////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2006-2022 The Octave Project Developers
//
// See the file COPYRIGHT.md in the top-level directory of this
// distribution or <https://octave.org/copyright/>.
//
// This file is part of Octave.
//
// Octave 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.
//
// Octave 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 Octave; see the file COPYING.  If not, see
// <https://www.gnu.org/licenses/>.
//
////////////////////////////////////////////////////////////////////////

#if ! defined (octave_load_path_h)
#define octave_load_path_h 1

#include "octave-config.h"

#include <functional>
#include <iosfwd>
#include <list>
#include <map>
#include <set>
#include <string>

#include "oct-time.h"
#include "pathsearch.h"
#include "str-vec.h"

OCTAVE_NAMESPACE_BEGIN

  class
  OCTINTERP_API
  load_path
  {
  public:

    load_path (interpreter& interp);

    typedef void (*hook_fcn_ptr) (const std::string& dir);

    load_path (const load_path&) = delete;

    load_path& operator = (const load_path&) = delete;

    ~load_path (void) = default;

    void initialize (bool set_initial_path = false);

    void clear (void);

    void set (const std::string& p, bool warn = false, bool is_init = false);

    void append (const std::string& dir, bool warn = false);

    void prepend (const std::string& dir, bool warn = false);

    bool remove (const std::string& dir);

    void update (void);

    bool contains_canonical (const std::string& dir_name) const;

    bool contains_file_in_dir (const std::string& file_name,
                               const std::string& dir_name);

    std::string find_method (const std::string& class_name,
                             const std::string& meth,
                             std::string& dir_name,
                             const std::string& pack_name = "")
    {
      return get_package (pack_name).find_method (class_name, meth, dir_name);
    }

    std::string find_method (const std::string& class_name,
                             const std::string& meth,
                             const std::string& pack_name = "")
    {
      std::string dir_name;
      return find_method (class_name, meth, dir_name, pack_name);
    }

    std::list<std::string> methods (const std::string& class_name,
                                    const std::string& pack_name = "")
    {
      return get_package (pack_name).methods (class_name);
    }

    std::list<std::string> overloads (const std::string& meth) const;

    bool find_package (const std::string& package_name) const
    {
      return (m_package_map.find (package_name) != m_package_map.end ());
    }

    std::list<std::string>
    get_all_package_names (bool only_top_level = true) const;

    std::string find_fcn (const std::string& fcn, std::string& dir_name,
                          const std::string& pack_name = "")
    {
      return get_package (pack_name).find_fcn (fcn, dir_name);
    }

    std::string find_fcn (const std::string& fcn,
                          const std::string& pack_name = "")
    {
      std::string dir_name;
      return find_fcn (fcn, dir_name, pack_name);
    }

    std::string find_private_fcn (const std::string& dir,
                                  const std::string& fcn,
                                  const std::string& pack_name = "")
    {
      return get_package (pack_name).find_private_fcn (dir, fcn);
    }

    std::string find_fcn_file (const std::string& fcn,
                               const std::string& pack_name = "")
    {
      std::string dir_name;
      return get_package (pack_name).find_fcn (fcn, dir_name, M_FILE);
    }

    std::string find_oct_file (const std::string& fcn,
                               const std::string& pack_name = "")
    {
      std::string dir_name;
      return get_package (pack_name).find_fcn (fcn, dir_name, M_FILE);
    }

    std::string find_mex_file (const std::string& fcn,
                               const std::string& pack_name = "")
    {
      std::string dir_name;
      return get_package (pack_name).find_fcn (fcn, dir_name, M_FILE);
    }

    std::string find_file (const std::string& file) const;

    std::string find_dir (const std::string& dir) const;

    string_vector find_matching_dirs (const std::string& dir) const;

    std::string find_first_of (const string_vector& files) const;

    string_vector find_all_first_of (const string_vector& files) const;

    string_vector dirs (void) const;

    std::list<std::string> dir_list (void) const;

    string_vector files (const std::string& dir, bool omit_exts = false) const;

    string_vector fcn_names (void) const;

    std::string path (void) const;

    void display (std::ostream& os) const;

    std::function<void (const std::string&)> get_add_hook (void)
    {
      return add_hook;
    }

    std::function<void (const std::string&)> get_remove_hook (void)
    {
      return remove_hook;
    }

    void set_add_hook (const std::function<void (const std::string&)>& f)
    {
      add_hook = f;
    }

    void set_remove_hook (const std::function<void (const std::string&)>& f)
    {
      remove_hook = f;
    }

    void read_dir_config (const std::string& dir) const;

    void execute_pkg_add (const std::string& dir);
    void execute_pkg_del (const std::string& dir);

    void set_command_line_path (const std::string& p)
    {
      if (m_command_line_path.empty ())
        m_command_line_path = p;
      else
        m_command_line_path += directory_path::path_sep_str () + p;
    }

    std::string get_command_line_path (void) const
    {
      return m_command_line_path;
    }

    std::string system_path (void) const { return s_sys_path; }

    static const int M_FILE = 1;
    static const int OCT_FILE = 2;
    static const int MEX_FILE = 4;

  private:

    class dir_info
    {
    public:

