package org.simantics.db.layer0.variable;

import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;

import org.simantics.databoard.Bindings;
import org.simantics.databoard.accessor.reference.ChildReference;
import org.simantics.databoard.binding.Binding;
import org.simantics.databoard.binding.impl.ObjectVariantBinding;
import org.simantics.databoard.type.Datatype;
import org.simantics.db.ReadGraph;
import org.simantics.db.Resource;
import org.simantics.db.WriteGraph;
import org.simantics.db.common.procedure.adapter.TransientCacheAsyncListener;
import org.simantics.db.common.validation.L0Validations;
import org.simantics.db.exception.DatabaseException;
import org.simantics.db.exception.ValidationException;
import org.simantics.db.layer0.exception.MissingVariableValueException;
import org.simantics.db.layer0.exception.PendingVariableException;
import org.simantics.db.layer0.exception.VariableException;
import org.simantics.db.layer0.function.All;
import org.simantics.db.layer0.request.PropertyInfo;
import org.simantics.db.layer0.request.PropertyInfoRequest;
import org.simantics.db.layer0.scl.SCLDatabaseException;
import org.simantics.db.layer0.util.Layer0Utils;
import org.simantics.layer0.Layer0;
import org.simantics.utils.Development;
import org.simantics.utils.datastructures.Pair;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class StandardGraphPropertyVariable extends AbstractPropertyVariable {
    private static final Logger LOGGER = LoggerFactory.getLogger(StandardGraphPropertyVariable.class);
    
	protected static final PropertyInfo NO_PROPERTY = new PropertyInfo(null, null,
			false, Collections.<String> emptySet(), null, null, null, null, null, null,
			Collections.<String, Pair<Resource, ChildReference>> emptyMap(),
			null, false);

	final public Variable parent;
	final public Resource parentResource;
	final public PropertyInfo property;
	final public Resource represents;
	
	transient private int hash = 0;

	public StandardGraphPropertyVariable(ReadGraph graph, Variable parent, VariableNode node, Resource property) throws DatabaseException {
		this(graph, parent, node, (Resource)parent.getPossibleRepresents(graph), getPropertyInfo(graph, property));
	}
	
	public StandardGraphPropertyVariable(ReadGraph graph, Variable parent, VariableNode node, Resource parentResource, Resource property) throws DatabaseException {
		this(graph, parent, node, parentResource, getPropertyInfo(graph, property));
	}

	public StandardGraphPropertyVariable(ReadGraph graph, Variable parent, Resource property) throws DatabaseException {
        this(graph, parent, null, (Resource)parent.getPossibleRepresents(graph), getPropertyInfo(graph, property));
    }

    public StandardGraphPropertyVariable(ReadGraph graph, Variable parent, Resource parentResource, PropertyInfo property) throws DatabaseException {
        this(parent, null, parentResource, property, getPossibleRepresents(graph, parentResource, property.predicate));
    }
    
    public StandardGraphPropertyVariable(ReadGraph graph, Variable parent, VariableNode node, Resource parentResource, PropertyInfo property) throws DatabaseException {
        this(parent, node, parentResource, property, getPossibleRepresents(graph, parentResource, property.predicate));
    }

    private static PropertyInfo getPropertyInfo(ReadGraph graph, Resource property) throws DatabaseException {
	    return property != null ? graph.syncRequest(new PropertyInfoRequest(property), TransientCacheAsyncListener.<PropertyInfo>instance()) : NO_PROPERTY;
    }
    
    private static Resource getPossibleRepresents(ReadGraph graph, Resource parentResource, Resource predicate) throws DatabaseException {
    	if(parentResource == null || predicate == null) return null;
    	return graph.getPossibleObject(parentResource, predicate);
    }
    
    public boolean isAsserted() {
    	return false;
    }

    public StandardGraphPropertyVariable(Variable parent, VariableNode node, Resource parentResource, PropertyInfo property, Resource represents) throws DatabaseException {
    	super(node);
		assert parent != null;
		this.parent = parent;
		this.property = property;
		this.parentResource = parentResource;
		this.represents = represents;
	}

	@Override
	public String getName(ReadGraph graph) throws DatabaseException {
	    if(node != null) return node.support.manager.getName(node.node);
		return property.name;
	}

	@Override
	public String getPossibleLabel(ReadGraph graph) throws DatabaseException {
		return graph.getPossibleRelatedValue2(property.predicate, graph.getService(Layer0.class).HasLabel, parent, Bindings.STRING);
	}

	@Override
	public String getLabel(ReadGraph graph) throws DatabaseException {
		return graph.getRelatedValue2(property.predicate, graph.getService(Layer0.class).HasLabel, parent, Bindings.STRING);
	}

	@Override
	public Variable getParent(ReadGraph graph) throws DatabaseException {
		return parent;
	}
	
	@Override
	public PropertyInfo getPropertyInfo(ReadGraph graph) throws DatabaseException {
		return property;
	}

