/*
 * Copyright (c) Contributors, http://opensimulator.org/
 * See CONTRIBUTORS.TXT for a full list of copyright holders.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the OpenSimulator Project nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

using System;
using System.Collections;
using System.Collections.Generic;
using System.Reflection;
using System.Text;
using log4net;
using OpenMetaverse;
using OpenSim.Framework;
using OpenSim.Data;

namespace OpenSim.Data.Null
{
    public class NullUserAccountData : IUserAccountData
    {
        private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);

        private Dictionary<UUID, UserAccountData> m_DataByUUID = new Dictionary<UUID, UserAccountData>();
        private Dictionary<string, UserAccountData> m_DataByName = new Dictionary<string, UserAccountData>();
        private Dictionary<string, UserAccountData> m_DataByEmail = new Dictionary<string, UserAccountData>();

        public NullUserAccountData(string connectionString, string realm)
        {
        }

        /// <summary>
        /// Tries to implement the Get [] semantics, but it cuts corners like crazy.
        /// Specifically, it relies on the knowledge that the only Gets used are
        /// keyed on PrincipalID, Email, and FirstName+LastName.
        /// </summary>
        /// <param name="fields"></param>
        /// <param name="values"></param>
        /// <returns></returns>
        public UserAccountData[] Get(string[] fields, string[] values)
        {
            //if (m_log.IsDebugEnabled)
            //{
            //    m_log.DebugFormat(
            //      "[NULL USER ACCOUNT DATA]: Called Get with fields [{0}], values [{1}]",
            //      string.Join(", ", fields), string.Join(", ", values));
            //}

            try
            {
                UserAccountData uad;
                int i = Array.FindIndex(fields, (fn) => fn == "PrincipalID");
                if (i >= 0)
                {
                    if (UUID.TryParse(values[i], out UUID id) && m_DataByUUID.TryGetValue(id, out uad))
                        return new UserAccountData[] { uad };
                }

                i = Array.FindIndex(fields, (fn) => fn == "FirstName");
                if (i >= 0)
                {
                    int lindex = Array.FindIndex(fields, i + 1, (fn) => fn == "LastName");
                    if(lindex >= 0 && m_DataByName.TryGetValue(values[i] + " " + values[lindex], out uad))
                        return new UserAccountData[] { uad };
                }

                i = Array.FindIndex(fields, (fn) => fn == "Email");
                if (i >= 0 && m_DataByEmail.TryGetValue(values[i], out uad))
                    return new UserAccountData[] { uad };
            }
            catch { }

            return Array.Empty<UserAccountData>();
        }

        public bool Store(UserAccountData data)
        {
            if (data == null)
                return false;

            m_log.DebugFormat(
                "[NULL USER ACCOUNT DATA]: Storing user account {0} {1} {2} {3}",
                data.FirstName, data.LastName, data.PrincipalID, this.GetHashCode());

            m_DataByUUID[data.PrincipalID] = data;
            m_DataByName[data.FirstName + " " + data.LastName] = data;
            if (data.Data.TryGetValue("Email", out string semail) && !string.IsNullOrEmpty(semail))
                m_DataByEmail[semail] = data;

            // m_log.DebugFormat("m_DataByUUID count is {0}, m_DataByName count is {1}", m_DataByUUID.Count, m_DataByName.Count);

            return true;
        }

        public UserAccountData[] GetUsers(UUID scopeID, string query)
        {
            //m_log.DebugFormat(
            //   "[NULL USER ACCOUNT DATA]: Called GetUsers with scope [{0}], query [{1}]", scopeID, query);

            string[] words = query.Split();

            for (int i = 0; i < words.Length; i++)
            {
                if (words[i].Length < 3)
                {
                    if (i != words.Length - 1)
                        Array.Copy(words, i + 1, words, i, words.Length - i - 1);
                    Array.Resize(ref words, words.Length - 1);
                }
            }

            if (words.Length == 0)
                return new UserAccountData[0];

            if (words.Length > 2)
                return new UserAccountData[0];

            List<string> lst = new List<string>(m_DataByName.Keys);
            if (words.Length == 1)
            {
                lst = lst.FindAll(delegate(string s) { return s.StartsWith(words[0]); });
            }
            else
            {
                lst = lst.FindAll(delegate(string s) { return s.Contains(words[0]) || s.Contains(words[1]); });
            }

            if (lst == null || (lst != null && lst.Count == 0))
                return new UserAccountData[0];

            UserAccountData[] result = new UserAccountData[lst.Count];
            int n = 0;
            foreach (string key in lst)
                result[n++] = m_DataByName[key];

            return result;
        }

        public bool Delete(string field, string val)
        {
            // Only delete by PrincipalID
            if (field.Equals("PrincipalID"))
            {
                if (UUID.TryParse(val, out UUID uuid) && m_DataByUUID.TryGetValue(uuid, out UserAccountData account))
                {
                    m_DataByUUID.Remove(uuid);
                    m_DataByName.Remove(account.FirstName + " " + account.LastName);
                    if (account.Data.TryGetValue("Email", out string semail) && !string.IsNullOrEmpty(semail))
                        m_DataByEmail.Remove(semail);

                    return true;
                }
            }

            return false;
        }

        public UserAccountData[] GetUsersWhere(UUID scopeID, string where)
        {
            return null;
        }
    }
}