namespace Diligent.WebAPI.Business.Services
{
    public class AdService : IAdService
    {
        private readonly ILogger<AdService> _logger;
        private readonly DatabaseContext _context;
        private readonly IMapper _mapper;
        private readonly ITechnologyService _technologyService;


        public AdService(DatabaseContext context, IMapper mapper, ITechnologyService technologyService, ILogger<AdService> logger)
        {
            _logger = logger;
            _context = context;
            _mapper = mapper;
            _technologyService = technologyService;
        }

        public async Task<List<AdResponseDto>> GetAllAsync()
        {
            _logger.LogInformation("Start getting all Ads");
            var today = DateTime.Now;
            _logger.LogInformation("Getting data from DB");
            var fromDb = await _context.Ads.Include(x => x.Technologies).Where(x => x.ExpiredAt > today).ToListAsync();
            _logger.LogInformation($"Received {fromDb.Count} ads from db.");
            _logger.LogInformation($"Mapping received ads to AdResponseDto");
            var result = _mapper.Map<List<AdResponseDto>>(fromDb);
            _logger.LogInformation($"Ads has been mapped and received to client: {result.Count} mapped ads");
            return result;
        }
        public async Task<List<AdResponseWithCountDto>> GetAllWithCountAsync()
        {
            _logger.LogInformation("Start getting all Ads with applicants count");
            var today = DateTime.Now;
            _logger.LogInformation("Getting data from database");
            var res = _mapper.Map<List<AdResponseWithCountDto>>(await _context.Ads.Include(x => x.Applicants).Where(x => x.ExpiredAt > today).ToListAsync());
            _logger.LogInformation($"Received {res.Count} ads with their counts");
            return res;
        }
        public async Task<AdResponseDto> GetByIdAsync(int id)
        {
            _logger.LogInformation($"Start searching Ad with id = {id}");
            var ad = await _context.Ads.FindAsync(id);

            if (ad is null)
            {
                _logger.LogError($"Ad with id = {id} not found");
                throw new EntityNotFoundException("Ad not found");
            }


            _logger.LogInformation($"Mapping Ad with id = {id}");
            AdResponseDto result = _mapper.Map<AdResponseDto>(ad);
            _logger.LogInformation($"Ad with id = {id} mapped successfully");
            return result;

        }

        public async Task<AdDetailsResponseDto> GetAdDetailsByIdAsync(int id)
        {
            _logger.LogInformation($"Start finding Ad with id = {id} with applicants");
            var ad = await _context.Ads.Include(x => x.Applicants).Where(x => x.Id == id).FirstOrDefaultAsync();

            if (ad is null)
            {
                _logger.LogError($"Ad with id = {id} not found");
                throw new EntityNotFoundException("Ad not found");
            }

            _logger.LogInformation($"Mapping Ad with id = {id}");
            AdDetailsResponseDto result = _mapper.Map<AdDetailsResponseDto>(ad);
            _logger.LogInformation($"Ad with id = {id} mapped successfully");

            return result;
        }

        public async Task<List<AdResponseDto>> GetArchiveAds()
        {
            _logger.LogInformation("Start getting all Archived Ads");
            var today = DateTime.Now;
            _logger.LogInformation("Getting data from DB");
            var archiveAds = await _context.Ads.Where(x => x.ExpiredAt < today).ToListAsync();
            _logger.LogInformation($"Received {archiveAds.Count} ads from db.");

            _logger.LogInformation($"Mapping received ads to AdResponseDto");
            List<AdResponseDto> result = _mapper.Map<List<AdResponseDto>>(archiveAds);
            _logger.LogInformation($"Ads has been mapped and received to client: {result.Count} mapped ads");
            return result;
        }

        public async Task<List<AdResponseDto>> GetFilteredAdsAsync(AdFilterDto filters)
        {
            _logger.LogInformation($"Start getting all filtered Ads");
            var today = DateTime.Now;
            _logger.LogInformation("Getting data from DB");
            var filteredAds = await _context.Ads.Include(x => x.Technologies).Where(x => x.ExpiredAt > today).ToListAsync();
            _logger.LogInformation($"Received {filteredAds.Count} ads from db.");

