using System.Collections.Concurrent;

namespace NeonSprawl.Server.Game.Rewards;

/// <summary>Thread-safe in-memory reward delivery records (NEO-126).</summary>
public sealed class InMemoryRewardDeliveryStore : IRewardDeliveryStore
{
    private readonly ConcurrentDictionary<string, RewardDeliveryEvent> eventsByKey = new(StringComparer.Ordinal);

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

    /// <inheritdoc />
    public bool TryRecord(RewardDeliveryEvent deliveryEvent)
    {
        var key = RewardDeliveryIds.MakeStoreKey(deliveryEvent);
        if (key.Length == 0)
        {
            return false;
        }

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

            eventsByKey[key] = deliveryEvent with
            {
                GrantedItems = [.. deliveryEvent.GrantedItems],
                GrantedSkillXp = [.. deliveryEvent.GrantedSkillXp],
                GrantedReputation = [.. deliveryEvent.GrantedReputation],
            };
            return true;
        }
    }

    /// <inheritdoc />
    public bool TryGet(string playerId, string questId, out RewardDeliveryEvent deliveryEvent) =>
        TryGet(playerId, RewardDeliverySourceKinds.QuestCompletion, questId, out deliveryEvent);

    /// <inheritdoc />
    public bool TryGet(string playerId, string sourceKind, string sourceId, out RewardDeliveryEvent deliveryEvent)
    {
        deliveryEvent = default;
        var key = RewardDeliveryIds.MakeStoreKey(playerId, sourceKind, sourceId);
        if (key.Length == 0)
        {
            return false;
        }

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

    /// <inheritdoc />
    public bool TryClear(string playerId, string questId) =>
        TryClear(playerId, RewardDeliverySourceKinds.QuestCompletion, questId);

    /// <summary>Dev fixture only — removes one player+source delivery row (Bruno / test reset).</summary>
    public bool TryClear(string playerId, string sourceKind, string sourceId)
    {
        var key = RewardDeliveryIds.MakeStoreKey(playerId, sourceKind, sourceId);
        if (key.Length == 0)
        {
            return false;
        }

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