/* Describe al escritor */
function Writer() {

	// La sección del documento sobre la cual el escritor esta focalizado
	this.documentSection = null;
	
	// Determina si el escritor va a escribir o no en mayusculas
	this.capitalStatus = false;
	
	// Ordena al escritor a focalizarse en una sección particular del documento 
	this.inDocumentSection = function(element) {
		this.documentSection = new DocumentSection(element);
	}
	
	// Ordena al escritor a escribir un numero en la sección del documento en la que este trabajando
	this.writeNumber = function(number) {
		this.write(function(documentSection, capitalStatus) {number.writeOn(documentSection);});
	}
	
	// Ordena al escritor a escribir una letra en la sección del documento en la que este trabajando
	this.writeLetter = function(letter) {
		this.write(function(documentSection, capitalStatus) {letter.writeOn(documentSection, capitalStatus);});
	}
	
	// Ordena al escritor a escribir en mayusculas
	this.inCapitalLetter = function() {
		this.capitalStatus = !this.capitalStatus;
	}
	
	// Ordena al escritor a que borre la ultima letra que escribio
	this.erase = function() {
		this.documentSection.deleteBackward();
	}
	
	// Realiza la escritura en la sección del documento
	this.write = function(callback) {
		if (this.documentSection != null) {
			try {
				callback(this.documentSection, this.capitalStatus);
			} catch (e) {
				alert(e.message);
			}
		} else {
			alert("Seleccione primero un elemento que permita texto donde pueda escribir.");
		}
	}
	
}

/* Describe una sección particular de un documento */
function DocumentSection(element) {

	// Representa la sección concreta del documento
	this.element = element;
	
	// Concatena un caracter a la sección
	this.append = function(character) {
		if (this.isWriteable()) {
			this.element.value += character;
		} else {
			throw "No es posible escribir sobre un elemento del tipo: " + this.element.type + 
				". Por favor seleccione un elemento donde escribir que permita el ingreso de texto.";
		}
	}
	
	// Borra de la sección la ultima letra escrita
	this.deleteBackward = function() {
		var value = this.element.value;
		this.element.value = value.slice(0, value.length - 1);
	}
	
	// Deduce si la sección admite ser escrita
	this.isWriteable = function() {
		var writeable = false;
		writeable |= this.element.type == 'text';
		writeable |= this.element.type == 'textarea';
		writeable |= this.element.type == 'password';
		return writeable;
	}

}

/** Describe un numero */
function Number(character) {
	
	// El caracter que representa en valor del numero
	this.character = character;
	
	// El numero se escribe sobre una sección de un documento 
	this.writeOn = function(documentSection) {
		documentSection.append(this.character);
	}

}

/** Describe una letra */
function Letter(character) {

	// El caracter que representa en valor de la letra en miniscula
	this.character = character;
	
	// El caracter que representa en valor de la letra pero en mayuscula
	this.capitalCharacter = String.fromCharCode(character.charCodeAt(0) - 32);
	
	// Escribe la letra sobre una sección de un documento
	this.writeOn = function(documentSection, capital) {
		if (this.character == "espacio") {
			documentSection.append(' ');
		} else {
			if (capital) {
				documentSection.append(this.capitalCharacter);
			} else {
				documentSection.append(this.character);			
			}
		}
	}

}

/** Algoritmo de utilidad que mezcla las posiciones de un array */
function ArrayUtils() {}
	ArrayUtils.mixContents = function(array) {
		var result = new Array(array.length);
		for (var i = 0; i < array.length; i++) {
			var randomIndex = Math.floor(Math.random() * array.length);
			while (result[randomIndex] != null) {
				randomIndex = Math.floor(Math.random() * array.length);
			}
			result[randomIndex] = array[i];
		}
		return result;	
}

function Builder() {
	
	var writer = new Writer();
	
	var factory = new DOMFactory();
	
	this.closeKeyboardCallback = null;
	this.form = null;
	this.parent = null;
	this.doMix = false;
	this.letters = new Array("a", "b", "c", "d", "e", "f", "g", "h", "i", 
		"j", "k", "l", "m", "n", "ñ", "o", "p", "q", 
		"r", "s", "t", "u", "v", "w", "x", "y", "z");
	this.numbers = new Array("0", "1", "2", "3", "4", "5", "6", "7", "8", "9");

	var keys = new Array(this.letters.length + this.numbers.length);
	var keyIndex = 0;
	
