--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/OrthancFramework/Sources/RestApi/RestApiHierarchy.cpp	Wed Jun 10 20:30:34 2020 +0200
@@ -0,0 +1,476 @@
+/**
+ * Orthanc - A Lightweight, RESTful DICOM Store
+ * Copyright (C) 2012-2016 Sebastien Jodogne, Medical Physics
+ * Department, University Hospital of Liege, Belgium
+ * Copyright (C) 2017-2020 Osimis S.A., Belgium
+ *
+ * This program is free software: you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * In addition, as a special exception, the copyright holders of this
+ * program give permission to link the code of its release with the
+ * OpenSSL project's "OpenSSL" library (or with modified versions of it
+ * that use the same license as the "OpenSSL" library), and distribute
+ * the linked executables. You must obey the GNU General Public License
+ * in all respects for all of the code used other than "OpenSSL". If you
+ * modify file(s) with this exception, you may extend this exception to
+ * your version of the file(s), but you are not obligated to do so. If
+ * you do not wish to do so, delete this exception statement from your
+ * version. If you delete this exception statement from all source files
+ * in the program, then also delete it here.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ **/
+
+
+#include "../PrecompiledHeaders.h"
+#include "RestApiHierarchy.h"
+
+#include "../OrthancException.h"
+
+#include <cassert>
+#include <stdio.h>
+
+namespace Orthanc
+{
+  RestApiHierarchy::Resource::Resource() : 
+    getHandler_(NULL), 
+    postHandler_(NULL),
+    putHandler_(NULL), 
+    deleteHandler_(NULL)
+  {
+  }
+
+
+  bool RestApiHierarchy::Resource::HasHandler(HttpMethod method) const
+  {
+    switch (method)
+    {
+      case HttpMethod_Get:
+        return getHandler_ != NULL;
+
+      case HttpMethod_Post:
+        return postHandler_ != NULL;
+
+      case HttpMethod_Put:
+        return putHandler_ != NULL;
+
+      case HttpMethod_Delete:
+        return deleteHandler_ != NULL;
+
+      default:
+        throw OrthancException(ErrorCode_ParameterOutOfRange);
+    }
+  }
+
+
+  bool RestApiHierarchy::Resource::IsEmpty() const
+  {
+    return (getHandler_ == NULL &&
+            postHandler_ == NULL &&
+            putHandler_ == NULL &&
+            deleteHandler_ == NULL);
+  }
+
+
+  RestApiHierarchy& RestApiHierarchy::AddChild(Children& children,
+                                               const std::string& name)
+  {
+    Children::iterator it = children.find(name);
+
+    if (it == children.end())
+    {
+      // Create new child
+      RestApiHierarchy *child = new RestApiHierarchy;
+      children[name] = child;
+      return *child;
+    }
+    else
+    {
+      return *it->second;
+    }
+  }
+
+
+
+  bool RestApiHierarchy::Resource::Handle(RestApiGetCall& call) const
+  {
+    if (getHandler_ != NULL)
+    {
+      getHandler_(call);
+      return true;
+    }
+    else
+    {
+      return false;
+    }
+  }
+
+
+  bool RestApiHierarchy::Resource::Handle(RestApiPutCall& call) const
+  {
+    if (putHandler_ != NULL)
+    {
+      putHandler_(call);
+      return true;
+    }
+    else
+    {
+      return false;
+    }
+  }
+
+
+  bool RestApiHierarchy::Resource::Handle(RestApiPostCall& call) const
+  {
+    if (postHandler_ != NULL)
+    {
+      postHandler_(call);
+      return true;
+    }
+    else
+    {
+      return false;
+    }
+  }
+
+
+  bool RestApiHierarchy::Resource::Handle(RestApiDeleteCall& call) const
+  {
+    if (deleteHandler_ != NULL)
+    {
+      deleteHandler_(call);
+      return true;
+    }
+    else
+    {
+      return false;
+    }
+  }
+
+
+
+  void RestApiHierarchy::DeleteChildren(Children& children)
+  {
+    for (Children::iterator it = children.begin();
+         it != children.end(); ++it)
+    {
+      delete it->second;
+    }
+  }
+
+
+  template <typename Handler>
