using System;
using System.Collections.Generic;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Net.Http;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Logging;
using Umbraco.Cms.Core;
using Umbraco.Cms.Core.Hosting;
using Umbraco.Cms.Core.Mapping;
using Umbraco.Cms.Core.Models;
using Umbraco.Cms.Core.Models.ContentEditing;
using Umbraco.Cms.Core.PropertyEditors;
using Umbraco.Cms.Core.Security;
using Umbraco.Cms.Core.Services;
using Umbraco.Cms.Core.Strings;
using Umbraco.Cms.Web.Common.Attributes;
using Umbraco.Cms.Web.Common.Authorization;
using Umbraco.Extensions;
using Constants = Umbraco.Cms.Core.Constants;

namespace Umbraco.Cms.Web.BackOffice.Controllers
{

    /// <summary>
    /// The API controller used for editing dictionary items
    /// </summary>
    [PluginController(Constants.Web.Mvc.BackOfficeApiArea)]
    [Authorize(Policy = AuthorizationPolicies.TreeAccessMacros)]
    [ParameterSwapControllerActionSelector(nameof(GetById), "id", typeof(int), typeof(Guid), typeof(Udi))]
    public class MacrosController : BackOfficeNotificationsController
    {
        private readonly ParameterEditorCollection _parameterEditorCollection;
        private readonly IMacroService _macroService;
        private readonly IShortStringHelper _shortStringHelper;
        private readonly IBackOfficeSecurityAccessor _backofficeSecurityAccessor;
        private readonly ILogger<MacrosController> _logger;
        private readonly IHostingEnvironment _hostingEnvironment;
        private readonly IUmbracoMapper _umbracoMapper;

        public MacrosController(
            ParameterEditorCollection parameterEditorCollection,
            IMacroService macroService,
            IShortStringHelper shortStringHelper,
            IBackOfficeSecurityAccessor backofficeSecurityAccessor,
            ILogger<MacrosController> logger,
            IHostingEnvironment hostingEnvironment,
            IUmbracoMapper umbracoMapper)
        {
            _parameterEditorCollection = parameterEditorCollection ?? throw new ArgumentNullException(nameof(parameterEditorCollection));
            _macroService = macroService ?? throw new ArgumentNullException(nameof(macroService));
            _shortStringHelper = shortStringHelper ?? throw new ArgumentNullException(nameof(shortStringHelper));
            _backofficeSecurityAccessor = backofficeSecurityAccessor ?? throw new ArgumentNullException(nameof(backofficeSecurityAccessor));
            _logger = logger ?? throw new ArgumentNullException(nameof(logger));
            _hostingEnvironment = hostingEnvironment ?? throw new ArgumentNullException(nameof(hostingEnvironment));
            _umbracoMapper = umbracoMapper ?? throw new ArgumentNullException(nameof(umbracoMapper));
        }


        /// <summary>
        /// Creates a new macro
        /// </summary>
        /// <param name="name">
        /// The name.
        /// </param>
        /// <returns>
        /// The id of the created macro
        /// </returns>
        [HttpPost]
        public ActionResult<int> Create(string name)
        {
            if (string.IsNullOrWhiteSpace(name))
            {
                return ValidationProblem("Name can not be empty");
            }

            var alias = name.ToSafeAlias(_shortStringHelper);

            if (_macroService.GetByAlias(alias) != null)
            {
                return ValidationProblem("Macro with this alias already exists");
            }

            if (name == null || name.Length > 255)
            {
                return ValidationProblem("Name cannnot be more than 255 characters in length.");
            }

            try
            {
                var macro = new Macro(_shortStringHelper)
                {
                    Alias = alias,
                    Name = name,
                    MacroSource = string.Empty
                };

                _macroService.Save(macro, _backofficeSecurityAccessor.BackOfficeSecurity.CurrentUser.Id);

                return macro.Id;
            }
            catch (Exception exception)
            {
                const string errorMessage = "Error creating macro";
                _logger.LogError(exception, errorMessage);
                return ValidationProblem(errorMessage);
            }
        }

