using UnityEngine;
using UnityEngine.InputSystem;

namespace MedievalShopkeeper
{
    /// <summary>
    /// Static Top-Down Camera for Medieval Shopkeeper.
    /// Positions the camera statically above the shop floor with a customizable height and pitch angle.
    /// Does not follow the player, giving a fixed overview of the shop.
    /// </summary>
    [ExecuteAlways]
    [RequireComponent(typeof(Camera))]
    public class TopDownCamera : MonoBehaviour
    {
        [Header("View Settings")]
        [Tooltip("World position the camera looks down at (e.g. center of the shop).")]
        [SerializeField] private Vector3 focusPoint = Vector3.zero;

        [Tooltip("Height of the camera above the shop floor.")]
        [Range(5f, 50f)]
        [SerializeField] private float cameraHeight = 16f;

        [Tooltip("Pitch angle (degrees): 90 = straight down (birds-eye), 55-65 = top-down angled/isometric.")]
        [Range(30f, 90f)]
        [SerializeField] private float pitchAngle = 60f;

        [Tooltip("Yaw angle (degrees) to rotate around the shop.")]
        [Range(-180f, 180f)]
        [SerializeField] private float yawAngle = 0f;

        [Header("Optional Zoom (PC Scroll Wheel / Pinch)")]
        [Tooltip("Allow zooming in/out while keeping the camera static over the shop.")]
        [SerializeField] private bool enableZoom = true;
        [SerializeField] private float zoomSpeed = 2f;
        [SerializeField] private float minHeight = 8f;
        [SerializeField] private float maxHeight = 30f;

        private void Start()
        {
            ApplyCameraTransform();
        }

        private void LateUpdate()
        {
#if UNITY_EDITOR
            if (!Application.isPlaying)
            {
                ApplyCameraTransform();
                return;
            }
#endif

            if (enableZoom)
            {
                HandleZoomInput();
            }

            ApplyCameraTransform();
        }

        private void HandleZoomInput()
        {
            float scroll = 0f;

            if (Mouse.current != null)
            {
                scroll = Mouse.current.scroll.ReadValue().y;
            }

            if (Mathf.Abs(scroll) > 0.01f)
            {
                cameraHeight -= Mathf.Sign(scroll) * zoomSpeed;
                cameraHeight = Mathf.Clamp(cameraHeight, minHeight, maxHeight);
            }
        }

        /// <summary>
        /// Positions and angles the camera so it statically frames the shop floor from above.
        /// </summary>
        [ContextMenu("Apply Camera Placement")]
        public void ApplyCameraTransform()
        {
            Quaternion rotation = Quaternion.Euler(pitchAngle, yawAngle, 0f);

            // Calculate distance backwards based on height and pitch
            float rad = Mathf.Clamp(pitchAngle, 10f, 90f) * Mathf.Deg2Rad;
            float distanceBack = pitchAngle >= 89.9f ? 0f : cameraHeight / Mathf.Tan(rad);

            Vector3 offset = Quaternion.Euler(0f, yawAngle, 0f) * new Vector3(0f, cameraHeight, -distanceBack);
            transform.position = focusPoint + offset;
            transform.rotation = rotation;
        }

        private void OnValidate()
        {
            ApplyCameraTransform();
        }

        private void OnDrawGizmosSelected()
        {
            Gizmos.color = Color.green;
            Gizmos.DrawWireSphere(focusPoint, 0.5f);
            Gizmos.DrawLine(transform.position, focusPoint);
        }
    }
}