using System;
using System.Collections.Generic;
using System.Linq;

namespace Vanguard.Battle
{
    /// <summary>
    /// Счётчик причин блокировки: анимация, оверлей, контекстное меню.
    /// Ввод возвращается только когда снята последняя причина.
    /// </summary>
    public sealed class InputLockService
    {
        private readonly Dictionary<string, int> _reasons =
            new Dictionary<string, int>(StringComparer.Ordinal);

        public bool IsLocked => _reasons.Count > 0;

        public string Describe() =>
            _reasons.Count == 0
                ? "none"
                : string.Join(",", _reasons.Select(pair => pair.Key + "=" + pair.Value));

        public event Action<bool> Changed;

        public void Acquire(string reason)
        {
            if (string.IsNullOrEmpty(reason))
                return;

            var wasLocked = _reasons.Count > 0;
            _reasons.TryGetValue(reason, out var count);
            _reasons[reason] = count + 1;

            if (!wasLocked)
                Changed?.Invoke(true);
        }

        public void Release(string reason)
        {
            if (string.IsNullOrEmpty(reason))
                return;

            if (!_reasons.TryGetValue(reason, out var count))
                return;

            if (count > 1)
            {
                _reasons[reason] = count - 1;
                return;
            }

            _reasons.Remove(reason);
            if (_reasons.Count == 0)
                Changed?.Invoke(false);
        }

        public void ReleaseAll()
        {
            if (_reasons.Count == 0)
                return;

            _reasons.Clear();
            Changed?.Invoke(false);
        }
    }
}