using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Reflection;
using TypeLite;
using TypeLite.TsModels;

namespace MyApp.Devel.TypeLite
{
    public class CustomScriptGenerator : TsGenerator
    {
        public CustomScriptGenerator()
        {
        }

        public string GenerateEnumsCustom(TsModel model)
        {
            var sb = new ScriptBuilder(IndentationString);

            foreach (var module in model.Modules)
                this.AppendCustomEnumModule(module, sb);

            return sb.ToString();
        }

        private void AppendCustomEnumModule(TsModule module, ScriptBuilder sb)
        {
            var enums = module.Enums.Where(e => !_typeConvertors.IsConvertorRegistered(e.Type) && !e.IsIgnored).ToList();

            var moduleName = GetModuleName(module);
            if (moduleName != module.Name)
            {
                _renamedModules.Add(module.Name, moduleName);
            }

            if (enums.Any())
            {
                sb.AppendLine(string.Format("module {0} {{", moduleName));
                using (sb.IncreaseIndentation())
                {
                    foreach (var enumModel in enums)
                    {
                        this.AppendCustomEnumDefinition(enumModel, sb);
                    }
                }
                sb.AppendLine("}");
                sb.AppendLine(string.Format("export = {0};", moduleName));
            }
        }

        private void AppendCustomEnumDefinition(TsEnum enumModel, ScriptBuilder sb)
        {
            var typeName = this.GetTypeName(enumModel);

            var descriptionDictionary = new Dictionary<string, string>();

            sb.AppendLineIndented(string.Format("export module {0} {{", typeName));

            using (sb.IncreaseIndentation())
            {
                sb.AppendLineIndented("export enum Enum {");
                using (sb.IncreaseIndentation())
                {
                    var i = 1;
                    foreach (var v in enumModel.Values)
                    {
                        sb.AppendLineIndented(string.Format(i < enumModel.Values.Count ? "{0} = {1}," : "{0} = {1}", v.Name, v.Value));
                        i++;

                        var description = v.Field.GetCustomAttributes(typeof(DescriptionAttribute))
                            .Cast<DescriptionAttribute>()
                            .Select(attribute => attribute.Description.Replace("\"", "\\\""))
                            .FirstOrDefault();

                        description = description ?? v.Name;

                        descriptionDictionary.Add(v.Name, description);
                    }
                }

                sb.AppendLineIndented("}");

                sb.AppendLine();

                sb.AppendLineIndented("export function describe (enumValue: Enum) {");
                using (sb.IncreaseIndentation())
                {
                    sb.AppendLineIndented("switch (enumValue) {");
                    using (sb.IncreaseIndentation())
                    {
                        foreach (var key in descriptionDictionary.Keys)
                        {
                            sb.AppendLineIndented(string.Format("case Enum.{0}:", key));
                            using (sb.IncreaseIndentation())
                            {
                                sb.AppendLineIndented(string.Format("return \"{0}\";", descriptionDictionary[key]));
                            }
                        }
                        sb.AppendLineIndented("default:");
                        using (sb.IncreaseIndentation())
                        {
                            sb.AppendLineIndented("throw Error(\"Unknown Enum Value\");");
                        }
                    }
                    sb.AppendLineIndented("}");
                }
                sb.AppendLineIndented("}");

            }
            sb.AppendLineIndented("}");

            _generatedEnums.Add(enumModel);
        }
    }
}