using System.Collections.Concurrent;

namespace NeonSprawl.Server.Game.Encounters;

/// <summary>Thread-safe in-memory encounter completion event records (NEO-107).</summary>
public sealed class InMemoryEncounterCompleteEventStore : IEncounterCompleteEventStore
{
    private readonly ConcurrentDictionary<string, EncounterCompleteEvent> eventsByKey = new(StringComparer.Ordinal);

    private readonly ConcurrentDictionary<string, object> keyLocks = new(StringComparer.Ordinal);

    /// <inheritdoc />
    public bool TryRecord(EncounterCompleteEvent completeEvent)
    {
        var key = EncounterProgressIds.MakeProgressKey(completeEvent.PlayerId, completeEvent.EncounterId);
        if (key.Length == 0)
        {
            return false;
        }

        lock (keyLocks.GetOrAdd(key, _ => new object()))
        {
            if (eventsByKey.ContainsKey(key))
            {
                return false;
            }

            eventsByKey[key] = completeEvent with
            {
                GrantedItems = [..completeEvent.GrantedItems],
            };
            return true;
        }
    }

    /// <inheritdoc />
    public bool TryGet(string playerId, string encounterId, out EncounterCompleteEvent completeEvent)
    {
        completeEvent = default;
        var key = EncounterProgressIds.MakeProgressKey(playerId, encounterId);
        if (key.Length == 0)
        {
            return false;
        }

        lock (keyLocks.GetOrAdd(key, _ => new object()))
        {
            return eventsByKey.TryGetValue(key, out completeEvent);
        }
    }

    /// <summary>Dev fixture only — removes one player+encounter event row (NEO-108 Bruno reset).</summary>
    public bool TryClear(string playerId, string encounterId)
    {
        var key = EncounterProgressIds.MakeProgressKey(playerId, encounterId);
        if (key.Length == 0)
        {
            return false;
        }

        lock (keyLocks.GetOrAdd(key, _ => new object()))
        {
            var removed = eventsByKey.TryRemove(key, out _);
            keyLocks.TryRemove(key, out _);
            return removed;
        }
    }
}