using System.Threading.Tasks;
using Core;
using Input;
using UnityEngine;

namespace Utils
{
    /// <summary>
    /// Utility methods for character movement operations.
    /// Extracted from interaction/controller code for reusability.
    /// </summary>
    public static class MovementUtilities
    {
        /// <summary>
        /// Moves a character to a target position and waits for arrival.
        /// Works with any controller implementing IInteractingCharacter.
        /// </summary>
        /// <param name="character">The character to move (must implement IInteractingCharacter)</param>
        /// <param name="targetPosition">World position to move to</param>
        /// <returns>Task that completes when the character arrives or movement is cancelled</returns>
        public static async Task<bool> MoveToPositionAsync(IInteractingCharacter character, Vector3 targetPosition)
        {
            if (character == null)
            {
                Logging.Warning("[MovementUtilities] Cannot move null character");
                return false;
            }
            
            var tcs = new TaskCompletionSource<bool>();
            
            void OnArrivedLocal()
            {
                character.OnArrivedAtTarget -= OnArrivedLocal;
                character.OnMoveToCancelled -= OnCancelledLocal;
                tcs.TrySetResult(true);
            }
            
            void OnCancelledLocal()
            {
                character.OnArrivedAtTarget -= OnArrivedLocal;
                character.OnMoveToCancelled -= OnCancelledLocal;
                tcs.TrySetResult(false);
            }
            
            character.OnArrivedAtTarget += OnArrivedLocal;
            character.OnMoveToCancelled += OnCancelledLocal;
            character.MoveToAndNotify(targetPosition);
            
            return await tcs.Task;
        }
        
        /// <summary>
        /// Calculates a stop position at a given distance from a target position towards a character.
        /// </summary>
        /// <param name="targetPosition">The target position</param>
        /// <param name="characterPosition">The character's current position</param>
        /// <param name="stopDistance">Distance from target to stop at</param>
        /// <returns>The calculated stop position</returns>
        public static Vector3 CalculateStopPosition(Vector3 targetPosition, Vector3 characterPosition, float stopDistance)
        {
            Vector3 toCharacter = (characterPosition - targetPosition).normalized;
            return targetPosition + toCharacter * stopDistance;
        }
    }
}