	/* Writing Actions */
	var writeInDocumentSectionAction = 
		function() {writer.inDocumentSection(this);};
	var writeInCapitalLettersAction = 
		function() {writer.inCapitalLetter();};
	var deleteLastTypedCharacterAction = 
		function() {writer.erase();};
	var writeLetterAction = 
		function() {writer.writeLetter(new Letter(this.fixedValue))};
	var writeNumberAction = 
		function() {writer.writeNumber(new Number(this.fixedValue))};
	var hideKeyValueAction = 
		function() {this.value = "#";};
	var restoreKeyValueAction = 
		function() {this.value = this.fixedValue;};
	var hideKeyValuesAction = 
		function() {for (var index = 0; index < keys.length; index++) { keys[index].value = "#"; }};
	var restoreKeyValuesAction = 
		function() {for (var index = 0; index < keys.length; index++) {keys[index].value = keys[index].fixedValue;}};
	var NOPAction = function() {};
	
	this.closeKeyboardCallback = function(callback) {
		this.closeKeyboardCallback = callback;
		return this;
	}
	
	this.givenForm = function(form) {
		this.form = form;
		return this;
	}
	
	this.mixLettersAndNumbers = function() {
		this.doMix = true;
		return this;
	}
	
	this.drawOnParent = function(parent) {
		this.parent = parent;
		return this;
	}
	
	this.doBuild = function() {
		this.mixLettersAndNumbersIfNecessary();
		this.initializeOnFocusEventForFormElements();
		this.drawLettersAndNumbers();
		return this;
	}
	
	this.initializeOnFocusEventForFormElements = function() {
		var inputElements = this.form.getElementsByTagName("input");
		for (var i = 0; i < inputElements.length; i++) {
			inputElements[i].onfocus = writeInDocumentSectionAction;
		}
	}
	
	this.mixLettersAndNumbersIfNecessary = function() {
		if (this.doMix) {
			this.letters = ArrayUtils.mixContents(this.letters);
			this.numbers = ArrayUtils.mixContents(this.numbers);
		}
	}
	
	this.createKeyboardForNumbers = function(characters, breakIndex, onlickCallback) {
		var tbl = factory.createTable();
		var tblBody = factory.createTableBody();
		
		var row = factory.createTableRow();
		
		var cell = factory.createTableCell();
		var keyButton = factory.createLetterNumberKey(characters[0],
			onlickCallback, 
			hideKeyValueAction, 
			restoreKeyValueAction, 
			hideKeyValuesAction,
			restoreKeyValuesAction);
		keys[keyIndex++] = keyButton;
		cell.appendChild(keyButton);
		row.appendChild(cell);
		
		var cell = factory.createTableCell();
		var keyButton = factory.createLetterNumberKey(characters[1],
			onlickCallback, 
			hideKeyValueAction, 
			restoreKeyValueAction, 
			hideKeyValuesAction,
			restoreKeyValuesAction);
		keys[keyIndex++] = keyButton;
		cell.appendChild(keyButton);
		row.appendChild(cell);
		
		var cell = factory.createTableCell();
		var keyButton = factory.createLetterNumberKey(characters[2],
			onlickCallback, 
			hideKeyValueAction, 
			restoreKeyValueAction, 
			hideKeyValuesAction,
			restoreKeyValuesAction);
		keys[keyIndex++] = keyButton;
		cell.appendChild(keyButton);
		row.appendChild(cell);
		
		tblBody.appendChild(row);
		
		var row = factory.createTableRow();
		
		var cell = factory.createTableCell();
		var keyButton = factory.createLetterNumberKey(characters[3],
			onlickCallback, 
			hideKeyValueAction, 
			restoreKeyValueAction, 
			hideKeyValuesAction,
			restoreKeyValuesAction);
		keys[keyIndex++] = keyButton;
		cell.appendChild(keyButton);
		row.appendChild(cell);
		
		var cell = factory.createTableCell();
		var keyButton = factory.createLetterNumberKey(characters[4],
			onlickCallback, 
			hideKeyValueAction, 
			restoreKeyValueAction, 
			hideKeyValuesAction,
			restoreKeyValuesAction);
		keys[keyIndex++] = keyButton;
		cell.appendChild(keyButton);
		row.appendChild(cell);
		
		var cell = factory.createTableCell();
		var keyButton = factory.createLetterNumberKey(characters[5],
			onlickCallback, 
			hideKeyValueAction, 
			restoreKeyValueAction, 
			hideKeyValuesAction,
			restoreKeyValuesAction);
		keys[keyIndex++] = keyButton;
		cell.appendChild(keyButton);
		row.appendChild(cell);
		
		tblBody.appendChild(row);
		
		var row = factory.createTableRow();
		
