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

public class Inventory : MonoBehaviour
{
    private const string PanelKey = "Inventory";

    public static Inventory Instance { get; private set; }

    [SerializeField] private GameObject inventoryPanel;
    [SerializeField] private Transform listRoot;
    [SerializeField] private Button noteButtonTemplate;
    [SerializeField] private Text emptyStateText;
    [SerializeField] private Button closeButton;
    [SerializeField] private List<NoteData> collectedNotes = new List<NoteData>();

    public bool IsOpen => inventoryPanel != null && inventoryPanel.activeSelf;

    public void Configure(GameObject panel, Transform notesRoot, Button templateButton, Text emptyText, Button closePanelButton)
    {
        inventoryPanel = panel;
        listRoot = notesRoot;
        noteButtonTemplate = templateButton;
        emptyStateText = emptyText;
        closeButton = closePanelButton;

        if (inventoryPanel != null)
        {
            inventoryPanel.SetActive(false);
        }

        if (noteButtonTemplate != null)
        {
            noteButtonTemplate.gameObject.SetActive(false);
        }
    }

    private void Awake()
    {
        if (Instance != null && Instance != this)
        {
            Destroy(gameObject);
            return;
        }

        Instance = this;

        if (closeButton != null)
        {
            closeButton.onClick.RemoveListener(CloseInventory);
            closeButton.onClick.AddListener(CloseInventory);
        }
    }

    private void Update()
    {
        if (!Input.GetKeyDown(KeyCode.I))
        {
            return;
        }

        if (IsOpen)
        {
            CloseInventory();
        }
        else
        {
            OpenInventory();
        }
    }

    public void AddNote(NoteData note)
    {
        if (note == null || string.IsNullOrWhiteSpace(note.title))
        {
            return;
        }

        foreach (var storedNote in collectedNotes)
        {
            if (storedNote.title == note.title && storedNote.content == note.content)
            {
                return;
            }
        }

        collectedNotes.Add(new NoteData(note.title, note.content));
        RebuildNoteList();
    }

    public void OpenInventory()
    {
        if (inventoryPanel == null || listRoot == null || noteButtonTemplate == null)
        {
            return;
        }

        if (NoteUI.Instance != null && NoteUI.Instance.IsOpen)
        {
            return;
        }

        if (DialogueUI.Instance != null && DialogueUI.Instance.IsOpen)
        {
            return;
        }

        RebuildNoteList();
        inventoryPanel.SetActive(true);
        GameUIState.SetPanelOpen(PanelKey, true);
    }

    public void CloseInventory()
    {
        if (inventoryPanel == null)
        {
            return;
        }

        inventoryPanel.SetActive(false);
        GameUIState.SetPanelOpen(PanelKey, false);
    }

    private void RebuildNoteList()
    {
        if (listRoot == null || noteButtonTemplate == null)
        {
            return;
        }

        for (var i = listRoot.childCount - 1; i >= 0; i--)
        {
            var child = listRoot.GetChild(i);

            if (child == noteButtonTemplate.transform)
            {
                continue;
            }

            Destroy(child.gameObject);
        }

        var hasNotes = collectedNotes.Count > 0;

        if (emptyStateText != null)
        {
            emptyStateText.gameObject.SetActive(!hasNotes);
            emptyStateText.text = "Пока что здесь пусто. Найдите записки на уровне.";
        }

        foreach (var note in collectedNotes)
        {
            var noteCopy = note;
            var noteButton = Instantiate(noteButtonTemplate, listRoot);
            noteButton.gameObject.SetActive(true);
            noteButton.onClick.RemoveAllListeners();
            noteButton.onClick.AddListener(() => OpenStoredNote(noteCopy));

            var buttonText = noteButton.GetComponentInChildren<Text>();

            if (buttonText != null)
            {
                buttonText.text = note.title;
            }
        }
    }

    private void OpenStoredNote(NoteData note)
    {
        CloseInventory();

        if (NoteUI.Instance != null)
        {
            NoteUI.Instance.ShowNote(note.title, note.content);
        }
    }
}