using GB5Shared.ActionProcessor;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;
using System;
using System.Threading;
using System.Threading.Tasks;
using Twilio.Rest.Api.V2010.Account;
using Twilio.Types;

namespace FrameworkBLL.ActionProcessor.Handlers
{
    /// <summary>
    /// ActionType = 1 (SMS). Sends SMS via Twilio.
    /// Twilio credentials must be configured in appsettings.json.
    /// </summary>
    public sealed class SmsActionHandler : IActionHandler
    {
        public int ActionType => 1;

        private readonly string? _fromNumber;
        private readonly ILogger<SmsActionHandler> _logger;

        public SmsActionHandler(
            IOptions<SmsSettings> smsSettings,
            ILogger<SmsActionHandler> logger)
        {
            _fromNumber = smsSettings?.Value?.FromNumber;
            _logger     = logger ?? throw new ArgumentNullException(nameof(logger));

            if (string.IsNullOrWhiteSpace(_fromNumber))
                _logger.LogWarning("SmsActionHandler: Twilio FromNumber is not configured — SMS actions will fail at runtime.");
        }

        public async Task<ActionResult> HandleAsync(ActionEventDto dto, CancellationToken ct = default)
        {
            if (dto == null)
                return ActionResult.Permanent("ActionEventDto cannot be null");

            if (string.IsNullOrWhiteSpace(_fromNumber))
                return ActionResult.Permanent("Twilio FromNumber is not configured.");

            if (string.IsNullOrWhiteSpace(dto.SendTo))
            {
                _logger.LogWarning(
                    "SMS handler validation failed | ActionRunId={ActionRunId} SendTo missing",
                    dto.ActionRunId);

                return ActionResult.Permanent("SendTo is required for SMS actions");
            }

            try
            {
                var message = await MessageResource.CreateAsync(
                    body: dto.Payload.ToString() ?? string.Empty,
                    from: new PhoneNumber(_fromNumber),
                    to: new PhoneNumber(dto.SendTo)
                ).ConfigureAwait(false);

                _logger.LogInformation(
                    "SMS sent successfully | ActionRunId={ActionRunId} To={Recipient} Sid={Sid}",
                    dto.ActionRunId,
                    dto.SendTo,
                    message.Sid);

                return ActionResult.Ok(message.Sid);
            }
            catch (Exception ex)
            {
                _logger.LogError(
                    ex,
                    "SMS handler exception | ActionRunId={ActionRunId}",
                    dto.ActionRunId);

                return ActionResult.Transient(ex.Message);
            }
        }
    }

    /// <summary>
    /// SMS configuration settings.
    /// </summary>
    public sealed class SmsSettings
    {
        public string FromNumber { get; set; } = string.Empty;
    }
}