+  void RestApiHierarchy::RegisterInternal(const RestApiPath& path,
+                                          Handler handler,
+                                          size_t level)
+  {
+    if (path.GetLevelCount() == level)
+    {
+      if (path.IsUniversalTrailing())
+      {
+        universalHandlers_.Register(handler);
+      }
+      else
+      {
+        handlers_.Register(handler);
+      }
+    }
+    else
+    {
+      RestApiHierarchy* child;
+      if (path.IsWildcardLevel(level))
+      {
+        child = &AddChild(wildcardChildren_, path.GetWildcardName(level));
+      }
+      else
+      {
+        child = &AddChild(children_, path.GetLevelName(level));
+      }
+
+      child->RegisterInternal(path, handler, level + 1);
+    }
+  }
+
+
+  bool RestApiHierarchy::LookupResource(IHttpHandler::Arguments& components,
+                                       const UriComponents& uri,
+                                       IVisitor& visitor,
+                                       size_t level)
+  {
+    if (uri.size() != 0 &&
+        level > uri.size())
+    {
+      return false;
+    }
+
+    UriComponents trailing;
+
+    // Look for an exact match on the resource of interest
+      if (uri.size() == 0 ||
+          level == uri.size())
+    {
+      if (!handlers_.IsEmpty() &&
+          visitor.Visit(handlers_, uri, components, trailing))
+      {
+        return true;
+      }
+    }
+
+
+    if (level < uri.size())  // A recursive call is possible
+    {
+      // Try and go down in the hierarchy, using an exact match for the child
+      Children::const_iterator child = children_.find(uri[level]);
+      if (child != children_.end())
+      {
+        if (child->second->LookupResource(components, uri, visitor, level + 1))
+        {
+          return true;
+        }
+      }
+
+      // Try and go down in the hierarchy, using wildcard rules for children
+      for (child = wildcardChildren_.begin();
+           child != wildcardChildren_.end(); ++child)
+      {
+        IHttpHandler::Arguments subComponents = components;
+        subComponents[child->first] = uri[level];
+
+        if (child->second->LookupResource(subComponents, uri, visitor, level + 1))
+        {
+          return true;
+        }        
+      }
+    }
+
+
+    // As a last resort, call the universal handlers, if any
+    if (!universalHandlers_.IsEmpty())
+    {
+      trailing.resize(uri.size() - level);
+      size_t pos = 0;
+      for (size_t i = level; i < uri.size(); i++, pos++)
+      {
+        trailing[pos] = uri[i];
+      }
+
+      assert(pos == trailing.size());
+
+      if (visitor.Visit(universalHandlers_, uri, components, trailing))
+      {
+        return true;
+      }
+    }
+
+    return false;
+  }
+
+
+  bool RestApiHierarchy::CanGenerateDirectory() const
+  {
+    return (universalHandlers_.IsEmpty() &&
+            wildcardChildren_.empty());
+  }
+
+
+  bool RestApiHierarchy::GetDirectory(Json::Value& result,
+                                      const UriComponents& uri,
+                                      size_t level)
+  {
+    if (uri.size() == level)
+    {
+      if (CanGenerateDirectory())
+      {
+        result = Json::arrayValue;
+
+        for (Children::const_iterator it = children_.begin();
+             it != children_.end(); ++it)
+        {
+          result.append(it->first);
+        }
+
+        return true;
+      }
+      else
+      {
+        return false;
+      }
+    }
+
+    Children::const_iterator child = children_.find(uri[level]);
+    if (child != children_.end())
+    {
+      if (child->second->GetDirectory(result, uri, level + 1))
+      {
+        return true;
+      }
+    }
+
+    for (child = wildcardChildren_.begin(); 
+         child != wildcardChildren_.end(); ++child)
+    {
+      if (child->second->GetDirectory(result, uri, level + 1))
+      {
+        return true;
+      }
