using ACE.Entity;
using ACE.Entity.Enum;
using ACE.Server.Entity;
using ACE.Server.Managers;
using ACE.Server.Network;
using ACE.Server.WorldObjects;

using System;
using System.Collections.Generic;
using System.Linq;
using System.Numerics;
using System.Text.RegularExpressions;

namespace ACE.Server.Command
{
    /// <summary>
    /// Command handler sanity preserving parameter parsing
    /// </summary>
    public class CommandParameterHelpers
    {
        /// <summary>
        /// Types of parameter values
        /// </summary>
        public enum ACECommandParameterType
        {
            /// <summary>
            /// don't use this one
            /// </summary>
            Invalid,
            /// <summary>
            /// normal coordinates, example: 37.3s,67w<para/>
            /// output is of type ACE.Entity.Position
            /// </summary>
            Location,
            /// <summary>
            /// a character name of an online player, example: the fat bastard<para/>
            /// output is of type ACE.Server.WorldObjects.Player<para/>
            /// only one of OnlinePlayerName or OnlinePlayerNameOrIid or PlayerName parameter can be used for one command<para/>
            /// must be the first parameter
            /// </summary>
            OnlinePlayerName,
            /// <summary>
            /// a character name of an online player, example: the fat bastard or a decimal iid, example: 1342177281<para/>
            /// output is of type ACE.Server.WorldObjects.Player<para/>
            /// only one of OnlinePlayerName or OnlinePlayerNameOrIid or PlayerName parameter can be used for one command<para/>
            /// must be the first parameter
            /// </summary>
            OnlinePlayerNameOrIid,
            /// <summary>
            /// a decimal or hexadecimal iid of an online player, examples: 1342177292 or 0x5000000C<para/>
            /// output is of type ACE.Server.WorldObjects.Player<para/>
            /// </summary>
            OnlinePlayerIid,
            /// <summary>
            /// a character name, example: the fat bastard<para/>
            /// output is of type string<para/>
            /// only one of OnlinePlayerName or OnlinePlayerNameOrIid or PlayerName parameter can be used for one command<para/>
            /// must be the first parameter
            /// </summary>
            PlayerName,
            /// <summary>
            /// a url, example: http://someserver.net:4321/?get=blah <para/>
            /// output is of type System.Uri
            /// </summary>
            Uri,
            /// <summary>
            /// a number, example: 01231242<para/>
            /// output is of type ulong: 1231242
            /// </summary>
            ULong,
            /// <summary>
            /// a number, example: -01231242<para/>
            /// output is of type long: -1231242
            /// </summary>
            Long,
            /// <summary>
            /// a number, example: 01231242<para/>
            /// output is of type long: 1231242
            /// </summary>
            PositiveLong,
            /// <summary>
            /// some text enclosed in double quotes, example: "the problem is solved"<para/>
            /// Note:  To accept this kind of parameter IncludeRaw must be true for the command handler attribute decoration and RawIncluded argument must be true for the call to ResolveACEParameters
            /// </summary>
            DoubleQuoteEnclosedText,
            /// <summary>
            /// some text preceeded by a comma, example (the part after char): /hug my girl, char, the reasons are plenty!<para/>
            /// Note: To accept this kind of parameter IncludeRaw must be true for the command handler attribute decoration and RawIncluded argument must be true for the call to ResolveACEParameters<para/>
            /// limit 1 per command, may not include commas
            /// </summary>
            CommaPrefixedText,
            /// <summary>
            /// a word, example: boat<para/>
            /// output is of type string<para/>
            /// word may be one or more of case insensitive a-z, 0-9, and underscore<para/>
            /// </summary>
            SimpleWord,
            /// <summary>
            /// an element of an enum<para/>
            /// output is of enum type you supply as PossibleValues<para/>
            /// set the PossibleValues object to the type of enum<para/>
            /// </summary>
            Enum,
        }
        /// <summary>
        /// A player supplied parameter
        /// </summary>
        public class ACECommandParameter
        {
            /// <summary>
            /// The type of the parameter value
            /// </summary>
            public ACECommandParameterType Type { get; set; } = ACECommandParameterType.Invalid;
            /// <summary>
            /// The value to use upon missing or invalid supplied parameter
            /// </summary>
            public object DefaultValue { get; set; } = null;
            /// <summary>
            /// If this parameter is required
            /// </summary>
            public bool Required { get; set; } = false;
            /// <summary>
            /// The resultant parsed Value (or the default value)
            /// </summary>
            public object Value { get; set; } = null;
            public Position AsPosition => (Position)Value;
            public Player AsPlayer => (Player)Value;
            public ulong AsULong => (ulong)Value;
            public long AsLong => (long)Value;
            public long AsInt => (int)Value;
            public string AsString => (string)Value;
            public Uri AsUri => (Uri)Value;
            /// <summary>
            /// The parameter either wasn't supplied or was invalid (doesn't parse, player doesn't exist, etc.)
            /// </summary>
            public bool Defaulted { get; set; } = true;
            /// <summary>
            /// The broadcast message to send to the session when the parameter is required and didn't parse or wasn't supplied.
            /// </summary>
            public string ErrorMessage { get; set; } = null;
            /// <summary>
            /// Automatically assigned during GetParameters procedure
            /// </summary>
            public int ParameterNo { get; set; } = -1;
            /// <summary>
            /// if the type is enum set this to the enum that the parameter should be part of
            /// </summary>
            public Type PossibleValues { get; set; } = null;
        }
        /// <summary>
        /// Resolve the parameters supplied by the player into usable values.
        /// </summary>
        /// <param name="session">the session of the player who sent the command</param>
        /// <param name="aceParsedParameters">the collection of parameters supplied by the default parameter parser</param>
        /// <param name="parameters">the resolution details for every parameter</param>
        /// <param name="rawIncluded">whether or not the raw unparsed command line minus the command name was included as the first parameter</param>
        /// <returns>the parameters were successfully resolved or not</returns>
        public static bool ResolveACEParameters(Session session, IEnumerable<string> aceParsedParameters, IEnumerable<ACECommandParameter> parameters, bool rawIncluded = false)
        {
            string parameterBlob = "";
            if (rawIncluded)
            {
                parameterBlob = aceParsedParameters.First();
            }
            else
            {
                parameterBlob = aceParsedParameters.Count() > 0 ? aceParsedParameters.Aggregate((a, b) => a + " " + b).Trim(new char[] { ' ', ',' }) : string.Empty;
            }
            int commaCount = parameterBlob.Count(x => x == ',');

