using Server.Accounting;
using Server.Commands;
using Server.Engines.Help;
using Server.Network;
using Server.Regions;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;

namespace Server.Misc
{
    public enum PasswordProtection
    {
        None,
        Crypt,
        NewCrypt,
        NewSecureCrypt
    }

    public class AccountHandler
    {
        public static PasswordProtection ProtectPasswords = Config.GetEnum(
            "Accounts.ProtectPasswords",
            PasswordProtection.NewSecureCrypt);

        private static readonly int MaxAccountsPerIP = Config.Get("Accounts.AccountsPerIp", 1);
        private static readonly bool AutoAccountCreation = Config.Get("Accounts.AutoCreateAccounts", true);
        private static readonly bool RestrictDeletion = Config.Get("Accounts.RestrictDeletion", !TestCenter.Enabled);
        private static readonly TimeSpan DeleteDelay = Config.Get("Accounts.DeleteDelay", TimeSpan.FromDays(7.0));

        private static readonly CityInfo[] StartingCities = new CityInfo[]
        {
            new CityInfo("New Haven",   "New Haven Bank",   1150168, 3503,  2574,   14),
            new CityInfo("Yew", "The Empath Abbey", 1075072, 633,   858,    0),
            new CityInfo("Minoc", "The Barnacle", 1075073, 2476,    413,    15),
            new CityInfo("Britain", "The Wayfarer's Inn",   1075074, 1602,  1591,   20),
            new CityInfo("Moonglow",    "The Scholars Inn", 1075075, 4408,  1168,   0),
            new CityInfo("Trinsic", "The Traveler's Inn",   1075076, 1845,  2745,   0),
            new CityInfo("Jhelom", "The Mercenary Inn", 1075078, 1374,  3826,   0),
            new CityInfo("Skara Brae",  "The Falconer's Inn",   1075079, 618,   2234,   0),
            new CityInfo("Vesper", "The Ironwood Inn",  1075080, 2771,  976,    0),
            new CityInfo("Royal City", "Royal City Inn", 1150169, 738, 3486, -19, Map.TerMur)
        };

        private static readonly CityInfo[] SiegeStartingCities = new CityInfo[]
        {
            new CityInfo("Britain", "The Wayfarer's Inn",   1075074, 1602,  1591,   20, Map.Felucca),
            new CityInfo("Royal City", "Royal City Inn", 1150169, 738, 3486, -19, Map.TerMur)
        };

        private static readonly bool PasswordCommandEnabled = Config.Get("Accounts.PasswordCommandEnabled", false);

        private static readonly char[] m_ForbiddenChars = new char[]
        {
            '<', '>', ':', '"', '/', '\\', '|', '?', '*', ' '
        };

        private static AccessLevel m_LockdownLevel;
        private static Dictionary<IPAddress, int> m_IPTable;

        public static AccessLevel LockdownLevel
        {
            get
            {
                return m_LockdownLevel;
            }
            set
            {
                m_LockdownLevel = value;
            }
        }

        public static Dictionary<IPAddress, int> IPTable
        {
            get
            {
                if (m_IPTable == null)
                {
                    m_IPTable = new Dictionary<IPAddress, int>();

                    foreach (Account a in Accounts.GetAccounts().OfType<Account>())
                    {
                        if (a.LoginIPs.Length > 0)
                        {
                            IPAddress ip = a.LoginIPs[0];

                            if (m_IPTable.ContainsKey(ip))
                                m_IPTable[ip]++;
                            else
                                m_IPTable[ip] = 1;
                        }
                    }
                }

                return m_IPTable;
            }
        }

        public static void Initialize()
        {
            EventSink.DeleteRequest += EventSink_DeleteRequest;
            EventSink.AccountLogin += EventSink_AccountLogin;
            EventSink.GameLogin += EventSink_GameLogin;

            if (PasswordCommandEnabled)
                CommandSystem.Register("Password", AccessLevel.Player, Password_OnCommand);
        }

