using Unity.Entities;
using Unity.NetCode;

namespace ProjectM.Simulation
{
    /// <summary>
    /// A PERMANENT periodic BLIGHT hazard fixture (Phase 1.5b bundle 3; see Geyser_Build_Spec). An ownerless
    /// INTERPOLATED ghost placed only in Blight-biome expedition rooms. <see cref="NextEruptTick"/> is the ABSOLUTE
    /// server tick of the next eruption — the ONLY replicated field; the client derives its telegraph countdown and
    /// erupt-fire from it against its own predicted ServerTick (absolute-tick, NEVER an edge on the field — so it
    /// survives snapshot loss + relevancy re-entry; the design-review-hardened contract, see Geyser_Build_Spec §7).
    /// Server-only <see cref="ProjectM.Server"/> GeyserEruptSystem radius-damages LIVING players AND enemies (friendly
    /// fire, like exploding barrels — also a tactical lure) when it elapses, then reschedules one period ahead of NOW
    /// (never destroyed; RoomTag teardown removes it). Born-correct: RoomFieldSystem stamps NextEruptTick from the
    /// live ServerTick at spawn, so the first snapshot never carries the 0 "ready/unstamped" sentinel (a baked 0 must
    /// be treated as not-ready and NEVER erupted — the inverted invalid-tick guard).
    /// </summary>
    public struct Geyser : IComponentData
    {
        /// <summary>Absolute server tick of the next eruption (via TickUtil.NonZero; 0 = unstamped = never erupt).</summary>
        [GhostField] public uint NextEruptTick;
    }
}