package {
	import flash.display.Sprite;
	import flash.events.KeyboardEvent;
	import flash.events.Event;
	public class rebuild extends Sprite {
		// array to store the map
		public var map:Array=new Array();
		// array to store bulldozer position
		public var bulldozer_pos:Array= new Array();
		// tree movieclip
		public var tree:tree_mc;
		// debris movieclip
		public var debris:debris_mc;
		// bulldozer movieclip
		public var bulldozer:bulldozer_mc;
		// external wall movieclip
		public var ext_wall:ext_wall_mc;
		// helicopter movieclip
		public var heli:heli_mc;
		// variable to store the last key pressed
		public var key_pressed:int=0;
		// flag to determine if the bulldozer is moving or not
		public var bulldozer_is_moving:Boolean=false;
		// bulldozer x and y direction
		public var bulldozer_x_dir:int=0;
		public var bulldozer_y_dir:int=0;
		// variable to determine which debris the helicopter is going to pick up
		public var heli_on_debris:int=1;
		// number of debris left to clear the screen
		public var debris_left:int=0;
		// variable to store the name of the debris we will move
		public var debris_to_move:String="";
		// main function
		public function rebuild():void {
			// initializing the map
			// 0: empty space (walkable)
			// 1: tree (unmovable object)
			// 2: debris (movable object)
			// 9: external wall (unmovable object)
			// 10: hole in external wall (unwalkable, but debris can be pushed on it)
			map=[[9,9,9,9,9,9,9,10,9,9,9],[9,0,0,2,0,0,0,0,0,0,9],[9,0,0,0,0,0,0,0,0,0,9],[9,1,1,1,1,1,0,1,0,0,9],[9,1,0,0,2,0,0,1,0,0,9],[9,1,0,0,0,0,0,1,0,0,9],[9,1,1,1,1,1,1,1,0,0,9],[9,0,0,0,0,2,0,0,0,0,9],[9,0,0,0,0,0,0,0,0,0,9],[9,0,0,0,0,0,0,0,0,0,9],[9,9,9,9,9,9,9,9,9,9,9]];
			// initializing bulldozer starting position
			bulldozer_pos=[7,3];
			// calling main functions
			draw_map();
			place_bulldozer();
			// adding listeners
			stage.addEventListener(KeyboardEvent.KEY_DOWN, on_key_down);
			stage.addEventListener(KeyboardEvent.KEY_UP, on_key_up);
			addEventListener(Event.ENTER_FRAME,on_enter_frame);
		}
		// function to draw the map
		public function draw_map():void {
			// looping though all map. What's that "11"? it's the map width/height
			for (var i:int=0; i<11; i++) {
				for (var j:int=0; j<11; j++) {
					switch (map[j][i]) {
							// I found a tree
						case 1 :
							// placing the tree
							tree = new tree_mc();
							// What's that "50"? it's the tile width/height
							// And the "25"? It's half a tile width/height
							// the whole game area is shifted by half a tile up and left
							// so that the external wall is only displayed at a half
							tree.x=i*50-25;
							tree.y=j*50-25;
							addChild(tree);
							break;
						case 2 :
							// placing a debris, same way as the tree
							debris=new debris_mc();
							debris.name="debris_"+j+"_"+i;
							debris.x=i*50-25;
							debris.y=j*50-25;
							addChild(debris);
							debris_left++;
							break;
						case 9 :
							// placing an external wall, same way as the tree
							ext_wall = new ext_wall_mc();
							ext_wall.x=i*50-25;
							ext_wall.y=j*50-25;
							addChild(ext_wall);
							break;
					}
				}
			}
		}
		// function to place the bulldozer, in the same way as the tree
		public function place_bulldozer():void {
			bulldozer = new bulldozer_mc();
			bulldozer.x=50*(bulldozer_pos[1])-25;
			bulldozer.y=50*(bulldozer_pos[0])-25;
			addChild(bulldozer);
		}
		// function to be executed every time a key is down
		public function on_key_down(e:KeyboardEvent):void {
			// storing key_pressed variable the keyCode of the latest key pressed
			key_pressed=e.keyCode;
		}
		// function to be executed every time a key is released
		public function on_key_up(e:KeyboardEvent):void {
			// if we are releasing the same key we pressed last time, then reset key_pressed variable
			// this way we allow to press only one key at time
			if (e.keyCode==key_pressed) {
				key_pressed=0;
			}
		}
		// function to be executed at every frame
		public function on_enter_frame(e:Event):void {
			// I am checking for keyboard input only if the bulldozer is not already moving
			// and there is at least one debris to remove
			if (! bulldozer_is_moving&&debris_left>0) {
				switch (key_pressed) {
						// right
					case 37 :
						walk(-1,0);
						break;
					case 38 :
						// up
						walk(0,-1);
						break;
					case 39 :
						//left
						walk(1,0);
						break;
					case 40 :
						//down
						walk(0,1);
						break;
					case 72 :
						// "H", calling the helicopter
						// resetting key_pressed
						key_pressed=0;
						// if the helicopter in not on stage...
						if (heli==null) {
							// place the helicopter on the first debris and don't remove the debris
							heli=new heli_mc();
							addChild(heli);
							place_heli(heli_on_debris,false);
						} else {
							// if the helicopter is already on stage, remove it and set the debris
							// to be picked up as the first one
							removeChild(heli);
							heli=null;
							heli_on_debris=1;
						}
						break;
					case 32 :
						// SPACEBAR, to remove selected debris
						// if the helicopter is on stage...
