package com.example.cosmos_serversb.models;

import java.lang.reflect.Member;
import java.util.*;
import javax.inject.Singleton;
import java.util.Date;

import com.example.cosmos_serversb.entities.*;
import com.example.cosmos_serversb.jsons.*;
import org.hibernate.Session;
import org.hibernate.SessionFactory;

import static com.example.cosmos_serversb.models.Users.getUserById;

@Singleton
public class Groups {
    private static Groups theInstance = null;
    private static ArrayList<Group> groups = new ArrayList<>();
    //private static HashMap<String, String> groupsMap = new HashMap<>();

    private static SessionFactory sessionFactory;
    private static String baseURI = "http://nitta-lab-www.is.konan-u.ac.jp/";
    private static String AppName = "cosmos";

    private Groups(){
        //sessionFactory = SessionFactoryManager.getInstance().getSessionFactory();
    }

    public static Groups getInstance(){
        if(theInstance == null){
            theInstance = new Groups();
        }
        return theInstance;
    }

    public static String createGId() {
        //gIdを作成し既存していないかチェック後DBに保存し作成したgIdを返す
        String gId = UUID.randomUUID().toString();
        return gId;
    }

    public static String createRId() {
        //rIdを作成し既存していないかチェック後DBに保存し作成したrIdを返す
        String rId = UUID.randomUUID().toString();
        return rId;
    }

    public static GroupsMapJson getGroupsListByUid(String uId){
        return getGroupsHashMap(uId);
    }

    public static Group createGroup(String name, String uId){
        if(name == null || uId == null){
            return null; //not-null制約
        }
        User user = getUserById(uId);
        if(user == null){
            return null; //存在しないユーザがグループを作成しようとした。
        }

        //先にGidとuriの発行を行う
        String gId = getInstance().createGId();
        String uri = baseURI + AppName + "/rest/groups/" + gId;
        Group testGroup = new Group(gId, uri, name, uId);
        Session session = SessionManager.getInstance().getSession();
        session.save(testGroup);

        return testGroup;
    }

    public static Group getGroupByGid(String gId){
        Group editGroup;
        Session session = SessionManager.getInstance().getSession();
        List groupResult = session.createQuery( "from Group" ).list();
        for ( Group group : (List<Group>) groupResult ) {
            editGroup = group;
            if (editGroup.getgId().equals(gId)) {
                return editGroup;
            }
        }
        return null;
    }

    public static DeleteResult deleteGroup(String gId){
        Session session = SessionManager.getInstance().getSession();
        Group editGroup = session.get(Group.class, gId);
        if(editGroup == null){
            return DeleteResult.FAILURE;
        }
        //削除するグループに所属しているユーザーに、退会してもらう。
        for(User member : editGroup.getMembers()){
            member.exitGroup(editGroup);
        }
        //削除するグループが持っているユーザの情報を全て削除する。
        editGroup.clearAllMembersForDeleteGroup();
        session.delete(editGroup);
        return DeleteResult.SUCCESS;
    }

    public static MembersJson getMembersListByGid(String gId){
        Session session = SessionManager.getInstance().getSession();
        Group editGroup = session.get(Group.class, gId);
        if(editGroup != null){
            MembersJson members = new MembersJson(editGroup);
            return members;
        }
        return null;
    }

    public static Group addMember(String gId, String uId){
        Session session = SessionManager.getInstance().getSession();
        Group editGroup = session.get(Group.class, gId);
        if(editGroup != null) {
            editGroup.addMember(uId);
            session.update(editGroup);
            //UsersMapJson usersMapJson = new UsersMapJson(editGroup);
            return editGroup;
        }
        //例外処理
        return null;
    }

    public static DeleteResult deleteMember(String gId, String uId){
        Session session = SessionManager.getInstance().getSession();
        Group editGroup = session.get(Group.class, gId);
        User editUser = session.get(User.class, uId);
        if(editGroup != null){
            if(editGroup.getMembers().contains(editUser)){
                editUser.exitGroup(editGroup);
                editGroup.deleteMember(editUser);
                if(editGroup.getMembers().size() == 0){
                    //ユーザーが存在しないグループは削除
                    session.delete(editGroup);
                }
                return DeleteResult.SUCCESS;
            }
        }
        return DeleteResult.FAILURE;
    }

    /*
    public static Group getGroupByGid(String gId){
        Group editGroup;
        Session session = SessionManager.getInstance().getSession();
        List groupResult = session.createQuery( "from Group" ).list();
        for ( Group group : (List<Group>) groupResult ) {
            editGroup = group;
            if (editGroup.getgId().equals(gId)) {
                return editGroup;
            }
        }
        return null;
    }

     */

    public static RequestsJson getRequestsListByGid(String gId, boolean detail, int quantity){
        Session session = SessionManager.getInstance().getSession();
        Group group = session.get(Group.class, gId);
        if(group != null) {
            RequestsJson requestsJson = new RequestsJson(group.getRequests(), quantity);
            return requestsJson;
        }
        //例外処理
        return null;
    }

    public static Request addRequests(String gId, String uId, String product, String deadline, int location){
        if(product == null || uId == null){
            return null; //not-null制約
        }
        String rId = getInstance().createRId();
        String uri = baseURI + AppName + "/rset/groups/" + gId + "/requests/" + rId;
        Request request = new Request(rId, uri, new Date(), uId, product, deadline, location);

        Session session = SessionManager.getInstance().getSession();
        Group editGroup = session.get(Group.class, gId);
        if(editGroup != null) {
            editGroup.addRequests(request);
            editGroup.updateRequestHash(request);
            session.update(editGroup);
            return request;
        }
        //例外処理
        return null;
    }

    public static Request getRequestDetailByGidAndRid(String gId, String rId){
        Session session = SessionManager.getInstance().getSession();
        Request request = session.get(Request.class, rId);
        Group group = session.get(Group.class, gId);
        if(group.getRequests().contains(request)) {
            return request;
        }
        //違うグループのリクエストは返せない。
        return null;
    }

    public static RidUriJson updateRequest(String gId, String rId, String uId, String product, String deadline, int location, boolean done){
        if(product ==  null){
            return null; //not-null制約
        }
        Session session = SessionManager.getInstance().getSession();
        Request editRequest = session.get(Request.class, rId);
        if(editRequest != null){
            editRequest.update(uId, product, deadline, location, done);
            session.update(editRequest);
            session.get(Group.class, gId).updateRequestHash(editRequest);
            return new RidUriJson(editRequest);
        }
        //例外処理
        return null;

//        //テスト用
//        Request testRequest = new Request(rId, "http://test.com", new Date(), uId, product, new Date(), 999);
//
//        return testRequest;
    }

    public static DeleteResult deleteRequest(String gId, String rId){
        Session session = SessionManager.getInstance().getSession();
        Request request = session.get(Request.class, rId);
        if(request != null) {
            session.get(Group.class, gId).updateRequestHash(request);
            session.delete(request);
            return DeleteResult.SUCCESS;
        }
        return DeleteResult.FAILURE;
    }

    /*
    //テスト用にHashMapの作成
    public static void createTestHashMap(String gId, String uri){
        testMap.put(gId, uri);
        /*
        //Key, valueの取り出し方例(拡張for文)
        for (String key : TestMap.keySet()) {
            System.out.println(key + " " + TestMap.get(key));
        }
    }
    */

    public static GroupsMapJson getGroupsHashMap(String uId){
        Session session = SessionManager.getInstance().getSession();
        GroupsMapJson groupsjson = new GroupsMapJson(session.load(User.class, uId));
        return groupsjson;
    }

}