using System.CodeDom;
using System.CodeDom.Compiler;
using System.IO;
using System.Linq;
using RobocraftX.Common;
using Svelto.ECS;
using Techblox.EngineBlock;

namespace CodeGenerator
{
    public class BlockClassGenerator
    {
        public void Generate(string name, string group)
        {
            if (group is null)
            {
                group = GetGroup(name) + "_BLOCK_GROUP";
                if (typeof(CommonExclusiveGroups).GetFields().All(field => field.Name != group))
                    group = GetGroup(name) + "_BLOCK_BUILD_GROUP";
            }

            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(name);
            cl.BaseTypes.Add(new CodeTypeReference("Block"));
            cl.Members.Add(new CodeConstructor
            {
                Parameters = {new CodeParameterDeclarationExpression("EGID", "egid")},
                Comments = {new CodeCommentStatement($"{name} constructor", true)},
                BaseConstructorArgs = {new CodeVariableReferenceExpression("egid")}
            });
            cl.Members.Add(new CodeConstructor
            {
                Parameters =
                {
                    new CodeParameterDeclarationExpression(typeof(uint), "id")
                },
                Comments = {new CodeCommentStatement($"{name} constructor", true)},
                BaseConstructorArgs =
                {
                    new CodeObjectCreateExpression("EGID", new CodeVariableReferenceExpression("id"),
                        new CodeFieldReferenceExpression(new CodeTypeReferenceExpression("CommonExclusiveGroups"),
                            group))
                }
            });
            GenerateProperties<EngineBlockComponent>(cl);
            ns.Types.Add(cl);
            codeUnit.Namespaces.Add(ns);

            var provider = CodeDomProvider.CreateProvider("CSharp");
            using (var sw = new StreamWriter($"{name}.cs"))
            {
                provider.GenerateCodeFromCompileUnit(codeUnit, sw, new CodeGeneratorOptions {BracingStyle = "C"});
            }
        }

        private static string GetGroup(string name)
        {
            var ret = "";
            foreach (var ch in name)
            {
                if (char.IsUpper(ch) && ret.Length > 0)
                    ret += "_" + ch;
                else
                    ret += char.ToUpper(ch);
            }

            return ret;
        }

        private void GenerateProperties<T>(CodeTypeDeclaration cl) where T : IEntityComponent
        {
            var type = typeof(T);
            foreach (var field in type.GetFields())
            {
                var propName = char.ToUpper(field.Name[0]) + field.Name.Substring(1);
                var structFieldReference = new CodeFieldReferenceExpression(new CodeMethodInvokeExpression(
                    new CodeMethodReferenceExpression(new CodeSnippetExpression("BlockEngine"),
                        "GetBlockInfo", new CodeTypeReference(type)),
                    new CodeThisReferenceExpression()), field.Name);
                cl.Members.Add(new CodeMemberProperty
                {
                    Name = propName,
                    HasGet = true,
                    HasSet = true,
                    GetStatements =
                    {
                        new CodeMethodReturnStatement(structFieldReference)
                    },
                    SetStatements =
                    {
                        new CodeAssignStatement(structFieldReference, new CodePropertySetValueReferenceExpression())
                    },
                    Type = new CodeTypeReference(field.FieldType)
                });
            }
        }
    }
}