using System;
using System.Collections.Generic;
using System.Text;
using System.Threading;
using Cysharp.Threading.Tasks;
using ShrinkNetwork;

namespace ShrinkCommand.Integration
{
    public sealed class ShrinkNetworkCommandSource : IShrinkCommandSource
    {
        private readonly List<string> _lines = new();
        private readonly ShrinkNetworkContext _context;
        private readonly ShrinkNetworkCommandRequest _request;

        public ShrinkNetworkCommandSource(ShrinkNetworkContext context, ShrinkNetworkCommandRequest request)
        {
            _context = context;
            _request = request;
            SourceId = $"network:{context.Session.SessionId}";
            DisplayName = ResolveDisplayName(context, request);
        }

        public string SourceId { get; }
        public string DisplayName { get; }
        public bool IsConsole => false;
        public ShrinkNetworkSession Session => _context.Session;

        public bool HasPermission(string permission)
        {
            return string.IsNullOrWhiteSpace(permission) || Session.HasPermission(permission);
        }

        public UniTask WriteLineAsync(string message, CancellationToken cancellationToken = default)
        {
            if (!string.IsNullOrWhiteSpace(message))
                _lines.Add(message);
            return UniTask.CompletedTask;
        }

        public string BuildOutputMessage(string resultMessage)
        {
            if (_lines.Count == 0)
                return resultMessage ?? string.Empty;

            var builder = new StringBuilder();
            for (var index = 0; index < _lines.Count; index++)
            {
                if (index > 0)
                    builder.AppendLine();
                builder.Append(_lines[index]);
            }

            if (!string.IsNullOrWhiteSpace(resultMessage))
            {
                if (builder.Length > 0 && !string.Equals(_lines[_lines.Count - 1], resultMessage, StringComparison.Ordinal))
                    builder.AppendLine();
                if (!string.Equals(_lines[_lines.Count - 1], resultMessage, StringComparison.Ordinal))
                    builder.Append(resultMessage);
            }

            return builder.ToString();
        }

        private static string ResolveDisplayName(ShrinkNetworkContext context, ShrinkNetworkCommandRequest request)
        {
            if (context.Session.Items.TryGetValue("auth.name", out var authName) && authName is string authNameText &&
                !string.IsNullOrWhiteSpace(authNameText))
            {
                return authNameText.Trim();
            }

            if (!string.IsNullOrWhiteSpace(request.ClientLabel))
                return request.ClientLabel.Trim();

            return context.Session.RemoteAddress;
        }
    }
}