using UnityEngine;

namespace Ashwild.Inventory
{
    /// <summary>
    /// The view payload for the hover description panel: exactly what the panel renders (icon,
    /// name, description, and an optional duration/uses bar), nothing more. The inventory manager
    /// builds one of these from a hovered slot and pushes it into the view, so the panel never
    /// touches ItemData or the inventory model — it just draws what it is handed.
    /// </summary>
    public readonly struct ItemDescriptionView
    {
        public readonly Sprite Icon;
        public readonly string Name;
        public readonly string Description;

        /// <summary>
        /// Whether the hovered item tracks uses/durability and should show its duration bar.
        /// </summary>
        public readonly bool HasDuration;

        /// <summary>
        /// Remaining uses as a 0..1 fill for the bar's Filled image.
        /// </summary>
        public readonly float DurationFill;

        /// <summary>
        /// The remaining/max label drawn over the bar, e.g. "3 / 5".
        /// </summary>
        public readonly string DurationText;

        public ItemDescriptionView(Sprite icon, string name, string description,
            bool hasDuration, float durationFill, string durationText)
        {
            Icon = icon;
            Name = name;
            Description = description;
            HasDuration = hasDuration;
            DurationFill = durationFill;
            DurationText = durationText;
        }

        /// <summary>
        /// Builds the payload for a hovered slot, including the uses bar for items that track
        /// durability. Shared by the inventory grid and the hotbar so both describe an item
        /// identically — they used to each build this by hand and could drift apart.
        /// </summary>
        public static ItemDescriptionView From(InventorySlot slot)
        {
            ItemData item = slot.ItemData;
            bool hasDuration = item.HasUses;
            float fill = hasDuration && item.MaxUses > 0 ? (float)slot.CurrentUses / item.MaxUses : 0f;
            string durationText = hasDuration ? $"{slot.CurrentUses} / {item.MaxUses}" : string.Empty;

            return new ItemDescriptionView(item.Icon, item.ItemName, item.Description,
                hasDuration, fill, durationText);
        }
    }
}