#include "TaskManager.h"
#include "sort.h"
#include "Func.h"

DataPtr data; // sort array
int data_length;
static int sort_count; // sort 完了に必要な回数
static int split_num; // data の分割数
static int half_num;
static int block_num; // 一つのタスクで sort する data 数
static int last_block_num;
static int half_block_num;
static int last_half_block_num;

static void sort_restart(void *);
static void sort_start(void);

/**
 * 一つの block にある data の数が MAX_BLOCK_SIZE 超えないような
 * len の分割数を返す
 *
 * @param  len  sort する data の総数
 * @param  num  使用する SPE の数
 *
 * @return data の分割数
 *
 * TODO:
 *   len が num 以下とか考えてません
 */
static int
get_split_num(int len, int num)
{
    if (len / num < MAX_BLOCK_SIZE) {
	return num;
    } else {
	// 切り上げ
	return (len + MAX_BLOCK_SIZE - 1) / MAX_BLOCK_SIZE;
    }
}	

/**
 * btask が全て終了したら、再び sort_start を実行する
 * @param d 生成された btask の数
 */
static void
sort_restart(void *d)
{
    static int cnt = 0;
    int max = (int)d;

    if (++cnt == max) {	
	cnt = 0;
	sort_start();
    }
}

static void
sort_start(void)
{
    if (--sort_count < 0) {
	return;
    }

    HTaskPtr fsort[split_num];

    for (int i = 0; i < split_num-1; i++) {
	fsort[i] = manager->create_task(QUICK_SORT);
	fsort[i]->add_inData(&data[i*block_num], sizeof(Data)*block_num);
	fsort[i]->add_outData(&data[i*block_num], sizeof(Data)*block_num);
	fsort[i]->add_param(block_num);
	fsort[i]->set_cpu(SPE_ANY);
    }

    // 最後の block は端数なので last_block_num を使う
    {
	int i = split_num-1;

	fsort[i] = manager->create_task(QUICK_SORT);
	fsort[i]->add_inData(&data[i*block_num], sizeof(Data)*last_block_num);
	fsort[i]->add_outData(&data[i*block_num], sizeof(Data)*last_block_num);
	fsort[i]->add_param(last_block_num);
	fsort[i]->set_cpu(SPE_ANY);
   }

    if (split_num > 1) {
	HTaskPtr bsort[half_num];

	for (int i = 0; i < half_num-1; i++) {
	    bsort[i] = manager->create_task(QUICK_SORT);
	    bsort[i]->add_inData(&data[i*block_num+half_block_num],
				 sizeof(Data)*block_num);
	    bsort[i]->add_outData(&data[i*block_num+half_block_num],
				  sizeof(Data)*block_num);
	    bsort[i]->add_param(block_num);
	    bsort[i]->set_cpu(SPE_ANY);
	}

	{
	    int i = half_num-1;

	    bsort[i] = manager->create_task(QUICK_SORT);
	    bsort[i]->add_inData(&data[i*block_num+half_block_num],
				 sizeof(Data)*last_half_block_num);
	    bsort[i]->add_outData(&data[i*block_num+half_block_num],
				  sizeof(Data)*last_half_block_num);
	    bsort[i]->add_param(last_half_block_num);
	    bsort[i]->set_cpu(SPE_ANY);	
	}
	
	for (int i = 0; i < half_num; i++) {
	    bsort[i]->wait_for(fsort[i]);
	    bsort[i]->wait_for(fsort[i+1]);
	    bsort[i]->set_post(sort_restart, (void*)(half_num));
	    bsort[i]->spawn();
	}
    }

    for (int i = 0; i < split_num; i++) {
	fsort[i]->spawn();
    }
}

void
sort_init(int cpuNum, int length)
{
    data = (DataPtr)manager->allocate(sizeof(Data)*length);
    data_length = length;

    for (int i = 0; i < length; i++) { 
        data[i].index = manager->get_random()%10000;
        data[i].ptr   = 0;
    }

    split_num = get_split_num(length, cpuNum);
    half_num = split_num-1;
    sort_count = split_num;

    block_num = (length + split_num -1)/split_num;
    half_block_num = block_num/2;

    last_block_num = length - (split_num-1)*block_num;
    last_half_block_num = half_block_num+(last_block_num/2);

    sort_start();
}