using System;
using System.Collections.Generic;
using System.Diagnostics.CodeAnalysis;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using Jellyfin.Api.Constants;
using MediaBrowser.Common.Progress;
using MediaBrowser.Controller;
using MediaBrowser.Controller.Configuration;
using MediaBrowser.Controller.Entities;
using MediaBrowser.Controller.Library;
using MediaBrowser.Model.Configuration;
using MediaBrowser.Model.Entities;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;

namespace Jellyfin.Api.Controllers
{
    /// <summary>
    /// The library structure controller.
    /// </summary>
    [Route("/Library/VirtualFolders")]
    [Authorize(Policy = Policies.FirstTimeSetupOrElevated)]
    public class LibraryStructureController : BaseJellyfinApiController
    {
        private readonly IServerApplicationPaths _appPaths;
        private readonly ILibraryManager _libraryManager;
        private readonly ILibraryMonitor _libraryMonitor;

        /// <summary>
        /// Initializes a new instance of the <see cref="LibraryStructureController"/> class.
        /// </summary>
        /// <param name="serverConfigurationManager">Instance of <see cref="IServerConfigurationManager"/> interface.</param>
        /// <param name="libraryManager">Instance of <see cref="ILibraryManager"/> interface.</param>
        /// <param name="libraryMonitor">Instance of <see cref="ILibraryMonitor"/> interface.</param>
        public LibraryStructureController(
            IServerConfigurationManager serverConfigurationManager,
            ILibraryManager libraryManager,
            ILibraryMonitor libraryMonitor)
        {
            _appPaths = serverConfigurationManager.ApplicationPaths;
            _libraryManager = libraryManager;
            _libraryMonitor = libraryMonitor;
        }

        /// <summary>
        /// Gets all virtual folders.
        /// </summary>
        /// <response code="200">Virtual folders retrieved.</response>
        /// <returns>An <see cref="IEnumerable{VirtualFolderInfo}"/> with the virtual folders.</returns>
        [HttpGet]
        [ProducesResponseType(StatusCodes.Status200OK)]
        public ActionResult<IEnumerable<VirtualFolderInfo>> GetVirtualFolders()
        {
            return _libraryManager.GetVirtualFolders(true);
        }

        /// <summary>
        /// Adds a virtual folder.
        /// </summary>
        /// <param name="name">The name of the virtual folder.</param>
        /// <param name="collectionType">The type of the collection.</param>
        /// <param name="refreshLibrary">Whether to refresh the library.</param>
        /// <param name="paths">The paths of the virtual folder.</param>
        /// <param name="libraryOptions">The library options.</param>
        /// <response code="204">Folder added.</response>
        /// <returns>A <see cref="NoContentResult"/>.</returns>
        [HttpPost]
        [ProducesResponseType(StatusCodes.Status204NoContent)]
        public async Task<ActionResult> AddVirtualFolder(
            [FromQuery] string name,
            [FromQuery] string collectionType,
            [FromQuery] bool refreshLibrary,
            [FromQuery] string[] paths,
            [FromQuery] LibraryOptions libraryOptions)
        {
            libraryOptions ??= new LibraryOptions();

            if (paths != null && paths.Length > 0)
            {
                libraryOptions.PathInfos = paths.Select(i => new MediaPathInfo { Path = i }).ToArray();
            }

            await _libraryManager.AddVirtualFolder(name, collectionType, libraryOptions, refreshLibrary).ConfigureAwait(false);

            return NoContent();
        }

        /// <summary>
        /// Removes a virtual folder.
        /// </summary>
        /// <param name="name">The name of the folder.</param>
        /// <param name="refreshLibrary">Whether to refresh the library.</param>
        /// <response code="204">Folder removed.</response>
        /// <returns>A <see cref="NoContentResult"/>.</returns>
        [HttpDelete]
        [ProducesResponseType(StatusCodes.Status204NoContent)]
        public async Task<ActionResult> RemoveVirtualFolder(
            [FromQuery] string name,
            [FromQuery] bool refreshLibrary)
        {
            await _libraryManager.RemoveVirtualFolder(name, refreshLibrary).ConfigureAwait(false);
            return NoContent();
        }