            List<ACECommandParameter> acps = parameters.ToList();
            for (int i = acps.Count - 1; i > -1; i--)
            {
                ACECommandParameter acp = acps[i];
                acp.ParameterNo = i + 1;
                if (parameterBlob.Length > 0)
                {
                    try
                    {
                        switch (acp.Type)
                        {
                            case ACECommandParameterType.PositiveLong:
                                Match match4 = Regex.Match(parameterBlob, @"(-?\d+)$", RegexOptions.IgnoreCase);
                                if (match4.Success)
                                {
                                    if (!long.TryParse(match4.Groups[1].Value, out long val))
                                    {
                                        return false;
                                    }
                                    if (val <= 0)
                                    {
                                        return false;
                                    }
                                    acp.Value = val;
                                    acp.Defaulted = false;
                                    parameterBlob = (match4.Groups[1].Index == 0) ? string.Empty : parameterBlob.Substring(0, match4.Groups[1].Index).Trim(new char[] { ' ' });
                                }
                                break;
                            case ACECommandParameterType.Long:
                                Match match3 = Regex.Match(parameterBlob, @"(-?\d+)$", RegexOptions.IgnoreCase);
                                if (match3.Success)
                                {
                                    if (!long.TryParse(match3.Groups[1].Value, out long val))
                                    {
                                        return false;
                                    }
                                    acp.Value = val;
                                    acp.Defaulted = false;
                                    parameterBlob = (match3.Groups[1].Index == 0) ? string.Empty : parameterBlob.Substring(0, match3.Groups[1].Index).Trim(new char[] { ' ', ',' });
                                }
                                break;
                            case ACECommandParameterType.ULong:
                                Match match2 = Regex.Match(parameterBlob, @"(-?\d+)$", RegexOptions.IgnoreCase);
                                if (match2.Success)
                                {
                                    if (!ulong.TryParse(match2.Groups[1].Value, out ulong val))
                                    {
                                        return false;
                                    }
                                    acp.Value = val;
                                    acp.Defaulted = false;
                                    parameterBlob = (match2.Groups[1].Index == 0) ? string.Empty : parameterBlob.Substring(0, match2.Groups[1].Index).Trim(new char[] { ' ', ',' });
                                }
                                break;
                            case ACECommandParameterType.Location:
                                Position position = null;
                                Match match = Regex.Match(parameterBlob, @"([\d\.]+[ns])[^\d\.]*([\d\.]+[ew])$", RegexOptions.IgnoreCase);
                                if (match.Success)
                                {
                                    string ns = match.Groups[1].Value;
                                    string ew = match.Groups[2].Value;
                                    if (!TryParsePosition(new string[] { ns, ew }, out string errorMessage, out position))
                                    {
                                        if (session != null)
                                        {
                                            ChatPacket.SendServerMessage(session, errorMessage, ChatMessageType.Broadcast);
                                        }
                                        else
                                        {
                                            Console.WriteLine(errorMessage);
                                        }
                                        return false;
                                    }
                                    else
                                    {
                                        acp.Value = position;
                                        acp.Defaulted = false;
                                        int coordsStartPos = Math.Min(match.Groups[1].Index, match.Groups[2].Index);
                                        parameterBlob = (coordsStartPos == 0) ? string.Empty : parameterBlob.Substring(0, coordsStartPos).Trim(new char[] { ' ', ',' });
                                    }
                                }
                                break;
                            case ACECommandParameterType.OnlinePlayerName:
                                if (i != 0)
                                {
                                    throw new Exception("Player parameter must be the first parameter, since it can contain spaces.");
                                }
                                parameterBlob = parameterBlob.TrimEnd(new char[] { ' ', ',' });
                                Player targetPlayer = PlayerManager.GetOnlinePlayer(parameterBlob);
                                if (targetPlayer == null)
                                {
                                    string errorMsg = $"Unable to find player {parameterBlob}";
                                    if (session != null)
                                    {
                                        ChatPacket.SendServerMessage(session, errorMsg, ChatMessageType.Broadcast);
                                    }
                                    else
                                    {
                                        Console.WriteLine(errorMsg);
                                    }
                                    return false;
                                }
                                else
                                {
                                    acp.Value = targetPlayer;
                                    acp.Defaulted = false;
                                }
                                break;
                            case ACECommandParameterType.OnlinePlayerNameOrIid:
                                if (i != 0)
                                {
                                    throw new Exception("Player parameter must be the first parameter, since it can contain spaces.");
                                }

