// Assets/_Project/Scripts/Gameplay/BuilderSpells/SlowAreaSpellDefinition.cs
using UnityEngine;
using TD.Audio;
using TD.Core;

namespace TD.Gameplay.BuilderSpells
{
    /// <summary>
    /// Builder spell #2 — slow every enemy within an area for a duration.
    /// </summary>
    /// <remarks>
    /// <para><see cref="BuilderSpellDefinition.TargetType"/> is <see cref="SpellTargetType.AreaOfEffect"/>
    /// — the cast controller previews <see cref="BuilderSpellDefinition.Radius"/> as a decal
    /// while aiming, and this spell resolves against that same radius (no separate field).
    /// </para>
    /// <para><b>Zone, not a snapshot.</b> <see cref="ServerCast"/> spawns a <see
    /// cref="SlowZoneRuntime"/> that keeps re-checking the area for <see cref="EffectDuration"/>
    /// seconds, so only enemies currently standing inside the radius are ever slowed — walking
    /// out drops the slow almost immediately. Always succeeds and starts the cooldown, even if
    /// no enemy is in the radius at the moment of cast, since the zone can still catch one later.
    /// </para>
    /// </remarks>
    [CreateAssetMenu(fileName = "SlowAreaSpell", menuName = "TD/Builder Spells/Slow Area")]
    public class SlowAreaSpellDefinition : BuilderSpellDefinition
    {
        public override BuilderSpellKind Kind => BuilderSpellKind.SlowArea;

        [Header("Area VFX")]
        [Tooltip("Prefab spawned at the target point on a successful cast, authored at a 1-unit " +
                 "radius — scaled up to match Radius here. Lives for EffectDuration, matching " +
                 "how long the slow itself lasts. Optional — leave empty for no visual.")]
        [SerializeField] private GameObject areaVfxPrefab;

        [Tooltip("Sound played on every peer when this spell resolves successfully.")]
        [SerializeField] private SoundConfig areaSound;

        [Header("Slow Area")]
        [Tooltip("Speed multiplier applied to affected enemies for EffectDuration " +
                 "(e.g. 0.5 = half speed).")]
        [Range(0f, 1f)]
        public float SlowFactor = 0.5f;

        [Tooltip("Seconds the zone itself persists. Enemies are only slowed while standing " +
                 "inside it — walking out drops the slow almost immediately.")]
        [Min(0f)]
        public float EffectDuration = 3f;

        public override bool ServerCast(ulong clientId, Vector3 targetPoint)
        {
            PlayerSlot owner = PlayerMatchState.SlotForClient(clientId);

            var zoneObject = new GameObject("SlowZone (server)");
            zoneObject.AddComponent<SlowZoneRuntime>().Initialize(
                targetPoint, Mathf.Max(Radius, 0.01f), SlowFactor, EffectDuration,
                enemyLayerMask, owner);

            // Always succeeds — placing the zone starts the cooldown even if no enemy is
            // standing in it yet, since it keeps slowing whoever walks in for EffectDuration.
            return true;
        }

        public override void ClientSpawnVfx(Vector3 targetPoint)
        {
            if (areaVfxPrefab != null)
            {
                var instance = Instantiate(areaVfxPrefab, targetPoint, Quaternion.identity);
                instance.transform.localScale *= Mathf.Max(Radius, 0.01f);
                Destroy(instance, EffectDuration);
            }
        }

        public override void ClientPlayImpact(Vector3 targetPoint)
        {
            // Instant spell (ImpactDelay = 0), so this fires on cast alongside ClientSpawnVfx.
            if (areaSound.clip != null)
                AudioManager.Instance?.Play(areaSound.clip, AudioCategory.Combat,
                                             areaSound.RandomPitch(), areaSound.volume);
        }
    }
}