using Plugin.Messaging;
using Serilog;
using System;
using System.Collections.Generic;
using System.Threading.Tasks;
using System.Windows.Input;
using TINK.Model.Services.CopriApi.ServerUris;
using TINK.Model.Station;
using TINK.MultilingualResources;
using TINK.View;
using Xamarin.Essentials;
using Xamarin.Forms;

namespace TINK.ViewModel.Info
{
    /// <summary> View model for contact page.</summary>
    public class ContactPageViewModel
    {
        /// <summary> Reference on view service to show modal notifications and to perform navigation. </summary>
        private IViewService ViewService { get; }

        /// <summary> Station selected by user. </summary>
        private IStation SelectedStation;

        Uri ActiveUri { get; }

        /// <summary> Holds a reference to the external trigger service. </summary>
        private Action OpenUrlInExternalBrowser { get; }

        Func<string> CreateAttachment { get; }

        /// <summary> Constructs a contact page view model. </summary>
        /// <param name="openUrlInExternalBrowser">Action to open an external browser.</param>
        /// <param name="viewService">View service to notify user.</param>
        public ContactPageViewModel(
            IStation selectedStation,
            Uri activeUri,
            Func<string> createAttachment,
            Action openUrlInExternalBrowser,
            IViewService viewService)
        {
            ActiveUri = activeUri
                ?? throw new ArgumentException("Can not instantiate contact page view model- object. No active uri available.");

            CreateAttachment = createAttachment
                ?? throw new ArgumentException("Can not instantiate contact page view model- object. No create attachment provider available.");

            ViewService = viewService
                ?? throw new ArgumentException("Can not instantiate contact page view model- object. No user view service available.");

            OpenUrlInExternalBrowser = openUrlInExternalBrowser
                ?? throw new ArgumentException("Can not instantiate contact page view model- object. No user external browse service available.");

            // Station might be null-station, if no station info is avialable.
            SelectedStation = selectedStation;
        }

        /// <summary> Command object to bind login button to view model. </summary>
        public ICommand OnMailRequest
            => new Command(
                    async () => await DoSendMail(),
                    () => IsSendMailAvailable);


        /// <summary>True if sending mail is possible.</summary>
        public bool IsSendMailAvailable =>
            CrossMessaging.Current.EmailMessenger.CanSendEmail;
 

        /// <summary>cTrue if doing a phone call is possible.</summary>
        public bool IsDoPhoncallAvailable
            => CrossMessaging.Current.PhoneDialer.CanMakePhoneCall;

        /// <summary>Holds the mail address to mail to.</summary>
        public string MailAddressText
            => SelectedStation?.OperatorData?.MailAddressText ?? string.Empty;

        /// <summary>Holds the mail address to send mail to.</summary>
        public string PhoneNumberText
            => SelectedStation?.OperatorData?.PhoneNumberText ?? string.Empty;

        /// <summary>Holds the mail address to send mail to.</summary>
        public string OfficeHoursText
            => SelectedStation?.OperatorData?.Hours ?? string.Empty;

        /// <summary> Gets whether any operator support info is avaliable. </summary>
        public bool IsOperatorInfoAvaliable
            => MailAddressText.Length > 0 || PhoneNumberText.Length > 0;

        /// <summary> Request to do a phone call. </summary>
        public async Task DoSendMail()
        {
            try
            {
                if (!IsSendMailAvailable)
                {
                    // Nothing to do because email can not be sent.
                    return;
                }

                var tinkMail = await ViewService.DisplayAlert(
                        AppResources.QuestionTitle,
                        string.Format(AppResources.QuestionSupportmailSubject, GetAppName(ActiveUri)),
                        string.Format(AppResources.QuestionSupportmailAnswerOperator, GetAppName(ActiveUri)),
                        string.Format(AppResources.QuestionSupportmailAnswerApp, GetAppName(ActiveUri)));

                if (tinkMail)
                {
                    // Send TINK- related support mail.
                    await Email.ComposeAsync(new EmailMessage { To = new List<string> { MailAddressText }, Subject = $"{GetAppName(ActiveUri)} Anfrage" });
                    return;
                }

