using System.IO;
using System.Linq;
using System.Web.Mvc;
using Lucene.Net.Util;
using Umbraco.Core.IO;

namespace Umbraco.Web.Mvc
{
    /// <summary>
    /// A view engine to look into the App_Plugins folder for views for packaged controllers
    /// </summary>
    public class PluginViewEngine : RazorViewEngine
    {

        /// <summary>
        /// Constructor
        /// </summary>
        public PluginViewEngine()
        {
            SetViewLocations();
        }

        private void SetViewLocations()
        {
            //these are the originals:

            //base.AreaViewLocationFormats = new string[] { "~/Areas/{2}/Views/{1}/{0}.cshtml", "~/Areas/{2}/Views/{1}/{0}.vbhtml", "~/Areas/{2}/Views/Shared/{0}.cshtml", "~/Areas/{2}/Views/Shared/{0}.vbhtml" };
            //base.AreaMasterLocationFormats = new string[] { "~/Areas/{2}/Views/{1}/{0}.cshtml", "~/Areas/{2}/Views/{1}/{0}.vbhtml", "~/Areas/{2}/Views/Shared/{0}.cshtml", "~/Areas/{2}/Views/Shared/{0}.vbhtml" };
            //base.AreaPartialViewLocationFormats = new string[] { "~/Areas/{2}/Views/{1}/{0}.cshtml", "~/Areas/{2}/Views/{1}/{0}.vbhtml", "~/Areas/{2}/Views/Shared/{0}.cshtml", "~/Areas/{2}/Views/Shared/{0}.vbhtml" };
            //base.ViewLocationFormats = new string[] { "~/Views/{1}/{0}.cshtml", "~/Views/{1}/{0}.vbhtml", "~/Views/Shared/{0}.cshtml", "~/Views/Shared/{0}.vbhtml" };
            //base.MasterLocationFormats = new string[] { "~/Views/{1}/{0}.cshtml", "~/Views/{1}/{0}.vbhtml", "~/Views/Shared/{0}.cshtml", "~/Views/Shared/{0}.vbhtml" };
            //base.PartialViewLocationFormats = new string[] { "~/Views/{1}/{0}.cshtml", "~/Views/{1}/{0}.vbhtml", "~/Views/Shared/{0}.cshtml", "~/Views/Shared/{0}.vbhtml" };
            //base.FileExtensions = new string[] { "cshtml", "vbhtml" };

            var viewLocationsArray = new[]
                {
                    string.Concat(SystemDirectories.AppPlugins, "/{2}/Views/{1}/{0}.cshtml"),
                    string.Concat(SystemDirectories.AppPlugins, "/{2}/Views/{1}/{0}.vbhtml")
                };

            //set all of the area view locations to the plugin folder
            AreaViewLocationFormats = viewLocationsArray
                .Concat(new[]
                    {
                        string.Concat(SystemDirectories.AppPlugins, "/{2}/Views/Shared/{0}.cshtml"),
                        string.Concat(SystemDirectories.AppPlugins, "/{2}/Views/Shared/{0}.vbhtml")
                    })
                .ToArray();

            AreaMasterLocationFormats = viewLocationsArray;

            AreaPartialViewLocationFormats = new[]
                {
                    //will be used when we have partial view and child action macros
                    string.Concat(SystemDirectories.AppPlugins, "/{2}/Views/Partials/{0}.cshtml"),
                    string.Concat(SystemDirectories.AppPlugins, "/{2}/Views/Partials/{0}.vbhtml"),
                    string.Concat(SystemDirectories.AppPlugins, "/{2}/Views/MacroPartials/{0}.cshtml"),
                    string.Concat(SystemDirectories.AppPlugins, "/{2}/Views/MacroPartials/{0}.vbhtml"),
                    //for partials
                    string.Concat(SystemDirectories.AppPlugins, "/{2}/Views/{1}/{0}.cshtml"),
                    string.Concat(SystemDirectories.AppPlugins, "/{2}/Views/{1}/{0}.vbhtml"),
                    string.Concat(SystemDirectories.AppPlugins, "/{2}/Views/Shared/{0}.cshtml"),
                    string.Concat(SystemDirectories.AppPlugins, "/{2}/Views/Shared/{0}.vbhtml")
                };

        }

        /// <summary>
        /// Ensures that the correct web.config for razor exists in the /Views folder.
        /// </summary>
        private void EnsureFolderAndWebConfig(ViewEngineResult result)
        {
            if (result.View == null) return;
            var razorResult = result.View as RazorView;
            if (razorResult == null) return;

            var folder = Path.GetDirectoryName(IOHelper.MapPath(razorResult.ViewPath));
            //now we need to get the /View/ folder
            var viewFolder = folder.Substring(0, folder.LastIndexOf("\\Views\\")) + "\\Views";

            //ensure the web.config file is in the ~/Views folder
            Directory.CreateDirectory(viewFolder);
            if (!File.Exists(Path.Combine(viewFolder, "web.config")))
            {
                using (var writer = File.CreateText(Path.Combine(viewFolder, "web.config")))
                {
                    writer.Write(Strings.WebConfigTemplate);
                }
            }
        }

        public override ViewEngineResult FindView(ControllerContext controllerContext, string viewName, string masterName, bool useCache)
        {
            var result = base.FindView(controllerContext, viewName, masterName, useCache);
            EnsureFolderAndWebConfig(result);
            return result;
        }

        public override ViewEngineResult FindPartialView(ControllerContext controllerContext, string partialViewName, bool useCache)
        {
            var result = base.FindPartialView(controllerContext, partialViewName, useCache);
            EnsureFolderAndWebConfig(result);
            return result;
        }
    }
}