using UnityEngine;
using UnityEngine.UI;
using UnityEngine.InputSystem;

/// <summary>
/// Полноэкранный просмотрщик найденных записок.
/// Отрисовывает крупную цифру на бумажке, её позицию в терминале лифта (1-я, 2-я, 3-я или 4-я),
/// гриф секретности и атмосферный сюжетный текст.
/// </summary>
public class NoteViewerUI : MonoBehaviour
{
    private static NoteViewerUI _instance;
    public static NoteViewerUI Instance
    {
        get
        {
            if (_instance == null)
            {
                _instance = Object.FindAnyObjectByType<NoteViewerUI>(FindObjectsInactive.Include);
            }
            return _instance;
        }
    }

    [Header("Корневая панель")]
    [SerializeField] private GameObject notePanelRoot;

    [Header("Элементы документа")]
    [SerializeField] private Text documentHeader;
    [SerializeField] private Text sectorText;
    [SerializeField] private Text positionNoticeText;
    [SerializeField] private Text bigDigitText;
    [SerializeField] private Text flavorBodyText;
    [SerializeField] private Button closeButton;

    private bool isOpen = false;
    public bool IsOpen => isOpen;

    private void Awake()
    {
        _instance = this;
        if (notePanelRoot == null)
            notePanelRoot = gameObject;

        if (closeButton != null)
        {
            closeButton.onClick.RemoveAllListeners();
            closeButton.onClick.AddListener(CloseNote);
        }
    }

    private int openFrame = -1;

    private void Update()
    {
        if (!isOpen) return;
        if (Time.frameCount == openFrame) return;

        bool closePressed = false;

        var keyboard = Keyboard.current;
        if (keyboard != null)
        {
            if (keyboard.escapeKey.wasPressedThisFrame || 
                keyboard.eKey.wasPressedThisFrame || 
                keyboard.spaceKey.wasPressedThisFrame ||
                keyboard.enterKey.wasPressedThisFrame)
            {
                closePressed = true;
            }
        }

#if ENABLE_LEGACY_INPUT_MANAGER
        if (Input.GetKeyDown(KeyCode.Escape) || Input.GetKeyDown(KeyCode.E) || Input.GetKeyDown(KeyCode.Space))
        {
            closePressed = true;
        }
#endif

        if (closePressed)
        {
            CloseNote();
        }
    }

    public void OpenNote(int positionIndex, int digit, string sector, string noteTitle, string storyText)
    {
        openFrame = Time.frameCount;

        if (!gameObject.activeSelf) gameObject.SetActive(true);
        if (notePanelRoot != null && !notePanelRoot.activeSelf)
            notePanelRoot.SetActive(true);

        isOpen = true;
        Time.timeScale = 0f;
        Cursor.lockState = CursorLockMode.None;
        Cursor.visible = true;

        if (documentHeader != null)
            documentHeader.text = "Секретный протокол";

        if (sectorText != null)
            sectorText.text = $"Отсек: {sector.ToUpper()}";

        string posStr = positionIndex switch
        {
            0 => "1-я цифра [ _ * * * ]",
            1 => "2-я цифра [ * _ * * ]",
            2 => "3-я цифра [ * * _ * ]",
            3 => "4-я цифра [ * * * _ ]",
            _ => $"{positionIndex + 1}-я цифра"
        };

        if (positionNoticeText != null)
            positionNoticeText.text = $"КОД ЛИФТА: {posStr}";

        if (bigDigitText != null)
            bigDigitText.text = digit.ToString();

        if (flavorBodyText != null)
            flavorBodyText.text = storyText;

        GameAudioSynthesizer.PlayPaperRustle();

        if (LevelCodeManager.Instance != null)
        {
            LevelCodeManager.Instance.DiscoverDigit(positionIndex);
        }
    }

    public void CloseNote()
    {
        if (!isOpen) return;

        isOpen = false;
        if (notePanelRoot != null)
            notePanelRoot.SetActive(false);

        Time.timeScale = 1f;
        Cursor.lockState = CursorLockMode.Locked;
        Cursor.visible = false;

        GameAudioSynthesizer.PlayKeypadClear();
    }
}