		var cell = factory.createTableCell();
		var keyButton = factory.createLetterNumberKey(characters[6],
			onlickCallback, 
			hideKeyValueAction, 
			restoreKeyValueAction, 
			hideKeyValuesAction,
			restoreKeyValuesAction);
		keys[keyIndex++] = keyButton;
		cell.appendChild(keyButton);
		row.appendChild(cell);
		
		var cell = factory.createTableCell();
		var keyButton = factory.createLetterNumberKey(characters[7],
			onlickCallback, 
			hideKeyValueAction, 
			restoreKeyValueAction, 
			hideKeyValuesAction,
			restoreKeyValuesAction);
		keys[keyIndex++] = keyButton;
		cell.appendChild(keyButton);
		row.appendChild(cell);
		
		var cell = factory.createTableCell();
		var keyButton = factory.createLetterNumberKey(characters[8],
			onlickCallback, 
			hideKeyValueAction, 
			restoreKeyValueAction, 
			hideKeyValuesAction,
			restoreKeyValuesAction);
		keys[keyIndex++] = keyButton;
		cell.appendChild(keyButton);
		row.appendChild(cell);
		
		tblBody.appendChild(row);
		
		var row = factory.createTableRow();
		
		row.appendChild(factory.createTableCell());
		var cell = factory.createTableCell();
		var keyButton = factory.createLetterNumberKey(characters[9],
			onlickCallback, 
			hideKeyValueAction, 
			restoreKeyValueAction, 
			hideKeyValuesAction,
			restoreKeyValuesAction);
		keys[keyIndex++] = keyButton;
		cell.appendChild(keyButton);
		row.appendChild(cell);
		row.appendChild(factory.createTableCell());
		
		tblBody.appendChild(row);
		
		tbl.appendChild(tblBody);
		return tbl;
	}
	
	this.createKeyboardForLetters = function(characters, breakIndex, onlickCallback) {
		
		var tbl = factory.createTable();
		var tblBody = factory.createTableBody();
		
		var row = factory.createTableRow();
		for (var index = 0; index < characters.length; index++) {
			
			var cell = factory.createTableCell();
			var keyButton = factory.createLetterNumberKey(characters[index],
				onlickCallback, 
				hideKeyValueAction, 
				restoreKeyValueAction, 
				hideKeyValuesAction,
				restoreKeyValuesAction);
			
			keys[keyIndex++] = keyButton;
			
			cell.appendChild(keyButton);
			row.appendChild(cell);
			
			if (((index + 1) % breakIndex) == 0) {
				tblBody.appendChild(row);
								
				if (index + 1 < characters.length) {
					row = factory.createTableRow();
				}
			}
		}
		
		tblBody.appendChild(row);
		tbl.appendChild(tblBody);
		return tbl;
	}

	this.createControlBoard = function() {
		var tbl = factory.createTable();
		var tblBody = factory.createTableBody();
				
		row = factory.createTableRow();
		cell = factory.createTableCell();
		var capslockButton = factory.createLetterNumberKey(
				/*String.fromCharCode(8593)*/"MAY",
				writeInCapitalLettersAction, 
				NOPAction, 
				NOPAction, 
				NOPAction,
				NOPAction);
		capslockButton.style.width = "62px";
		capslockButton.style.height = "23px";
		cell.appendChild(capslockButton);		
		row.appendChild(cell);
		
		cell = factory.createTableCell();
		var capslockButton = factory.createLetterNumberKey(
				"espacio",
				writeLetterAction, 
				NOPAction, 
				NOPAction, 
				NOPAction,
				NOPAction);
		capslockButton.style.width = "95px";
		capslockButton.style.height = "23px";
		cell.appendChild(capslockButton);		
		row.appendChild(cell);
				
		var cell = factory.createTableCell();
		var backspaceButton = factory.createLetterNumberKey(
				/*String.fromCharCode(8592)*/"borrar",
				deleteLastTypedCharacterAction, 
				NOPAction, 
				NOPAction, 
				NOPAction,
				NOPAction);		
		
		backspaceButton.style.width = "62px";
		backspaceButton.style.height = "23px";
		cell.appendChild(backspaceButton);
		row.appendChild(cell);
		tblBody.appendChild(row);
		
		tbl.appendChild(tblBody);
		return tbl;
	}
	
	this.drawEntireKeyboard = function() {
		var tbl = factory.createTable();
		var tblBody = factory.createTableBody();
		var row = factory.createTableRow();
	
		var cell = factory.createTableCell();
		cell.appendChild(this.createKeyboardForLettersWithControls());
		row.appendChild(cell);
		
		cell = factory.createTableCell();
		cell.appendChild(this.createKeyboardForNumbers(this.numbers, 3, writeNumberAction));
		row.appendChild(cell);
	
		tblBody.appendChild(row);
        tbl.appendChild(tblBody);
        return tbl;
	}
	
