using Unity.Entities;
using Unity.Mathematics;

namespace ProjectM.Simulation
{
    /// <summary>
    /// Server-only per-Husk navigation / anti-stuck state (NOT replicated — clients never simulate enemies, so this
    /// carries no <c>[GhostField]</c> and does not change the ghost hash). Tracks the enemy's XZ position at the end
    /// of last tick plus how long it has failed to make progress toward its target, so <c>EnemyAISystem</c> can
    /// phase-nudge a genuinely stuck enemy (wedged on a cover rock or a rock-vs-boundary pocket) toward the nearest
    /// player — the guaranteed backstop that keeps an expedition room from ever soft-locking on one unreachable Husk.
    /// Baked onto every enemy by <c>EnemyAuthoring</c>. Complements the collide-and-slide fixes in
    /// <see cref="EnemyAIMath.SlideVelocity"/> / <c>EnemyMoveUtil</c> (which make sticking rare in the first place).
    /// </summary>
    public struct EnemyNavState : IComponentData
    {
        /// <summary>Enemy XZ position at the end of last tick (progress baseline; Y unused).</summary>
        public float3 LastPos;

        /// <summary>Consecutive ticks the enemy wanted to move toward its target but made ~no progress.</summary>
        public uint StuckTicks;

        /// <summary>While a <c>NetworkTick</c> newer than the current tick is stored here the enemy is phase-nudging
        /// toward its target (collide-and-slide bypassed) to escape geometry; <c>0</c> = not nudging. Routed through
        /// <c>TickUtil.NonZero</c> so a computed tick never collides with the 0 "inactive" sentinel.</summary>
        public uint NudgeUntilTick;
    }
}