      // <FCN_NAME, TYPE>
      typedef std::map<std::string, int> fcn_file_map_type;

      typedef fcn_file_map_type::const_iterator const_fcn_file_map_iterator;
      typedef fcn_file_map_type::iterator fcn_file_map_iterator;

      struct class_info
      {
      public:
        class_info (void) : method_file_map (), private_file_map () { }

        class_info (const class_info& ci)
          : method_file_map (ci.method_file_map),
            private_file_map (ci.private_file_map)
        { }

        class_info& operator = (const class_info& ci)
        {
          if (this != &ci)
            {
              method_file_map = ci.method_file_map;
              private_file_map = ci.private_file_map;
            }
          return *this;
        }

        ~class_info (void) = default;

        fcn_file_map_type method_file_map;
        fcn_file_map_type private_file_map;
      };

      // <CLASS_NAME, CLASS_INFO>
      typedef std::map<std::string, class_info> method_file_map_type;

      typedef method_file_map_type::const_iterator const_method_file_map_iterator;
      typedef method_file_map_type::iterator method_file_map_iterator;

      // <PACKAGE_NAME, DIR_INFO>
      typedef std::map<std::string, dir_info> package_dir_map_type;

      typedef package_dir_map_type::const_iterator const_package_dir_map_iterator;
      typedef package_dir_map_type::iterator package_dir_map_iterator;

      // This default constructor is only provided so we can create a
      // std::map of dir_info objects.  You should not use this
      // constructor for any other purpose.
      dir_info (void) = default;

      dir_info (const std::string& d)
        : dir_name (d), abs_dir_name (), is_relative (false),
          dir_mtime (), dir_time_last_checked (), all_files (), fcn_files (),
          private_file_map (), method_file_map (), package_dir_map ()
      {
        initialize ();
      }

      dir_info (const dir_info&) = default;

      ~dir_info (void) = default;

      dir_info& operator = (const dir_info&) = default;

      bool update (void);

      std::string dir_name;
      std::string abs_dir_name;
      bool is_relative;
      sys::time dir_mtime;
      sys::time dir_time_last_checked;
      string_vector all_files;
      string_vector fcn_files;
      fcn_file_map_type private_file_map;
      method_file_map_type method_file_map;
      package_dir_map_type package_dir_map;

      bool is_package (const std::string& name) const;

    private:

      void initialize (void);

      void get_file_list (const std::string& d);

      void get_private_file_map (const std::string& d);

      void get_method_file_map (const std::string& d,
                                const std::string& class_name);

      void get_package_dir (const std::string& d,
                            const std::string& package_name);

      friend fcn_file_map_type get_fcn_files (const std::string& d);
    };

    class file_info
    {
    public:

      file_info (const std::string& d, int t) : dir_name (d), types (t) { }

      file_info (const file_info& fi)
        : dir_name (fi.dir_name), types (fi.types) { }

      ~file_info (void) = default;

      file_info& operator = (const file_info& fi)
      {
        if (&fi != this)
          {
            dir_name = fi.dir_name;
            types = fi.types;
          }

        return *this;
      }

      std::string dir_name;
      int types;
    };

    // We maintain two ways of looking at the same information.
    //
    // First, a list of directories and the set of "public" files and
    // private files (those found in the special "private" subdirectory)
    // in each directory.
    //
    // Second, a map from filenames (the union of all "public" files for all
    // directories, but without filename extensions) to a list of
    // corresponding information (directory name and file types).  This
    // way, we can quickly find shadowed filenames and look up all
    // overloaded functions (in the "@" directories used to implement
    // classes).

    typedef std::list<dir_info> dir_info_list_type;

    typedef dir_info_list_type::const_iterator const_dir_info_list_iterator;
    typedef dir_info_list_type::iterator dir_info_list_iterator;

    typedef std::map<std::string, dir_info> abs_dir_cache_type;

    typedef abs_dir_cache_type::const_iterator const_abs_dir_cache_iterator;
    typedef abs_dir_cache_type::iterator abs_dir_cache_iterator;

    typedef std::list<file_info> file_info_list_type;

    typedef file_info_list_type::const_iterator const_file_info_list_iterator;
    typedef file_info_list_type::iterator file_info_list_iterator;

    // <FCN_NAME, FILE_INFO_LIST>
    typedef std::map<std::string, file_info_list_type> fcn_map_type;

    typedef fcn_map_type::const_iterator const_fcn_map_iterator;
    typedef fcn_map_type::iterator fcn_map_iterator;

    // <DIR_NAME, <FCN_NAME, TYPES>>
    typedef std::map<std::string, dir_info::fcn_file_map_type>
      private_fcn_map_type;

    typedef private_fcn_map_type::const_iterator const_private_fcn_map_iterator;
    typedef private_fcn_map_type::iterator private_fcn_map_iterator;