        [Usage("Password <newPassword> <repeatPassword>")]
        [Description("Changes the password of the commanding players account. Requires the same C-class IP address as the account's creator.")]
        public static void Password_OnCommand(CommandEventArgs e)
        {
            Mobile from = e.Mobile;
            Account acct = from.Account as Account;

            if (acct == null)
                return;

            IPAddress[] accessList = acct.LoginIPs;

            if (accessList.Length == 0)
                return;

            NetState ns = from.NetState;

            if (ns == null)
                return;

            if (e.Length == 0)
            {
                from.SendMessage("You must specify the new password.");
                return;
            }
            else if (e.Length == 1)
            {
                from.SendMessage("To prevent potential typing mistakes, you must type the password twice. Use the format:");
                from.SendMessage("Password \"(newPassword)\" \"(repeated)\"");
                return;
            }

            string pass = e.GetString(0);
            string pass2 = e.GetString(1);

            if (pass != pass2)
            {
                from.SendMessage("The passwords do not match.");
                return;
            }

            bool isSafe = true;

            for (int i = 0; isSafe && i < pass.Length; ++i)
                isSafe = (pass[i] >= 0x20 && pass[i] < 0x7F);

            if (!isSafe)
            {
                from.SendMessage("That is not a valid password.");
                return;
            }

            try
            {
                IPAddress ipAddress = ns.Address;

                if (Utility.IPMatchClassC(accessList[0], ipAddress))
                {
                    acct.SetPassword(pass);
                    from.SendMessage("The password to your account has changed.");
                }
                else
                {
                    PageEntry entry = PageQueue.GetEntry(from);

                    if (entry != null)
                    {
                        if (entry.Message.StartsWith("[Automated: Change Password]"))
                            from.SendMessage("You already have a password change request in the help system queue.");
                        else
                            from.SendMessage("Your IP address does not match that which created this account.");
                    }
                    else if (PageQueue.CheckAllowedToPage(from))
                    {
                        from.SendMessage("Your IP address does not match that which created this account.  A page has been entered into the help system on your behalf.");

                        from.SendLocalizedMessage(501234, "", 0x35); /* The next available Counselor/Game Master will respond as soon as possible.
                        * Please check your Journal for messages every few minutes.
                        */

                        PageQueue.Enqueue(new PageEntry(from, string.Format("[Automated: Change Password]<br>Desired password: {0}<br>Current IP address: {1}<br>Account IP address: {2}", pass, ipAddress, accessList[0]), PageType.Account));
                    }
                }
            }
            catch (Exception ex)
            {
                Diagnostics.ExceptionLogging.LogException(ex);
            }
        }

        public static bool CanCreate(IPAddress ip)
        {
            if (!IPTable.ContainsKey(ip) || IPLimiter.IsExempt(ip))
                return true;

            return (IPTable[ip] < MaxAccountsPerIP);
        }

        public static void EventSink_AccountLogin(AccountLoginEventArgs e)
        {
            // If the login attempt has already been rejected by another event handler
            // then just return
            if (e.Accepted == false)
                return;

            if (!IPLimiter.SocketBlock && !IPLimiter.Verify(e.State.Address))
            {
                e.Accepted = false;
                e.RejectReason = ALRReason.InUse;

                Utility.PushColor(ConsoleColor.Red);
                Console.WriteLine("Login: {0}: Past IP limit threshold", e.State);
                Utility.PopColor();

                using (StreamWriter op = new StreamWriter("ipLimits.log", true))
                    op.WriteLine("{0}\tPast IP limit threshold\t{1}", e.State, DateTime.UtcNow);

                return;
            }

            string un = e.Username;
            string pw = e.Password;

            e.Accepted = false;
            Account acct = Accounts.GetAccount(un) as Account;

