package models.terms.meta;

import java.util.Collection;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import java.util.stream.Collectors;
import java.util.stream.IntStream;

import lombok.Getter;
import models.algebra.Expression;
import models.algebra.Symbol;
import models.algebra.Variable;
import models.terms.Dependency;
import models.terms.DependencyTerm;
import models.terms.EvaluatableTerm;
import models.terms.LinearRightNormalizedType;
import models.terms.RDLTerm;
import models.terms.Resource;
@Getter
public abstract class MetaRDLTerm extends RDLTerm {

	protected TermType termType;
	protected LinearRightNormalizedType linearRightNormalizedType = LinearRightNormalizedType.UNDEFINED;
	
	protected MetaRDLTerm(Symbol symbol, TermType termType, int size) {
		super(symbol, -1, size);
		this.termType = termType;
		if (isResource()) {
			linearRightNormalizedType = LinearRightNormalizedType.LINEAR_RIGHT_NORMALIZED;
		}
	}
	
	
	public Set<MatchConstraint> isMatchedBy(RDLTerm another) {
		return isMatchedBy(another, MatchConstraint.createDefault(), 0);
	}
	
	public Set<MatchConstraint> isMatchedBy(RDLTerm another, MatchConstraint constraint) {
		return isMatchedBy(another, constraint, 0);
	}
	
	public Set<MatchConstraint> isMatchedBy(RDLTerm another, Set<MatchConstraint> constraints) {
		return isMatchedBy(another, constraints, 0);
	}
	
	protected Set<MatchConstraint> isMatchedBy(RDLTerm another, Set<MatchConstraint> constraints, int depth) {
		Set<MatchConstraint> result = new HashSet<>();
		for (MatchConstraint constraint : constraints) {
			result.addAll(isMatchedBy(another, constraint, depth + 1));
		}
		return result;
	}
	
	abstract protected Set<MatchConstraint> isMatchedBy(RDLTerm another, MatchConstraint constraint, int depth);
	
	
	public RDLTerm substitute(Map<Variable, RDLTerm> binding) {
		return substitute(binding, 0);
	}
	
	abstract protected RDLTerm substitute(Map<Variable, RDLTerm> binding, int depth); 
	
	
	public boolean checkTermType(Class<? extends RDLTerm> clazz) {
		return clazz.isAssignableFrom(termType.getBaseTermClass());
	}
	
	public boolean isVariable() {
		return false;
	}
	
	public boolean isDependency() {
		return checkTermType(Dependency.class);
	}
	
	public boolean isEvaluatableTerm() {
		return checkTermType(EvaluatableTerm.class);
	}
	
	public boolean isDependencyTerm() {
		return checkTermType(DependencyTerm.class);
	}
	
	public boolean isResource() {
		return checkTermType(Resource.class);
	}
	
	public void setLinearRightNormalizedType(LinearRightNormalizedType next) {
		if (isDependency()) {
			return;
		}
		this.linearRightNormalizedType = next;
	}
	
	public Collection<MetaVariable> getAllVariables() {
		return getSubTerms(MetaVariable.class).values();
	}
	
	protected boolean islinearRightNormalizedMatchedBy(RDLTerm another) {
		if (linearRightNormalizedType != LinearRightNormalizedType.UNDEFINED) {
			if (another instanceof DependencyTerm) {
				if (((DependencyTerm) another).getLinearRightNormalizedType() != linearRightNormalizedType) {
					return false;
				}
			}
			else if (another instanceof MetaRDLTerm) {
				if (((MetaRDLTerm) another).getLinearRightNormalizedType() != linearRightNormalizedType) {
					return false;
				}
			}
		}
		return true;
	}
	
	
	@Override
	public String toString() {
		switch(termType) {
		case META_DEPENDENCY:
			return "[" + getChild(0).toString() + " : " + getChildren().stream().skip(1).map(Expression::toString).collect(Collectors.joining(",")) + "]";
		case META_DEPENDENCY_TERM:
			return "[" + getChild(0).toString() + " : " + IntStream.range(0, (getChildren().size() - 1) / 2)
					.mapToObj(i -> getChild(i * 2 + 1).toString() + " -> " + getChild(i * 2 + 2)).collect(Collectors.joining(",")) + "]";
		default:
			return "";
		}
	}

	@Override
	public String toStringWithOrder() {
		switch(termType) {
		case META_DEPENDENCY:
			return "[" + ((RDLTerm) getChild(0)).toStringWithOrder() + " : " + ((RDLTerm) getChild(1)).toStringWithOrder() + "]";
		case META_DEPENDENCY_LIST:
			return "[" + ((RDLTerm) getChild(0)).toStringWithOrder() + "]";
		case META_DEPENDENCY_TERM:
			return "[" + ((RDLTerm) getChild(0)).toStringWithOrder() + " : "
					+ ((RDLTerm) getChild(1)).toStringWithOrder() + " -> " + ((RDLTerm) getChild(2)).toStringWithOrder() + "]";
		default:
			return "";
		}
	}

	@Override
	public boolean equals(Object another) {
		if(! (another instanceof MetaRDLTerm)) {
			return false;
		}
		MetaRDLTerm anotherTerm = (MetaRDLTerm) another;
		return super.equals(another) && termType == anotherTerm.getTermType();
	}

	@Override
	public int hashCode() {
		return (termType.toString() + toStringWithOrder()).hashCode();
	}

	@Override
	public Object clone() {

		return null;
	}

	protected static enum TermType {
		META_RDL_TERM(RDLTerm.class),
		META_DEPENDENCY(Dependency.class),
		META_DEPENDENCY_LIST(Dependency.class),
		META_DEPENDENCY_VARIABLE(Dependency.class),
		META_DEPENDENCY_TERM(DependencyTerm.class),
		META_DEPENDENCY_TERM_VARIABLE(DependencyTerm.class),
		META_EVALUATABLE_TERM_VARIABLE(EvaluatableTerm.class),
		META_RESOURCE_VARIABLE(Resource.class);
		
		@Getter
		private Class<?> baseTermClass;
		
		private TermType(Class<?> clazz) {
			this.baseTermClass = clazz;
		}
		
	}
	
}