/* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */
/*
 *  Main authors:
 *     Christian Schulte <schulte@gecode.org>
 *
 *  Copyright:
 *     Christian Schulte, 2017
 *
 *  This file is part of Gecode, the generic constraint
 *  development environment:
 *     http://www.gecode.org
 *
 *  Permission is hereby granted, free of charge, to any person obtaining
 *  a copy of this software and associated documentation files (the
 *  "Software"), to deal in the Software without restriction, including
 *  without limitation the rights to use, copy, modify, merge, publish,
 *  distribute, sublicense, and/or sell copies of the Software, and to
 *  permit persons to whom the Software is furnished to do so, subject to
 *  the following conditions:
 *
 *  The above copyright notice and this permission notice shall be
 *  included in all copies or substantial portions of the Software.
 *
 *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 *  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 *  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 */

namespace Gecode { namespace Search {

  /// Recorder for engine events (for access control)
  class WrapTraceRecorder {
  public:
    /// Register engine
    static void engine(SearchTracer* tracer, 
                       SearchTracer::EngineType t, unsigned int n);
  };

  /// Simple recorder for a search tracer
  class TraceRecorder {
  protected:
    /// The actual tracer
    SearchTracer& tracer;
    /// The engine id
    unsigned int _eid;
    /// The worker id
    unsigned int _wid;
    /// The next free node id
    unsigned int _nid;
  public:
    /// Class for storing identifiers
    class ID {
    protected:
      /// The actual identifier
      unsigned int _id;
    public:
      /// Do not initialize
      ID(void);
      /// Initialize
      ID(unsigned int id);
      /// Access
      operator unsigned int(void) const;
    };
    /// Initialize
    TraceRecorder(SearchTracer* t);
    /// Register engine
    void engine(SearchTracer::EngineType t, unsigned int n);
    /// Register worker
    void worker(void);
    /// Generate new node id
    unsigned int nid(void);
    /// Return worker id
    unsigned int wid(void) const;
    /// The workers goes to a next round (restart or next iteration in LDS)
    void round(void);
    /// The engine skips an edge
    void skip(const SearchTracer::EdgeInfo& ei);
    /// The engine creates a new node with information \a ei and \a ni
    void node(const SearchTracer::EdgeInfo& ei,
              const SearchTracer::NodeInfo& ni);
    /// The worker is done
    void done(void);
    /// Whether this is a real tracer
    operator bool(void) const;
  };

  /// Recorder for a search tracer with edge information
  class EdgeTraceRecorder : public TraceRecorder {
  protected:
    /// Edge information
    SearchTracer::EdgeInfo _ei;
  public:
    /// Initialize
    EdgeTraceRecorder(SearchTracer* t);
    /// Invalidate edge information
    void invalidate(void);
    /// Provide access to edge information
    SearchTracer::EdgeInfo* ei(void);
  };

  /// Empty trace recorder
  class NoTraceRecorder {
  public:
    /// Class for storing node identifiers
    class ID {
    public:
      /// Do not initialize
      ID(void);
      /// Initialize
      ID(unsigned int id);
      /// Access
      operator unsigned int(void) const;
    };
    /// Initialize
    NoTraceRecorder(SearchTracer* t);
    /// Register engine
    void engine(SearchTracer::EngineType t, unsigned int n);
    /// Register worker
    void worker(void);
    /// Return worker id
    unsigned int wid(void) const;
    /// Generate new node id
    unsigned int nid(void);
    /// Invalidate edge information
    void invalidate(void);
    /// Provide access to edge information
    SearchTracer::EdgeInfo* ei(void);
    /// The workers goes to a next round (restart or next iteration in LDS)
    void round(void);
    /// The engine skips an edge
    void skip(const SearchTracer::EdgeInfo& ei);
    /// The engine creates a new node with information \a ei and \a ni
    void node(const SearchTracer::EdgeInfo& ei,
              const SearchTracer::NodeInfo& ni);
    /// The worker is done
    void done(void);
    /// Whether this is a real tracer
    operator bool(void) const;
  };


