using Unity.Entities;
using Unity.NetCode;

namespace ProjectM.Simulation
{
    /// <summary>
    /// One runtime stat modifier (from an upgrade, pickup, or buff) on a modifiable entity. The
    /// per-entity DynamicBuffer of these is the server-authoritative source StatRecomputeSystem folds
    /// into the effective-stat components, on both the server and the predicting client.
    ///
    /// Replication: this is a GhostField buffer, so it is part of the ghost snapshot and is restored on
    /// rollback - that is what lets the predicting owner recompute identical effective stats.
    /// OwnerSendType.All is explicit so the owning (predicting) client receives it; without it the
    /// owner would recompute from an empty list and mispredict every tick. Target/Op replicate as raw
    /// bytes (not the enums) to keep the generated serializer trivial and avoid the cross-assembly
    /// enum-codegen hazard that already de-Bursted ProjectileClassificationSystem.
    /// </summary>
    [GhostComponent(OwnerSendType = SendToOwnerType.All)]
    [InternalBufferCapacity(8)]
    public struct StatModifier : IBufferElementData
    {
        /// <summary>The <see cref="StatTarget"/> this modifier applies to (stored as a byte).</summary>
        [GhostField] public byte Target;

        /// <summary>The <see cref="ModOp"/> combine operation (stored as a byte).</summary>
        [GhostField] public byte Op;

        /// <summary>Magnitude: a flat amount, or a fractional percent (0.1 = +10%).</summary>
        [GhostField(Quantization = 1000)] public float Value;

        /// <summary>Provenance tag (e.g. pickup SpawnId / debug sentinel). Reserved for future ClearByType / timed buffs.</summary>
        [GhostField] public uint SourceId;
    }
}