/*
 *
 * (c) Copyright Ascensio System Limited 2010-2018
 *
 * This program is freeware. You can redistribute it and/or modify it under the terms of the GNU 
 * General Public License (GPL) version 3 as published by the Free Software Foundation (https://www.gnu.org/copyleft/gpl.html). 
 * In accordance with Section 7(a) of the GNU GPL its Section 15 shall be amended to the effect that 
 * Ascensio System SIA expressly excludes the warranty of non-infringement of any third-party rights.
 *
 * THIS PROGRAM IS DISTRIBUTED WITHOUT ANY WARRANTY; WITHOUT EVEN THE IMPLIED WARRANTY OF MERCHANTABILITY OR
 * FITNESS FOR A PARTICULAR PURPOSE. For more details, see GNU GPL at https://www.gnu.org/copyleft/gpl.html
 *
 * You can contact Ascensio System SIA by email at sales@onlyoffice.com
 *
 * The interactive user interfaces in modified source and object code versions of ONLYOFFICE must display 
 * Appropriate Legal Notices, as required under Section 5 of the GNU GPL version 3.
 *
 * Pursuant to Section 7 § 3(b) of the GNU GPL you must retain the original ONLYOFFICE logo which contains 
 * relevant author attributions when distributing the software. If the display of the logo in its graphic 
 * form is not reasonably feasible for technical reasons, you must include the words "Powered by ONLYOFFICE" 
 * in every copy of the program you distribute. 
 * Pursuant to Section 7 § 3(e) we decline to grant you any rights under trademark law for use of our trademarks.
 *
*/

namespace ASC.VoipService.Twilio;

public class TwilioResponseHelper
{
    private readonly VoipSettings _settings;
    private readonly string _baseUrl;
    private readonly AuthContext _authContext;
    private readonly TenantUtil _tenantUtil;
    private readonly SecurityContext _securityContext;

    public TwilioResponseHelper(
        VoipSettings settings,
        string baseUrl,
        AuthContext authContext,
        TenantUtil tenantUtil,
        SecurityContext securityContext)
    {
        _settings = settings;
        _authContext = authContext;
        _tenantUtil = tenantUtil;
        _securityContext = securityContext;
        _baseUrl = baseUrl.TrimEnd('/') + "/twilio/";
    }

    public VoiceResponse Inbound(Tuple<Agent, bool> agentTuple)
    {
        var agent = agentTuple?.Item1;
        var anyOnline = agentTuple != null && agentTuple.Item2;
        var response = new VoiceResponse();

        if (_settings.WorkingHours != null && _settings.WorkingHours.Enabled)
        {
            var now = _tenantUtil.DateTimeFromUtc(DateTime.UtcNow);
            if (!(_settings.WorkingHours.From <= now.TimeOfDay && _settings.WorkingHours.To >= now.TimeOfDay))
            {
                return AddVoiceMail(response);
            }
        }

        if (anyOnline)
        {
            if (!string.IsNullOrEmpty(_settings.GreetingAudio))
            {
                response.Play(Uri.EscapeDataString(_settings.GreetingAudio));
            }

            response.Enqueue(_settings.Queue.Name, GetEcho("Enqueue", agent != null), "POST",
                GetEcho("Wait", agent != null), "POST");
        }

        return AddVoiceMail(response);
    }

    public VoiceResponse Outbound()
    {
        return !_settings.Caller.AllowOutgoingCalls
                    ? new VoiceResponse()
                    : AddToResponse(new VoiceResponse(), _settings.Caller);
    }

    public VoiceResponse Dial()
    {
        return new VoiceResponse();
    }

    public VoiceResponse Queue()
    {
        return new VoiceResponse();
    }

    public VoiceResponse Enqueue(string queueResult)
    {
        return queueResult == "leave" ? AddVoiceMail(new VoiceResponse()) : new VoiceResponse();
    }

    public VoiceResponse Dequeue()
    {
        return AddToResponse(new VoiceResponse(), _settings.Caller);
    }

    public VoiceResponse Leave()
    {
        return AddVoiceMail(new VoiceResponse());
    }

    public VoiceResponse Wait(string queueTime, string queueSize)
    {
        var response = new VoiceResponse();
        var queue = _settings.Queue;

        if (Convert.ToInt32(queueTime) > queue.WaitTime || Convert.ToInt32(queueSize) > queue.Size) return response.Leave();

        if (!string.IsNullOrEmpty(queue.WaitUrl))
        {
            var gather = new Gather(method: "POST", action: GetEcho("gatherQueue"));
            gather.Play(Uri.EscapeDataString(queue.WaitUrl));
            response.Gather(gather);
        }
        else
        {
            response.Pause(queue.WaitTime);
        }

        return response;
    }

    public VoiceResponse GatherQueue(string digits, List<Agent> availableOperators)
    {
        var response = new VoiceResponse();

        if (digits == "#") return AddVoiceMail(response);

        var oper = _settings.Operators.Find(r => r.PostFix == digits && availableOperators.Contains(r)) ??
            _settings.Operators.FirstOrDefault(r => availableOperators.Contains(r));

        return oper != null ? AddToResponse(response, oper) : response;
    }

    public VoiceResponse Redirect(string to)
    {
        if (to == "hold")
        {
            return new VoiceResponse().Play(Uri.EscapeDataString(_settings.HoldAudio), 0);
        }


        if (Guid.TryParse(to, out var newCallerId))
        {
            _securityContext.AuthenticateMeWithoutCookie(newCallerId);
        }

        return new VoiceResponse().Enqueue(_settings.Queue.Name, GetEcho("enqueue"), "POST",
            GetEcho("wait") + "&RedirectTo=" + to, "POST");
    }

    public VoiceResponse VoiceMail()
    {
        return new VoiceResponse();
    }

    private VoiceResponse AddToResponse(VoiceResponse response, Agent agent)
    {
        var dial = new Dial(method: "POST", action: GetEcho("dial"), timeout: agent.TimeOut, record: agent.Record ? "record-from-answer" : "do-not-record");

        switch (agent.Answer)
        {
            case AnswerType.Number:
                response.Dial(dial.Number(agent.PhoneNumber, method: "POST", url: GetEcho("client")));
                break;
            case AnswerType.Client:
                response.Dial(dial.Client(agent.ClientID, "POST", GetEcho("client")));
                break;
            case AnswerType.Sip:
                response.Dial(dial.Sip(agent.ClientID, method: "POST", url: GetEcho("client")));
                break;
        }

        return response;
    }


    private VoiceResponse AddVoiceMail(VoiceResponse response)
    {
        return string.IsNullOrEmpty(_settings.VoiceMail)
                    ? response.Say("")
                    : response.Play(Uri.EscapeDataString(_settings.VoiceMail)).Record(method: "POST", action: GetEcho("voiceMail"), maxLength: 30);
    }

    public string GetEcho(string action, bool user = true)
    {
        var result = _baseUrl.TrimEnd('/');

        if (!string.IsNullOrEmpty(action))
        {
            result += "/" + action.TrimStart('/');
        }
        if (user)
        {
            result += "?CallerId=" + _authContext.CurrentAccount.ID;
        }

        return result;
    }
}