  /*
   * Recorder for engine events
   *
   */
  forceinline void
  WrapTraceRecorder::engine(SearchTracer* tracer, 
                            SearchTracer::EngineType t, unsigned int n) {
    if (tracer) tracer->engine(t,n);
  }


  /*
   * Simple trace recorder for a search tracer
   *
   */
  forceinline
  TraceRecorder::ID::ID(void) {}

  forceinline
  TraceRecorder::ID::ID(unsigned int id) : _id(id) {}

  forceinline
  TraceRecorder::ID::operator unsigned int(void) const {
    return _id;
  }

  forceinline
  TraceRecorder::TraceRecorder(SearchTracer* t)
    : tracer(*t), _eid(0U), _wid(0U), _nid(0U) {}

  forceinline void
  TraceRecorder::engine(SearchTracer::EngineType t, unsigned int n) {
    tracer.engine(t,n);
  }

  forceinline void
  TraceRecorder::worker(void) {
    tracer.worker(_wid,_eid);
  }

  forceinline unsigned int
  TraceRecorder::nid(void) {
    return _nid++;
  }

  forceinline unsigned int
  TraceRecorder::wid(void) const {
    return _wid;
  }
  
  forceinline void
  TraceRecorder::round(void) {
    tracer._round(_eid);
  }

  forceinline void
  TraceRecorder::skip(const SearchTracer::EdgeInfo& ei) {
    tracer._skip(ei);
  }

  forceinline void
  TraceRecorder::node(const SearchTracer::EdgeInfo& ei,
                      const SearchTracer::NodeInfo& ni) {
    tracer._node(ei,ni);
  }

  forceinline void
  TraceRecorder::done(void) {
    tracer.worker();
  }

  forceinline
  TraceRecorder::operator bool(void) const {
    return true;
  }

  
  /*
   * Recorder for a search tracer with edge information
   *
   */
  forceinline
  EdgeTraceRecorder::EdgeTraceRecorder(SearchTracer* t)
    : TraceRecorder(t) {}

  forceinline void
  EdgeTraceRecorder::invalidate(void) {
    _ei.invalidate();
  }

  forceinline SearchTracer::EdgeInfo*
  EdgeTraceRecorder::ei(void) {
    return &_ei;
  }


  /*
   * Empty trace recorder
   *
   */
  forceinline
  NoTraceRecorder::ID::ID(void) {}

  forceinline
  NoTraceRecorder::ID::ID(unsigned int) {}

  forceinline
  NoTraceRecorder::ID::operator unsigned int(void) const {
    return 0U;
  }

  forceinline
  NoTraceRecorder::NoTraceRecorder(SearchTracer*) {}

  forceinline void
  NoTraceRecorder::engine(SearchTracer::EngineType, unsigned int) {}

  forceinline void
  NoTraceRecorder::worker(void) {}

  forceinline unsigned int
  NoTraceRecorder::wid(void) const {
    return 0U;
  }

  forceinline unsigned int
  NoTraceRecorder::nid(void) {
    return 0U;
  }

  forceinline void
  NoTraceRecorder::invalidate(void) {}

  forceinline SearchTracer::EdgeInfo*
  NoTraceRecorder::ei(void) {
    return nullptr;
  }

  forceinline void
  NoTraceRecorder::round(void) {}

  forceinline void
  NoTraceRecorder::skip(const SearchTracer::EdgeInfo&) {}

  forceinline void
  NoTraceRecorder::node(const SearchTracer::EdgeInfo&,
                        const SearchTracer::NodeInfo&) {
  }

  forceinline void
  NoTraceRecorder::done(void) {
  }

  forceinline
  NoTraceRecorder::operator bool(void) const {
    return false;
  }

}}

// STATISTICS: search-trace