+    }
+
+    return false;
+  }
+                       
+
+  RestApiHierarchy::~RestApiHierarchy()
+  {
+    DeleteChildren(children_);
+    DeleteChildren(wildcardChildren_);
+  }
+
+  void RestApiHierarchy::Register(const std::string& uri,
+                                  RestApiGetCall::Handler handler)
+  {
+    RestApiPath path(uri);
+    RegisterInternal(path, handler, 0);
+  }
+
+  void RestApiHierarchy::Register(const std::string& uri,
+                                  RestApiPutCall::Handler handler)
+  {
+    RestApiPath path(uri);
+    RegisterInternal(path, handler, 0);
+  }
+
+  void RestApiHierarchy::Register(const std::string& uri,
+                                  RestApiPostCall::Handler handler)
+  {
+    RestApiPath path(uri);
+    RegisterInternal(path, handler, 0);
+  }
+
+  void RestApiHierarchy::Register(const std::string& uri,
+                                  RestApiDeleteCall::Handler handler)
+  {
+    RestApiPath path(uri);
+    RegisterInternal(path, handler, 0);
+  }
+
+  void RestApiHierarchy::CreateSiteMap(Json::Value& target) const
+  {
+    target = Json::objectValue;
+
+    /*std::string s = " ";
+      if (handlers_.HasHandler(HttpMethod_Get))
+      {
+      s += "GET ";
+      }
+
+      if (handlers_.HasHandler(HttpMethod_Post))
+      {
+      s += "POST ";
+      }
+
+      if (handlers_.HasHandler(HttpMethod_Put))
+      {
+      s += "PUT ";
+      }
+
+      if (handlers_.HasHandler(HttpMethod_Delete))
+      {
+      s += "DELETE ";
+      }
+
+      target = s;*/
+      
+    for (Children::const_iterator it = children_.begin();
+         it != children_.end(); ++it)
+    {
+      it->second->CreateSiteMap(target[it->first]);
+    }
+      
+    for (Children::const_iterator it = wildcardChildren_.begin();
+         it != wildcardChildren_.end(); ++it)
+    {
+      it->second->CreateSiteMap(target["<" + it->first + ">"]);
+    }
+  }
+
+
+  bool RestApiHierarchy::LookupResource(const UriComponents& uri,
+                                        IVisitor& visitor)
+  {
+    IHttpHandler::Arguments components;
+    return LookupResource(components, uri, visitor, 0);
+  }    
+
+
+
+  namespace
+  {
+    // Anonymous namespace to avoid clashes between compilation modules
+
+    class AcceptedMethodsVisitor : public RestApiHierarchy::IVisitor
+    {
+    private:
+      std::set<HttpMethod>& methods_;
+
+    public:
+      AcceptedMethodsVisitor(std::set<HttpMethod>& methods) : methods_(methods)
+      {
+      }
+
+      virtual bool Visit(const RestApiHierarchy::Resource& resource,
+                         const UriComponents& uri,
+                         const IHttpHandler::Arguments& components,
+                         const UriComponents& trailing)
+      {
+        if (trailing.size() == 0)  // Ignore universal handlers
+        {
+          if (resource.HasHandler(HttpMethod_Get))
+          {
+            methods_.insert(HttpMethod_Get);
+          }
+
+          if (resource.HasHandler(HttpMethod_Post))
+          {
+            methods_.insert(HttpMethod_Post);
+          }
+
+          if (resource.HasHandler(HttpMethod_Put))
+          {
+            methods_.insert(HttpMethod_Put);
+          }
+
+          if (resource.HasHandler(HttpMethod_Delete))
+          {
+            methods_.insert(HttpMethod_Delete);
+          }
+        }
+
+        return false;  // Continue to check all the possible ways to access this URI
+      }
+    };
+  }
+
+  void RestApiHierarchy::GetAcceptedMethods(std::set<HttpMethod>& methods,
+                                            const UriComponents& uri)
+  {
+    IHttpHandler::Arguments components;
+    AcceptedMethodsVisitor visitor(methods);
+    if (LookupResource(components, uri, visitor, 0))
+    {
+      Json::Value d;
+      if (GetDirectory(d, uri))
+      {
+        methods.insert(HttpMethod_Get);
+      }
+    }
+  }
+}