using NUnit.Framework;
using System.Globalization;
using System.Linq;
using System.Reflection;
using AngleSharp.Common;
using Discord.Commands;
using NadekoBot.Common.Attributes;
using NadekoBot.Core.Services;
using NadekoBot.Modules;
using YamlDotNet.Serialization;

namespace Nadeko.Tests
{
    public class CommandStringsTests
    {
        private const string responsesPath = "../../../../src/NadekoBot/data/strings/responses";
        private const string commandsPath = "../../../../src/NadekoBot/data/strings/commands";
        private const string aliasesPath = "../../../../src/NadekoBot/data/aliases.yml";
        [Test]
        public void AllCommandNamesHaveStrings()
        {
            var stringsSource = new LocalFileStringsSource(
                responsesPath,
                commandsPath);
            var strings = new LocalBotStringsProvider(stringsSource);

            var culture = new CultureInfo("en-US");

            var isSuccess = true;
            foreach (var entry in CommandNameLoadHelper.LoadCommandNames(aliasesPath))
            {
                var commandName = entry.Value[0];

                var cmdStrings = strings.GetCommandStrings(culture.Name, commandName);
                if (cmdStrings is null)
                {
                    isSuccess = false;
                    TestContext.Out.WriteLine($"{commandName} doesn't exist in commands.en-US.yml");
                }
            }

            Assert.IsTrue(isSuccess);
        }

        private static string[] GetCommandMethodNames()
            => typeof(NadekoBot.NadekoBot).Assembly
                .GetExportedTypes()
                .Where(type => type.IsClass && !type.IsAbstract)
                .Where(type => typeof(NadekoModule).IsAssignableFrom(type) // if its a top level module
                               || !(type.GetCustomAttribute<GroupAttribute>(true) is null)) // or a submodule
                .SelectMany(x => x.GetMethods()
                        .Where(mi => mi.CustomAttributes
                            .Any(ca => ca.AttributeType == typeof(NadekoCommandAttribute))))
                .Select(x => x.Name.ToLowerInvariant())
                .ToArray();

        [Test]
        public void AllCommandMethodsHaveNames()
        {
            var allAliases = CommandNameLoadHelper.LoadCommandNames(
                aliasesPath);

            var methodNames = GetCommandMethodNames();

            var isSuccess = true;
            foreach (var methodName in methodNames)
            {
                if (!allAliases.TryGetValue(methodName, out var _))
                {
                    TestContext.Error.WriteLine($"{methodName} is missing an alias.");
                    isSuccess = false;
                }
            }
            
            Assert.IsTrue(isSuccess);
        }
        
        [Test]
        public void NoObsoleteAliases()
        {
            var allAliases = CommandNameLoadHelper.LoadCommandNames(aliasesPath);

            var methodNames = GetCommandMethodNames()
                .ToHashSet();

            var isSuccess = true;

            foreach (var item in allAliases)
            {
                var methodName = item.Key;

                if (!methodNames.Contains(methodName))
                {
                    TestContext.WriteLine($"'{methodName}' from aliases.yml doesn't have a matching command method.");
                    isSuccess = false;
                }
            }
            
            Assert.IsTrue(isSuccess);
        }
        
        // [Test]
        // public void NoObsoleteCommandStrings()
        // {
        //     var stringsSource = new LocalFileStringsSource(responsesPath, commandsPath);
        //
        //     var culture = new CultureInfo("en-US");
        //
        //     var isSuccess = true;
        //     var allCommandNames = CommandNameLoadHelper.LoadCommandNames(aliasesPath);
        //     var enUsCommandNames = allCommandNames
        //         .Select(x => x.Value[0]) // first alias is command name
        //         .ToHashSet();
        //     foreach (var entry in stringsSource.GetCommandStrings()[culture.Name])
        //     {
        //         // key is command name which should be specified in aliases[0] of any method name
        //         var cmdName = entry.Key;
        //
        //         if (!enUsCommandNames.Contains(cmdName))
        //         {
        //             TestContext.Out.WriteLine($"'{cmdName}' It's either obsolete or missing an alias entry.");
        //             isSuccess = false;
        //         }
        //     }
        //
        //     Assert.IsTrue(isSuccess);
        // }
    }
}