public async Task Invoke(HttpContext context, Mp3EhbContext dbContext)
{
var path = context.Request.Path.ToUriComponent();
var transformResult = await this.TransformPathAsync(path, dbContext, context.Items);
//If is an category, change the request path to be "Content/Index/{path}" so it is handled by the content controller, index action
switch (transformResult.Action)
{
case TransformAction.Substitute:
//Let the next middleware (MVC routing) handle the request
//In case the path was updated, the MVC routing will see the updated path
context.Request.Path = transformResult.NewPath;
break;
case TransformAction.Redirect:
context.Response.StatusCode = 302;
context.Response.Headers.Add(LOCATION_HEADER_NAME, transformResult.NewPath);
return;
case TransformAction.None:
break;
default:
throw new ArgumentOutOfRangeException();
}
await this._next.Invoke(context);
}
/// <summary>
/// Converts hierarchical category structure to mvc route
/// </summary>
/// <param name="path">The route being processed</param>
/// <param name="dbContext">The main app storage: <see cref="Mp3EhbContext"/></param>
/// <returns></returns>
private async Task <TransformResult> TransformPathAsync(string path, Mp3EhbContext dbContext,
IDictionary <object, object> contextItems)
{
//The middleware will try to find a Category and a content in the database that matches the current path
var transformResult = new TransformResult();
var trimmedPath = path.TrimTail(tail: DEFAULT_EXTENSION);
var names = trimmedPath.Split(new[] { FOLDER_SEPARATOR_CHAR }, StringSplitOptions.RemoveEmptyEntries);
if (names.Length == 0)
{
return(transformResult); //None
}
string bestMatchingPath = null;
string correctPath = null;
var contentId = default(int);
var bestMatchingCategoryId = default(int);
var categores = dbContext.Categories.AsNoTracking();
foreach (var name in names)
{
var categoryId = default(int);
var currentPath = name;
if (bestMatchingPath == null) //first entry
{
if (MenuDictionary.ContainsKey(name))
{
categoryId = MenuDictionary[name];
}
}
else
{
currentPath = bestMatchingPath + "/" + name;
}
//let check if name is in idNumber-aliasString format
var match = Regex.Match(name, @"^(\d+)-(.*)$");
Expression <Func <Category, bool> > categoryPredicate = c => c.Path == currentPath;
int id = 0;
if (match.Success && match.Groups.Count > 2)
{
id = int.Parse(match.Groups[1].Value);
//name = match.Groups[2].Value;
categoryPredicate = c => c.Id == id; // && c.Alias == name;
}
if (categoryId == default(int))
{
//The midleware will try to find a Category in the database that matches the current Path
categoryId = await categores
.Where(categoryPredicate)
.Select(c => c.Id)
.FirstOrDefaultAsync();
}
if (categoryId == default(int)) //name may be content name
{
Expression <Func <Content, bool> > contentPredicate = c => c.Alias.Contains(name);
if (id != 0)
{
contentPredicate = c => c.Id == id; // || c.Alias.Contains(name);
}
//The midleware will try to find a content in the database that matches the current name
var contents = dbContext.Contents.AsNoTracking();
var content = await contents
.Where(contentPredicate)
.Select(c => new { c.Id, c.CatId, c.Alias })
.FirstOrDefaultAsync();
if (content == null)
{
break;
}
contentId = content.Id;
correctPath = await categores.GetCategoryPath(content.CatId) + "/" + content.Alias;
break;
}
bestMatchingPath = currentPath;
bestMatchingCategoryId = categoryId;
}
if (contentId != default(int))
{
contextItems[CATEGORY_ID] = contentId;
if (correctPath == path)
{
return(new TransformResult(HOME_CONTENT_URL + contentId, TransformAction.Substitute));
}
}
else if (bestMatchingCategoryId != default(int))
{
contextItems[CATEGORY_ID] = bestMatchingCategoryId;
correctPath = await categores.GetCategoryPath(bestMatchingCategoryId);
if (correctPath == path)
{
return(new TransformResult(HOME_CONTENT_URL + bestMatchingCategoryId, TransformAction.Substitute));
}
}
else
{
return(transformResult); //None
}
return(new TransformResult(correctPath, TransformAction.Redirect));
}
/// <summary>
/// Home controller constructor
/// </summary>
/// <param name="dbContext">The <see cref="Mp3EhbContext"/> instance,
/// <seealso cref="DbContext"</param>
public HomeController(Mp3EhbContext dbContext)
{
this.Db = dbContext;
}
