/* SavePropertyBindingImpl.java

	Purpose:
		
	Description:
		
	History:
		Aug 1, 2011 2:45:43 PM, Created by henrichen

Copyright (C) 2011 Potix Corporation. All Rights Reserved.
*/

package org.zkoss.bind.impl;

import java.io.Serializable;
import java.lang.reflect.Method;
import java.util.Map;

import org.zkoss.bind.BindContext;
import org.zkoss.bind.Binder;
import org.zkoss.bind.Converter;
import org.zkoss.bind.Property;
import org.zkoss.bind.ValidationContext;
import org.zkoss.bind.Validator;
import org.zkoss.bind.proxy.FormProxyObject;
import org.zkoss.bind.sys.BindEvaluatorX;
import org.zkoss.bind.sys.BinderCtrl;
import org.zkoss.bind.sys.ConditionType;
import org.zkoss.bind.sys.SavePropertyBinding;
import org.zkoss.bind.sys.debugger.BindingExecutionInfoCollector;
import org.zkoss.bind.sys.debugger.impl.info.SaveInfo;
import org.zkoss.bind.sys.debugger.impl.info.ValidationInfo;
import org.zkoss.xel.ExpressionX;
import org.zkoss.xel.ValueReference;
import org.zkoss.zel.PropertyNotFoundException;
import org.zkoss.zk.ui.Component;
import org.zkoss.zk.ui.UiException;
import org.zkoss.zk.ui.WrongValueException;
import org.zkoss.zk.ui.WrongValuesException;

/**
 * Implementation of {@link SavePropertyBinding}.
 * @author henrichen
 * @since 6.0.0
 */
public class SavePropertyBindingImpl extends PropertyBindingImpl implements SavePropertyBinding {
	private static final long serialVersionUID = 1463169907348730644L;
	private final ExpressionX _validator;
	private final Map<String, Object> _validatorArgs;
	private FormFieldInfo _formFieldInfo;

	public SavePropertyBindingImpl(Binder binder, Component comp, String attr, String saveAttr, String saveExpr,
			ConditionType conditionType, String command, Map<String, Object> bindingArgs, String converterExpr,
			Map<String, Object> converterArgs, String validatorExpr, Map<String, Object> validatorArgs) {

		super(binder, comp, attr, "self." + saveAttr, saveExpr, conditionType, command, bindingArgs, converterExpr,
				converterArgs);
		final BindEvaluatorX eval = binder.getEvaluatorX();
		_validator = validatorExpr == null ? null : parseValidator(eval, validatorExpr);
		_validatorArgs = validatorArgs;

		//ZK-3185: Enable form validation with reference and collection binding
		final BindContext ctx = BindContextUtil.newBindContext(getBinder(), this, true, null, getComponent(), null);
		ctx.setAttribute(BinderImpl.IGNORE_REF_VALUE, Boolean.FALSE);
		ctx.setAttribute(BinderImpl.IGNORE_TRACKER, Boolean.TRUE);
		ValueReference valref = null;
		try {
			valref = eval.getValueReference(ctx, getComponent(), _accessInfo.getProperty());
		} catch (PropertyNotFoundException e) {
			//ignore null
		}
		if (valref != null) {
			Object base = valref.getBase();
			if (base instanceof FormProxyObject)
				((FormProxyObject) base).cacheSavePropertyBinding((String) valref.getProperty(), this);
		}
	}

	public Map<String, Object> getValidatorArgs() {
		return _validatorArgs;
	}

	protected boolean ignoreTracker() {
		return true;
	}

	private ExpressionX parseValidator(BindEvaluatorX eval, String validatorExpr) {

		//		final BindContext ctx = BindContextUtil.newBindContext(getBinder(), this, false, null, getComponent(), null);
		//		ctx.setAttribute(BinderImpl.IGNORE_TRACKER, Boolean.TRUE);//ignore tracker when doing el, we don't need to trace validator
		//expression will/should not be tracked, (although, from the impl, tracker don't care savebinding)
		return eval.parseExpressionX(/*ctx*/null, validatorExpr, Object.class);
	}

	public Validator getValidator() {
		if (_validator == null)
			return null;

		//		final BindContext ctx = BindContextUtil.newBindContext(getBinder(), this, false, null, getComponent(), null);
		//		ctx.setAttribute(BinderImpl.IGNORE_TRACKER, Boolean.TRUE);//ignore tracker when doing el, we don't need to trace validator
		final BindEvaluatorX eval = getBinder().getEvaluatorX();

