using System;
using System.Collections.Generic;
using System.Text;
using System.Text.RegularExpressions;
using System.Diagnostics;
using System.IO;
using System.Runtime.ConstrainedExecution;

namespace cscz
{
	public enum GenerationMode
	{
		PrivateVariablesWithProperties,
		PublicVariables,
		PublicAutoProperties
	}

	public class ClassGenerator
	{
		/// <summary>
		/// A mapping of namespaces to using shortcuts.
		/// </summary>
		public Dictionary<string, string> UsingShortcuts = new Dictionary<string, string>()
		{
			["c"] = "System.Collections.Generic",
			["cc"] = "System.Collections.Concurrent",
			["r"] = "System.Text.RegularExpressions",
			["n"] = "System.Net",
			["s"] = "System.Net.Sockets",
			["x"] = "Microsoft.Xna.Framework",
			["xg"] = "Microsoft.Xna.Framework.Graphics",
			["xs"] = "Microsoft.Xna.Framework.Storage",
			["xi"] = "Microsoft.Xna.Framework.Input",
			["oo"] = "OpenTK.Graphics.OpenGL"
		};

		/// <summary>
		/// The using statements to add to the generated class.
		/// </summary>
		public List<string> UsingStatements = new List<string>()
		{
			"System"
		};
		public List<string> Signatures = new List<string>();

		public string ClassName = "Carrot";
		public string Namespace = string.Empty;

		public GenerationMode GenerationMode = GenerationMode.PublicVariables;

		/// <summary>
		/// Whether to make data members private and create public properties for them instead of making the
		/// data members public.
		/// This is read only. Please refer to GenerationMode in order to change this field.
		/// </summary>
		public bool CreateProperties
		{
			get
			{
				if (GenerationMode == GenerationMode.PrivateVariablesWithProperties)
					return true;
				return false;
			}
		}

		public ClassGenerator ()
		{
		}

		public void ParseString(string source)
		{
			StringReader lines = new StringReader(source);

			string nextLine = string.Empty;
			do {
				nextLine = lines.ReadLine();

				if(nextLine == null) break;
				if(nextLine.Length == 0) continue;

				nextLine = nextLine.Trim();

				// It's a using statement
				if(nextLine.StartsWith("- "))
				{
					string[] parts = Regex.Split(nextLine, @"\s+");
					UsingStatements.Add(parts[1]);
				}
				else if(nextLine.StartsWith("#"))
				{
					// It's the class name
					ClassName = UppercaseFirstLetter(nextLine.TrimStart(new char[] { '#' })).Trim();
					// Parse the namespace, if one is present
					if(ClassName.Contains("."))
					{
						Namespace = ClassName.Substring(0, ClassName.LastIndexOf("."));
						ClassName = ClassName.Substring(ClassName.LastIndexOf(".") + 1);
					}
				}
				else
				{
					Signatures.Add(nextLine.Trim());
				}
			} while(nextLine != null);
		}

		public override string ToString()
		{
			StringWriter usingStatements = new StringWriter();

			// Generate the using statements
			foreach(string usingStatement in UsingStatements)
				usingStatements.WriteLine("using {0};", expandUsingShortcut(usingStatement));

			// Generate the class itself
			StringWriter classCode = new StringWriter();

			// Class name
			classCode.WriteLine("class {0} ", ClassName);
			classCode.WriteLine("{");

			// Class body parts declaration
			StringBuilder constructorSignature = new StringBuilder(string.Format("\tpublic {0}(", ClassName)); // This has to be a StringBuilder because of the Remove() class later on
			StringWriter properties = new StringWriter();
			StringWriter constructorBody = new StringWriter();

			// Data member signature handling
			foreach (string signature in Signatures)
			{
				string[] signatureParts = Regex.Split(signature, @"\s+");
				string datatypeName = signatureParts[0];
				string privateDataMemberName = LowercaseFirstLetter(signatureParts[1]);
				string publicDataMemberName = UppercaseFirstLetter(signatureParts[1]);

				constructorSignature.AppendFormat("{0} in{1}, ", datatypeName, publicDataMemberName);

				if (CreateProperties)
				{
					// Private data member
					classCode.WriteLine("\tprivate {0} {1};", datatypeName, privateDataMemberName);

					// Public property associated with above private data member
					properties.WriteLine("\tpublic {0} {1}", datatypeName, publicDataMemberName);
					properties.WriteLine("\t{");
					properties.WriteLine("\t\tget {{ return {0}; }}", privateDataMemberName);
					properties.WriteLine("\t\tset {{ {0} = value; }}", privateDataMemberName);
					properties.WriteLine("\t}");

					// Constructor body
					constructorBody.WriteLine("\t\t{0} = in{0};", publicDataMemberName);
				}
				else
				{
					// Constuctor body
					classCode.WriteLine("\tpublic {0} {1};", datatypeName, publicDataMemberName);
					constructorBody.WriteLine("\t\t{0} = in{0};", publicDataMemberName);
				}
			}

			// Add the properties to the output
			classCode.WriteLine(properties.ToString());

			// Add the constructor to the output
			constructorSignature.Remove(constructorSignature.Length - 2, 2); // Remove the last ", "
			constructorSignature.Append(")");
			classCode.WriteLine(constructorSignature.ToString());
			classCode.WriteLine("\t{");
			classCode.Write(constructorBody.ToString());
			classCode.WriteLine("\t}");

			// Close the class off and end the file
			classCode.WriteLine("}");

			StringWriter result = new StringWriter();
			result.WriteLine(usingStatements);

			if(Namespace == string.Empty)
			{
				result.WriteLine(classCode);
			}
			else
			{
				result.WriteLine("namespace {0}", Namespace);
				result.WriteLine("{");
				result.WriteLine("\t" + classCode.ToString().Replace("\n", "\n\t"));
				result.WriteLine("}");
			}

			return result.ToString();
		}

		protected string expandUsingShortcut(string shortcut)
		{
			if (UsingShortcuts.ContainsKey(shortcut))
				return UsingShortcuts[shortcut];
			else
				return shortcut;
		}

		private string UppercaseFirstLetter(string str)
		{
			if (str == null)
				return null;
			if (str.Length > 1)
				return char.ToUpper(str[0]) + str.Substring(1);
			return str.ToUpper();
		}
		private string LowercaseFirstLetter(string str)
		{
			if (str == null)
				return null;
			if (str.Length > 1)
				return char.ToLower(str[0]) + str.Substring(1);
			return str.ToLower();
		}
	}
}