using UnityEngine;
#if ENABLE_INPUT_SYSTEM
using UnityEngine.InputSystem;
#endif

namespace MazeGen
{
    /// <summary>
    /// Small input-backend-agnostic helpers. This project has the Input System package
    /// installed, and Active Input Handling may be set to "Input System Package (New)"
    /// only - which silently breaks legacy-only APIs like OnMouseDown/Input.GetKey. These
    /// helpers pick the right backend at compile time via the ENABLE_INPUT_SYSTEM symbol
    /// Unity defines automatically when the package is present.
    /// </summary>
    public static class MazeInput
    {
        public static bool WasLeftClickedThisFrame()
        {
#if ENABLE_INPUT_SYSTEM
            return Mouse.current != null && Mouse.current.leftButton.wasPressedThisFrame;
#else
            return Input.GetMouseButtonDown(0);
#endif
        }

        public static bool IsMiddleMouseHeld()
        {
#if ENABLE_INPUT_SYSTEM
            return Mouse.current != null && Mouse.current.middleButton.isPressed;
#else
            return Input.GetMouseButton(2);
#endif
        }

        public static Vector2 GetPointerScreenPosition()
        {
#if ENABLE_INPUT_SYSTEM
            return Mouse.current != null ? Mouse.current.position.ReadValue() : Vector2.zero;
#else
            return Input.mousePosition;
#endif
        }

        /// <summary>Mouse wheel movement this frame, normalized to roughly "notches" on both input backends (positive = scroll up/away from the user).</summary>
        public static float GetScrollDelta()
        {
#if ENABLE_INPUT_SYSTEM
            // The new Input System reports raw OS wheel delta (~120 per notch on Windows),
            // not pre-normalized like the legacy API - scale it down to match.
            return Mouse.current != null ? Mouse.current.scroll.ReadValue().y / 120f : 0f;
#else
            return Input.mouseScrollDelta.y;
#endif
        }

        /// <summary>Normalized WASD movement axis: (right/left, up/down).</summary>
        public static Vector2 ReadWasdAxis()
        {
            float x = 0f, y = 0f;
#if ENABLE_INPUT_SYSTEM
            var kb = Keyboard.current;
            if (kb != null)
            {
                if (kb.aKey.isPressed) x -= 1f;
                if (kb.dKey.isPressed) x += 1f;
                if (kb.sKey.isPressed) y -= 1f;
                if (kb.wKey.isPressed) y += 1f;
            }
#else
            if (Input.GetKey(KeyCode.A)) x -= 1f;
            if (Input.GetKey(KeyCode.D)) x += 1f;
            if (Input.GetKey(KeyCode.S)) y -= 1f;
            if (Input.GetKey(KeyCode.W)) y += 1f;
#endif
            Vector2 v = new Vector2(x, y);
            return v.sqrMagnitude > 1f ? v.normalized : v;
        }
    }
}