using System;
using System.CodeDom;
using System.CodeDom.Compiler;
using System.IO;
using System.Linq;

namespace CodeGenerator
{
    public static class ECSClassGenerator
    {
        public static void Generate(Type entityDescriptorType)
        {
            var info = ECSAnalyzer.AnalyzeEntityDescriptor(entityDescriptorType);
            
            var codeUnit = new CodeCompileUnit();
            var ns = new CodeNamespace("TechbloxModdingAPI.Blocks");
            ns.Imports.Add(new CodeNamespaceImport("RobocraftX.Common"));
            ns.Imports.Add(new CodeNamespaceImport("Svelto.ECS"));
            var cl = new CodeTypeDeclaration(info.Name);
            cl.BaseTypes.Add(new CodeTypeReference("SignalingBlock"));
            cl.Members.Add(new CodeConstructor
            {
                Parameters = {new CodeParameterDeclarationExpression("EGID", "egid")},
                Comments =
                {
                    _start,
                    new CodeCommentStatement($"Constructs a(n) {info.Name} object representing an existing block.", true),
                    _end
                },
                BaseConstructorArgs = {new CodeVariableReferenceExpression("egid")},
                Attributes = MemberAttributes.Public | MemberAttributes.Final
            });
            foreach (var propertyInfo in info.Properties)
            {
                if (propertyInfo is ECSReflectedPropertyInfo reflectedPropertyInfo)
                    GenerateReflectedProperty(reflectedPropertyInfo, cl);
                else
                    GenerateProperty(propertyInfo, cl);
            }
            ns.Types.Add(cl);
            codeUnit.Namespaces.Add(ns);
            
            var provider = CodeDomProvider.CreateProvider("CSharp");
            var path = $"../../../../TechbloxModdingAPI/Blocks/{info.Name}.cs";
            using (var sw = new StreamWriter(path))
            {
                provider.GenerateCodeFromCompileUnit(codeUnit, sw, new CodeGeneratorOptions {BracingStyle = "C"});
            }

            File.WriteAllLines(path,
                File.ReadAllLines(path).SkipWhile(line => line.StartsWith("//") || line.Length == 0));
        }

        private static void GenerateProperty(ECSPropertyInfo info, CodeTypeDeclaration cl)
        {
                var getStruct = new CodeMethodInvokeExpression(
                        new CodeMethodReferenceExpression(new CodeSnippetExpression("BlockEngine"),
                            "GetBlockInfo", new CodeTypeReference(info.ComponentType)),
                        new CodeThisReferenceExpression());
                CodeExpression structFieldReference = new CodeFieldReferenceExpression(getStruct, info.Name);
                cl.Members.Add(new CodeMemberProperty
                {
                    Name = info.Name,
                    HasGet = true,
                    HasSet = true,
                    GetStatements =
                    {
                        new CodeMethodReturnStatement(structFieldReference)
                    },
                    SetStatements =
                    {
                            new CodeAssignStatement(structFieldReference, new CodePropertySetValueReferenceExpression())
                    },
                    Type = new CodeTypeReference(info.Type),
                    Attributes = MemberAttributes.Public | MemberAttributes.Final,
                    Comments =
                    {
                        _start,
                        new CodeCommentStatement($"Gets or sets the {info.ComponentType.Name}'s {info.Name} property." +
                                                 " May not be saved.", // TODO: Doesn't know if tweakable stat
                            true),
                        _end
                    }
                });
        }

        private static void GenerateReflectedProperty(ECSReflectedPropertyInfo info, CodeTypeDeclaration cl)
        {
            var reflectedType = new CodeSnippetExpression($"HarmonyLib.AccessTools.TypeByName(\"{info.OriginalClassName}\")");
            
            CodeExpression reflectedGet = new CodeCastExpression(info.Type, new CodeMethodInvokeExpression(
                new CodeMethodReferenceExpression(new CodeSnippetExpression("BlockEngine"),
                    "GetBlockInfo"),
                new CodeThisReferenceExpression(), reflectedType, new CodePrimitiveExpression(info.Name)));
            CodeExpression reflectedSet = new CodeMethodInvokeExpression(
                new CodeMethodReferenceExpression(new CodeSnippetExpression("BlockEngine"),
                    "SetBlockInfo"),
                new CodeThisReferenceExpression(), reflectedType, new CodePrimitiveExpression(info.Name),
                new CodePropertySetValueReferenceExpression());
            cl.Members.Add(new CodeMemberProperty
            {
                Name = info.Name,
                HasGet = true,
                HasSet = true,
                GetStatements =
                {
                    new CodeMethodReturnStatement(reflectedGet)
                },
                SetStatements =
                {
                        (CodeStatement)new CodeExpressionStatement(reflectedSet)
                },
                Type = new CodeTypeReference(info.Type),
                Attributes = MemberAttributes.Public | MemberAttributes.Final,
                Comments =
                {
                    _start,
                    new CodeCommentStatement($"Gets or sets the {info.ComponentType.Name}'s {info.Name} property." +
                                             " May not be saved.", // TODO: Doesn't know if tweakable stat
                        true),
                    _end
                }
            });
        }
        
        private static readonly CodeCommentStatement _start = new("<summary>", true);
        private static readonly CodeCommentStatement _end = new("</summary>", true);
    }
}