namespace qtc_api.Services.ContactService
{
    public class ContactService : IContactService
    {
        private readonly DataContext _dataContext;

        public ContactService(DataContext dataContext)
        {
            _dataContext = dataContext;
        }

        public async Task<ServiceResponse<Contact>> CreateContact(string ownerId, string userId)
        {
            var serviceResponse = new ServiceResponse<Contact>();
            var rnd = LongRandom(1, 900000000000000000, new Random());

            var contact = new Contact()
            {
                Id = rnd.ToString(),
                OwnerId = ownerId,
                UserId = userId,
                OwnerStatus = Contact.ContactStatus.AwaitingApprovalFromOther,
                UserStatus = Contact.ContactStatus.AwaitingApprovalFromSelf,
            };

            await _dataContext.Contacts.AddAsync(contact);
            await _dataContext.SaveChangesAsync();

            serviceResponse.Success = true;
            serviceResponse.Data = contact;

            return serviceResponse;
        }

        public async Task<ServiceResponse<bool>> UpdateContactStatus(string ownerId, string userId, Contact.ContactStatus ownerStatus, Contact.ContactStatus userStatus)
        {
            var serviceResponse = new ServiceResponse<bool>();

            var contact = await _dataContext.Contacts.FirstOrDefaultAsync(e => (e.OwnerId == ownerId && e.UserId == userId) || (e.OwnerId == userId && e.UserId == ownerId));

            if (contact != null)
            {
                contact.OwnerStatus = ownerStatus;
                contact.UserStatus = userStatus;
                serviceResponse.Success = true;
            }
            else serviceResponse.Success = false;

            await _dataContext.SaveChangesAsync();

            return serviceResponse;
        }

        public async Task<ServiceResponse<Contact>> DeleteContact(string ownerId, string userId)
        {
            var serviceResponse = new ServiceResponse<Contact>();
            var contact = await _dataContext.Contacts.FirstOrDefaultAsync(e => (e.OwnerId == ownerId && e.UserId == userId) || (e.OwnerId == userId && e.UserId == ownerId));

            if (contact != null)
            {
                var result = _dataContext.Contacts.Remove(contact);
                await _dataContext.SaveChangesAsync();

                serviceResponse.Success = true;
                serviceResponse.Data = result.Entity;

                return serviceResponse;
            }
            else
            {
                serviceResponse.Success = false;
                serviceResponse.Data = null;
                serviceResponse.Message = "Contact Not Found";

                return serviceResponse;
            }
        }

        public async Task<ServiceResponse<Contact>> GetContactById(string id)
        {
            var serviceResponse = new ServiceResponse<Contact>();

            var contact = await _dataContext.Contacts.FirstOrDefaultAsync(x => x.Id == id);

            if (contact == null) { serviceResponse.Success = false; serviceResponse.Message = "Contact Does Not Exist."; }
            else { serviceResponse.Success = true; serviceResponse.Data = contact; }

            return serviceResponse;
        }

        public async Task<ServiceResponse<List<Contact>>> GetUserContacts(User user)
        {
            var serviceResponse = new ServiceResponse<List<Contact>>();

            var contactsMade = await _dataContext.Contacts.Where(x => x.OwnerId == user.Id).ToListAsync();
            var contactsList = await _dataContext.Contacts.Where(x => x.UserId == user.Id).ToListAsync();

            var contactsCombined = new List<Contact>();

            foreach (var contact in contactsMade)
                contactsCombined.Add(contact); // all contacts the user has made
            foreach (var contact in contactsList)
                contactsCombined.Add(contact); // all contacts the user has received

            if (contactsCombined.Count == 0) { serviceResponse.Success = true; serviceResponse.Message = "User Has No Contacts."; }
            else { serviceResponse.Success = true; serviceResponse.Data = contactsCombined; }

            return serviceResponse;
        }

        private long LongRandom(long min, long max, Random rnd)
        {
            long result = rnd.Next((int)(min >> 32), (int)(max >> 32));
            result = result << 32;
            result = result | (long)rnd.Next((int)min, (int)max);
            return result;
        }
    }
}