using System;
using System.IO;
using System.Threading;
using System.Threading.Tasks;
using Jellyfin.Plugin.SRFPlay.Services.Interfaces;
using MediaBrowser.Controller.Library;
using MediaBrowser.Model.Dto;
using Microsoft.Extensions.Logging;

namespace Jellyfin.Plugin.SRFPlay.Providers;

/// <summary>
/// Live stream wrapper for SRF Play streams to handle transcoding sessions.
/// </summary>
internal sealed class SRFLiveStream : ILiveStream
{
    private readonly ILogger _logger;
    private readonly IStreamProxyService _proxyService;
    private readonly string _originalItemId;
    private MediaSourceInfo? _mediaSource;

    /// <summary>
    /// Initializes a new instance of the <see cref="SRFLiveStream"/> class.
    /// </summary>
    /// <param name="logger">The logger.</param>
    /// <param name="proxyService">The stream proxy service.</param>
    /// <param name="originalItemId">The original item ID.</param>
    /// <param name="openToken">The open token.</param>
    public SRFLiveStream(
        ILogger logger,
        IStreamProxyService proxyService,
        string originalItemId,
        string openToken)
    {
        _logger = logger;
        _proxyService = proxyService;
        _originalItemId = originalItemId;
        OriginalStreamId = openToken;
        UniqueId = openToken;
    }

    /// <inheritdoc />
    public int ConsumerCount { get; set; }

    /// <inheritdoc />
    public string OriginalStreamId { get; set; }

    /// <inheritdoc />
    public string UniqueId { get; }

    /// <inheritdoc />
    public string TunerHostId => string.Empty;

    /// <inheritdoc />
    public bool EnableStreamSharing => false;

    /// <inheritdoc />
    public MediaSourceInfo MediaSource
    {
        get => _mediaSource ?? throw new InvalidOperationException("MediaSource not set");
        set
        {
            _mediaSource = value;
            _logger.LogInformation(
                "SRFLiveStream MediaSource set - Id: {MediaSourceId}, Path: {Path}, OriginalItemId: {OriginalItemId}",
                value.Id,
                value.Path,
                _originalItemId);

            // When Jellyfin assigns a live stream ID (for transcoding), register the stream with that ID too
            if (value.Id != _originalItemId)
            {
                _logger.LogInformation(
                    "Transcoding session detected - LiveStream ID {LiveStreamId} differs from original item ID {OriginalItemId}. Registering stream with both IDs.",
                    value.Id,
                    _originalItemId);

                // Get the authenticated URL and metadata from the original registration
                var authenticatedUrl = _proxyService.GetAuthenticatedUrl(_originalItemId);
                var metadata = _proxyService.GetStreamMetadata(_originalItemId);
                if (authenticatedUrl != null)
                {
                    // Register the same stream URL with the transcoding session ID, preserving metadata
                    var urn = metadata?.Urn;
                    var isLiveStream = metadata?.IsLiveStream ?? false;
                    _proxyService.RegisterStream(value.Id, authenticatedUrl, urn, isLiveStream);
                    _logger.LogInformation(
                        "Registered stream for transcoding session ID: {LiveStreamId} (URN: {Urn}, IsLiveStream: {IsLiveStream})",
                        value.Id,
                        urn ?? "null",
                        isLiveStream);
                }
                else
                {
                    _logger.LogWarning("Could not find authenticated URL for original item {OriginalItemId}", _originalItemId);
                }
            }
        }
    }

    /// <inheritdoc />
    public Task Close()
    {
        _logger.LogInformation("Closing SRF live stream for item {OriginalItemId}", _originalItemId);
        return Task.CompletedTask;
    }

    /// <inheritdoc />
    public Task Open(CancellationToken cancellationToken)
    {
        _logger.LogInformation("Opening SRF live stream for item {OriginalItemId}", _originalItemId);
        return Task.CompletedTask;
    }

    /// <inheritdoc />
    public Stream GetStream()
    {
        throw new NotSupportedException("Direct stream access not supported for SRF streams");
    }

    /// <inheritdoc />
    public void Dispose()
    {
        Dispose(true);
        GC.SuppressFinalize(this);
    }

    /// <summary>
    /// Releases the unmanaged resources used by the SRFLiveStream and optionally releases the managed resources.
    /// </summary>
    /// <param name="disposing">True to release both managed and unmanaged resources; false to release only unmanaged resources.</param>
    private void Dispose(bool disposing)
    {
        if (disposing)
        {
            _logger.LogDebug("Disposing SRF live stream for item {OriginalItemId}", _originalItemId);
        }
    }
}