	this.drawWindowHeaderElements = function() {
		var tbl = factory.createTable();
		tbl.style.emptyCells = "show";
		var tblBody = factory.createTableBody();
		var row = factory.createTableRow();
		
		var cell = factory.createTableCell();
		cell.style.width = "280px";
		row.appendChild(cell);
		
		var cell = factory.createTableCell();
		var inputButton = document.createElement("input");
		inputButton.id = 'X';
		inputButton.type = 'button';
		inputButton.value = 'X';
		inputButton.onclick = this.closeKeyboardCallback;
		
		inputButton.style.backgroundColor = "white";
		inputButton.style.fontSize = "15";
		inputButton.style.fontWeight = "bolder";
		inputButton.style.color = "Black";
		inputButton.style.width = "23px";
		inputButton.style.height = "23px";
		inputButton.style.margin= "auto";
		inputButton.style.marginRight= "auto";
		inputButton.style.marginLeft= "auto";
		inputButton.style.marginBottom= "auto";
		inputButton.style.marginTop= "auto";
		inputButton.style.textTransform = "uppercase";
		inputButton.style.fontFamily="tahoma";
		
		cell.appendChild(inputButton);
		row.appendChild(cell);
	
		tblBody.appendChild(row);
        tbl.appendChild(tblBody);
        return tbl;
	}
	
	this.drawLettersAndNumbers = function() {
		var tbl = factory.createTable();
		tbl.id = "keyboardTable";
		var tblBody = factory.createTableBody();
		
		var row = factory.createTableRow();
		var cell = factory.createTableCell();
		cell.appendChild(this.drawWindowHeaderElements());
		row.appendChild(cell);
		tblBody.appendChild(row);
		
		row = factory.createTableRow();
		cell = factory.createTableCell();
		cell.appendChild(this.drawEntireKeyboard());
		row.appendChild(cell);
		
		tblBody.appendChild(row);
        tbl.appendChild(tblBody);
        this.parent.appendChild(tbl);
	}
	
	this.createKeyboardForLettersWithControls = function() {
		var tbl = factory.createTable();
		var tblBody = factory.createTableBody();
		
		var row = factory.createTableRow();	
		cell = factory.createTableCell();
		cell.appendChild(this.createKeyboardForLetters(this.letters, 9, writeLetterAction));
		row.appendChild(cell);
		tblBody.appendChild(row);
		
		var row = factory.createTableRow();	
		var cell = factory.createTableCell();
		cell.appendChild(this.createControlBoard());
		row.appendChild(cell);		
		tblBody.appendChild(row);
		
        tbl.appendChild(tblBody);
		return tbl;
	}
	
}

function DOMFactory() {

	this.createTable = function() {
		var table = document.createElement("table");
		table.style.borderSpacing = "0px";
		table.style.borderCollapse = "collapse";
		table.style.backgroundColor="#F0F0F0";
		return table;
	}
	
	this.createTableBody = function() {
		return document.createElement("tbody");
	}
	
	this.createTableRow = function() {
		return document.createElement("tr");
	}
	
	this.createTableCell = function() {
		return document.createElement("td");
	}	
	
	this.createLetterNumberKey = function(value, onclickCallback, onmouseoverCallback, onmouseoutCallback,
			onmousedownCallback, onmouseupCallback) {
		var cellButton = document.createElement("input");
		cellButton.id = value + 'Id';
		cellButton.type = 'button';
		cellButton.value = value;
		cellButton.fixedValue = value;
		cellButton.onclick = onclickCallback;
		cellButton.onmouseover = onmouseoverCallback;
		cellButton.onmouseout = onmouseoutCallback;
		cellButton.onmousedown = onmousedownCallback;
		cellButton.onmouseup = onmouseupCallback;

		cellButton.style.backgroundColor = "#E8E8E8";
		cellButton.style.fontSize = "10";
		cellButton.style.fontWeight = "bolder";
		cellButton.style.color = "Black";
		cellButton.style.width = "23px";
		cellButton.style.height = "23px";
		cellButton.style.margin= "auto";
		cellButton.style.marginRight= "auto";
		cellButton.style.marginLeft= "auto";
		cellButton.style.marginBottom= "auto";
		cellButton.style.marginTop= "auto";
		cellButton.style.textTransform = "uppercase";
		cellButton.style.fontFamily="tahoma";
		
		//cellButton.style.borderTop = "thin solid Gray";
		//cellButton.style.borderRight = "thin solid Gray";
		cellButton.style.borderLeft = "thin solid Gray";
		cellButton.style.borderBottom = "medium solid Gray";

		return cellButton;
	}

}