using System;
using UnityEngine;

public class TextInput : MonoBehaviour
{
    public event Action<string> OnComplete;

    [Header("Генерация")]
    [SerializeField] private LetterSlot _letterSlotPrefab;
    [SerializeField] private RectTransform _cellsRoot;

    [Header("Звуки")]
    [SerializeField] private AudioClip switchSlotSound;
    [SerializeField] private AudioClip switchLetterSound;
    [SerializeField] private AudioClip acceptSound;
    [SerializeField] private AudioClip openSound;

    [Header("Скорость переключения букв")]
    [SerializeField] private float MaxSpeedLetterPerSecond = 8;
    [SerializeField] private float MinSpeedLetterPerSecond = 3;
    [SerializeField] private float MaxSpeedTime = 3;
    [SerializeField] private float MinSpeedTime = 0.5f;

    private float switchButtonPressedTime = 0;
    private float letterSwitchSpeed = 0;
    private float switchDelayRest = 1;

    private int _slotIndex = 0;

    private LetterSlot[] _slots;


    private LetterSlot _activeSlot => _slots[_slotIndex];

    private bool completionRequested = false;

    private void Start()
    {
        string initial = PlayerPrefs.GetString(PrefsKeyVault.NUMBER_TECH, "");
        Initialize(11, Alphabets.DIGITS, initial);
    }

    public void Initialize(int cellsAmount, string alphabet, string initialString = "")
    {
        Generate(cellsAmount, alphabet);
        InitializeSlots(initialString);
    }

    private void Update()
    {
        int dir_h = In.GetAxis(Axis.Horizontal, JoystickSide.Both, InteractMode.Discrete);
        SwitchSlot(dir_h);

        int dir_v = In.GetAxis(Axis.Vertical, JoystickSide.Both, InteractMode.Continious);
        SwitchLetter(dir_v);

        completionRequested = In.GetButtonAnyPlayer(PlayerAction.action);
        if (completionRequested)
            Complete();
    }

    private void Complete()
    {
        string result = CollectText();
        OnComplete?.Invoke(result);
        gameObject.SetActive(false);
    }

    private void Generate(int cellsAmount, string alphabet)
    {
        ClearCells();
        _slots = new LetterSlot[cellsAmount];
        
        for (int i = 0; i < cellsAmount; i++)
        {
            var cell = Instantiate(_letterSlotPrefab, _cellsRoot);
            cell.Init(alphabet[0], alphabet);
            _slots[i] = cell;
        }

        _slotIndex = 0;
        _slots[_slotIndex].SetSelected(true);
    }

    private void InitializeSlots(string initialString)
    {
        for (int i = 0; i < _slots.Length; i++)
            _slots[i].SetSymbol(0);

        if (string.IsNullOrEmpty(initialString))
            return;

        int minLength = Mathf.Min(initialString.Length, _slots.Length);

        for (int i = 0; i < minLength; i++)
            _slots[i].SetSymbol(initialString[i]);
    }

    public void SwitchSlot(int dir)
    {
        if (dir == 0) return;

        _activeSlot.SetSelected(false);
        _slotIndex = Mathf.Clamp(_slotIndex + dir, 0, _slots.Length);
        _activeSlot.SetSelected(true);
    }

    public void SwitchLetter(int dir)
    {
        if (dir == 0)
        {
            switchDelayRest = 0;
            switchButtonPressedTime = 0;
            return;
        }

        if (switchDelayRest < 0)
        {
            _activeSlot.ChangeSymbol(dir);
            recalculateRest();
        }

        switchDelayRest -= Time.deltaTime;
        switchButtonPressedTime += Time.deltaTime;


        void recalculateRest()
        {
            float k = (MaxSpeedLetterPerSecond - MinSpeedLetterPerSecond)
                      / (MaxSpeedTime - MinSpeedTime);
            float b = MinSpeedLetterPerSecond - k * MinSpeedTime;
            letterSwitchSpeed = k * switchButtonPressedTime + b;
            letterSwitchSpeed = Mathf.Clamp(letterSwitchSpeed,
                                            MinSpeedLetterPerSecond,
                                            MaxSpeedLetterPerSecond);
            switchDelayRest = 1 / letterSwitchSpeed;
        }
    }

    private void ClearCells()
    {
        for (int i = _cellsRoot.childCount - 1; i >= 0; i--)
        {
            var cell = _cellsRoot.GetChild(i).gameObject;
            Destroy(cell);
        }
        _slots = null;
    }

    private string CollectText()
    {
        System.Text.StringBuilder sb = new();
        foreach (var slot in _slots)
            sb.Append(slot.Symbol);
        return sb.ToString().Trim();
    }
}