	@SuppressWarnings("unchecked")
	@Override
	public <T> T getValue(ReadGraph graph) throws DatabaseException {
		
		if(Development.DEVELOPMENT) {
			String error = L0Validations.checkValueType(graph, parentResource, property.predicate);
			if(error != null) {
			    LOGGER.error(error);
				//throw new ValidationException(error);
			}
		}
		
		return (T)getValueAccessor(graph).getValue(graph, this);
		
	}

	@SuppressWarnings("unchecked")
	@Override
	public <T> T getValue(ReadGraph graph, Binding binding) throws DatabaseException {
		// Fall back to the bindingless method, if the expected output is a Java object 
		if (binding instanceof ObjectVariantBinding)
			return getValue(graph);		

		if(Development.DEVELOPMENT) {
			String error = L0Validations.checkValueType(graph, parentResource, property.predicate);
			if(error != null) {
			    LOGGER.error(error);
				throw new ValidationException(error);
			}
		}
        
		try {
			
			return (T) getValueAccessor(graph).getValue(graph, this, binding);
		} catch (SCLDatabaseException e) { // these can be thrown when compiling e.g. derived properties
			throw e;
		} catch (MissingVariableValueException | PendingVariableException e) {
			throw e;
		} catch (Throwable t) {
			throw new MissingVariableValueException(t);
		}
		
	}
	
	@Override
	public Resource getRepresents(ReadGraph graph) throws DatabaseException {
		if(represents == null)
			throw new VariableException("Variable is not represented by any resource (URI=" + getPossibleURI(graph) + ").");
		return represents;
//		return graph.getSingleObject(parentResource, property.predicate);
	}

	@Override
	public Resource getPossibleRepresents(ReadGraph graph) throws DatabaseException {
//        if(parentResource == null) return null;
//		return graph.getPossibleObject(parentResource, property.predicate);
		return represents;
	}

	@Override
	public void setValue(WriteGraph graph, Object value, Binding binding) throws DatabaseException {
		
		if(Development.DEVELOPMENT) {
			String error = L0Validations.checkValueType(graph, parentResource, property.predicate);
			if(error != null) {
			    LOGGER.error(error);
				//throw new ValidationException(error);
			}
		}
		
		getValueAccessor(graph).setValue(graph, this, value, binding);
		
	}
	
	@Override
	public void setValue(WriteGraph graph, Object value) throws DatabaseException {
		
		if(Development.DEVELOPMENT) {
			String error = L0Validations.checkValueType(graph, parentResource, property.predicate);
			if(error != null) {
			    LOGGER.error(error);
				throw new ValidationException(error);
			}
		}
		
		getValueAccessor(graph).setValue(graph, this, value);
		
	}

	@Override
	public Binding getDefaultBinding(ReadGraph graph) throws DatabaseException {
		return Layer0Utils.getDefaultBinding(graph, this);
	}
	
	@Override
	public Binding getPossibleDefaultBinding(ReadGraph graph) throws DatabaseException {
		return Layer0Utils.getPossibleDefaultBinding(graph, this);
	}

	@Override
	public Datatype getDatatype(ReadGraph graph) throws DatabaseException {
//<<<<<<< .mine
//		
//    	Binding binding = getPossibleDefaultBinding(graph);
//        if(binding != null) return binding.type();
//
//		Variant vt = getVariantValue(graph);
//		binding = vt.getBinding();
//		if(binding == null) throw new DatabaseException("No binding in Variant with value " + vt.getValue());
//		return binding.type();
//=======
		Datatype type;
		try {			
			type = getValueAccessor(graph).getDatatype(graph, this);
		} catch (Throwable t) {
			throw new MissingVariableValueException(t);
		}
		
		if (type == null) {
			String uri = this.getPossibleURI(graph);
			if (uri != null)
				throw new DatabaseException("No data type for " + uri);
			else
				throw new DatabaseException("No data type for " + this.getIdentifier());
		}
		
		return type;
//>>>>>>> .r30794
		
	}
	
	@Override
	public Datatype getPossibleDatatype(ReadGraph graph) throws DatabaseException {

		try {
			return getDatatype(graph);
		} catch (DatabaseException e) {
			return null;
		}
		
	}
	
	@Override
	public String getUnit(ReadGraph graph) throws DatabaseException {
		try {
			return Layer0Utils.getUnit(graph, this);
		} catch (DatabaseException e) {
			return null;
		}
	}

	@Override
	public Resource getPropertyResource(ReadGraph graph) {
		return property.predicate;
	}
	
	@Override
	public Resource getContainerResource(ReadGraph graph) throws DatabaseException {
		return parentResource;
	}

	@Override
	public Collection<Variable> getChildren(ReadGraph graph) throws DatabaseException {

		Map<String, Variable> result = new HashMap<String, Variable>();
		VariableMap map = getPossibleChildVariableMap(graph);
		if(map != null) map.getVariables(graph, this, result);
		return result.values();
		
	}
	
	@Override
	public Variable getPossibleChild(ReadGraph graph, String name) throws DatabaseException {

		VariableMap map = getPossibleChildVariableMap(graph);
		if(map == null) return null;
		try {
			return map.getVariable(graph, this, name);
		} catch (DatabaseException e) {
			return null;
		}
		