						if (heli!=null) {
							// remove the debris under the helicopter
							place_heli(heli_on_debris,true);
							// remove the helicopter itself
							removeChild(heli);
							heli=null;
							// set the debris to be picked up as the first one
							heli_on_debris=1;
						}
						break;
				}
			}
			// if the bulldozer is moving...
			if (bulldozer_is_moving) {
				// move the bulldozer one more step. One step = 10 pixels = 1/5 a tile
				bulldozer.x+=10*bulldozer_x_dir;
				bulldozer.y+=10*bulldozer_y_dir;
				// if there is a debris to move...
				if (debris_to_move!="") {
					// move the debris one more step
					with (getChildByName(debris_to_move)) {
						x+=10*bulldozer_x_dir;
						y+=10*bulldozer_y_dir;
					}
				}
				// if the bulldozer is completely on a tile...
				if ((bulldozer.x+bulldozer.y)%50==0) {
					// stop moving the bulldozer
					bulldozer_is_moving=false;
					// update bulldozer position
					bulldozer_pos[0]+=bulldozer_y_dir;
					bulldozer_pos[1]+=bulldozer_x_dir;
					// if there is a debris to move...
					if (debris_to_move!="") {
						// set the tile occupied by the debris BEFORE it moved to "0" (walkable)
						map[bulldozer_pos[0]][bulldozer_pos[1]]=0;
						// if the debris is on the map tile marked as "10" (hole in external wall)...
						if (map[bulldozer_pos[0]+bulldozer_y_dir][bulldozer_pos[1]+bulldozer_x_dir]==10) {
							// remove the debris
							removeChild(getChildByName(debris_to_move));
							// decrease number of remaining debris
							debris_left--;
						} else {
							// if it's not on a "10" map, then simply update debris name and the map
							getChildByName(debris_to_move).name="debris_"+(bulldozer_pos[0]+1*bulldozer_y_dir)+"_"+(bulldozer_pos[1]+1*bulldozer_x_dir);
							map[bulldozer_pos[0]+bulldozer_y_dir][bulldozer_pos[1]+bulldozer_x_dir]=2;
						}
						// set the debris_to_move variable as "no debris to move"
						debris_to_move="";
					}
				}
			}
		}
		// Function to move the bulldozer or the helicopter. px and py are the amount of tiles we want to move the bulldozer
		// Possible values passed:
		// 1,0: right
		// -1,0: left
		// 0,1: down
		// 0,-1: up
		public function walk(px:int,py:int):void {
			// if the helicopter is not on stage...
			if (heli==null) {
				// setting a "moved" flag as "false". It says the bulldozer did not move
				var moved:Boolean=false;
				// if the tile that the bulldozer should walk on is walkable...
				if (map[bulldozer_pos[0]+py][bulldozer_pos[1]+px]==0) {
					// the bulldozer moved
					moved=true;
				} else {
					// else, if the tile that the bulldozer should walk on is occupied by a debris and
					// the next one is a walkable tile or an hole in external wall...
					if (map[bulldozer_pos[0]+py][bulldozer_pos[1]+px]==2&&(map[bulldozer_pos[0]+2*py][bulldozer_pos[1]+2*px]==0||map[bulldozer_pos[0]+2*py][bulldozer_pos[1]+2*px]==10)) {
						// set which debris has to move
						debris_to_move=getChildByName("debris_"+(bulldozer_pos[0]+py)+"_"+(bulldozer_pos[1]+px)).name;
						// the bulldozer moved
						moved=true;
					}
				}
				// if the bulldozer moved...
				if (moved) {
					// setting variables to let it move and the direction it has to move
					bulldozer_is_moving=true;
					bulldozer_x_dir=px;
					bulldozer_y_dir=py;
				}
			} else {
				// if the helicopter is on stage...
				// reset key_pressed variable
				key_pressed=0;
				// increase heli_on_debris value by 1 if the direction is "down" or "right"
				// decrease it by 1 if the direction is "left" or "up"
				heli_on_debris+=px+py;
				// checking if we completely cycled through debris
				if (heli_on_debris<1) {
					heli_on_debris=debris_left;
				}
				if (heli_on_debris>debris_left) {
					heli_on_debris=1;
				}
				// place the helicopter on the selected debris and don't remove it
				place_heli(heli_on_debris,false);
			}
		}
		// function to place the helicopter on a debris and eventually remove it
		// n: n-th debris, starting from the upper left corner
		// del: if true, remove the debris
		public function place_heli(n:int,del:Boolean):void {
			// debris already found on the map
			var debris_found=0;
			// scanning the map...
			for (var i:int=1; i<10; i++) {
				for (var j:int=1; j<10; j++) {
					// if I found a debris...
					if (map[i][j]==2) {
						// increasing the number of debris I found
						debris_found++;
						// if I am on the right debris...
						if (debris_found==n) {
							// place the helicopter on the debris
							heli.x=j*50-25;
							heli.y=i*50-25;
							// if I have to remove the debris...
							if (del) {
								// update the map
								map[i][j]=0;
								// remove the debris
								removeChild(getChildByName("debris_"+i+"_"+j));
								// update remaining debris
								debris_left--;
							}
							// exit the cycle
							j=10;
							i=10;
						}
					}
				}
			}
		}
	}
}