        [HttpGet]
        public ActionResult<MacroDisplay> GetById(int id)
        {
            var macro = _macroService.GetById(id);

            if (macro == null)
            {
                return ValidationProblem($"Macro with id {id} does not exist");
            }

            var macroDisplay = MapToDisplay(macro);

            return macroDisplay;
        }

        [HttpGet]
        public ActionResult<MacroDisplay> GetById(Guid id)
        {
            var macro = _macroService.GetById(id);

            if (macro == null)
            {
                return ValidationProblem($"Macro with id {id} does not exist");
            }

            var macroDisplay = MapToDisplay(macro);

            return macroDisplay;
        }

        [HttpGet]
        public ActionResult<MacroDisplay> GetById(Udi id)
        {
            var guidUdi = id as GuidUdi;
            if (guidUdi == null)
                return ValidationProblem($"Macro with id {id} does not exist");

            var macro = _macroService.GetById(guidUdi.Guid);
            if (macro == null)
            {
                return ValidationProblem($"Macro with id {id} does not exist");
            }

            var macroDisplay = MapToDisplay(macro);

            return macroDisplay;
        }

        [HttpPost]
        public IActionResult DeleteById(int id)
        {
            var macro = _macroService.GetById(id);

            if (macro == null)
            {
                return ValidationProblem($"Macro with id {id} does not exist");
            }

            _macroService.Delete(macro);

            return Ok();
        }

        [HttpPost]
        public ActionResult<MacroDisplay> Save(MacroDisplay macroDisplay)
        {
            if (macroDisplay == null)
            {
                return ValidationProblem("No macro data found in request");
            }

            if (macroDisplay.Name == null || macroDisplay.Name.Length > 255)
            {
                return ValidationProblem("Name cannnot be more than 255 characters in length.");
            }

            var macro = _macroService.GetById(int.Parse(macroDisplay.Id.ToString(), CultureInfo.InvariantCulture));

            if (macro == null)
            {
                return ValidationProblem($"Macro with id {macroDisplay.Id} does not exist");
            }

            if (macroDisplay.Alias != macro.Alias)
            {
                var macroByAlias = _macroService.GetByAlias(macroDisplay.Alias);

                if (macroByAlias != null)
                {
                    return ValidationProblem("Macro with this alias already exists");
                }
            }

            macro.Alias = macroDisplay.Alias;
            macro.Name = macroDisplay.Name;
            macro.CacheByMember = macroDisplay.CacheByUser;
            macro.CacheByPage = macroDisplay.CacheByPage;
            macro.CacheDuration = macroDisplay.CachePeriod;
            macro.DontRender = !macroDisplay.RenderInEditor;
            macro.UseInEditor = macroDisplay.UseInEditor;
            macro.MacroSource = macroDisplay.View;
            macro.Properties.ReplaceAll(macroDisplay.Parameters.Select((x,i) => new MacroProperty(x.Key, x.Label, i, x.Editor)));

            try
            {
                _macroService.Save(macro, _backofficeSecurityAccessor.BackOfficeSecurity.CurrentUser.Id);

                macroDisplay.Notifications.Clear();

                macroDisplay.Notifications.Add(new BackOfficeNotification("Success", "Macro saved", NotificationStyle.Success));

                return macroDisplay;
            }
            catch (Exception exception)
            {
                const string errorMessage = "Error creating macro";
                _logger.LogError(exception, errorMessage);
                return ValidationProblem(errorMessage);
            }
        }

        /// <summary>
        /// Gets a list of available macro partials
        /// </summary>
        /// <returns>
        /// The <see cref="HttpResponseMessage"/>.
        /// </returns>
        public IEnumerable<string> GetPartialViews()
        {
            var views = new List<string>();

            views.AddRange(this.FindPartialViewsFiles());

            return views;
        }

        /// <summary>
        /// Gets the available parameter editors
        /// </summary>
        /// <returns>
        /// The <see cref="HttpResponseMessage"/>.
        /// </returns>
        public ParameterEditorCollection GetParameterEditors()
        {
            return _parameterEditorCollection;
        }

        /// <summary>
        /// Gets the available parameter editors grouped by their group.
        /// </summary>
        /// <returns>
        /// The <see cref="HttpResponseMessage"/>.
        /// </returns>
        public IDictionary<string, IEnumerable<IDataEditor>> GetGroupedParameterEditors()
        {
            var parameterEditors = _parameterEditorCollection.ToArray();

            var grouped = parameterEditors
                .GroupBy(x => x.Group.IsNullOrWhiteSpace() ? "" : x.Group.ToLower())
                .OrderBy(x => x.Key)
                .ToDictionary(group => group.Key, group => group.OrderBy(d => d.Name).AsEnumerable());

            return grouped;
        }

        /// <summary>
        /// Get parameter editor by alias.
        /// </summary>
        /// <returns>
        /// The <see cref="HttpResponseMessage"/>.
        /// </returns>
        public IDataEditor GetParameterEditorByAlias(string alias)
        {
            var parameterEditors = _parameterEditorCollection.ToArray();

            var parameterEditor = parameterEditors.FirstOrDefault(x => x.Alias.InvariantEquals(alias));

