/*
 * Copyright (c) 2003-2023, John Wiegley.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 *
 * - Neither the name of New Artisans LLC nor the names of its
 *   contributors may be used to endorse or promote products derived from
 *   this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/**
 * @defgroup python Python API
 */

/**
 * @file   pyinterp.h
 * @author John Wiegley
 *
 * @ingroup python
 *
 * @brief Basic type for Python API.
 */
#pragma once

#include "session.h"

#if HAVE_BOOST_PYTHON

namespace ledger {

class python_module_t : public scope_t, public noncopyable
{
public:
  string                module_name;
  boost::python::object module_object;
  boost::python::dict   module_globals;

  explicit python_module_t(const string& name);
  explicit python_module_t(const string& name, boost::python::object obj);

  void import_module(const string& name, bool import_direct = false);

  virtual expr_t::ptr_op_t lookup(const symbol_t::kind_t kind,
                                  const string& name);

  void define_global(const string& name, boost::python::object obj) {
    module_globals[name] = obj;
  }

  virtual string description() {
    return module_name;
  }
};

typedef std::map<PyObject *, shared_ptr<python_module_t> > python_module_map_t;

class python_interpreter_t : public session_t
{
public:
  bool is_initialized;

  shared_ptr<python_module_t> main_module;
  python_module_map_t         modules_map;

  shared_ptr<python_module_t> import_module(const string& name) {
    shared_ptr<python_module_t> mod(new python_module_t(name));
    if (name != "__main__")
      main_module->define_global(name, mod->module_object);
    return mod;
  }

  python_interpreter_t() : session_t(), is_initialized(false) {
    TRACE_CTOR(python_interpreter_t, "");
  }
  virtual ~python_interpreter_t() {
    TRACE_DTOR(python_interpreter_t);
    if (is_initialized)
      Py_Finalize();
  }

  void initialize();
  void hack_system_paths();

  boost::python::object import_option(const string& name);

  enum py_eval_mode_t {
    PY_EVAL_EXPR,
    PY_EVAL_STMT,
    PY_EVAL_MULTI
  };

  boost::python::object eval(std::istream& in, py_eval_mode_t mode = PY_EVAL_EXPR);
  boost::python::object eval(const string& str, py_eval_mode_t mode = PY_EVAL_EXPR);
  boost::python::object eval(const char * c_str, py_eval_mode_t mode = PY_EVAL_EXPR) {
    return eval(string(c_str), mode);
  }

  value_t python_command(call_scope_t& scope);

  class functor_t {
    functor_t();

  protected:
    boost::python::object func;

  public:
    string name;

    functor_t(boost::python::object _func, const string& _name)
      : func(_func), name(_name) {
      TRACE_CTOR(functor_t, "boost::python::object, const string&");
    }
    functor_t(const functor_t& other)
      : func(other.func), name(other.name) {
      TRACE_CTOR(functor_t, "copy");
    }
    virtual ~functor_t() throw() {
      TRACE_DTOR(functor_t);
    }
    virtual value_t operator()(call_scope_t& args);
  };

  option_t<python_interpreter_t> * lookup_option(const char * p);

  virtual expr_t::ptr_op_t lookup(const symbol_t::kind_t kind,
                                  const string& name);

  OPTION_(python_interpreter_t, import_, DO_(str) {
      parent->import_option(str);
    });
};

extern shared_ptr<python_interpreter_t> python_session;

} // namespace ledger

#endif // HAVE_BOOST_PYTHON