using FrameworkDAL.DTO.EIPConversation;
using GB5Shared.DTO.Framework.Login;
using Microsoft.Extensions.Logging;
using System;
using System.Collections.Generic;
using System.Threading;
using System.Threading.Tasks;

namespace FrameworkBLL.EIPConversation.EIPHandlers.ChannelHandler
{
    /// <summary>
    /// Handles voice channel responses. Does not make HTTP calls; instead it returns a
    /// structured response with TtsText and SsmlText so the calling voice platform
    /// (Twilio, Azure Bot, Google Dialogflow, etc.) can synthesise speech.
    ///
    /// The response is available in EIPChannelResponseDTO.AdditionalData:
    ///   "TtsText"  — plain text for platforms that don't support SSML
    ///   "SsmlText" — SSML markup (falls back to plain text when VoiceHint is null)
    ///   "IsCompleted" — whether the conversation flow is done
    /// </summary>
    public class VoiceChannelHandler : IEIPChannelHandler
    {
        public string ChannelName => "VOICE";

        private readonly ILogger<VoiceChannelHandler> _logger;

        public VoiceChannelHandler(ILogger<VoiceChannelHandler> logger)
        {
            _logger = logger ?? throw new ArgumentNullException(nameof(logger));
        }

        public bool CanHandle(string channel)
            => string.Equals(channel, ChannelName, StringComparison.OrdinalIgnoreCase);

        public Task<EIPChannelResponseDTO> SendAsync(
            EIPResponseContext context,
            LoginDTO loginDTO,
            CancellationToken cancellationToken)
        {
            cancellationToken.ThrowIfCancellationRequested();

            var plainText = context.Message ?? string.Empty;
            var ssmlText  = context.VoiceHint ?? plainText;

            _logger.LogInformation(
                "VoiceChannelHandler: Tenant={Tenant} | IsCompleted={Done} | TtsLength={Len}",
                context.TenantId, context.IsCompleted, plainText.Length);

            var response = new EIPChannelResponseDTO
            {
                IsSent  = true,
                Status  = "VOICE_READY",
                AdditionalData = new Dictionary<string, object>
                {
                    ["TtsText"]     = plainText,
                    ["SsmlText"]    = ssmlText,
                    ["IsCompleted"] = context.IsCompleted ?? false
                }
            };

            return Task.FromResult(response);
        }
    }
}