(function(){
    "use strict";
    // canonical client-side student collection
    angular.module('shared')
        .provider('students', function studentsProvider() {
            var students;
            return {
                $get: ['groups', 'NameUtil', 'memberInfo', 'StudentsUtil', '_', studentsFactory],
                setStudents: setStudents,
            };

            function studentsFactory(groups, NameUtil, memberInfo, StudentsUtil, _) {
                groups.get().$promise.then(function (groups) {
                    initStudentGroups(groups);
                });
                //Ensure referential integrity for student group collections client side (build collections of
                // references to canonical group objects)
                function initStudentGroups(groups) {
                    _.each(students, function replaceStudentGroupsCanonically(student) {
                        student.groups = _.map(student.groups, function replaceGroupWithCanonical(student_group) {
                            return _.find(groups, function groupMatchesStudentGroup(group) {
                                return group.grouping_id == student_group.grouping_id;
                            });
                        });
                    });
                }

                (function initStudentsSharedWith() {
                    memberInfo.showSharedWith =
                        memberInfo.canShareStudents
                        && anyStudentsSharedWithOthers(students);
                    if (!memberInfo.showSharedWith) {
                        return;
                    }
                    _.map(students, function initStudentSharedWith(student) {
                        student.others_shared_with =
                            student.is_shared ? [] : sortMembers(otherMembers(student.shared_with));
                    });
                    function anyStudentsSharedWithOthers(students) {
                        return _.any(students, isSharedWithOthers);
                    }

                    function isSharedWithOthers(student) {
                        return !student.is_shared && otherMembers(student.shared_with).length > 0;
                    }

                    function otherMembers(members) {
                        return _.reject(members, isMe);
                    }

                    function sortMembers(members) {
                        return _.chain(members)
                            .sortBy('username')
                            .sortBy('last_name')
                            .sortBy('first_name').value();
                    }

                    function isMe(member) {
                        return member.member_id == memberInfo.member_id;
                    }
                })();
                (function () {
                    memberInfo.showTeacherUsername =
                        memberInfo.canShareStudents
                        && getShared().length > 0;
                })();

                function get() {
                    return students;
                }

                function indexOfStudentById(student) {
                    var idx;
                    for (idx = 0; idx < students.length; ++idx) {
                        if (students[idx].student_id == student.student_id) {
                            return idx;
                        }
                    }
                    return -1;
                }

                function getStudentByStudentId(studentId) {
                    return _.find(students, function (student) {
                        return student.student_id == studentId;
                    });
                }

                function remove(student) {
                    var idx = indexOfStudentById(student);
                    if (idx != -1) {
                        students.splice(idx, 1);
                    }
                }

                function getHomeroom() {
                    return _.reject(students, function (student) {
                        return student.is_shared;
                    });
                }

                function getShared() {
                    return StudentsUtil.getShared(students);
                }

                return {
                    get: get,
                    getStudentByStudentId: getStudentByStudentId,
                    getHomeroom: getHomeroom,
                    getShared: getShared,
                    remove: remove
                };
            }

            function setStudents(src) {
                students = src;
            }
        });
})();