#include "stdafx.h"
#include "spell.h"
#include <stdlib.h>
#include <time.h>

CSpell::CSpell(int w, int h, int bx, int by){
	// 構造函數，傳入長和寬
	width = w;
	height = h;
	bx = (bx>=w)?(w-1):(bx<0 ? 0 : bx);
	by = (by>=h)?(h-1):(by<0 ? 0 : by);
	blank = by * w + bx;
	map = new int[w*h];
	for(int i = 0; i < w*h; i++){
		map[i] = i;
	}
	// 初始化
	Init();
}

CSpell::~CSpell(){
	delete [] map;
}

void CSpell::ReCreate(int w, int h, int bx, int by){
	// 重新構建大小
	delete [] map;
	width = w;
	height = h;
	bx = (bx>=w)?(w-1):(bx<0 ? 0 : bx);
	by = (by>=h)?(h-1):(by<0 ? 0 : by);
	blank = by * w + bx;
	map = new int[w*h];
	for(int i = 0; i < w*h; i++){
		map[i] = i;
	}
	// 初始化
	Init();
}

int CSpell::GetPic(int w, int h){
	// 獲取個某個位置的圖片
	if(w < 0 || w >= width || h < 0 || h >= height){
		return -1;
	}
	return map[h*width + w];
}

int CSpell::Move(int w, int h){
	// 移動某個位置的圖片
	if(w < 0 || w >= width || h < 0 || h >= height){
		return -10;
	}
	if(blank == map[h*width+w]){
		return -1;
	}
	if(blank == GetPic(w-1, h)){
		int t = map[h*width+w];
		map[h*width+w] = map[h*width+w-1];
		map[h*width+w-1] = t;
	}
	else if(blank == GetPic(w+1, h)){
		int t = map[h*width+w];
		map[h*width+w] = map[h*width+w+1];
		map[h*width+w+1] = t;
	}
	else if(blank == GetPic(w, h-1)){
		int t = map[h*width+w];
		map[h*width+w] = map[(h-1)*width+w];
		map[(h-1)*width+w] = t;
	}
	else if(blank == GetPic(w, h+1)){
		int t = map[h*width+w];
		map[h*width+w] = map[(h+1)*width+w];
		map[(h+1)*width+w] = t;
	}
	else{
		return -1;
	}
	for(int i = 0; i < LENGTH; i++){
		if(i != map[i]){
			return 0;
		}
	}
	return 1;
}

void CSpell::Init(){
	// 初始化(生成隨機位置)
	srand(time(NULL));
	int a, b, t;
	int i = 0, d = 1;
	while(i++ < LENGTH || d == 0){// 交換至少單位數量次
		do{
			a = rand()%(LENGTH);
			b = rand()%(LENGTH);
		}
		while(a == b);
		t = map[a];
		map[a] = map[b];
		map[b] = t;
		// 計算距離，必須要模為1有解
		if(blank == map[a] || blank == map[b]){
			int w = a%width - b%width + 1;
			int h = a/width - b/width;
			w = w<0?-w:w;
			h = h<0?-h:h;
			d = (d+w+h)%2;
		}
		else{
			d = !d;
		}
	}
}