                                if (!parameterBlob.Contains(' '))
                                {
                                    if (uint.TryParse(parameterBlob, out uint iid))
                                    {
                                        Player targetPlayer2 = PlayerManager.GetOnlinePlayer(iid);
                                        if (targetPlayer2 == null)
                                        {
                                            string logMsg = $"Unable to find player with iid {iid}";
                                            if (session != null)
                                            {
                                                ChatPacket.SendServerMessage(session, logMsg, ChatMessageType.Broadcast);
                                            }
                                            else
                                            {
                                                Console.WriteLine(logMsg);
                                            }
                                            return false;
                                        }
                                        else
                                        {
                                            acp.Value = targetPlayer2;
                                            acp.Defaulted = false;
                                            break;
                                        }
                                    }
                                }
                                Player targetPlayer3 = PlayerManager.GetOnlinePlayer(parameterBlob);
                                if (targetPlayer3 == null)
                                {
                                    string logMsg = $"Unable to find player {parameterBlob}";
                                    if (session != null)
                                    {
                                        ChatPacket.SendServerMessage(session, logMsg, ChatMessageType.Broadcast);
                                    }
                                    else
                                    {
                                        Console.WriteLine(logMsg);
                                    }

                                    return false;
                                }
                                else
                                {
                                    acp.Value = targetPlayer3;
                                    acp.Defaulted = false;
                                }
                                break;
                            case ACECommandParameterType.OnlinePlayerIid:
                                Match matcha5 = Regex.Match(parameterBlob, /*((i == 0) ? "" : @"\s+") +*/ @"(\d{10})$|(0x[0-9a-f]{8})$", RegexOptions.IgnoreCase);
                                if (matcha5.Success)
                                {
                                    string strIid = "";
                                    if (matcha5.Groups[2].Success)
                                    {
                                        strIid = matcha5.Groups[2].Value;
                                    }
                                    else if (matcha5.Groups[1].Success)
                                    {
                                        strIid = matcha5.Groups[1].Value;
                                    }
                                    try
                                    {
                                        uint iid = 0;
                                        if (strIid.StartsWith("0x"))
                                        {
                                            iid = Convert.ToUInt32(strIid, 16);
                                        }
                                        else
                                        {
                                            iid = uint.Parse(strIid);
                                        }

