#nullable enable

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using Cysharp.Threading.Tasks;

namespace ShrinkCommand
{
    public enum ShrinkCommandSourceKind
    {
        Any = 0,
        ConsoleOnly = 1,
        NonConsoleOnly = 2
    }

    public interface IShrinkCommandSource
    {
        string SourceId { get; }
        string DisplayName { get; }
        bool IsConsole { get; }

        bool HasPermission(string permission);

        UniTask WriteLineAsync(string message, CancellationToken cancellationToken = default);
    }

    public sealed class ShrinkCommandExecutionResult
    {
        public bool IsSuccess { get; private set; }
        public string Message { get; private set; } = string.Empty;

        public static ShrinkCommandExecutionResult Success(string message = "")
        {
            return new ShrinkCommandExecutionResult
            {
                IsSuccess = true,
                Message = message ?? string.Empty
            };
        }

        public static ShrinkCommandExecutionResult Failure(string message)
        {
            return new ShrinkCommandExecutionResult
            {
                IsSuccess = false,
                Message = message ?? string.Empty
            };
        }
    }

    public sealed class ShrinkCommandDescriptor
    {
        public string Path { get; set; } = string.Empty;
        public IReadOnlyList<string> Aliases { get; set; } = Array.Empty<string>();
        public string Description { get; set; } = string.Empty;
        public string Permission { get; set; } = string.Empty;
        public ShrinkCommandSourceKind SourceKind { get; set; }
        public bool Hidden { get; set; }

        public IReadOnlyList<string> GetAllPaths()
        {
            if (Aliases == null || Aliases.Count == 0)
                return new[] { Path };

            return new[] { Path }.Concat(Aliases).ToArray();
        }
    }

    public sealed class ShrinkCommandRegistration
    {
        public string Path { get; set; } = string.Empty;
        public string[] Aliases { get; set; } = Array.Empty<string>();
        public string Description { get; set; } = string.Empty;
        public string Permission { get; set; } = string.Empty;
        public ShrinkCommandSourceKind SourceKind { get; set; } = ShrinkCommandSourceKind.Any;
        public bool Hidden { get; set; }
        public Func<ShrinkCommandContext, UniTask<ShrinkCommandExecutionResult>> Handler { get; set; } =
            _ => UniTask.FromResult(ShrinkCommandExecutionResult.Success());
    }

    public sealed class ShrinkCommandContext
    {
        private readonly IReadOnlyDictionary<string, string> _arguments;

        internal ShrinkCommandContext(
            ShrinkCommandService service,
            IShrinkCommandSource source,
            ShrinkCommandDescriptor command,
            string rawInput,
            IReadOnlyDictionary<string, string> arguments,
            CancellationToken cancellationToken)
        {
            Service = service;
            Source = source;
            Command = command;
            RawInput = rawInput ?? string.Empty;
            _arguments = arguments ?? new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
            CancellationToken = cancellationToken;
        }

        public ShrinkCommandService Service { get; }
        public IShrinkCommandSource Source { get; }
        public ShrinkCommandDescriptor Command { get; }
        public string RawInput { get; }
        public CancellationToken CancellationToken { get; }
        public IReadOnlyDictionary<string, string> Arguments => _arguments;

        public string GetArgument(string name, string fallback = "")
        {
            if (string.IsNullOrWhiteSpace(name))
                return fallback;

            return _arguments.TryGetValue(name.Trim(), out var value) ? value : fallback;
        }

        public UniTask ReplyAsync(string message)
        {
            return Source.WriteLineAsync(message ?? string.Empty, CancellationToken);
        }
    }

    public sealed class ShrinkCommandExecutingInfo
    {
        public ShrinkCommandService Service { get; set; } = null!;
        public IShrinkCommandSource Source { get; set; } = null!;
        public ShrinkCommandDescriptor Command { get; set; } = null!;
        public string RawInput { get; set; } = string.Empty;
        public IReadOnlyDictionary<string, string> Arguments { get; set; } =
            new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
    }

    public sealed class ShrinkCommandExecutedInfo
    {
        public ShrinkCommandService Service { get; set; } = null!;
        public IShrinkCommandSource Source { get; set; } = null!;
        public ShrinkCommandDescriptor? Command { get; set; }
        public string RawInput { get; set; } = string.Empty;
        public IReadOnlyDictionary<string, string> Arguments { get; set; } =
            new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
        public ShrinkCommandExecutionResult Result { get; set; } = ShrinkCommandExecutionResult.Success();
    }
}