using UnityEngine;

/// <summary>
/// Types of interactions available in the game.
/// </summary>
public enum InteractionType
{
    Generic,
    Pickup,
    Use,
    Talk,
    Enter,
    Build,
    Open,
    Activate
}

/// <summary>
/// Contains preview information about an interaction for UI display.
/// </summary>
[System.Serializable]
public struct InteractionPreview
{
    /// <summary>
    /// The action verb (e.g., "Pick up", "Enter", "Use").
    /// </summary>
    public string ActionVerb;

    /// <summary>
    /// The name of the target object (e.g., "Iron Ore", "Tunnel").
    /// </summary>
    public string TargetName;

    /// <summary>
    /// Optional icon to display in UI.
    /// </summary>
    public Sprite Icon;

    /// <summary>
    /// The type of interaction.
    /// </summary>
    public InteractionType Type;

    /// <summary>
    /// Whether this interaction requires holding the button.
    /// </summary>
    public bool RequiresHold;

    /// <summary>
    /// Duration to hold if RequiresHold is true.
    /// </summary>
    public float HoldDuration;

    /// <summary>
    /// Input hint to display (e.g., "[F]", "[E]").
    /// </summary>
    public string InputHint;

    /// <summary>
    /// Create a simple interaction preview.
    /// </summary>
    public static InteractionPreview Simple(string actionVerb, string targetName,
        InteractionType type = InteractionType.Generic)
    {
        return new InteractionPreview
        {
            ActionVerb = actionVerb,
            TargetName = targetName,
            Type = type,
            RequiresHold = false,
            HoldDuration = 0f,
            InputHint = "[F]"
        };
    }

    /// <summary>
    /// Create a pickup interaction preview.
    /// </summary>
    public static InteractionPreview Pickup(string itemName, Sprite icon = null)
    {
        return new InteractionPreview
        {
            ActionVerb = "Pick up",
            TargetName = itemName,
            Icon = icon,
            Type = InteractionType.Pickup,
            RequiresHold = false,
            InputHint = "[F]"
        };
    }

    /// <summary>
    /// Create an enter/use interaction preview.
    /// </summary>
    public static InteractionPreview Enter(string targetName)
    {
        return new InteractionPreview
        {
            ActionVerb = "Enter",
            TargetName = targetName,
            Type = InteractionType.Enter,
            RequiresHold = false,
            InputHint = "[F]"
        };
    }

    /// <summary>
    /// Create a hold-to-interact preview.
    /// </summary>
    public static InteractionPreview Hold(string actionVerb, string targetName, float duration,
        InteractionType type = InteractionType.Use)
    {
        return new InteractionPreview
        {
            ActionVerb = actionVerb,
            TargetName = targetName,
            Type = type,
            RequiresHold = true,
            HoldDuration = duration,
            InputHint = "[Hold F]"
        };
    }

    /// <summary>
    /// Get the full display string (e.g., "[F] Pick up Iron Ore").
    /// </summary>
    public string GetDisplayString()
    {
        return $"{InputHint} {ActionVerb} {TargetName}";
    }
}

/// <summary>
/// Interface for objects that can be interacted with by the player.
/// </summary>
public interface IInteractable
{
    /// <summary>
    /// Perform the interaction.
    /// </summary>
    /// <param name="interactor">The GameObject performing the interaction (usually the player)</param>
    void Interact(GameObject interactor);

    /// <summary>
    /// Get preview information about this interaction for UI display.
    /// Default implementation returns a generic preview.
    /// </summary>
    InteractionPreview GetInteractionPreview()
    {
        return InteractionPreview.Simple("Interact", "Object");
    }

    /// <summary>
    /// Check if this object can currently be interacted with.
    /// Default implementation always returns true.
    /// </summary>
    /// <param name="interactor">The GameObject attempting to interact</param>
    /// <returns>True if interaction is possible</returns>
    bool CanInteract(GameObject interactor)
    {
        return true;
    }

    /// <summary>
    /// Get the world position of this interactable for distance calculations.
    /// Default implementation returns zero vector (override in implementation).
    /// </summary>
    Vector3 GetInteractionPoint()
    {
        return Vector3.zero;
    }
}