using System;
using System.Collections.Generic;
using System.Reflection;

namespace MbUnit.ReSharperRunner.MbUnit
{
    public class ReflectionUtility
    {
        public static MethodInfo FindMethod(string assembly, string methodName)
        {
            Type type = Type.GetType(string.Format("{0}, {1}", GetTypeName(methodName), assembly), true);
            return FindMethod(type, GetMethodSignature(methodName));
        }

        public static MethodInfo FindMethod(string methodName)
        {
            Type type = Type.GetType(GetTypeName(methodName), true);
            return FindMethod(type, GetMethodSignature(methodName));
        }

        public static string GetTypeName(string methodName)
        {
            int bracketPosition = methodName.IndexOf('(');
            int dotPosition = methodName.LastIndexOf('.', bracketPosition > 0 ? bracketPosition : methodName.Length);
            return methodName.Substring(0, dotPosition);
        }

        public static MethodInfo FindMethod(Type type, string methodSignature)
        {
            return type.GetMethod(GetMethodName(methodSignature), GetParameterTypes(methodSignature));
        }

        private static Type[] GetParameterTypes(string methodSignature)
        {
            List<Type> resultTypes = new List<Type>();
            foreach (string typeName in GetParameterList(methodSignature))
            {
                if (typeName.IndexOf(' ') > 0) // Wenn noch eine Variablenname dran hängt
                {
                    resultTypes.Add(Type.GetType(typeName.Substring(0, typeName.IndexOf(' ')), true));
                }
                else
                {
                    resultTypes.Add(Type.GetType(typeName, true));
                }
            }
            return resultTypes.ToArray();
        }

        private static string[] GetParameterList(string methodSignature)
        {
            List<string> parameterList = new List<string>();
            int firstBracket = methodSignature.IndexOf('(');
            if (firstBracket > 0)
            {
                int lastBracket = methodSignature.LastIndexOf(')');
                if (lastBracket > 0)
                {
                    string textParameters = methodSignature.Substring(firstBracket + 1, lastBracket - firstBracket - 1);
                    string[] parameters = textParameters.Split(',');
                    for (int i = 0; i < parameters.Length; i++)
                    {
                        parameterList.Add(parameters[i].Trim());
                    }
                }
            }
            return parameterList.ToArray();
        }

        private static string GetMethodName(string methodSignature)
        {
            int bracketPos = methodSignature.IndexOf('(');
            int lastDotPos = bracketPos > 0
                                 ? methodSignature.LastIndexOf('.', bracketPos)
                                 : methodSignature.LastIndexOf('.');
            lastDotPos++;
            int methodLength = bracketPos > 0 ? bracketPos - lastDotPos : methodSignature.Length - lastDotPos;

            return methodSignature.Substring(lastDotPos, methodLength);
        }

        private static string GetMethodSignature(string fullMethodName)
        {
            int bracketPos = fullMethodName.IndexOf('(');
            int lastDotPos = bracketPos > 0
                                 ? fullMethodName.LastIndexOf('.', bracketPos)
                                 : fullMethodName.LastIndexOf('.');
            return lastDotPos >= 0 ? fullMethodName.Substring(lastDotPos + 1) : fullMethodName;
        }
    }
}