/**

 * 

 */

package org.junit.experimental.theories.internal;

import java.lang.reflect.Method;

import java.util.ArrayList;

import java.util.List;

import org.junit.experimental.theories.ParameterSignature;

import org.junit.experimental.theories.ParameterSupplier;

import org.junit.experimental.theories.ParametersSuppliedBy;

import org.junit.experimental.theories.PotentialAssignment;

import org.junit.experimental.theories.PotentialAssignment.CouldNotGenerateValueException;

import org.junit.runners.model.TestClass;

public class Assignments {

	private List<PotentialAssignment> fAssigned;

	private final List<ParameterSignature> fUnassigned;

	private final TestClass fClass;

	public Assignments(List<PotentialAssignment> assigned,

			List<ParameterSignature> unassigned, TestClass testClass) {

		fUnassigned= unassigned;

		fAssigned= assigned;

		fClass= testClass;

	}

	public static Assignments allUnassigned(Method testMethod,

			TestClass testClass) throws Exception {

		List<ParameterSignature> signatures;

		signatures= ParameterSignature.signatures(testClass.getOnlyConstructor());

		signatures.addAll(ParameterSignature.signatures(testMethod));

		return new Assignments(new ArrayList<PotentialAssignment>(),

				signatures, testClass);

	}

	public boolean isComplete() {

		return fUnassigned.size() == 0;

	}

	public ParameterSignature nextUnassigned() {

		return fUnassigned.get(0);

	}

	public Assignments assignNext(PotentialAssignment source) {

		List<PotentialAssignment> assigned= new ArrayList<PotentialAssignment>(

				fAssigned);

		assigned.add(source);

		return new Assignments(assigned, fUnassigned.subList(1, fUnassigned

				.size()), fClass);

	}

	public Object[] getActualValues(int start, int stop, boolean nullsOk)

			throws CouldNotGenerateValueException {

		Object[] values= new Object[stop - start];

		for (int i= start; i < stop; i++) {

			Object value= fAssigned.get(i).getValue();

			if (value == null && !nullsOk)

				throw new CouldNotGenerateValueException();

			values[i - start]= value;

		}

		return values;

	}

	public List<PotentialAssignment> potentialsForNextUnassigned()

			throws InstantiationException, IllegalAccessException {

		ParameterSignature unassigned= nextUnassigned();

		return getSupplier(unassigned).getValueSources(unassigned);

	}

	public ParameterSupplier getSupplier(ParameterSignature unassigned)

			throws InstantiationException, IllegalAccessException {

		ParameterSupplier supplier= getAnnotatedSupplier(unassigned);

		if (supplier != null)

			return supplier;

		return new AllMembersSupplier(fClass);

	}

	public ParameterSupplier getAnnotatedSupplier(ParameterSignature unassigned)

			throws InstantiationException, IllegalAccessException {

		ParametersSuppliedBy annotation= unassigned

				.findDeepAnnotation(ParametersSuppliedBy.class);

		if (annotation == null)

			return null;

		return annotation.value().newInstance();

	}

	public Object[] getConstructorArguments(boolean nullsOk)

			throws CouldNotGenerateValueException {

		return getActualValues(0, getConstructorParameterCount(), nullsOk);

	}

	public Object[] getMethodArguments(boolean nullsOk)

			throws CouldNotGenerateValueException {

		return getActualValues(getConstructorParameterCount(),

				fAssigned.size(), nullsOk);

	}

	public Object[] getAllArguments(boolean nullsOk)

			throws CouldNotGenerateValueException {

		return getActualValues(0, fAssigned.size(), nullsOk);

	}

	private int getConstructorParameterCount() {

		List<ParameterSignature> signatures= ParameterSignature

				.signatures(fClass.getOnlyConstructor());

		int constructorParameterCount= signatures.size();

		return constructorParameterCount;

	}

	public Object[] getArgumentStrings(boolean nullsOk) throws CouldNotGenerateValueException {

		Object[] values= new Object[fAssigned.size()];

		for (int i= 0; i < values.length; i++) {

			values[i]= fAssigned.get(i).getDescription();

		}

		return values;

	}

}