        /// <summary>
        /// Renames a virtual folder.
        /// </summary>
        /// <param name="name">The name of the virtual folder.</param>
        /// <param name="newName">The new name.</param>
        /// <param name="refreshLibrary">Whether to refresh the library.</param>
        /// <response code="204">Folder renamed.</response>
        /// <response code="404">Library doesn't exist.</response>
        /// <response code="409">Library already exists.</response>
        /// <returns>A <see cref="NoContentResult"/> on success, a <see cref="NotFoundResult"/> if the library doesn't exist, a <see cref="ConflictResult"/> if the new name is already taken.</returns>
        /// <exception cref="ArgumentNullException">The new name may not be null.</exception>
        [HttpPost("Name")]
        [ProducesResponseType(StatusCodes.Status204NoContent)]
        [ProducesResponseType(StatusCodes.Status404NotFound)]
        [ProducesResponseType(StatusCodes.Status409Conflict)]
        public ActionResult RenameVirtualFolder(
            [FromQuery] string name,
            [FromQuery] string newName,
            [FromQuery] bool refreshLibrary)
        {
            if (string.IsNullOrWhiteSpace(name))
            {
                throw new ArgumentNullException(nameof(name));
            }

            if (string.IsNullOrWhiteSpace(newName))
            {
                throw new ArgumentNullException(nameof(newName));
            }

            var rootFolderPath = _appPaths.DefaultUserViewsPath;

            var currentPath = Path.Combine(rootFolderPath, name);
            var newPath = Path.Combine(rootFolderPath, newName);

            if (!Directory.Exists(currentPath))
            {
                return NotFound("The media collection does not exist.");
            }

            if (!string.Equals(currentPath, newPath, StringComparison.OrdinalIgnoreCase) && Directory.Exists(newPath))
            {
                return Conflict($"The media library already exists at {newPath}.");
            }

            _libraryMonitor.Stop();

            try
            {
                // Changing capitalization. Handle windows case insensitivity
                if (string.Equals(currentPath, newPath, StringComparison.OrdinalIgnoreCase))
                {
                    var tempPath = Path.Combine(
                        rootFolderPath,
                        Guid.NewGuid().ToString("N", CultureInfo.InvariantCulture));
                    Directory.Move(currentPath, tempPath);
                    currentPath = tempPath;
                }

                Directory.Move(currentPath, newPath);
            }
            finally
            {
                CollectionFolder.OnCollectionFolderChange();

                Task.Run(async () =>
                {
                    // No need to start if scanning the library because it will handle it
                    if (refreshLibrary)
                    {
                        await _libraryManager.ValidateMediaLibrary(new SimpleProgress<double>(), CancellationToken.None).ConfigureAwait(false);
                    }
                    else
                    {
                        // Need to add a delay here or directory watchers may still pick up the changes
                        // Have to block here to allow exceptions to bubble
                        await Task.Delay(1000).ConfigureAwait(false);
                        _libraryMonitor.Start();
                    }
                });
            }

            return NoContent();
        }

        /// <summary>
        /// Add a media path to a library.
        /// </summary>
        /// <param name="name">The name of the library.</param>
        /// <param name="path">The path to add.</param>
        /// <param name="pathInfo">The path info.</param>
        /// <param name="refreshLibrary">Whether to refresh the library.</param>
        /// <returns>A <see cref="NoContentResult"/>.</returns>
        /// <response code="204">Media path added.</response>
        /// <exception cref="ArgumentNullException">The name of the library may not be empty.</exception>
        [HttpPost("Paths")]
        [ProducesResponseType(StatusCodes.Status204NoContent)]
        public ActionResult AddMediaPath(
            [FromQuery] string name,
            [FromQuery] string path,
            [FromQuery] MediaPathInfo pathInfo,
            [FromQuery] bool refreshLibrary)
        {
            if (string.IsNullOrWhiteSpace(name))
            {
                throw new ArgumentNullException(nameof(name));
            }

