using System.Net.Http.Headers;
using System.Text;
using System.Text.Json;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;
using SaasMediaWorker.Configuration;
using SaasMediaWorker.Models;

namespace SaasMediaWorker.Services;

/// <summary>
/// OpenAI TTS API Client — Metin → Ses dönüşümü.
/// </summary>
public class OpenAiTtsService
{
    private readonly HttpClient _httpClient;
    private readonly ILogger<OpenAiTtsService> _logger;
    private readonly ApiSettings _settings;

    public OpenAiTtsService(
        HttpClient httpClient,
        ILogger<OpenAiTtsService> logger,
        IOptions<ApiSettings> settings)
    {
        _httpClient = httpClient;
        _logger = logger;
        _settings = settings.Value;

        _httpClient.BaseAddress = new Uri("https://api.openai.com/v1/");
        _httpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", _settings.OpenAiApiKey);
        _httpClient.Timeout = TimeSpan.FromMinutes(2);
    }

    /// <summary>
    /// Bir sahnenin narration metnini sese çevirir ve dosyaya kaydeder.
    /// </summary>
    public async Task<GeneratedMediaFile> GenerateNarrationAsync(
        ScenePayload scene,
        string outputDirectory,
        string voiceStyle,
        CancellationToken ct)
    {
        _logger.LogInformation(
            "🎙️ OpenAI TTS üretimi — Sahne {Order}: \"{Text}\"",
            scene.Order,
            scene.NarrationText[..Math.Min(60, scene.NarrationText.Length)]);

        // Varsayılan voiceStyle kullan veya fallback
        var voiceId = string.IsNullOrWhiteSpace(voiceStyle) ? _settings.OpenAiTtsVoiceId : voiceStyle;

        var requestBody = new
        {
            model = "tts-1",
            input = scene.NarrationText,
            voice = voiceId,
            response_format = "mp3"
        };

        var content = new StringContent(
            JsonSerializer.Serialize(requestBody),
            Encoding.UTF8,
            "application/json");

        var response = await _httpClient.PostAsync("audio/speech", content, ct);

        response.EnsureSuccessStatusCode();

        // Ses dosyasını kaydet
        var outputPath = Path.Combine(outputDirectory, $"scene_{scene.Order:D2}_narration.mp3");
        await using var fileStream = File.Create(outputPath);
        await response.Content.CopyToAsync(fileStream, ct);

        var fileInfo = new FileInfo(outputPath);

        _logger.LogInformation(
            "OpenAI TTS tamamlandı — Sahne {Order}: {Size} bytes",
            scene.Order, fileInfo.Length);

        return new GeneratedMediaFile
        {
            SceneId = scene.Id,
            SceneOrder = scene.Order,
            Type = MediaFileType.AudioNarration,
            LocalPath = outputPath,
            FileSizeBytes = fileInfo.Length,
            DurationSeconds = scene.Duration,
            MimeType = "audio/mpeg",
            AiProvider = "openai"
        };
    }
}