            return parameterEditor;
        }



        /// <summary>
        /// Finds all the macro partials
        /// </summary>
        /// <returns>
        /// The <see cref="IEnumerable"/>.
        /// </returns>
        private IEnumerable<string> FindPartialViewsFiles()
        {
            var files = new List<string>();

            files.AddRange(this.FindPartialViewFilesInViewsFolder());
            files.AddRange(this.FindPartialViewFilesInPluginFolders());

            return files;
        }

        /// <summary>
        /// Finds all macro partials in the views folder
        /// </summary>
        /// <returns>
        /// The <see cref="IEnumerable"/>.
        /// </returns>
        private IEnumerable<string> FindPartialViewFilesInViewsFolder()
        {
            // TODO: This is inconsistent. We have FileSystems.MacroPartialsFileSystem but we basically don't use
            // that at all except to render the tree. In the future we may want to use it. This also means that
            // we are storing the virtual path of the macro like ~/Views/MacroPartials/Login.cshtml instead of the
            // relative path which would work with the FileSystems.MacroPartialsFileSystem, but these are incompatible.
            // At some point this should all be made consistent and probably just use FileSystems.MacroPartialsFileSystem.

            var partialsDir = _hostingEnvironment.MapPathContentRoot(Constants.SystemDirectories.MacroPartials);

            return this.FindPartialViewFilesInFolder(
                 partialsDir,
                 partialsDir,
                 Constants.SystemDirectories.MacroPartials);
        }

        /// <summary>
        /// Finds partial view files in app plugin folders.
        /// </summary>
        /// <returns>
        /// </returns>
        private IEnumerable<string> FindPartialViewFilesInPluginFolders()
        {
            var files = new List<string>();

            var appPluginsFolder = new DirectoryInfo(_hostingEnvironment.MapPathContentRoot(Constants.SystemDirectories.AppPlugins));

            if (!appPluginsFolder.Exists)
            {
                return files;
            }

            foreach (var directory in appPluginsFolder.GetDirectories())
            {
                var viewsFolder = directory.GetDirectories("Views");
                if (viewsFolder.Any())
                {
                    var macroPartials = viewsFolder.First().GetDirectories("MacroPartials");
                    if (macroPartials.Any())
                    {
                        files.AddRange(this.FindPartialViewFilesInFolder(macroPartials.First().FullName, macroPartials.First().FullName, Constants.SystemDirectories.AppPlugins + "/" + directory.Name + "/Views/MacroPartials"));
                    }
                }
            }

            return files;
        }

        /// <summary>
        /// Finds all partial views in a folder and subfolders
        /// </summary>
        /// <param name="orgPath">
        /// The org path.
        /// </param>
        /// <param name="path">
        /// The path.
        /// </param>
        /// <param name="prefixVirtualPath">
        /// The prefix virtual path.
        /// </param>
        /// <returns>
        /// The <see cref="IEnumerable"/>.
        /// </returns>
        private IEnumerable<string> FindPartialViewFilesInFolder(string orgPath, string path, string prefixVirtualPath)
        {
            var files = new List<string>();
            var dirInfo = new DirectoryInfo(path);

            if (dirInfo.Exists)
            {
                foreach (var dir in dirInfo.GetDirectories())
                {
                    files.AddRange(this.FindPartialViewFilesInFolder(orgPath, path + "/" + dir.Name, prefixVirtualPath));
                }

                var fileInfo = dirInfo.GetFiles("*.*");

                files.AddRange(
                    fileInfo.Select(file =>
                        prefixVirtualPath.TrimEnd(Constants.CharArrays.ForwardSlash) + "/" + (path.Replace(orgPath, string.Empty).Trim(Constants.CharArrays.ForwardSlash) + "/" + file.Name).Trim(Constants.CharArrays.ForwardSlash)));

            }

            return files;
        }

        /// <summary>
        /// Used to map an <see cref="IMacro"/> instance to a <see cref="MacroDisplay"/>
        /// </summary>
        /// <param name="macro"></param>
        /// <returns></returns>
        private MacroDisplay MapToDisplay(IMacro macro)
        {
            var display = _umbracoMapper.Map<MacroDisplay>(macro);

            var parameters = macro.Properties.Values
                                .OrderBy(x => x.SortOrder)
                                .Select(x => new MacroParameterDisplay()
                                {
                                    Editor = x.EditorAlias,
                                    Key = x.Alias,
                                    Label = x.Name,
                                    Id = x.Id
                                });

            display.Parameters = parameters;

            return display;
        }
    }
}