using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;

public class SettingsScreen : MonoBehaviour
{
    [Header("Управление")]
    [SerializeField] private InSignal NextSetting;
    [SerializeField] private InSignal PreviousSetting;
    [SerializeField] private InSignal ChangeSettingPositive;
    [SerializeField] private InSignal ChangeSettingNegative;
    private bool controlsEnabled = true;
    private bool readyToGetInput = false;

    [Header("Ссылки")]
    [SerializeField] private SettingGroupView GroupViewPrefab;
    [SerializeField] private RectTransform pointer;
    [SerializeField] private ScrollRect scrollRect;
    [SerializeField] private RectTransform Content;

    [Header("Настройки scroll view")]
    [SerializeField] private float scrollSmoothTime = 0.2f;

    private int interactionDirection = 0;
    private SettingView SelectedSetting => settingsGroups[activeGroup].GeneratedSettingViews[activeSetting];

    private bool Generated = false;
    private int activeGroup;
    private int activeSetting;
    private List<SettingGroupView> settingsGroups;

    // Для плавного скролла
    private float targetVerticalPosition = 0f;
    private float scrollVelocity = 0f;
    private bool isFirstFrame = true;

    private void Update()
    {
        if (!Generated) return;

        if (isFirstFrame)
        {
            isFirstFrame = false;
            scrollRect.verticalNormalizedPosition = 1f;
            UpdateScrollTarget();
            return;
        }

    }

    private void LateUpdate()
    {
        if (controlsEnabled && readyToGetInput)
        {
            SelectedSetting.InteractView(interactionDirection);
        }

        SmoothScrollToSelected();
        DisplayPointer();
        interactionDirection = 0;
    }

    public void _ChangeInteractionDirection(int delta) => interactionDirection += delta;
    public void EnableControls() => controlsEnabled = true;
    public void DisableControls() => controlsEnabled = false;
    public void SetReadyToGetInput() => readyToGetInput = true;

    public void Generate()
    {
        // Очищаем старые группы
        if (settingsGroups != null)
        {
            foreach (var group in settingsGroups)
            {
                if (group != null)
                    Destroy(group.gameObject);
            }
        }



        settingsGroups = new List<SettingGroupView>();

        foreach (var group in SettingsManager.currentSchemeDTO.groups)
        {
            var generatedGroup = GenerateGroup(group);
            settingsGroups.Add(generatedGroup);
        }

        activeGroup = 0;
        activeSetting = 0;

        Generated = true;
    }

    public void SwitchItem(int direction)
    {
        if (direction == 0 || !controlsEnabled) return;

        activeSetting += direction;
        SettingGroupView currentGroup = settingsGroups[activeGroup];

        //Выход за пределы группы (верхний предел) 
        if (activeSetting > currentGroup.GeneratedSettingViews.Count - 1)
        {
            activeGroup = (activeGroup + 1 + settingsGroups.Count) % settingsGroups.Count;
            activeSetting = 0;
        }
        //Выход за пределы группы (нижний предел)
        else if (activeSetting < 0)
        {
            activeGroup = (activeGroup - 1 + settingsGroups.Count) % settingsGroups.Count;
            activeSetting = settingsGroups[activeGroup].GeneratedSettingViews.Count - 1;
        }

        UpdateScrollTarget();
    }

    private void DisplayPointer()
    {
        pointer.SetParent(SelectedSetting.transform);
        pointer.localPosition = Vector3.zero;
    }



    private SettingGroupView GenerateGroup(SettingsGroupDTO group)
    {
        var go = Instantiate(GroupViewPrefab.gameObject, Content);
        var groupView = go.GetComponent<SettingGroupView>();
        groupView.Generate(group);
        return groupView;
    }

    private void UpdateScrollTarget()
    {
        float targetNormalizedPosition = CalculateNormalizedPosition();
        targetVerticalPosition = targetNormalizedPosition;

    }

    private float CalculateNormalizedPosition()
    {
        // Проверка наличия необходимых компонентов
        if (scrollRect.viewport == null)
        {
            Debug.LogError("ScrollRect Viewport is not assigned!");
            return 0f;
        }

        RectTransform selectedRect = SelectedSetting.GetComponent<RectTransform>();

        // Получаем мировые координаты углов
        Vector3[] worldCorners = new Vector3[4];
        selectedRect.GetWorldCorners(worldCorners);

        // Получаем локальные координаты относительно Content
        Vector3 localPos = Content.InverseTransformPoint(worldCorners[1]); // Верхний левый угол элемента

        // Вычисляем нормализованную позицию (0 = вверху, 1 = внизу)
        float contentHeight = Content.rect.height;
        float viewportHeight = scrollRect.viewport.rect.height;

        if (contentHeight <= viewportHeight) return 0f;

        float maxScroll = contentHeight - viewportHeight;
        float scrollPosition = -localPos.y; // Инвертируем, т.к. UI координаты Y вниз

        // Центрируем элемент
        float elementHeight = selectedRect.rect.height;
        scrollPosition -= (viewportHeight / 2f) - (elementHeight / 2f);

        float normalizedPosition = Mathf.Clamp01(scrollPosition / maxScroll);

        return 1f - normalizedPosition; // Инвертируем для ScrollRect
    }

    private void SmoothScrollToSelected()
    {
        float currentPos = scrollRect.verticalNormalizedPosition;
        float newPos = Mathf.SmoothDamp(currentPos, targetVerticalPosition,
                                        ref scrollVelocity, scrollSmoothTime);
        scrollRect.verticalNormalizedPosition = newPos;
    }
}