using System;
using System.Collections.Generic;
using System.Collections;
using System.Reflection;
using ln.logging;
using System.ComponentModel;
namespace ln.types
{

    public class Argument
    {
        public char Short { get; }
        public String Long { get; }

        public bool NeedsValue { get; }
        public bool HasValue => Value != null;

        public String Value { get; set; }
        public int IntegerValue => int.Parse(Value);
        public double DoubleValue => double.Parse(Value);

        public bool IsSet { get; set; }

        public Argument(char shortName, string longName)
        {
            Short = shortName;
            Long = longName;

            NeedsValue = false;
        }
        public Argument(char shortName, string longName, int defaultValue)
            : this(shortName, longName, defaultValue.ToString()) { }
        public Argument(char shortName, string longName, double defaultValue)
            : this(shortName, longName, defaultValue.ToString()) { }

        public Argument(char shortName, string longName, string defaultValue)
        {
            Short = shortName;
            Long = longName;

            NeedsValue = true;
            Value = defaultValue;
        }



    }

    /// <summary>
    /// Argument container.
    /// </summary>
    /// <remarks>
    /// This class parses command line arguments to a list of predefined well known arguments.
    /// Remaining arguments will be found in <c>AdditionalArguments</c>.
    /// 
    /// <c>ArgumentContainer</c> also provides a global command line option:
    ///   --change-static <para>typename</para> <para>fieldname</para> <para>value</para>
    /// It may be used multiple times on the command line.
    /// It will load the type referenced by the qualified name <para>typename</para> and try to set the static field <para>fieldname</para> to <para>value</para>.
    /// <para>value</para> will be casted to field type via Convert.ChangeType(...)
    /// </remarks>
    public class ArgumentContainer
    {
        List<Argument> arguments;
        List<String> additionalArguments;

        public string[] AdditionalArguments => additionalArguments.ToArray();

        public ArgumentContainer()
        {
            arguments = new List<Argument>();
            additionalArguments = new List<string>();
        }
        public ArgumentContainer(IEnumerable<Argument> argumentDefinitions)
            : this()
        {
            arguments.AddRange(argumentDefinitions);
        }

        public Argument this[string longName]
        {
            get
            {
                if (longName == null)
                    throw new ArgumentNullException(nameof(longName));

                foreach (Argument argument in arguments)
                {
                    if (longName.Equals(argument.Long))
                        return argument;
                }
                throw new KeyNotFoundException();
            }
        }
        public Argument this[char shortName]
        {
            get
            {
                if (shortName == 0)
                    throw new ArgumentNullException(nameof(shortName));

                foreach (Argument argument in arguments)
                {
                    if (shortName.Equals(argument.Short))
                        return argument;
                }
                throw new KeyNotFoundException();
            }
        }

        public bool Contains(string longName)
        {
            if (longName != null)
            foreach (Argument argument in arguments)
            {
                if (longName.Equals(argument.Long))
                    return true;
            }
            return false;
        }
        public bool Contains(char shortName)
        {
            if (shortName == (char)0)
                return false;

            foreach (Argument argument in arguments)
            {
                if (shortName.Equals(argument.Short))
                    return true;
            }
            return false;
        }

        public ArgumentContainer Add(Argument argument)
        {
            if (Contains(argument.Short) || Contains(argument.Long))
                throw new ArgumentException(nameof(argument),String.Format("0x{0:x} / {1}",(int)argument.Short,argument.Long));

            arguments.Add(argument);
            return this;
        }
        public ArgumentContainer Add(char shortName) => Add(new Argument(shortName, null));
        public ArgumentContainer Add(string longName) => Add(new Argument((char)0, longName));
        public ArgumentContainer Add(char shortName, string longName) => Add(new Argument(shortName, longName));
        public ArgumentContainer Add(char shortName, string longName, string defaultValue) => Add(new Argument(shortName, longName, defaultValue));
        public ArgumentContainer Add(int shortName, string longName, string defaultValue) => Add(new Argument((char)shortName, longName, defaultValue));

        public void Parse(IEnumerable<string> args)
        {
            Queue<string> q = new Queue<string>(args);
            while (q.Count > 0)
            {
                string currentOption = q.Dequeue();

                if (currentOption[0].Equals('-'))
                {
                    if (currentOption[1].Equals('-'))
                    {
                        String aname = currentOption.Substring(2);

                        if (aname.Equals("change-static"))
                        {
                            string typeName = q.Dequeue();
                            string fieldName = q.Dequeue();
                            string value = q.Dequeue();
                            ChangeStatic(typeName, fieldName, value);
                        }
                        else
                        {
                            Argument argument = this[aname];
                            argument.IsSet = true;
                            if (argument.NeedsValue)
                                argument.Value = q.Dequeue();
                        }
                    }
                    else
                    {
                        foreach (char option in currentOption.Substring(1))
                        {
                            Argument argument = this[option];
                            argument.IsSet = true;
                            if (argument.NeedsValue)
                                argument.Value = q.Dequeue();
                        }

                    }
                }
                else
                {
                    additionalArguments.Add(currentOption);
                }
            }
        }

        public void ChangeStatic(string typeName,string fieldname,string value)
        {
            Type type = Type.GetType(typeName);
            Logging.Log(LogLevel.INFO, "ArgumentContainer: ChangeStatic: Type:  {0}",type);

            FieldInfo fieldInfo = type.GetField(fieldname, BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic);
            Logging.Log(LogLevel.INFO, "ArgumentContainer: ChangeStatic: Field: {0} {1}", fieldname, fieldInfo);

            object castValue = Convert.ChangeType(value, fieldInfo.FieldType);
            fieldInfo.SetValue(null,castValue);
        }
    }
}