                                        Player targetPlayer2 = PlayerManager.GetOnlinePlayer(iid);
                                        if (targetPlayer2 == null)
                                        {
                                            string logMsg = $"Unable to find player with iid {strIid}";
                                            if (session != null)
                                            {
                                                ChatPacket.SendServerMessage(session, logMsg, ChatMessageType.Broadcast);
                                            }
                                            else
                                            {
                                                Console.WriteLine(logMsg);
                                            }
                                            return false;
                                        }
                                        else
                                        {
                                            acp.Value = targetPlayer2;
                                            acp.Defaulted = false;
                                            parameterBlob = (matcha5.Groups[1].Index == 0) ? string.Empty : parameterBlob.Substring(0, matcha5.Groups[1].Index).Trim(new char[] { ' ', ',' });
                                        }
                                    }
                                    catch (Exception)
                                    {
                                        string errorMsg = $"Unable to parse {strIid} into a player iid";
                                        if (session != null)
                                        {
                                            ChatPacket.SendServerMessage(session, errorMsg, ChatMessageType.Broadcast);
                                        }
                                        else
                                        {
                                            Console.WriteLine(errorMsg);
                                        }
                                        return false;
                                    }
                                }
                                break;
                            case ACECommandParameterType.PlayerName:
                                if (i != 0)
                                {
                                    throw new Exception("Player name parameter must be the first parameter, since it can contain spaces.");
                                }
                                parameterBlob = parameterBlob.TrimEnd(new char[] { ' ', ',' });
                                if (string.IsNullOrWhiteSpace(parameterBlob))
                                {
                                    break;
                                }
                                else
                                {
                                    acp.Value = parameterBlob;
                                    acp.Defaulted = false;
                                }
                                break;
                            case ACECommandParameterType.Uri:
                                Match match5 = Regex.Match(parameterBlob, @"(https?:\/\/(www\.)?[-a-zA-Z0-9@:%._\+~#=]{2,256}\.[a-z]{2,6}\b([-a-zA-Z0-9@:%_\+.~#?&//=]*))$", RegexOptions.IgnoreCase);
                                if (match5.Success)
                                {
                                    string strUri = match5.Groups[1].Value;
                                    try
                                    {
                                        Uri url = new Uri(strUri);
                                        acp.Value = url;
                                        acp.Defaulted = false;
                                        parameterBlob = (match5.Groups[1].Index == 0) ? string.Empty : parameterBlob.Substring(0, match5.Groups[1].Index).Trim(new char[] { ' ', ',' });
                                    }
                                    catch (Exception)
                                    {
                                        return false;
                                    }
                                }
                                break;
                            case ACECommandParameterType.DoubleQuoteEnclosedText:
                                Match match6 = Regex.Match(parameterBlob.TrimEnd(), @"(\"".*\"")$", RegexOptions.IgnoreCase);
                                if (match6.Success)
                                {
                                    string txt = match6.Groups[1].Value;
                                    try
                                    {
                                        acp.Value = txt.Trim('"');
                                        acp.Defaulted = false;
                                        parameterBlob = (match6.Groups[1].Index == 0) ? string.Empty : parameterBlob.Substring(0, match6.Groups[1].Index).Trim(new char[] { ' ', ',' });
                                    }
                                    catch (Exception)
                                    {
                                        return false;
                                    }
                                }
                                break;
                            case ACECommandParameterType.CommaPrefixedText:
                                if (i == 0)
                                {
                                    throw new Exception("this parameter type is not appropriate as the first parameter");
                                }
                                if (i == acps.Count - 1 && !acp.Required && commaCount < acps.Count - 1)
                                {
                                    break;
                                }
                                Match match7 = Regex.Match(parameterBlob.TrimEnd(), @"\,\s*([^,]*)$", RegexOptions.IgnoreCase);
                                if (match7.Success)
                                {
                                    string txt = match7.Groups[1].Value;
                                    try
                                    {
                                        acp.Value = txt.TrimStart(new char[] { ' ', ',' });
                                        acp.Defaulted = false;
                                        parameterBlob = (match7.Groups[1].Index == 0) ? string.Empty : parameterBlob.Substring(0, match7.Groups[1].Index).Trim(new char[] { ' ', ',' });
                                    }
                                    catch (Exception)
                                    {
                                        return false;
                                    }
                                }
                                break;
                            case ACECommandParameterType.SimpleWord:
                                Match match8 = Regex.Match(parameterBlob.TrimEnd(), @"([a-zA-Z1-9_]+)\s*$", RegexOptions.IgnoreCase);
                                if (match8.Success)
                                {
                                    string txt = match8.Groups[1].Value;
                                    try
                                    {
                                        acp.Value = txt.TrimStart(' ');
                                        acp.Defaulted = false;
                                        parameterBlob = (match8.Groups[1].Index == 0) ? string.Empty : parameterBlob.Substring(0, match8.Groups[1].Index).Trim(new char[] { ' ', ',' });
                                    }
                                    catch (Exception)
                                    {
                                        return false;
                                    }
                                }
                                break;
                            case ACECommandParameterType.Enum:
                                if (acp.PossibleValues == null)
                                {
                                    throw new Exception("The enum parameter type must be accompanied by the PossibleValues");
                                }
                                if (!acp.PossibleValues.IsEnum)
                                {
                                    throw new Exception("PossibleValues must be an enum type");
                                }
                                Match match9 = Regex.Match(parameterBlob.TrimEnd(), @"([a-zA-Z1-9_]+)\s*$", RegexOptions.IgnoreCase);
                                if (match9.Success)
                                {
                                    string txt = match9.Groups[1].Value;
                                    try
                                    {
                                        txt = txt.Trim(new char[] { ' ', ',' });
                                        Array etvs = Enum.GetValues(acp.PossibleValues);
                                        foreach (object etv in etvs)
                                        {
                                            if (etv.ToString().ToLower() == txt.ToLower())
                                            {
                                                acp.Value = etv;
                                                acp.Defaulted = false;
                                                parameterBlob = (match9.Groups[1].Index == 0) ? string.Empty : parameterBlob.Substring(0, match9.Groups[1].Index).Trim(new char[] { ' ' });
                                                break;
                                            }
                                        }
                                    }
                                    catch (Exception)
                                    {
                                        return false;
                                    }
                                }
                                break;
                        }
                    }
                    catch
                    {
                        return false;
                    }
                }
                if (acp.Defaulted)
                {
                    acp.Value = acp.DefaultValue;
                }