	}
	
	
	@Override
	protected Variable getPossibleDomainProperty(ReadGraph graph, String name) throws DatabaseException {

		VariableMap valueMap = getPossiblePropertyVariableMap(graph);
		if(valueMap == null) return null;
		try {
			return valueMap.getVariable(graph, this, name);
		} catch (DatabaseException e) {
			return null;
		} catch (Exception t) {
			LOGGER.error("getPossibleDomainProperty is implemented incorrectly, but returns null on Exception for backward compatibility. URI="+getURI(graph)+", name="+name+".", t);
			return null;
		}
		
	}
	
	@Override
	public Map<String, Variable> collectDomainProperties(ReadGraph graph, Map<String, Variable> properties) throws DatabaseException {

		VariableMap valueMap = getPossiblePropertyVariableMap(graph);
		if(valueMap == null) return properties;
		return valueMap.getVariables(graph, this, properties);
		
	}
	
	@Override
	public Variable getPredicate(ReadGraph graph) throws DatabaseException {
		return Variables.getVariable(graph, graph.getURI(property.predicate));
	}
	
	@Override
	public Resource getPredicateResource(ReadGraph graph) throws DatabaseException {
		return property.predicate;
	}
	
	@Override
	public Resource getPossiblePredicateResource(ReadGraph graph) throws DatabaseException {
		return property.predicate;
	}

	@Override
	public int hashCode() {
		if(hash == 0) {
			final int prime = 31;
			int result = 1;
            result = prime * result + (parent != null ? parent.hashCode() : 0);
            result = prime * result + (node != null ? node.hashCode() : 0);
            result = prime * result + (property.predicate != null ? property.predicate.hashCode() : 0);
            result = prime * result + (parentResource != null ? parentResource.hashCode() : 0);
            result = prime * result + (represents != null ? represents.hashCode() : 0);
			hash =result;
		}
		return hash;
	}

	@Override
	public boolean equals(Object obj) {
		if (this == obj)
			return true;
		if (obj == null)
			return false;
		if (getClass() != obj.getClass())
			return false;
		StandardGraphPropertyVariable other = (StandardGraphPropertyVariable) obj;
		
        if(node != null) {
        	if(!node.equals(other.node)) return false;
        } else if (other.node != null) return false;

        if(property.predicate != null) {
        	if(!property.predicate.equals(other.property.predicate)) return false;
        } else if (other.property.predicate != null) return false;
        
        if(parentResource != null) {
        	if(!parentResource.equals(other.parentResource)) return false;
        } else if (other.parentResource != null) return false;

        if(parent != null) {
        	if(!parent.equals(other.parent)) return false;
        } else if (other.parent != null) return false;

        if(represents != null) {
        	if(!represents.equals(other.represents)) return false;
        } else if (other.represents != null) return false;

        return true;
		
	}

	@Override
	protected Variable getNameVariable(ReadGraph graph) throws DatabaseException {
	    throw new UnsupportedOperationException();
	}
	
	protected ValueAccessor getValueAccessor(ReadGraph graph) throws DatabaseException {
		if((property == null || property == NO_PROPERTY) && parentResource == null) return All.standardValueAccessor;
	    ValueAccessor accessor = property.valueAccessor;
	    if(accessor != null) return accessor;
	    else {
	    	System.err.println("No value accessor for " + getURI(graph));
	    	return All.standardValueAccessor;
	    }
	}

	protected VariableMap getPossibleChildVariableMap(ReadGraph graph) throws DatabaseException {
		if(represents == null) return All.standardPropertyDomainChildren;
	    Resource domainChildren = Layer0.getInstance(graph).domainChildren;
		return graph.getPossibleRelatedValue2(represents, domainChildren, 
				new StandardGraphPropertyVariable(graph, this, domainChildren));
	}

	protected VariableMap getPossiblePropertyVariableMap(ReadGraph graph) throws DatabaseException {
        if(property == null) return All.standardPropertyDomainProperties;
        if(property.predicate == null) return null;
		return graph.syncRequest(new PropertyVariableMapRequest(property.predicate), TransientCacheAsyncListener.<VariableMap>instance());
	}
	
	public Set<String> getClassifications(ReadGraph graph) throws DatabaseException {
		return property.classifications;
	}
	
	@Override
    public Map<String, Variable> collectDomainProperties(ReadGraph graph, String classification, Map<String, Variable> properties) throws DatabaseException {
    	
    	VariableMap valueMap = getPossiblePropertyVariableMap(graph);
		if(valueMap == null) return properties;
		return valueMap.getVariables(graph, this, classification, properties);
		
    }
	
    public Collection<Variable> getProperties(ReadGraph graph, String classification) throws DatabaseException {
    	
    	VariableMap valueMap = getPossiblePropertyVariableMap(graph);
		if(valueMap == null) return Collections.emptyList();
		Map<String,Variable> propertyMap = valueMap.getVariables(graph, this, classification, null);
    	if(propertyMap == null || propertyMap.isEmpty()) return Collections.emptyList();
    	else return propertyMap.values();
    	
    }
	
}