using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Bit.App.Abstractions;
using Bit.App.Models;
using Bit.App.Models.Api;
using Bit.App.Models.Data;
using Xamarin.Forms;
using System.Net.Http;

namespace Bit.App.Services
{
    public class LoginService : ILoginService
    {
        private readonly ILoginRepository _loginRepository;
        private readonly IAttachmentRepository _attachmentRepository;
        private readonly IAuthService _authService;
        private readonly ILoginApiRepository _loginApiRepository;
        private readonly ISettingsService _settingsService;
        private readonly ICryptoService _cryptoService;

        public LoginService(
            ILoginRepository loginRepository,
            IAttachmentRepository attachmentRepository,
            IAuthService authService,
            ILoginApiRepository loginApiRepository,
            ISettingsService settingsService,
            ICryptoService cryptoService)
        {
            _loginRepository = loginRepository;
            _attachmentRepository = attachmentRepository;
            _authService = authService;
            _loginApiRepository = loginApiRepository;
            _settingsService = settingsService;
            _cryptoService = cryptoService;
        }

        public async Task<Login> GetByIdAsync(string id)
        {
            var data = await _loginRepository.GetByIdAsync(id);
            if(data == null || data.UserId != _authService.UserId)
            {
                return null;
            }

            var attachments = await _attachmentRepository.GetAllByLoginIdAsync(id);
            var login = new Login(data, attachments);
            return login;
        }

        public async Task<IEnumerable<Login>> GetAllAsync()
        {
            var data = await _loginRepository.GetAllByUserIdAsync(_authService.UserId);
            var logins = data.Select(f => new Login(f));
            return logins;
        }

        public async Task<IEnumerable<Login>> GetAllAsync(bool favorites)
        {
            var data = await _loginRepository.GetAllByUserIdAsync(_authService.UserId, favorites);
            var logins = data.Select(f => new Login(f));
            return logins;
        }

        public async Task<Tuple<IEnumerable<Login>, IEnumerable<Login>>> GetAllAsync(string uriString)
        {
            if(string.IsNullOrWhiteSpace(uriString))
            {
                return null;
            }

            Uri uri = null;
            DomainName domainName = null;
            var androidApp = UriIsAndroidApp(uriString);

            if(!androidApp &&
                (!Uri.TryCreate(uriString, UriKind.Absolute, out uri) || !DomainName.TryParse(uri.Host, out domainName)))
            {
                return null;
            }

            var androidAppWebUriString = WebUriFromAndroidAppUri(uriString);
            var eqDomains = (await _settingsService.GetEquivalentDomainsAsync()).Select(d => d.ToArray());
            var matchingDomains = new List<string>();
            var matchingFuzzyDomains = new List<string>();
            foreach(var eqDomain in eqDomains)
            {
                if(androidApp)
                {
                    if(Array.IndexOf(eqDomain, uriString) >= 0)
                    {
                        matchingDomains.AddRange(eqDomain.Select(d => d).ToList());
                    }
                    else if(androidAppWebUriString != null && Array.IndexOf(eqDomain, androidAppWebUriString) >= 0)
                    {
                        matchingFuzzyDomains.AddRange(eqDomain.Select(d => d).ToList());
                    }
                }
                else if(Array.IndexOf(eqDomain, domainName.BaseDomain) >= 0)
                {
                    matchingDomains.AddRange(eqDomain.Select(d => d).ToList());
                }
            }

            if(!matchingDomains.Any())
            {
                matchingDomains.Add(androidApp ? uriString : domainName.BaseDomain);
            }

            if(androidApp && androidAppWebUriString != null &&
                !matchingFuzzyDomains.Any() && !matchingDomains.Contains(androidAppWebUriString))
            {
                matchingFuzzyDomains.Add(androidAppWebUriString);
            }

            var matchingDomainsArray = matchingDomains.ToArray();
            var matchingFuzzyDomainsArray = matchingFuzzyDomains.ToArray();
            var matchingLogins = new List<Login>();
            var matchingFuzzyLogins = new List<Login>();
            var logins = await _loginRepository.GetAllByUserIdAsync(_authService.UserId);
            foreach(var login in logins)
            {
                if(string.IsNullOrWhiteSpace(login.Uri))
                {
                    continue;
                }

