using Diligent.WebAPI.Contracts.DTOs.SelectionProcess;
using static System.Net.Mime.MediaTypeNames;
using System.Collections.Generic;

namespace Diligent.WebAPI.Business.Services
{
    public class SelectionProcessService : ISelectionProcessService
    {
        private readonly DatabaseContext _context;
        private readonly IMapper _mapper;

        public SelectionProcessService(DatabaseContext context, IMapper mapper)
        {
            _context = context;
            _mapper = mapper;
        }

        public async Task<List<SelectionProcessResposneDto>> GetAllAsync() =>
            _mapper.Map<List<SelectionProcessResposneDto>>(await _context.SelectionProcesses.ToListAsync());

        public async Task<SelectionProcessResposneDto> GetByIdAsync(int id)
        {
            var sp = await _context.SelectionProcesses.FindAsync(id);

            if (sp is null)
                throw new EntityNotFoundException("Selection process not found");

            return _mapper.Map<SelectionProcessResposneDto>(sp);

        }

        public async Task CreateAsync(SelectionProcessCreateDto model)
        {
            await _context.SelectionProcesses.AddAsync(_mapper.Map<SelectionProcess>(model));

            await _context.SaveChangesAsync();
        }

        public async Task UpdateAsync(int id, SelectionProcessCreateDto model)
        {
            var sp = await _context.SelectionProcesses.FindAsync(id);

            if (sp is null)
                throw new EntityNotFoundException("Selection process not found");

            _mapper.Map(model, sp);

            _context.Entry(sp).State = EntityState.Modified;
            await _context.SaveChangesAsync();
        }

        public async Task DeleteAsync(int id)
        {
            var sp = await _context.SelectionProcesses.FindAsync(id);

            if (sp is null)
                throw new EntityNotFoundException("Selection process not found");

            _context.SelectionProcesses.Remove(sp);
            await _context.SaveChangesAsync();
        }

        public async Task<bool> FinishSelectionProcess(int id)
        {
            var sp = await _context.SelectionProcesses.FindAsync(id);

            if (sp is null)
                throw new EntityNotFoundException("Selection process not found");

            sp.Status = "Odrađen";

            var nextLevel = _context.SelectionLevels.AsEnumerable().SkipWhile(obj => obj.Id != sp.SelectionLevelId).Skip(1).First();

            if (nextLevel is null)
                throw new EntityNotFoundException("Candidate came to last selection level");

            SelectionProcess newProcess = new SelectionProcess
            {
                Name = sp.Name,
                SelectionLevelId = nextLevel.Id,
                Status = "Čeka na zakazivanje",
                ApplicantId = sp.ApplicantId
            };
            _context.SelectionProcesses.Add(newProcess);

            return await _context.SaveChangesAsync() > 0;
        }
    }
}