// Assets/_Project/Scripts/Gameplay/Draft/TowerUpgradeDraftOption.cs
using UnityEngine;
using TD.Towers;

namespace TD.Gameplay.Draft
{
    /// <summary>
    /// Draft choice — "upgrade a tower you already have". Replaces <see cref="BaseTower"/>
    /// with <see cref="UpgradedTower"/> in the player's <see cref="PlayerTowerDeck"/>: every
    /// tower of that type placed from now on is the upgraded version. Already-placed towers
    /// are unaffected.
    /// </summary>
    /// <remarks>
    /// Mirrors <see cref="NewTowerDraftOption"/>, but swaps rather than adds. Only offered
    /// while the player currently has <see cref="BaseTower"/> unlocked — once taken,
    /// <see cref="BaseTower"/> is removed from the deck, which automatically makes this option
    /// (and any sibling upgrade branching off the same base) invalid for future drafts.
    /// </remarks>
    [CreateAssetMenu(fileName = "TowerUpgradeOption", menuName = "TD/Draft/Tower Upgrade Option")]
    public class TowerUpgradeDraftOption : DraftOption
    {
        [Header("Payload")]
        [Tooltip("The tower this option upgrades from. Must be present in the player's deck " +
                 "for this option to be offered.")]
        public TowerDefinition BaseTower;

        [Tooltip("The tower this option upgrades to. Must also be present in the " +
                 "TowerPlacementManager catalog (that's where its TowerTypeId comes from).")]
        public TowerDefinition UpgradedTower;

        public override bool IsValidFor(ulong clientId)
        {
            var deck = PlayerTowerDeck.GetForClient(clientId);
            var pm   = TowerPlacementManager.Instance;
            if (deck == null || pm == null || BaseTower == null || UpgradedTower == null) return false;

            if (!pm.TryGetTypeId(BaseTower, out int baseTypeId)) return false;

            return deck.Contains(baseTypeId);
        }

        public override bool ServerApply(ulong clientId)
        {
            var deck = PlayerTowerDeck.GetForClient(clientId);
            var pm   = TowerPlacementManager.Instance;
            if (deck == null || pm == null || BaseTower == null || UpgradedTower == null) return false;

            if (!pm.TryGetTypeId(BaseTower, out int baseTypeId))
            {
                Debug.LogError($"[TowerUpgradeDraftOption] '{BaseTower.name}' is not in the tower " +
                               $"catalog; cannot apply. Add it to TowerPlacementManager.towerDefinitions.");
                return false;
            }

            if (!pm.TryGetTypeId(UpgradedTower, out int upgradedTypeId))
            {
                Debug.LogError($"[TowerUpgradeDraftOption] '{UpgradedTower.name}' is not in the " +
                               $"tower catalog; cannot apply. Add it to " +
                               $"TowerPlacementManager.towerDefinitions.");
                return false;
            }

            return deck.ServerUpgradeTower(baseTypeId, upgradedTypeId);
        }

        /// <summary>Inherits the upgraded tower's icon unless this option assigns an override.</summary>
        public override Sprite ResolveIcon()
            => Icon != null ? Icon : (UpgradedTower != null ? UpgradedTower.Icon : null);
    }
}