using ProjectM.Simulation;
using Unity.Entities;
using UnityEngine;

namespace ProjectM.Authoring
{
    /// <summary>
    /// Authoring for the Husk enemy prefab. Bakes the gameplay components onto a prefab whose ghost setup
    /// (GhostAuthoringComponent: interpolated, ownerless) is inherited by DUPLICATING an existing interpolated
    /// ghost (UpgradePickup.prefab) — so the Husk replicates to all clients with no hand-written <c>[GhostField]</c>
    /// (the stock LocalTransform variant carries its server-driven position). Damageable exactly like the training
    /// dummy (Health/HitRadius/DamageEvent) plus the Husk AI tunables. <c>GetEntity(Dynamic)</c> gives a
    /// runtime-mutable LocalTransform for server-authoritative movement and hit tests.
    /// </summary>
    public class EnemyAuthoring : MonoBehaviour
    {
        [Min(0f), Tooltip("Starting and maximum health for the Husk.")]
        public float MaxHealth = 30f;

        [Min(0f), Tooltip("World-unit radius used by the projectile hit test.")]
        public float HitRadius = 0.7f;

        [Min(0f), Tooltip("Planar seek speed toward the nearest player, units/second.")]
        public float MoveSpeed = 3.5f;

        [Min(0f), Tooltip("Centre-to-centre distance at which the Husk can strike a player.")]
        public float AttackRange = 1.6f;

        [Min(0f), Tooltip("Damage dealt per strike.")]
        public float AttackDamage = 8f;

        [Min(1), Tooltip("Simulation ticks between strikes (~60 ticks/sec).")]
        public int AttackCooldownTicks = 36;

        private class EnemyBaker : Baker<EnemyAuthoring>
        {
            public override void Bake(EnemyAuthoring authoring)
            {
                var entity = GetEntity(authoring, TransformUsageFlags.Dynamic);

                AddComponent<EnemyTag>(entity);
                AddComponent(entity, new Health { Current = authoring.MaxHealth, Max = authoring.MaxHealth });
                AddComponent(entity, new HitRadius { Value = authoring.HitRadius });
                AddBuffer<DamageEvent>(entity);
                AddComponent(entity, new EnemyStats
                {
                    MoveSpeed = authoring.MoveSpeed,
                    AttackRange = authoring.AttackRange,
                    AttackDamage = authoring.AttackDamage,
                    AttackCooldownTicks = authoring.AttackCooldownTicks,
                });
                AddComponent(entity, new EnemyAttackCooldown { NextAttackTick = 0 });
                AddComponent<KnockbackState>(entity); // server-only recoil state (zero = not knocked)
                AddComponent<AttackWindup>(entity);   // replicated telegraph signal (zero = not winding up)
                // Slice 1 (Feature C): client-safe baked telegraph metadata. EnemyBaker is the SOLE writer of
                // EnemyTelegraph even on a Charger (the prefab composes both authorings on one entity); reading the
                // sibling ChargerAuthoring here avoids a double-AddComponent. WindupTicks = the client danger-ramp
                // denominator per variant; IsCharger lets the client pick the Charger look (LungeState is server-only).
                // Kind byte (client telegraph look) — derived from the sibling variant authoring (EnemyBaker is the
                // SOLE EnemyTelegraph writer). Grunt=0 / Charger=1 / Spitter=2 / Swarmer=3 (ZoneEnemyMath.Kind*).
                byte kind = ZoneEnemyMath.KindGrunt;
                byte windup = (byte)Tuning.AttackWindupTicks;
                var spitter = GetComponent<SpitterAuthoring>();
                // Bake-time guard (DR-041 sole-Position-writer invariant): a prefab must carry at most ONE of
                // {ChargerAuthoring(LungeState), SpitterAuthoring(SpitterState)} — both would match ZERO AI passes.
                if (GetComponent<ChargerAuthoring>() != null && spitter != null)
                    Debug.LogError($"Enemy '{authoring.name}' has BOTH ChargerAuthoring and SpitterAuthoring; it would match no AI pass and never move. Remove one.", authoring);
                if (GetComponent<ChargerAuthoring>() != null) { kind = ZoneEnemyMath.KindCharger; windup = 30; }
                else if (spitter != null) { kind = ZoneEnemyMath.KindSpitter; windup = (byte)Mathf.Clamp(spitter.WindupTicks, 1, 255); }
                else if (GetComponent<SwarmerAuthoring>() != null) { kind = ZoneEnemyMath.KindSwarmer; windup = 6; }
                AddComponent(entity, new EnemyTelegraph { WindupTicks = windup, Kind = kind });
            }
        }
    }
}