		Object obj = eval.getValue(null, getComponent(), _validator);

		if (obj instanceof Validator) {
			return (Validator) obj;
		} else if (obj instanceof String) {
			return getBinder().getValidator((String) obj); //binder will throw exception if not found
		} else {
			throw new ClassCastException(
					"result of expression '" + _validator.getExpressionString() + "' is not a Validator, is " + obj);
		}
	}

	private static final String COMPVALUE = "$COMPVALUE$";
	private static final String COMPVALUENOCONVERT = "$COMPVALUENOCONVERT$";
	private static final String VALUEREF = "$VALUEREF$";

	private Object getComponentValue(BindContext ctx) {
		if (!containsAttribute(ctx, COMPVALUE)) {
			final Component comp = getComponent(); //ctx.getComponent();
			final BindEvaluatorX eval = getBinder().getEvaluatorX();

			//get data from component attribute
			Object value = eval.getValue(null, comp, _fieldExpr);
			setAttribute(ctx, COMPVALUENOCONVERT, value);
			//use converter to convert type if any
			@SuppressWarnings("unchecked")
			final Converter<Object, Object, Component> conv = getConverter();
			if (conv != null) {
				value = conv.coerceToBean(value, comp, ctx);
				//				ValueReference ref = getValueReference(ctx);
				//					//collect Property for @NotifyChange, kept in BindContext
				//					//see BinderImpl$CommandEventListener#onEvent()
				//				BindELContext.addNotifys(getConverterMethod(conv.getClass()), ref.getBase(), null, value, ctx);
			}
			setAttribute(ctx, COMPVALUE, value);
		}
		return getAttribute(ctx, COMPVALUE);
	}

	public String getValidatorExpressionString() {
		return _validator == null ? null : BindEvaluatorXUtil.getExpressionString(_validator);
	}

	public void save(BindContext ctx) {
		final BindingExecutionInfoCollector collector = ((BinderCtrl) getBinder()).getBindingExecutionInfoCollector();
		final Component comp = getComponent();
		//get data from component attribute
		Object value = getComponentValue(ctx);

		if (value == Converter.IGNORED_VALUE) {
			if (collector != null) {
				Object old = getAttribute(ctx, COMPVALUENOCONVERT);
				collector.addInfo(new SaveInfo(SaveInfo.PROP_SAVE, comp, getConditionString(ctx), getFieldName(),
						getPropertyString(), old, getArgs(), "*Converter.IGNORED_VALUE"));
			}
			return;
		}

		if (collector != null) {
			collector.addInfo(new SaveInfo(SaveInfo.PROP_SAVE, comp, getConditionString(ctx), getFieldName(),
					getPropertyString(), value, getArgs(), null));
		}

		//set data into bean property
		final BindEvaluatorX eval = getBinder().getEvaluatorX();
		eval.setValue(ctx, comp, _accessInfo.getProperty(), value);
	}

	private String getConditionString(BindContext ctx) {
		StringBuilder condition = new StringBuilder();
		if (getConditionType() == ConditionType.BEFORE_COMMAND) {
			condition.append("before = '").append(getCommandName()).append("'");
		} else if (getConditionType() == ConditionType.AFTER_COMMAND) {
			condition.append("after = '").append(getCommandName()).append("'");
		} else {
			condition.append(ctx.getTriggerEvent() == null ? "" : "event = " + ctx.getTriggerEvent().getName());
		}
		return condition.toString();
	}

	//get and cache value reference of this binding
	private ValueReference getValueReference(BindContext ctx) {
		ValueReference valref = (ValueReference) getAttribute(ctx, VALUEREF);
		if (valref == null) {
			//ZK-1017: Property of a form is not correct when validation
			if (_formFieldInfo != null && _formFieldInfo._fieldName.indexOf("[$INDEX$]") == -1) { // skip collection field name
				final Object form = getComponent().getAttribute(_formFieldInfo._id, true);
				final String fieldName = _formFieldInfo._fieldName;
				valref = new org.zkoss.xel.zel.ELXelExpression.ValueReferenceImpl(form, fieldName);
			} else {
				final Component comp = getComponent(); //ctx.getComponent();
				final BindEvaluatorX eval = getBinder().getEvaluatorX();
				valref = eval.getValueReference(ctx, comp, _accessInfo.getProperty());
				if (valref == null) {
					throw new UiException("value reference not found by expression ["
							+ _accessInfo.getProperty().getExpressionString()
							+ "], check if you are trying to save to a variable only expression");
				}
			}
			setAttribute(ctx, VALUEREF, valref);
		}
		return valref;
	}