                if (acp.Required && acp.Defaulted)
                {
                    if (!string.IsNullOrWhiteSpace(acp.ErrorMessage))
                    {
                        if (session != null)
                        {
                            ChatPacket.SendServerMessage(session, acp.ErrorMessage, ChatMessageType.Broadcast);
                        }
                        else
                        {
                            Console.WriteLine(acp.ErrorMessage);
                        }
                    }

                    return false;
                }
            }
            return true;
        }
        /// <summary>
        /// Try to parse a player supplied coordinate into a position
        /// </summary>
        /// <param name="parameters">parameter array containing 2 contiguous elements: first is north/south, second is east/west</param>
        /// <param name="errorMessage">the problem encountered while trying to parse</param>
        /// <param name="position">the resultant ACE.Entity.Position</param>
        /// <param name="startingElement">the first zero based element index of the 2 contiguous elements in the parameter array</param>
        /// <returns>the parsing was successful or not</returns>
        public static bool TryParsePosition(string[] parameters, out string errorMessage, out Position position, int startingElement = 0)
        {
            errorMessage = string.Empty;
            position = null;
            if (parameters.Length - startingElement - 1 < 1)
            {
                errorMessage = "not enough parameters";
                return false;
            }

            string northSouth = parameters[startingElement].ToLower().Replace(",", "").Trim();
            string eastWest = parameters[startingElement + 1].ToLower().Replace(",", "").Trim();


            if (!northSouth.EndsWith("n") && !northSouth.EndsWith("s"))
            {
                errorMessage = "Missing n or s indicator on first parameter";
                return false;
            }

            if (!eastWest.EndsWith("e") && !eastWest.EndsWith("w"))
            {
                errorMessage = "Missing e or w indicator on second parameter";
                return false;
            }

            if (!float.TryParse(northSouth.Substring(0, northSouth.Length - 1), out float coordNS))
            {
                errorMessage = "North/South coordinate is not a valid number.";
                return false;
            }

            if (!float.TryParse(eastWest.Substring(0, eastWest.Length - 1), out float coordEW))
            {
                errorMessage = "East/West coordinate is not a valid number.";
                return false;
            }

            if (northSouth.EndsWith("s"))
            {
                coordNS *= -1.0f;
            }

            if (eastWest.EndsWith("w"))
            {
                coordEW *= -1.0f;
            }

            try
            {
                position = new Position(new Vector2(coordEW, coordNS));
                position.AdjustMapCoords();
            }
            catch (Exception e)
            {
                Console.WriteLine(e);
                errorMessage = $"There was a problem with that location (bad coordinates?).";
                return false;
            }
            return true;
        }
    }
}