package net.sourceforge.fenixedu.presentationTier.backBeans.publico;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.SortedSet;
import java.util.TreeMap;
import java.util.TreeSet;

import net.sourceforge.fenixedu.domain.Department;
import net.sourceforge.fenixedu.domain.Teacher;
import net.sourceforge.fenixedu.domain.organizationalStructure.DepartmentUnit;
import net.sourceforge.fenixedu.domain.organizationalStructure.Unit;
import net.sourceforge.fenixedu.domain.organizationalStructure.UnitUtils;
import net.sourceforge.fenixedu.domain.teacher.Category;
import net.sourceforge.fenixedu.presentationTier.backBeans.base.FenixBackingBean;

import org.joda.time.YearMonthDay;

public class DepartmentManagementBackingBean extends FenixBackingBean {

    public static final Comparator<DepartmentUnit> COMPARATOR_BY_REAL_NAME = new Comparator<DepartmentUnit>() {

	@Override
	public int compare(DepartmentUnit o1, DepartmentUnit o2) {
	    return o1.getDepartment().getRealName().compareTo(o2.getDepartment().getRealName());
	}

    };

    private Collection<Category> sortedDepartmentCategories = new TreeSet<Category>();

    private Map<Category, List<Teacher>> teachersByCategory;

    public List<DepartmentUnit> getDepartmentUnits() {
	final List<DepartmentUnit> result = new ArrayList<DepartmentUnit>(UnitUtils.readAllDepartmentUnits());
	removeUnitsWithoutDepartment(result);
	Collections.sort(result, COMPARATOR_BY_REAL_NAME);
	return result;
    }

    private void removeUnitsWithoutDepartment(final List<DepartmentUnit> result) {
	final Iterator<DepartmentUnit> iterator = result.iterator();
	while (iterator.hasNext()) {
	    if (!iterator.next().hasDepartment()) {
		iterator.remove();
	    }
	}
    }

    public Department getDepartment() {
	Integer selectedDepartmentUnitID = getAndHoldIntegerParameter("selectedDepartmentUnitID");
	if (selectedDepartmentUnitID != null) {
	    Unit departmentUnit = (Unit) rootDomainObject.readPartyByOID(selectedDepartmentUnitID);
	    return departmentUnit.getDepartment();
	} else {
	    return null;
	}
    }

    private List<Teacher> getDepartmentTeachers() {
	final SortedSet<Teacher> result = new TreeSet<Teacher>(Teacher.TEACHER_COMPARATOR_BY_CATEGORY_AND_NUMBER);

	Department department = getDepartment();
	if (department != null) {
	    YearMonthDay today = new YearMonthDay();
	    YearMonthDay tomorrow = today.plusDays(1);
	    result.addAll(department.getAllTeachers(today, tomorrow));
	}

	return new ArrayList<Teacher>(result);
    }

    private void initializeStructures() {
	teachersByCategory = new TreeMap<Category, List<Teacher>>();

	for (final Teacher teacher : getDepartmentTeachers()) {
	    Category category = teacher.getCategory();

	    if (!teachersByCategory.containsKey(category)) {
		final List<Teacher> categoryTeachers = new ArrayList<Teacher>();
		categoryTeachers.add(teacher);

		teachersByCategory.put(category, categoryTeachers);
		sortedDepartmentCategories.add(category);
	    } else {
		final List<Teacher> categoryTeachers = teachersByCategory.get(category);
		categoryTeachers.add(teacher);
	    }
	}
    }

    public Map<Category, List<Teacher>> getTeachersByCategory() {
	if (teachersByCategory == null) {
	    initializeStructures();
	}

	return teachersByCategory;
    }

    public List<Category> getSortedDepartmentCategories() {
	if (sortedDepartmentCategories.isEmpty()) {
	    initializeStructures();
	}

	return new ArrayList<Category>(sortedDepartmentCategories);
    }

}