                var loginUriString = new CipherString(login.Uri).Decrypt(login.OrganizationId);
                if(string.IsNullOrWhiteSpace(loginUriString))
                {
                    continue;
                }

                if(Array.IndexOf(matchingDomainsArray, loginUriString) >= 0)
                {
                    matchingLogins.Add(new Login(login));
                    continue;
                }
                else if(androidApp && Array.IndexOf(matchingFuzzyDomainsArray, loginUriString) >= 0)
                {
                    matchingFuzzyLogins.Add(new Login(login));
                    continue;
                }
                else if(!androidApp && Array.IndexOf(matchingDomainsArray, WebUriFromAndroidAppUri(loginUriString)) >= 0)
                {
                    matchingFuzzyLogins.Add(new Login(login));
                    continue;
                }

                Uri loginUri;
                DomainName loginDomainName;
                if(!Uri.TryCreate(loginUriString, UriKind.Absolute, out loginUri)
                    || !DomainName.TryParse(loginUri.Host, out loginDomainName))
                {
                    continue;
                }

                if(Array.IndexOf(matchingDomainsArray, loginDomainName.BaseDomain) >= 0)
                {
                    matchingLogins.Add(new Login(login));
                }
                else if(androidApp && Array.IndexOf(matchingFuzzyDomainsArray, loginDomainName.BaseDomain) >= 0)
                {
                    matchingFuzzyLogins.Add(new Login(login));
                }
            }

            return new Tuple<IEnumerable<Login>, IEnumerable<Login>>(matchingLogins, matchingFuzzyLogins);
        }

        public async Task<ApiResult<LoginResponse>> SaveAsync(Login login)
        {
            ApiResult<LoginResponse> response = null;
            var request = new LoginRequest(login);

            if(login.Id == null)
            {
                response = await _loginApiRepository.PostAsync(request);
            }
            else
            {
                response = await _loginApiRepository.PutAsync(login.Id, request);
            }

            if(response.Succeeded)
            {
                var data = new LoginData(response.Result, _authService.UserId);
                if(login.Id == null)
                {
                    await _loginRepository.InsertAsync(data);
                    login.Id = data.Id;
                }
                else
                {
                    await _loginRepository.UpdateAsync(data);
                }
            }
            else if(response.StatusCode == System.Net.HttpStatusCode.Forbidden
                || response.StatusCode == System.Net.HttpStatusCode.Unauthorized)
            {
                MessagingCenter.Send(Application.Current, "Logout", (string)null);
            }

            return response;
        }

        public async Task<ApiResult> DeleteAsync(string id)
        {
            var response = await _loginApiRepository.DeleteAsync(id);
            if(response.Succeeded)
            {
                await _loginRepository.DeleteAsync(id);
            }
            else if(response.StatusCode == System.Net.HttpStatusCode.Forbidden
                || response.StatusCode == System.Net.HttpStatusCode.Unauthorized)
            {
                MessagingCenter.Send(Application.Current, "Logout", (string)null);
            }

            return response;
        }

        public async Task<byte[]> DownloadAndDecryptAttachmentAsync(SymmetricCryptoKey key, string url)
        {
            using(var client = new HttpClient())
            {
                try
                {
                    var response = await client.GetAsync(new Uri(url)).ConfigureAwait(false);
                    if(!response.IsSuccessStatusCode)
                    {
                        return null;
                    }

                    var data = await response.Content.ReadAsByteArrayAsync();
                    if(data == null)
                    {
                        return null;
                    }

                    return _cryptoService.DecryptToBytes(data, key);
                }
                catch
                {
                    return null;
                }
            }
        }

        private string WebUriFromAndroidAppUri(string androidAppUriString)
        {
            if(!UriIsAndroidApp(androidAppUriString))
            {
                return null;
            }

            var androidUriParts = androidAppUriString.Replace(Constants.AndroidAppProtocol, string.Empty).Split('.');
            if(androidUriParts.Length >= 2)
            {
                return string.Join(".", androidUriParts[1], androidUriParts[0]);
            }

            return null;
        }

        private bool UriIsAndroidApp(string uriString)
        {
            return uriString.StartsWith(Constants.AndroidAppProtocol);
        }
    }
}