// Assets/_Project/Scripts/Gameplay/EnemyUpgrades/EnemyUpgradeOption.cs
using UnityEngine;
using TD.Gameplay.Waves;

namespace TD.Gameplay.EnemyUpgrades
{
    /// <summary>
    /// Base class for one card in the post-wave enemy-buff vote. Players collectively choose one
    /// of these to permanently attach to the wave they just cleared; it takes effect the next time
    /// that wave comes round in the cycle.
    /// </summary>
    /// <remarks>
    /// <para><b>Mirrors <c>DraftOption</c> deliberately.</b> Same shape — abstract SO, one asset
    /// per card, concrete subclasses carry the payload — so the two authoring surfaces read the
    /// same way. The difference is who it targets: a draft option applies to a player, an enemy
    /// upgrade applies to a <i>wave slot</i>.</para>
    ///
    /// <para><b>Identity.</b> Options live in <see cref="EnemyUpgradePool"/> and cross the network
    /// as their pool index, the same stable-within-a-match id pattern used by the tower catalog
    /// and draft pool.</para>
    ///
    /// <para><b>Recording is not this type's job.</b> <c>WaveVote</c> records the winning option id
    /// onto the slot via <c>RunState.ServerAddUpgrade</c>; <see cref="ServerOnApplied"/> is only
    /// for cards that need a side effect <i>beyond</i> being recorded (the vote-meta cards).
    /// Ability cards need nothing here — the spawn path reads the slot's recorded set.</para>
    /// </remarks>
    public abstract class EnemyUpgradeOption : ScriptableObject
    {
        [Header("Presentation")]
        [Tooltip("Name shown on the vote card.")]
        public string DisplayName;

        [Tooltip("Short description shown on the vote card. Say what it does to the enemies, in " +
                 "the players' terms — this is the only thing they get to judge the vote on.")]
        [TextArea(2, 4)]
        public string Description;

        [Tooltip("OPTIONAL override for the vote card icon. Leave empty to inherit the icon of " +
                 "whatever this option grants.")]
        public Sprite Icon;

        /// <summary>
        /// Icon actually shown on the vote card. Subclasses override to fall back to the icon of
        /// the thing they grant; the base has nothing to inherit from, so it returns
        /// <see cref="Icon"/> (which may be null).
        /// </summary>
        public virtual Sprite ResolveIcon() => Icon;

        /// <summary>
        /// Server-only: may this option be OFFERED for <paramref name="slot"/> right now? Default
        /// true; override for cards with prerequisites or ones that would be a no-op.
        /// </summary>
        /// <remarks>
        /// Callers already skip options the slot has taken before, so implementations don't need
        /// to re-check that.
        /// </remarks>
        public virtual bool IsValidForSlot(RunState run, int slot) => true;

        /// <summary>
        /// Server-only: side effect to run after this option has been recorded onto
        /// <paramref name="slot"/>. Default no-op — most cards do their work at enemy-spawn time
        /// by virtue of being on the slot, not at vote-resolution time.
        /// </summary>
        public virtual void ServerOnApplied(RunState run, int slot) { }
    }
}