	//ZK-1017: Property of a form is not correct when validation
	//@see BinderImpl#addFormAssociatedSaveBinding
	/*package*/ void setFormFieldInfo(Component formComp, String formId, String fieldName) {
		if (_formFieldInfo == null) {
			_formFieldInfo = new FormFieldInfo();
		}
		_formFieldInfo._component = formComp;
		_formFieldInfo._id = formId;
		_formFieldInfo._fieldName = fieldName;
	}

	//--SaveBinding--//
	public Property getValidate(BindContext ctx) {
		//we should not check this binding need to validate or not, 
		//maybe other validator want to know the value of this binding, so just provide it
		final ValueReference ref = getValueReference(ctx);
		try {
			final Object value = getComponentValue(ctx);
			return new PropertyImpl(ref.getBase(), String.valueOf(ref.getProperty()),
					value == Converter.IGNORED_VALUE ? null : value);
		} catch (Exception e) {
			// ZK-878 Exception if binding a form with errorMessage
			// a wrong value exception might be thrown when a component has constraint
			Throwable t = e;
			while (t != null) {
				if (t instanceof WrongValueException || t instanceof WrongValuesException) {
					return new WrongValuePropertyImpl(ref.getBase(), (String) ref.getProperty(), t);
				} else {
					t = t.getCause();
				}
			}
			throw UiException.Aide.wrap(e);
		}
	}

	public boolean hasValidator() {
		return _validator == null ? false : true;
	}

	public void validate(ValidationContext vctx) {
		Validator validator = getValidator();
		if (validator == null) {
			throw new NullPointerException("cannot find validator for " + this);
		}
		//ZK-1005 ZK 6.0.1 validation fails on nested bean
		if (_formFieldInfo != null) {
			vctx.getBindContext().setAttribute(BinderImpl.LOAD_FORM_COMPONENT, _formFieldInfo._component);
		}

		validator.validate(vctx);

		BindingExecutionInfoCollector collector = ((BinderCtrl) getBinder()).getBindingExecutionInfoCollector();
		if (collector != null) {
			collector.addInfo(new ValidationInfo(ValidationInfo.PROP, getComponent(), getValidatorExpressionString(),
					validator.toString(), Boolean.valueOf(vctx.isValid()),
					((BindContextImpl) vctx.getBindContext()).getValidatorArgs(), null));
		}

		//		//collect notify change
		//		collectNotifyChange(validator,vctx);
	}

	//	private void collectNotifyChange(Validator validator, ValidationContext vctx) {
	//		ValueReference ref = getValueReference(vctx.getBindContext());
	//		BindELContext.addNotifys(getValidatorMethod(validator.getClass()), ref.getBase(), null, null, vctx.getBindContext());
	//	}

	private Method getConverterMethod(Class<? extends Converter> cls) {
		try {
			return cls.getMethod("coerceToBean", new Class[] { Object.class, Component.class, BindContext.class });
		} catch (NoSuchMethodException e) {
			//ignore
		}
		return null; //shall never come here
	}

	private Method getValidatorMethod(Class<? extends Validator> cls) {
		try {
			return cls.getMethod("validate", new Class[] { ValidationContext.class });
		} catch (NoSuchMethodException e) {
			//ignore
		}
		return null; //shall never come here
	}

	//ZK-1005 ZK 6.0.1 validation fails on nested bean
	private static class FormFieldInfo implements Serializable {
		private static final long serialVersionUID = 1L;

		private Component _component;
		private String _fieldName;
		private String _id;
	}

	/**
	 * Internal use only, only for collections
	 */
	public Property getBasePropertyIfFromCollection() {
		Property p = null;
		int index = -1;
		String fieldName = "";
		if (_formFieldInfo != null && (fieldName = _formFieldInfo._fieldName) != null && (index = fieldName.indexOf("[$INDEX$]")) != -1) {
			final BindContext ctx = BindContextUtil.newBindContext(getBinder(), this, false, null, getComponent(), null);
			final ValueReference valref = getValueReference(ctx);
			if (valref != null) {
				Object base = valref.getBase();
				if (base instanceof FormProxyObject)
					base = ((FormProxyObject) base).getOriginObject();
				if (base != null) {
					final BindEvaluatorX eval = getBinder().getEvaluatorX();
					Object value = eval.getValue(ctx, getComponent(), _accessInfo.getProperty());
					String replacedFieldString = fieldName.substring(0, index) + ".$each";
					if (fieldName.length() > (index + 9))
						replacedFieldString += fieldName.substring(index + 9);
					p = new PropertyImpl(base, replacedFieldString, value);
				}
			}
		}
		return p;
	}

}
