// Assets/_Project/Scripts/Gameplay/Draft/BuilderSpellDraftOption.cs
using UnityEngine;
using TD.Core;
using TD.Gameplay.BuilderSpells;

namespace TD.Gameplay.Draft
{
    /// <summary>
    /// Draft choice — "gain a builder spell". Grants the player a key-triggered active ability,
    /// adding it to their <see cref="PlayerSpellLoadout"/>.
    /// </summary>
    /// <remarks>
    /// Mirrors <see cref="BuilderEffectDraftOption"/>: carries the <see cref="BuilderSpellKind"/>
    /// directly rather than an asset reference, since the enum value is the stable identifier
    /// <see cref="PlayerSpellLoadout"/> and <see cref="BuilderSpellPool"/> already key off of.
    /// <see cref="IsValidFor"/> also checks slot capacity — once
    /// <see cref="PlayerSpellLoadout.MaxSpellSlots"/> is reached, no further spell options are
    /// offered. Gates on <see cref="PlayerSpellLoadout.PlayerHasEverGranted"/> rather than
    /// current possession, so a base spell already upgraded past (see
    /// <see cref="BuilderSpellUpgradeDraftOption"/>) is never re-offered.
    /// </remarks>
    [CreateAssetMenu(fileName = "BuilderSpellOption", menuName = "TD/Draft/Builder Spell Option")]
    public class BuilderSpellDraftOption : DraftOption
    {
        [Header("Payload")]
        [Tooltip("The builder spell this option grants.")]
        public BuilderSpellKind Kind;

        public override bool IsValidFor(ulong clientId)
        {
            var loadout = PlayerSpellLoadout.GetForClient(clientId);
            if (loadout == null) return false;
            if (loadout.SlotCount >= PlayerSpellLoadout.MaxSpellSlots) return false;
            return !loadout.PlayerHasEverGranted(Kind);
        }

        public override bool ServerApply(ulong clientId)
        {
            var loadout = PlayerSpellLoadout.GetForClient(clientId);
            return loadout != null && loadout.ServerGrantSpell(Kind);
        }

        /// <summary>Inherits the granted spell's icon (resolved from the pool by
        /// <see cref="Kind"/>) unless this option assigns an override.</summary>
        public override Sprite ResolveIcon()
        {
            if (Icon != null) return Icon;
            var def = BuilderSpellPool.Instance != null ? BuilderSpellPool.Instance.Get(Kind) : null;
            return def != null ? def.Icon : null;
        }
    }
}