using System.Collections;
using Core.Helpers;
using Core.SpecConfig;

namespace Core;

public class ProcessEnumerator : IEnumerator
{

    private int _languagePosition;
    private int _typePosition;
    
    private readonly List<ProcessTask> _enumerable;
    
    object IEnumerator.Current => Current;

    public ProcessTask Current
    {
        get
        {
            return _enumerable.First(pt => (int)pt.GenerationType == _typePosition 
                                           && (int)pt.Language == _languagePosition);
        }
    }

    public ProcessEnumerator(List<ProcessTask> current)
    {
        _languagePosition = -1;
        _typePosition = -1;
        _enumerable = current;
    }
    
    public bool MoveNext()
    {
        if (_typePosition == -1 && _languagePosition == -1)
        {
            _typePosition += 1;
            _languagePosition += 1;
            
        } else if (PassedTypeBoundaries())
        {
            _typePosition = 0;
            _languagePosition += 1;
        }
        else
        {
            _typePosition += 1;
        }

        if (!HasElement() && !PassedMaxPosition())
        {
            MoveNext();
        }
        return !PassedMaxPosition();
    }

    public void Reset()
    {
        _languagePosition = -1;
        _typePosition = -1;
    }

    private bool PassedLanguageBoundaries() => _languagePosition >= EnumHelper.GetMaxValue<Language>() - 1;
    
    private bool PassedTypeBoundaries() => _typePosition >= EnumHelper.GetMaxValue<GenerationType>() - 1;

    private bool PassedMaxPosition() => PassedLanguageBoundaries() && PassedTypeBoundaries();

    private bool HasElement()
    {
        var e= _enumerable.FirstOrDefault(pt => (int)pt.GenerationType == _typePosition 
                                       && (int)pt.Language == _languagePosition);
        return e != null;
    }
    
}