using System;
using System.Globalization;
using System.IO;
using System.Reflection;
using System.Threading;
using System.Threading.Tasks;
using Jellyfin.Plugin.RedditComments.Models;
using Jellyfin.Plugin.RedditComments.Services;
using MediaBrowser.Controller.Library;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Logging;

namespace Jellyfin.Plugin.RedditComments.Api;

/// <summary>
/// API endpoints for the Reddit Comments plugin.
/// </summary>
[ApiController]
[Route("RedditComments")]
public class RedditCommentsController : ControllerBase
{
    private readonly ILogger<RedditCommentsController> _logger;
    private readonly ILibraryManager _libraryManager;
    private readonly RedditCommentsService _commentsService;
    private readonly RedditClient _redditClient;

    /// <summary>
    /// Initializes a new instance of the <see cref="RedditCommentsController"/> class.
    /// </summary>
    /// <param name="logger">Logger.</param>
    /// <param name="libraryManager">Library manager.</param>
    /// <param name="commentsService">Comments service.</param>
    /// <param name="redditClient">Reddit client.</param>
    public RedditCommentsController(
        ILogger<RedditCommentsController> logger,
        ILibraryManager libraryManager,
        RedditCommentsService commentsService,
        RedditClient redditClient)
    {
        _logger = logger;
        _libraryManager = libraryManager;
        _commentsService = commentsService;
        _redditClient = redditClient;
    }

    /// <summary>
    /// Gets the Reddit discussion comments for a Jellyfin item. Served from the local cache
    /// unless this is the first lookup or the cache expired.
    /// </summary>
    /// <param name="itemId">The Jellyfin item id.</param>
    /// <param name="cancellationToken">Cancellation token.</param>
    /// <returns>The comments response.</returns>
    [HttpGet("Item/{itemId}")]
    [Authorize]
    [ProducesResponseType(StatusCodes.Status200OK)]
    [ProducesResponseType(StatusCodes.Status404NotFound)]
    public async Task<ActionResult<CommentsResponse>> GetComments([FromRoute] Guid itemId, CancellationToken cancellationToken)
    {
        var item = _libraryManager.GetItemById(itemId);
        if (item is null)
        {
            return NotFound();
        }

        try
        {
            return await _commentsService.GetForItemAsync(item, forceRefresh: false, cancellationToken).ConfigureAwait(false);
        }
        catch (OperationCanceledException)
        {
            throw;
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Failed to get Reddit comments for item {ItemId}", itemId);
            return new CommentsResponse
            {
                Found = false,
                ItemId = itemId.ToString("N", CultureInfo.InvariantCulture),
                Message = "Failed to fetch Reddit comments: " + ex.Message
            };
        }
    }

    /// <summary>
    /// Forces a fresh lookup for an item, bypassing and replacing the cache.
    /// </summary>
    /// <param name="itemId">The Jellyfin item id.</param>
    /// <param name="cancellationToken">Cancellation token.</param>
    /// <returns>The comments response.</returns>
    [HttpPost("Item/{itemId}/Refresh")]
    [Authorize]
    [ProducesResponseType(StatusCodes.Status200OK)]
    [ProducesResponseType(StatusCodes.Status404NotFound)]
    public async Task<ActionResult<CommentsResponse>> RefreshComments([FromRoute] Guid itemId, CancellationToken cancellationToken)
    {
        var item = _libraryManager.GetItemById(itemId);
        if (item is null)
        {
            return NotFound();
        }

        try
        {
            return await _commentsService.GetForItemAsync(item, forceRefresh: true, cancellationToken).ConfigureAwait(false);
        }
        catch (OperationCanceledException)
        {
            throw;
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Failed to refresh Reddit comments for item {ItemId}", itemId);
            return new CommentsResponse
            {
                Found = false,
                ItemId = itemId.ToString("N", CultureInfo.InvariantCulture),
                Message = "Failed to fetch Reddit comments: " + ex.Message
            };
        }
    }

    /// <summary>
    /// Tests the configured Reddit API credentials. Admin only.
    /// </summary>
    /// <param name="cancellationToken">Cancellation token.</param>
    /// <returns>Whether the credentials work.</returns>
    [HttpGet("Test")]
    [Authorize(Policy = "RequiresElevation")]
    [ProducesResponseType(StatusCodes.Status200OK)]
    public async Task<ActionResult<object>> TestCredentials(CancellationToken cancellationToken)
    {
        if (!RedditClient.IsConfigured)
        {
            return new { ok = false, message = "Client id and secret are not configured." };
        }

        try
        {
            await _redditClient.TestCredentialsAsync(cancellationToken).ConfigureAwait(false);
            return new { ok = true, message = "Successfully authenticated with Reddit." };
        }
        catch (Exception ex)
        {
            return new { ok = false, message = ex.Message };
        }
    }

    /// <summary>
    /// Serves the web client script that adds the comments button/sidebar to the player.
    /// </summary>
    /// <returns>The JavaScript file.</returns>
    [HttpGet("Static/reddit-comments.js")]
    [AllowAnonymous]
    [ProducesResponseType(StatusCodes.Status200OK)]
    public ActionResult GetScript()
    {
        var stream = Assembly.GetExecutingAssembly().GetManifestResourceStream("Jellyfin.Plugin.RedditComments.Web.reddit-comments.js");
        if (stream is null)
        {
            return NotFound();
        }

        // Cache for an hour so restarts/plugin updates pick up changes reasonably fast.
        Response.Headers.CacheControl = "public, max-age=3600";
        return File(stream, "text/javascript");
    }
}