using UnityEngine;
using UnityEngine.InputSystem;

public class CameraHandler : MonoBehaviour
{
    bool isDragging = false;
    Vector2 pointerDownPos;
    bool pointerDown = false;
    float prevPinchDistance = -1;
    Vector3 dragWorldStart;

    void Update()
    {
        HandleCameraMovement();
        HandleZoom();
    }

    void HandleCameraMovement()
    {
        Vector2 inputPos = Vector2.zero;
        bool pressed = false;

        if (Application.isMobilePlatform && Touchscreen.current != null)
        {
            var touch = Touchscreen.current.primaryTouch;

            if (touch.press.isPressed)
            {
                inputPos = touch.position.ReadValue();
                pressed = true;
            }
        }
        else if (Mouse.current != null)
        {
            if (Mouse.current.leftButton.isPressed)
            {
                inputPos = Mouse.current.position.ReadValue();
                pressed = true;
            }
        }

        if (!pressed)
        {
            pointerDown = false;
            isDragging = false;
            return;
        }

        Camera cam = Camera.main;

        if (!pointerDown)
        {
            pointerDown = true;
            pointerDownPos = inputPos;

            dragWorldStart = cam.ScreenToWorldPoint(
                new Vector3(inputPos.x, inputPos.y, -cam.transform.position.z)
            );

            return;
        }

        if (!isDragging)
        {
            if (Vector2.Distance(inputPos, pointerDownPos) < 5f)
                return;

            isDragging = true;
        }

        Vector3 currentWorld = cam.ScreenToWorldPoint(
            new Vector3(inputPos.x, inputPos.y, -cam.transform.position.z)
        );

        Vector3 movement = dragWorldStart - currentWorld;
        cam.transform.position += movement;
    }

    void HandleZoom()
    {
        if (Application.isMobilePlatform && Touchscreen.current != null)
        {
            var touches = Touchscreen.current.touches;
            if (touches.Count >= 2)
            {
                Vector2 pos1 = touches[0].position.ReadValue();
                Vector2 pos2 = touches[1].position.ReadValue();

                if (touches[0].press.isPressed && touches[1].press.isPressed)
                {
                    float currentDist = Vector2.Distance(pos1, pos2);
                    if (prevPinchDistance > 0)
                    {
                        float diff = currentDist - prevPinchDistance;
                        Camera.main.orthographicSize = Mathf.Clamp(Camera.main.orthographicSize - (diff * 0.1f), 1f, 100f);
                    }
                    prevPinchDistance = currentDist;
                    return;
                }
            }
            prevPinchDistance = -1;
        }
        else
        {
            float scroll = Mouse.current.scroll.ReadValue().y;
            if (scroll != 0)
            {
                if (Keyboard.current.leftCtrlKey.isPressed)
                {
                    Camera.main.orthographicSize = Mathf.Clamp(Camera.main.orthographicSize - scroll, 1f, 100f);
                }
                else
                {
                    var pos = Camera.main.transform.position;
                    pos.y += scroll * 5f;
                    Camera.main.transform.position = pos;
                }
            }
        }
    }
}