using System;
using System.CodeDom;
using System.CodeDom.Compiler;
using System.Globalization;
using System.IO;
using System.Text;
using Microsoft.CSharp;

namespace ChristianHelle.DeveloperTools.CodeGenerators.Resw.VSPackage.CustomTool
{
    public class CodeDomCodeGenerator : CodeGenerator
    {
        private readonly string className;
        private readonly CodeNamespace codeNamespace;
        private readonly CodeCompileUnit compileUnit;
        private readonly CodeDomProvider provider;

        public CodeDomCodeGenerator(IResourceParser resourceParser, string className, string defaultNamespace, CodeDomProvider codeDomProvider = null)
            : base(resourceParser, defaultNamespace)
        {
            this.className = className;
            compileUnit = new CodeCompileUnit();
            provider = codeDomProvider ?? new CSharpCodeProvider();
            codeNamespace = new CodeNamespace(defaultNamespace);
        }

        public override string GenerateCode()
        {
            codeNamespace.Comments.Add(new CodeCommentStatement("--------------------------------------------------------------------------------------------------"));
            codeNamespace.Comments.Add(new CodeCommentStatement("<auto-generatedInfo>"));
            codeNamespace.Comments.Add(new CodeCommentStatement("\tThis code was generated by ResW File Code Generator (http://reswcodegen.codeplex.com)"));
            codeNamespace.Comments.Add(new CodeCommentStatement("\tResW File Code Generator was written by Christian Resma Helle"));
            codeNamespace.Comments.Add(new CodeCommentStatement("\tand is under GNU General Public License version 2 (GPLv2)"));
            codeNamespace.Comments.Add(new CodeCommentStatement(string.Empty));
            codeNamespace.Comments.Add(new CodeCommentStatement("\tThis code contains a helper class exposing property representations"));
            codeNamespace.Comments.Add(new CodeCommentStatement("\tof the string resources defined in the specified .ResW file"));
            codeNamespace.Comments.Add(new CodeCommentStatement(string.Empty));
            codeNamespace.Comments.Add(new CodeCommentStatement("\tGenerated: " + DateTime.Now.ToString(CultureInfo.InvariantCulture)));
            codeNamespace.Comments.Add(new CodeCommentStatement("</auto-generatedInfo>"));
            codeNamespace.Comments.Add(new CodeCommentStatement("--------------------------------------------------------------------------------------------------"));

            codeNamespace.Imports.Add(new CodeNamespaceImport("Windows.ApplicationModel.Resources"));

            var targetClass = new CodeTypeDeclaration(className)
                                  {
                                      IsClass = true,
                                      IsPartial = true,
                                      Attributes = MemberAttributes.Public | MemberAttributes.Static
                                  };

            const string resourceLoaderType = "ResourceLoader";
            var resourceLoaderField = new CodeMemberField(resourceLoaderType, "resourceLoader")
                                          {
                                              Attributes = MemberAttributes.Private | MemberAttributes.Static | MemberAttributes.Final
                                          };
            targetClass.Members.Add(resourceLoaderField);

            var constructor = new CodeTypeConstructor();

            var executingAssemblyVar = new CodeVariableDeclarationStatement(typeof(string), "executingAssemblyName");
            var executingAssemblyInit = new CodeAssignStatement(
                new CodeVariableReferenceExpression("executingAssemblyName"),
                new CodeSnippetExpression("Windows.UI.Xaml.Application.Current.GetType().AssemblyQualifiedName"));
            var executingAssemblySplit = new CodeVariableDeclarationStatement(typeof(string[]), "executingAssemblySplit");
            var executingAssemblyInit2 = new CodeAssignStatement(
                new CodeVariableReferenceExpression("executingAssemblySplit"),
                new CodeMethodInvokeExpression(new CodeVariableReferenceExpression("executingAssemblyName"), "Split", new CodePrimitiveExpression(',')));
            var executingAssemblyInit3 = new CodeAssignStatement(
                new CodeVariableReferenceExpression("executingAssemblyName"),
                new CodeArrayIndexerExpression(new CodeVariableReferenceExpression("executingAssemblySplit"), new CodePrimitiveExpression(1)));

