// file      : cutl/xml/serializer.cxx
// copyright : Copyright (c) 2009-2017 Code Synthesis Tools CC
// license   : MIT; see accompanying LICENSE file

#include <new>     // std::bad_alloc
#include <cstring> // std::strlen

#include <cutl/xml/serializer.hxx>

using namespace std;

namespace cutl
{
  namespace xml
  {
    // serialization
    //
    serialization::
    ~serialization () throw () {}

    serialization::
    serialization (const string& n, const string& d)
        : name_ (n), description_ (d)
    {
      init ();
    }

    serialization::
    serialization (const serializer& s, const std::string& d)
        : name_ (s.output_name ()), description_ (d)
    {
      init ();
    }

    void serialization::
    init ()
    {
      if (!name_.empty ())
      {
        what_ += name_;
        what_ += ": ";
      }

      what_ += "error: ";
      what_ += description_;
    }

    char const* serialization::
    what () const throw ()
    {
      return what_.c_str ();
    }

    // serializer
    //
    extern "C" genxStatus
    genx_write (void* p, constUtf8 us)
    {
      // It would have been easier to throw the exception directly,
      // however, the Genx code is most likely not exception safe.
      //
      ostream* os (static_cast<ostream*> (p));
      const char* s (reinterpret_cast<const char*> (us));
      os->write (s, static_cast<streamsize> (strlen (s)));
      return os->good () ? GENX_SUCCESS : GENX_IO_ERROR;
    }

    extern "C" genxStatus
    genx_write_bound (void* p, constUtf8 start, constUtf8 end)
    {
      ostream* os (static_cast<ostream*> (p));
      const char* s (reinterpret_cast<const char*> (start));
      streamsize n (static_cast<streamsize> (end - start));
      os->write (s, n);
      return os->good () ? GENX_SUCCESS : GENX_IO_ERROR;
    }

    extern "C" genxStatus
    genx_flush (void* p)
    {
      ostream* os (static_cast<ostream*> (p));
      os->flush ();
      return os->good () ? GENX_SUCCESS : GENX_IO_ERROR;
    }

    serializer::
    ~serializer ()
    {
      if (s_ != 0)
        genxDispose (s_);
    }

    serializer::
    serializer (ostream& os, const string& oname, unsigned short ind)
        : os_ (os), os_state_ (os.exceptions ()), oname_ (oname), depth_ (0)
    {
      // Temporarily disable exceptions on the stream.
      //
      os_.exceptions (ostream::goodbit);

      // Allocate the serializer. Make sure nothing else can throw after
      // this call since otherwise we will leak it.
      //
      s_ = genxNew (0, 0, 0);

      if (s_ == 0)
        throw bad_alloc ();

      genxSetUserData (s_, &os_);

      if (ind != 0)
        genxSetPrettyPrint (s_, ind);

      sender_.send = &genx_write;
      sender_.sendBounded = &genx_write_bound;
      sender_.flush = &genx_flush;

      if (genxStatus e = genxStartDocSender (s_, &sender_))
      {
        string m (genxGetErrorMessage (s_, e));
        genxDispose (s_);
        throw serialization (oname, m);
      }
    }

    void serializer::
    handle_error (genxStatus e)
    {
      switch (e)
      {
      case GENX_ALLOC_FAILED:
        throw bad_alloc ();
      case GENX_IO_ERROR:
        // Restoring the original exception state should trigger the
        // exception. If it doesn't (e.g., because the user didn't
        // configure the stream to throw), then fall back to the
        // serialiation exception.
        //
        os_.exceptions (os_state_);
        // Fall through.
      default:
        throw serialization (oname_, genxGetErrorMessage (s_, e));
      }
    }

    void serializer::
    start_element (const string& ns, const string& name)
    {
      if (genxStatus e = genxStartElementLiteral (
            s_,
            reinterpret_cast<constUtf8> (ns.empty () ? 0 : ns.c_str ()),
            reinterpret_cast<constUtf8> (name.c_str ())))
        handle_error (e);

      depth_++;
    }

    void serializer::
    end_element ()
    {
      if (genxStatus e = genxEndElement (s_))
        handle_error (e);

      // Call EndDocument() if we are past the root element.
      //
      if (--depth_ == 0)
      {
        if (genxStatus e = genxEndDocument (s_))
          handle_error (e);

        // Also restore the original exception state on the stream.
        //
        os_.exceptions (os_state_);
      }
    }

    void serializer::
    start_attribute (const string& ns, const string& name)
    {
      if (genxStatus e = genxStartAttributeLiteral (
            s_,
            reinterpret_cast<constUtf8> (ns.empty () ? 0 : ns.c_str ()),
            reinterpret_cast<constUtf8> (name.c_str ())))
        handle_error (e);
    }

    void serializer::
    end_attribute ()
    {
      if (genxStatus e = genxEndAttribute (s_))
        handle_error (e);
    }

    void serializer::
    attribute (const string& ns,
               const string& name,
               const string& value)
    {
      if (genxStatus e = genxAddAttributeLiteral (
            s_,
            reinterpret_cast<constUtf8> (ns.empty () ? 0 : ns.c_str ()),
            reinterpret_cast<constUtf8> (name.c_str ()),
            reinterpret_cast<constUtf8> (value.c_str ())))
        handle_error (e);
    }

    void serializer::
    characters (const string& value)
    {
      if (genxStatus e = genxAddCountedText (
            s_,
            reinterpret_cast<constUtf8> (value.c_str ()),
            static_cast<int> (value.size ())))
        handle_error (e);
    }

    void serializer::
    namespace_decl (const string& ns, const string& p)
    {
      if (genxStatus e = ns.empty () && p.empty ()
          ? genxUnsetDefaultNamespace (s_)
          : genxAddNamespaceLiteral (
              s_,
              reinterpret_cast<constUtf8> (ns.c_str ()),
              reinterpret_cast<constUtf8> (p.c_str ())))
        handle_error (e);
    }

    void serializer::
    xml_decl (const string& ver, const string& enc, const string& stl)
    {
      if (genxStatus e = genxXmlDeclaration (
            s_,
            reinterpret_cast<constUtf8> (ver.c_str ()),
            (enc.empty () ? 0 : reinterpret_cast<constUtf8> (enc.c_str ())),
            (stl.empty () ? 0 : reinterpret_cast<constUtf8> (stl.c_str ()))))
        handle_error (e);
    }

    bool serializer::
    lookup_namespace_prefix (const string& ns, string& p)
    {
      // Currently Genx will create a namespace mapping if one doesn't
      // already exist.
      //
      genxStatus e;
      genxNamespace gns (
        genxDeclareNamespace (
          s_, reinterpret_cast<constUtf8> (ns.c_str ()), 0, &e));

      if (e != GENX_SUCCESS)
        handle_error (e);

      p = reinterpret_cast<const char*> (genxGetNamespacePrefix (gns));
      return true;
    }
  }
}