// ==========================================================================
//  Squidex Headless CMS
// ==========================================================================
//  Copyright (c) Squidex UG (haftungsbeschraenkt)
//  All rights reserved. Licensed under the MIT license.
// ==========================================================================

using System.Globalization;
using System.Text;
using System.Text.Json;

namespace GenerateLanguages
{
    public static class Program
    {
        public static void Main()
        {
            var languageCodesFile = new FileInfo("../../../../../src/Squidex.Infrastructure/Languages.cs");

            var languages = ReadLanguages();

            var writer = new SourceBuilder();
            writer.WriteLine("// ==========================================================================");
            writer.WriteLine("//  Languages.cs");
            writer.WriteLine("//  Squidex Headless CMS");
            writer.WriteLine("// ==========================================================================");
            writer.WriteLine("//  Copyright (c) Squidex UG (haftungsbeschränkt)");
            writer.WriteLine("//  All rights reserved. Licensed under the MIT license.");
            writer.WriteLine("// ==========================================================================");
            writer.WriteLine("// <autogenerated/>");
            writer.WriteLine();
            writer.WriteLine("using System.CodeDom.Compiler;");
            writer.WriteLine();
            writer.WriteLine("namespace Squidex.Infrastructure");
            writer.WriteLine("{");
            writer.WriteLine("[GeneratedCode(\"LanguagesGenerator\", \"1.0\")]");
            writer.WriteLine("public partial record Language");
            writer.WriteLine("{");
            writer.WriteLine("private static readonly Dictionary<string, Language> LanguageByCode = new Dictionary<string, Language>(StringComparer.OrdinalIgnoreCase);");
            writer.WriteLine("private static readonly Dictionary<string, string> NamesEnglish = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);");
            writer.WriteLine("private static readonly Dictionary<string, string> NamesNative = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);");
            writer.WriteLine();
            writer.WriteLine("internal static Language AddLanguage(string iso2Code, string englishName, string nativeName)");
            writer.WriteLine("{");
            writer.WriteLine("NamesEnglish[iso2Code] = englishName;");
            writer.WriteLine("NamesNative[iso2Code] = nativeName;");
            writer.WriteLine();
            writer.WriteLine("return LanguageByCode.GetOrAdd(iso2Code, code => new Language(code));");
            writer.WriteLine("}");
            writer.WriteLine();

            foreach (var language in languages)
            {
                writer.WriteLine($"public static readonly Language {language.FieldName} = AddLanguage(\"{language.Code}\", \"{language.NameEnglish}\", \"{language.NameNative}\");");
            }

            writer.WriteLine("}");
            writer.WriteLine("}");

            File.WriteAllText(languageCodesFile.FullName, writer.ToString());
        }

        private static List<Language> ReadLanguages()
        {
            var languages = new List<Language>();

            var json = File.ReadAllText("languages.json");

            var deserialized = JsonSerializer.Deserialize<Dictionary<string, Dictionary<string, string>>>(json);

            static string ToFieldName(string name)
            {
                var sb = new StringBuilder();

                foreach (var c in name)
                {
                    if (char.IsLetterOrDigit(c))
                    {
                        sb.Append(c);
                    }
                }

                return sb.ToString();
            }

            foreach (var (code, value) in deserialized)
            {
                var name = value["name"];

                languages.Add(new Language
                {
                    Code = code,
                    NameNative = value["nativeName"],
                    NameEnglish = value["name"],
                    FieldName = code.ToUpperInvariant()
                });
            }

            foreach (var culture in CultureInfo.GetCultures(CultureTypes.SpecificCultures))
            {
                var code = culture.ToString();

                if (code.Length == 5 && languages.Any(l => l.Code.Equals(culture.TwoLetterISOLanguageName, StringComparison.OrdinalIgnoreCase)))
                {
                    languages.Add(new Language
                    {
                        Code = code,
                        NameNative = culture.NativeName,
                        NameEnglish = culture.EnglishName,
                        FieldName = ToFieldName(culture.EnglishName)
                    });
                }
            }

            var oldFile = File.ReadAllLines("old-languages.csv");

            foreach (var line in oldFile.Skip(1))
            {
                var code = line.Substring(1, 2);

                if (!languages.Any(x => x.Code == code))
                {
                    throw new InvalidOperationException($"Cannot find old language code {code}.");
                }
            }

            return languages;
        }
    }
}