            _libraryMonitor.Stop();

            try
            {
                var mediaPath = pathInfo ?? new MediaPathInfo { Path = path };

                _libraryManager.AddMediaPath(name, mediaPath);
            }
            finally
            {
                Task.Run(async () =>
                {
                    // No need to start if scanning the library because it will handle it
                    if (refreshLibrary)
                    {
                        await _libraryManager.ValidateMediaLibrary(new SimpleProgress<double>(), CancellationToken.None).ConfigureAwait(false);
                    }
                    else
                    {
                        // Need to add a delay here or directory watchers may still pick up the changes
                        // Have to block here to allow exceptions to bubble
                        await Task.Delay(1000).ConfigureAwait(false);
                        _libraryMonitor.Start();
                    }
                });
            }

            return NoContent();
        }

        /// <summary>
        /// Updates a media path.
        /// </summary>
        /// <param name="name">The name of the library.</param>
        /// <param name="pathInfo">The path info.</param>
        /// <returns>A <see cref="NoContentResult"/>.</returns>
        /// <response code="204">Media path updated.</response>
        /// <exception cref="ArgumentNullException">The name of the library may not be empty.</exception>
        [HttpPost("Paths/Update")]
        [ProducesResponseType(StatusCodes.Status204NoContent)]
        public ActionResult UpdateMediaPath(
            [FromQuery] string name,
            [FromQuery] MediaPathInfo pathInfo)
        {
            if (string.IsNullOrWhiteSpace(name))
            {
                throw new ArgumentNullException(nameof(name));
            }

            _libraryManager.UpdateMediaPath(name, pathInfo);
            return NoContent();
        }

        /// <summary>
        /// Remove a media path.
        /// </summary>
        /// <param name="name">The name of the library.</param>
        /// <param name="path">The path to remove.</param>
        /// <param name="refreshLibrary">Whether to refresh the library.</param>
        /// <returns>A <see cref="NoContentResult"/>.</returns>
        /// <response code="204">Media path removed.</response>
        /// <exception cref="ArgumentNullException">The name of the library may not be empty.</exception>
        [HttpDelete("Paths")]
        [ProducesResponseType(StatusCodes.Status204NoContent)]
        public ActionResult RemoveMediaPath(
            [FromQuery] string name,
            [FromQuery] string path,
            [FromQuery] bool refreshLibrary)
        {
            if (string.IsNullOrWhiteSpace(name))
            {
                throw new ArgumentNullException(nameof(name));
            }

            _libraryMonitor.Stop();

            try
            {
                _libraryManager.RemoveMediaPath(name, path);
            }
            finally
            {
                Task.Run(async () =>
                {
                    // No need to start if scanning the library because it will handle it
                    if (refreshLibrary)
                    {
                        await _libraryManager.ValidateMediaLibrary(new SimpleProgress<double>(), CancellationToken.None).ConfigureAwait(false);
                    }
                    else
                    {
                        // Need to add a delay here or directory watchers may still pick up the changes
                        // Have to block here to allow exceptions to bubble
                        await Task.Delay(1000).ConfigureAwait(false);
                        _libraryMonitor.Start();
                    }
                });
            }

            return NoContent();
        }

        /// <summary>
        /// Update library options.
        /// </summary>
        /// <param name="id">The library name.</param>
        /// <param name="libraryOptions">The library options.</param>
        /// <response code="204">Library updated.</response>
        /// <returns>A <see cref="NoContentResult"/>.</returns>
        [HttpPost("LibraryOptions")]
        [ProducesResponseType(StatusCodes.Status204NoContent)]
        public ActionResult UpdateLibraryOptions(
            [FromQuery] string id,
            [FromQuery] LibraryOptions libraryOptions)
        {
            var collectionFolder = (CollectionFolder)_libraryManager.GetItemById(id);

            collectionFolder.UpdateLibraryOptions(libraryOptions);
            return NoContent();
        }
    }
}