            if (acct == null)
            {
                if (AutoAccountCreation && un.Trim().Length > 0) // To prevent someone from making an account of just '' or a bunch of meaningless spaces
                {
                    e.State.Account = acct = CreateAccount(e.State, un, pw);
                    e.Accepted = acct == null ? false : acct.CheckAccess(e.State);

                    if (!e.Accepted)
                        e.RejectReason = ALRReason.BadComm;
                }
                else
                {
                    Utility.PushColor(ConsoleColor.Red);
                    Console.WriteLine("Login: {0}: Invalid username '{1}'", e.State, un);
                    Utility.PopColor();
                    e.RejectReason = ALRReason.Invalid;
                }
            }
            else if (!acct.HasAccess(e.State))
            {
                Utility.PushColor(ConsoleColor.Red);
                Console.WriteLine("Login: {0}: Access denied for '{1}'", e.State, un);
                Utility.PopColor();
                e.RejectReason = (m_LockdownLevel > AccessLevel.VIP ? ALRReason.BadComm : ALRReason.BadPass);
            }
            else if (!acct.CheckPassword(pw))
            {
                Utility.PushColor(ConsoleColor.Red);
                Console.WriteLine("Login: {0}: Invalid password for '{1}'", e.State, un);
                Utility.PopColor();
                e.RejectReason = ALRReason.BadPass;
            }
            else if (acct.Banned)
            {
                Utility.PushColor(ConsoleColor.Red);
                Console.WriteLine("Login: {0}: Banned account '{1}'", e.State, un);
                Utility.PopColor();
                e.RejectReason = ALRReason.Blocked;
            }
            else
            {
                Utility.PushColor(ConsoleColor.Green);
                Console.WriteLine("Login: {0}: Valid credentials for '{1}'", e.State, un);
                Console.WriteLine("Client Type: {0}: {1}", e.State, e.State.IsEnhancedClient ? "Enhanced Client" : "Classic Client");
                Utility.PopColor();
                e.State.Account = acct;
                e.Accepted = true;

                acct.LogAccess(e.State);
            }

            if (!e.Accepted)
                AccountAttackLimiter.RegisterInvalidAccess(e.State);
        }

        public static void EventSink_GameLogin(GameLoginEventArgs e)
        {
            if (!IPLimiter.SocketBlock && !IPLimiter.Verify(e.State.Address))
            {
                e.Accepted = false;

                Utility.PushColor(ConsoleColor.Red);
                Console.WriteLine("Login: {0}: Past IP limit threshold", e.State);
                Utility.PopColor();

                using (StreamWriter op = new StreamWriter("ipLimits.log", true))
                    op.WriteLine("{0}\tPast IP limit threshold\t{1}", e.State, DateTime.UtcNow);

                return;
            }

            string un = e.Username;
            string pw = e.Password;

            Account acct = Accounts.GetAccount(un) as Account;

            if (acct == null)
            {
                e.Accepted = false;
            }
            else if (!acct.HasAccess(e.State))
            {
                Utility.PushColor(ConsoleColor.Red);
                Console.WriteLine("Login: {0}: Access denied for '{1}'", e.State, un);
                Utility.PopColor();
                e.Accepted = false;
            }
            else if (!acct.CheckPassword(pw))
            {
                Utility.PushColor(ConsoleColor.Red);
                Console.WriteLine("Login: {0}: Invalid password for '{1}'", e.State, un);
                Utility.PopColor();
                e.Accepted = false;
            }
            else if (acct.Banned)
            {
                Utility.PushColor(ConsoleColor.Red);
                Console.WriteLine("Login: {0}: Banned account '{1}'", e.State, un);
                Utility.PopColor();
                e.Accepted = false;
            }
            else
            {
                acct.LogAccess(e.State);

