1;
	
	if(a->date.month > b->date.month) return 1;
	if(a->date.month < b->date.month) return -1;
	
	if(a->date.day > b->date.day) return 1;
	if(a->date.day < b->date.day) return -1;
	
	if(a->millis > b->millis) return 1;
	if(a->millis < b->millis) return -1;
	return 0;
}


db_data_set_t* db_get(db_t* db, db_time_t* start, db_time_t* end)
{
	db_interval_t s, e, total;
	s=db_inter_get(db, start->date);
	e=db_inter_get(db, end->date);
	total.start=s.start;
	total.len=e.start+e.len-s.start;
	
	return NULL;
}

/*
int main(int argc, char** argv)
{
	cache_t cache;
	cache_init(&cache, CACHE_PAGE_SIZE, CACHE_PAGE_COUNT);
	
	
	cache_free(&cache);
}
*/