                // Send a tink app related mail
                var appendFile = false;
                appendFile = await ViewService.DisplayAlert(
                    AppResources.QuestionTitle,
                    AppResources.QuestionSupportmailAttachment,
                    AppResources.QuestionAnswerYes,
                    AppResources.QuestionAnswerNo);

                var message = new EmailMessage { To = new List<string> { MailAddressText }, Subject = $"{GetAppName(ActiveUri)}-App Anfrage" };

                if (appendFile == false)
                {
                    // Send a tink app related mail
                    await Email.ComposeAsync(message);
                    return;
                }

                var logFileName = string.Empty;
                try
                {
                    logFileName = CreateAttachment();
                }
                catch (Exception l_oException)
                {
                    await ViewService.DisplayAdvancedAlert(
                        AppResources.MessageWaring,
                        AppResources.ErrorSupportmailCreateAttachment,
                        l_oException.Message, 
                        AppResources.MessageAnswerOk);
                    Log.Error("An error occurred creating attachment. {@l_oException)", l_oException);
                }

                if (!string.IsNullOrEmpty(logFileName))
                {
                    message.Attachments.Add(new Xamarin.Essentials.EmailAttachment(logFileName));
                }

                // Send a tink app related mail
                await Email.ComposeAsync(message);
            }
            catch (Exception p_oException)
            {
                Log.Error("An unexpected error occurred sending mail. {@Exception}", p_oException);
                await ViewService.DisplayAdvancedAlert(
                    AppResources.MessageWaring,
                    AppResources.ErrorSupportmailMailingFailed, 
                    p_oException.Message,
                    AppResources.MessageAnswerOk);
                return;
            }
        }

        /// <summary> Command object to bind login button to view model. </summary>
        public ICommand OnPhoneRequest
            => new Command(
                    async () => await DoPhoneCall(),
                    () => IsDoPhoncallAvailable);

        /// <summary> Request to do a phone call. </summary>
        public async Task DoPhoneCall()
        {
            try
            {
                // Make Phone Call
                if (IsDoPhoncallAvailable)
                {
                    CrossMessaging.Current.PhoneDialer.MakePhoneCall(PhoneNumberText);
                }
            }
            catch (Exception p_oException)
            {
                Log.Error("An unexpected error occurred doing a phone call. {@Exception}", p_oException);
                await ViewService.DisplayAdvancedAlert(
                    AppResources.MessageWaring,
                    AppResources.ErrorSupportmailPhoningFailed, 
                    p_oException.Message,
                    AppResources.MessageAnswerOk);
                return;
            }
        }

        /// <summary> Text providing mail address and possilbe reasons to contact. </summary>
        public FormattedString MaliAddressAndMotivationsText
        {
            get
            {
                var hint = new FormattedString();
                hint.Spans.Add(new Span { Text = AppResources.MessageContactMail });
                return hint;
            }
        }

        /// <summary> Invitation to rate app.</summary>
        public FormattedString LikeTinkApp
        {
            get
            {
                var l_oHint = new FormattedString();
                l_oHint.Spans.Add(new Span { Text = string.Format(AppResources.MessageRateMail, GetAppName(ActiveUri)) });
                return l_oHint;
            }
        }

        /// <summary> User clicks rate button.</summary>
        public ICommand OnRateRequest
            => new Command(() => RegisterRequest());

        /// <summary> Opens login page.</summary>
        public void RegisterRequest()
        {
            try
            {
                OpenUrlInExternalBrowser();
            }
            catch (Exception p_oException)
            {
                Log.Error("Ein unerwarteter Fehler ist auf der Login Seite beim Öffnen eines Browsers, Seite {url}, aufgetreten. {@Exception}", p_oException);
                return;
            }
        }

        /// <summary> Invitation to rate app.</summary>
        public FormattedString PhoneContactText
        {
            get
            {
                var l_oHint = new FormattedString();
                l_oHint.Spans.Add(new Span
                {
                    Text = string.Format(AppResources.MessagePhoneMail, GetAppName(ActiveUri)) + $"{(OfficeHoursText.Length > 0 ? $" {OfficeHoursText}" : string.Empty)}"
                });
                return l_oHint;
            }
        }

        /// <summary>Gets the application name.</summary>
        public static string GetAppName(Uri activeUri)
        {
            switch (activeUri.AbsoluteUri)
            {
                case CopriServerUriList.TINK_DEVEL:
                case CopriServerUriList.TINK_LIVE:
                    return "TINK";

                case CopriServerUriList.SHAREE_DEVEL:
                case CopriServerUriList.SHAREE_LIVE:
                    return "sharee.bike";

                default:
                    return "Teilrad";
            }
        }
    }
}