                Utility.PushColor(ConsoleColor.Yellow);
                Console.WriteLine("Login: {0}: Account '{1}' at character list", e.State, un);
                Utility.PopColor();
                e.State.Account = acct;
                e.Accepted = true;

                if (Siege.SiegeShard)
                {
                    e.CityInfo = SiegeStartingCities;
                }
                else
                {
                    e.CityInfo = StartingCities;
                }
            }

            if (!e.Accepted)
                AccountAttackLimiter.RegisterInvalidAccess(e.State);
        }

        public static bool CheckAccount(Mobile mobCheck, Mobile accCheck)
        {
            if (accCheck != null)
            {
                Account a = accCheck.Account as Account;

                if (a != null)
                {
                    for (int i = 0; i < a.Length; ++i)
                    {
                        if (a[i] == mobCheck)
                            return true;
                    }
                }
            }

            return false;
        }

        private static void EventSink_DeleteRequest(DeleteRequestEventArgs e)
        {
            NetState state = e.State;
            int index = e.Index;

            Account acct = state.Account as Account;

            if (acct == null)
            {
                state.Dispose();
            }
            else if (index < 0 || index >= acct.Length)
            {
                state.Send(new DeleteResult(DeleteResultType.BadRequest));
                state.Send(new CharacterListUpdate(acct));
            }
            else
            {
                Mobile m = acct[index];

                if (m == null)
                {
                    state.Send(new DeleteResult(DeleteResultType.CharNotExist));
                    state.Send(new CharacterListUpdate(acct));
                }
                else if (m.NetState != null)
                {
                    state.Send(new DeleteResult(DeleteResultType.CharBeingPlayed));
                    state.Send(new CharacterListUpdate(acct));
                }
                else if (RestrictDeletion && DateTime.UtcNow < (m.CreationTime + DeleteDelay))
                {
                    state.Send(new DeleteResult(DeleteResultType.CharTooYoung));
                    state.Send(new CharacterListUpdate(acct));
                }
                else if (m.IsPlayer() && Region.Find(m.LogoutLocation, m.LogoutMap).GetRegion(typeof(Jail)) != null)	//Don't need to check current location, if netstate is null, they're logged out
                {
                    state.Send(new DeleteResult(DeleteResultType.BadRequest));
                    state.Send(new CharacterListUpdate(acct));
                }
                else
                {
                    Utility.PushColor(ConsoleColor.Red);
                    Console.WriteLine("Client: {0}: Deleting character {1} (0x{2:X})", state, index, m.Serial.Value);
                    Utility.PopColor();

                    acct.Comments.Add(new AccountComment("System", string.Format("Character #{0} {1} deleted by {2}", index + 1, m, state)));

                    m.Delete();
                    state.Send(new CharacterListUpdate(acct));
                }
            }
        }

        private static bool IsForbiddenChar(char c)
        {
            for (int i = 0; i < m_ForbiddenChars.Length; ++i)
                if (c == m_ForbiddenChars[i])
                    return true;

            return false;
        }

        private static Account CreateAccount(NetState state, string un, string pw)
        {
            if (un.Length == 0 || pw.Length == 0)
                return null;

            bool isSafe = !(un.StartsWith(" ") || un.EndsWith(" ") || un.EndsWith("."));

            for (int i = 0; isSafe && i < un.Length; ++i)
                isSafe = (un[i] >= 0x20 && un[i] < 0x7F && !IsForbiddenChar(un[i]));

            for (int i = 0; isSafe && i < pw.Length; ++i)
                isSafe = (pw[i] >= 0x20 && pw[i] < 0x7F);

            if (!isSafe)
                return null;

            if (!CanCreate(state.Address))
            {
                Utility.PushColor(ConsoleColor.DarkYellow);
                Console.WriteLine("Login: {0}: Account '{1}' not created, ip already has {2} account{3}.", state, un, MaxAccountsPerIP, MaxAccountsPerIP == 1 ? "" : "s");
                Utility.PopColor();
                return null;
            }

            Utility.PushColor(ConsoleColor.Green);
            Console.WriteLine("Login: {0}: Creating new account '{1}'", state, un);
            Utility.PopColor();

            Account a = new Account(un, pw);

            return a;
        }
    }
}