            _logger.LogInformation($"Mapping received ads to AdResponseDto");
            List<AdResponseDto> result = _mapper.Map<List<AdResponseDto>>(filteredAds.Filter(filters));
            _logger.LogInformation($"Ads has been mapped and received to client: {result.Count} mapped ads");
            return result;
        }

        public async Task CreateAsync(AdCreateDto adCreateDto)
        {
            _logger.LogInformation($"Start creating Ad");
            var ad = _mapper.Map<Ad>(adCreateDto);
            _logger.LogInformation($"Ad created successfully");

            _logger.LogInformation($"Start adding technologies to Ad");
            for (int i = 0; i < adCreateDto.TechnologiesIds.Count; i++)
            {
                var technology = await _technologyService.GetEntityByIdAsync(adCreateDto.TechnologiesIds[i]);
                ad.Technologies.Add(technology);
                _logger.LogInformation($"Technology with id {technology.TechnologyId} added to Ad");
            }
            _logger.LogInformation($"Finished adding techonologies");

            await _context.Ads.AddAsync(ad);
            _logger.LogInformation($"Saving Ad to db...");
            var result = _context.SaveChangesAsync();
            _logger.LogInformation($"Ad saved to DB");
            await result;
        }

        public async Task UpdateAsync(int id, AdUpdateDto adUpdateDto)
        {
            _logger.LogInformation($"Start searching Ad with id = {id}");
            var ad = await _context.Ads.FindAsync(id);

            if (ad is null)
            {
                _logger.LogError($"Ad with id = {id} not found");
                throw new EntityNotFoundException("Ad not found");
            }

            _logger.LogInformation($"Mapping Ad with id = {id}");
            _mapper.Map(adUpdateDto, ad);
            _logger.LogInformation($"Ad with id = {id} mapped successfully");

            _context.Entry(ad).State = EntityState.Modified;

            var result = _context.SaveChangesAsync();
            _logger.LogInformation($"Ad saved to DB");
            await result;
        }

        public async Task ArchiveAdAsync(int id)
        {
            _logger.LogInformation($"Start searching Ad with id = {id}");
            var ad = await _context.Ads.FindAsync(id);

            if (ad is null)
            {
                _logger.LogError($"Ad with id = {id} not found");
                throw new EntityNotFoundException("Ad not found");
            }

            _logger.LogInformation($"Change ad expired time");
            ad.ExpiredAt = DateTime.Now;
            _logger.LogInformation($"Ad expired time changed successfully");

            _context.Entry(ad).State = EntityState.Modified;

            var result = _context.SaveChangesAsync();
            _logger.LogInformation($"Ad saved to DB");
            await result;
        }

        public async Task DeleteAsync(int id)
        {
            _logger.LogInformation($"Start searching Ad with id = {id}");
            var ad = await _context.Ads.FindAsync(id);

            if (ad is null)
            {
                _logger.LogError($"Ad with id = {id} not found");
                throw new EntityNotFoundException("Ad not found");
            }

            _context.Ads.Remove(ad);
            var result = _context.SaveChangesAsync();
            _logger.LogInformation($"Ad saved to DB");
            await result;
        }

        public async Task<Ad> ImportAsync(AdCreateDto adCreateDto)
        {
            _logger.LogInformation($"Start importing Ad");
            var ad = _mapper.Map<Ad>(adCreateDto);
            _logger.LogInformation($"Ad imported successfully");

            await _context.Ads.AddAsync(ad);
            _logger.LogInformation($"Saving Ad to db...");
            await _context.SaveChangesAsync();
            _logger.LogInformation($"Ad saved to DB");
            return ad;
        }

        public async Task<Ad> GetByIdEntityAsync(int id)
        {
            _logger.LogInformation($"Start searching Ad with id = {id}");
            var ad = await _context.Ads.FindAsync(id);

            if (ad is null)
            {
                _logger.LogError($"Ad with id = {id} not found");
                throw new EntityNotFoundException("Ad not found");
            }

            return ad;
        }
    }
}