    // <CLASS_NAME, <FCN_NAME, FILE_INFO_LIST>>
    typedef std::map<std::string, fcn_map_type> method_map_type;

    typedef method_map_type::const_iterator const_method_map_iterator;
    typedef method_map_type::iterator method_map_iterator;

    class package_info
    {
    public:

      package_info (const std::string& package_name = "")
        : m_package_name (package_name), m_dir_list (), m_fcn_map (),
          m_private_fcn_map (),
          m_method_map ()
      { }

      package_info (const package_info& l)
        : m_package_name (l.m_package_name), m_dir_list (l.m_dir_list),
          m_private_fcn_map (l.m_private_fcn_map), m_method_map (l.m_method_map)
      { }

      ~package_info (void) = default;

      package_info& operator = (const package_info& l)
      {
        if (&l != this)
          {
            m_package_name = l.m_package_name;
            m_dir_list = l.m_dir_list;
            m_fcn_map = l.m_fcn_map;
            m_private_fcn_map = l.m_private_fcn_map;
            m_method_map = l.m_method_map;
          }

        return *this;
      }

      void add (const dir_info& di, bool at_end, bool updating)
      {
        if (at_end)
          m_dir_list.push_back (di.dir_name);
        else
          m_dir_list.push_front (di.dir_name);

        add_to_fcn_map (di, at_end, updating);

        add_to_private_fcn_map (di);

        add_to_method_map (di, at_end);
      }

      void move (const dir_info& di, bool at_end);

      void remove (const dir_info& di);

      void clear (void)
      {
        m_dir_list.clear ();

        m_fcn_map.clear ();

        m_private_fcn_map.clear ();

        m_method_map.clear ();
      }

      void display (std::ostream& out) const;

      std::string
      find_fcn (const std::string& fcn, std::string& dir_name,
                int type = M_FILE | OCT_FILE | MEX_FILE) const;

      std::string
      find_private_fcn (const std::string& dir, const std::string& fcn,
                        int type = M_FILE | OCT_FILE | MEX_FILE) const;

      std::string
      find_method (const std::string& class_name, const std::string& meth,
                   std::string& dir_name,
                   int type = M_FILE | OCT_FILE | MEX_FILE) const;

      std::list<std::string> methods (const std::string& class_name) const;

      void overloads (const std::string& meth, std::list<std::string>& l) const;

      string_vector fcn_names (void) const;

    private:

      void add_to_fcn_map (const dir_info& di, bool at_end, bool updating);

      void add_to_private_fcn_map (const dir_info& di);

      void add_to_method_map (const dir_info& di, bool at_end);

      void move_fcn_map (const std::string& dir,
                         const string_vector& fcn_files, bool at_end);

      void move_method_map (const std::string& dir, bool at_end);

      void remove_fcn_map (const std::string& dir,
                           const string_vector& fcn_files);

      void remove_private_fcn_map (const std::string& dir);

      void remove_method_map (const std::string& dir);

      bool check_file_type (std::string& fname, int type, int possible_types,
                            const std::string& fcn, const char *who) const;

      void print_types (std::ostream& os, int types) const;

      void print_fcn_list (std::ostream& os,
                           const dir_info::fcn_file_map_type& lst) const;

      std::string m_package_name;

      std::list<std::string> m_dir_list;

      fcn_map_type m_fcn_map;

      private_fcn_map_type m_private_fcn_map;

      method_map_type m_method_map;
    };

    // <PACKAGE_NAME, PACKAGE_INFO>
    typedef std::map<std::string, package_info> package_map_type;

    typedef package_map_type::const_iterator const_package_map_iterator;
    typedef package_map_type::iterator package_map_iterator;

    std::function<void (const std::string&)> add_hook;

    std::function<void (const std::string&)> remove_hook;

    void execute_pkg_add_or_del (const std::string& dir,
                                 const std::string& script_file);

    const_dir_info_list_iterator find_dir_info (const std::string& dir) const;
    dir_info_list_iterator find_dir_info (const std::string& dir);

    bool contains (const std::string& dir) const;

    void move (dir_info_list_iterator i, bool at_end);

    void move (const dir_info& di, bool at_end, const std::string& pname = "");

    void remove (const dir_info& di, const std::string& pname = "");

    void add (const std::string& dir, bool at_end, bool warn);

    void add (const dir_info& di, bool at_end, const std::string& pname = "",
              bool updating = false);

    bool is_package (const std::string& name) const;

    package_info& get_package (const std::string& name)
    {
      if (! name.empty () && is_package (name))
        {
          package_map_iterator l = m_package_map.find (name);

          if (l == m_package_map.end ())
            l = m_package_map.insert (m_package_map.end (),
                                      package_map_type::value_type (name, package_info (name)));

          return l->second;
        }

      return m_top_level_package;
    }

    string_vector get_file_list (const dir_info::fcn_file_map_type& lst) const;

    friend dir_info::fcn_file_map_type get_fcn_files (const std::string& d);

    //--------

    static std::string s_sys_path;

    static abs_dir_cache_type s_abs_dir_cache;

    interpreter& m_interpreter;

    package_map_type m_package_map;

    package_info m_top_level_package;

    dir_info_list_type m_dir_info_list;

    std::set<std::string> m_init_dirs;

    std::string m_command_line_path;

  };

  extern std::string
  genpath (const std::string& dir, const string_vector& skip = "private");

OCTAVE_NAMESPACE_END

#endif