            var currentAssemblyVar = new CodeVariableDeclarationStatement(typeof(string), "currentAssemblyName");
            var currentAssemblyInit = new CodeAssignStatement(
                new CodeVariableReferenceExpression("currentAssemblyName"),
                new CodePropertyReferenceExpression(new CodeTypeOfExpression(className), "AssemblyQualifiedName"));
            var currentAssemblySplit = new CodeVariableDeclarationStatement(typeof(string[]), "currentAssemblySplit");
            var currentAssemblyInit2 = new CodeAssignStatement(
                 new CodeVariableReferenceExpression("currentAssemblySplit"),
                 new CodeMethodInvokeExpression(new CodeVariableReferenceExpression("currentAssemblyName"), "Split", new CodePrimitiveExpression(',')));
            var currentAssemblyInit3 = new CodeAssignStatement(
                new CodeVariableReferenceExpression("currentAssemblyName"),
                new CodeArrayIndexerExpression(new CodeVariableReferenceExpression("currentAssemblySplit"), new CodePrimitiveExpression(1)));

            var createResourceLoader = new CodeConditionStatement(
                new CodeSnippetExpression("executingAssemblyName.Equals(currentAssemblyName)"),
                new CodeStatement[] // true
                    {
                        new CodeAssignStatement(
                            new CodeFieldReferenceExpression(null, "resourceLoader"),
                            new CodeObjectCreateExpression(new CodeTypeReference("ResourceLoader"),
                                                           new CodeSnippetExpression("\"" + className + "\"")))
                    },
                new CodeStatement[] // false
                    {
                        new CodeAssignStatement(
                            new CodeFieldReferenceExpression(null, "resourceLoader"),
                            new CodeObjectCreateExpression(new CodeTypeReference("ResourceLoader"),
                                                           new CodeSnippetExpression("currentAssemblyName + \"/" + className + "\"")))
                    });

            constructor.Statements.Add(executingAssemblyVar);
            constructor.Statements.Add(executingAssemblyInit);
            constructor.Statements.Add(executingAssemblySplit);
            constructor.Statements.Add(executingAssemblyInit2);
            constructor.Statements.Add(executingAssemblyInit3);
            constructor.Statements.Add(currentAssemblyVar);
            constructor.Statements.Add(currentAssemblyInit);
            constructor.Statements.Add(currentAssemblySplit);
            constructor.Statements.Add(currentAssemblyInit2);
            constructor.Statements.Add(currentAssemblyInit3);
            constructor.Statements.Add(createResourceLoader);

            targetClass.Members.Add(constructor);

            var resources = ResourceParser.Parse();
            foreach (var item in resources)
            {
                if (string.IsNullOrEmpty(item.Name) || item.Name.Contains("."))
                    continue;

                var property = new CodeMemberProperty
                                   {
                                       Name = item.Name.Trim(),
                                       Attributes = MemberAttributes.Public | MemberAttributes.Static,
                                       HasGet = true,
                                       Type = new CodeTypeReference(typeof(string))
                                   };

                property.Comments.Add(new CodeCommentStatement("<summary>", true));
                property.Comments.Add(new CodeCommentStatement("Localized resource similar to \"" + (item.Value ?? item.Name) + "\"", true));
                property.Comments.Add(new CodeCommentStatement("</summary>", true));
                property.GetStatements.Add(
                    new CodeMethodReturnStatement(
                        new CodeMethodInvokeExpression(
                            new CodeFieldReferenceExpression(null, "resourceLoader"), "GetString",
                            new CodePrimitiveExpression(item.Name))));

                targetClass.Members.Add(property);
            }

            codeNamespace.Types.Add(targetClass);
            compileUnit.Namespaces.Add(codeNamespace);

            return GenerateCodeFromCompileUnit();
        }

        private string GenerateCodeFromCompileUnit()
        {
            var options = new CodeGeneratorOptions { BracingStyle = "C" };

            var code = new StringBuilder();

            using (var writer = new StringWriter(code))
                provider.GenerateCodeFromCompileUnit(compileUnit, writer, options);

            return code.ToString();
        }
    }
}