//-----------------------------------------------------------
// Copyright Christian Arnault LAL-Orsay CNRS
// arnault@lal.in2p3.fr
// See the complete license in cmt_license.txt "http://www.cecill.info". 
//-----------------------------------------------------------

#include "cmt_deps_builder.h"
#include "cmt_system.h"
#include "cmt_use.h"
#include "cmt_include.h"
#include "cmt_symbol.h"
#include "cmt_log.h"

//
//  While parsing a C++ file, these are the possible usefull
// states we can reach.
//  Each state correspond to a specific state action function.
//
enum state_def
  {
    at_start,                                // beginning of the file
    in_line,                                // along a line
    in_string,                        // inside a quoted string
    in_char,                                // inside a quoted char
    in_comment,                        // inside a multi-line comment
    in_string_comment,        // inside a quoted string in a comment
    in_char_comment,                // inside a quoted char in a comment
    in_line_comment                // inside a single-line comment
  };

//--------------------------------------------------
static int build_deps (const cmt_string& name,
                       const cmt_string& dir_name,
                       int current_path_index,
                       const CmtSystem::cmt_string_vector& include_paths,
                       const CmtSystem::cmt_string_vector& substitutions,
                       CmtSystem::cmt_string_vector& all_deps,
                       CmtSystem::cmt_string_vector& deps);


//--------------------------------------------------
static void header_file_action (const char* header_file,
                                const cmt_string& dir_name,
                                int current_path_index,
                                const CmtSystem::cmt_string_vector& include_paths,
                                const CmtSystem::cmt_string_vector& substitutions,
                                CmtSystem::cmt_string_vector& all_deps,
                                CmtSystem::cmt_string_vector& deps)
{
  Log;

  bool found = false;

  for (int i = 0; i < all_deps.size (); i++)
    {
      const cmt_string& n = all_deps[i];

      log << "CMT> check old header file name=" << n << " against " << header_file << log_endl;

      if (n == header_file)
        {
          found = true;
          break;
        }
    }
  
  if (!found)
    {
      log << "CMT> parsing new header file name=" << header_file << log_endl;

      all_deps.push_back (header_file);
      
      int path_index = build_deps (header_file,
                                   dir_name,
                                   current_path_index,
                                   include_paths,
                                   substitutions,
                                   all_deps,
                                   deps);
      
      if (path_index >= 0)
        {
          cmt_string full_name;
          
          if (path_index == 1)
            {
              full_name = dir_name;
              full_name += CmtSystem::file_separator ();
              
              if (current_path_index >= 2)
                {
                  full_name.replace (include_paths[current_path_index - 2],
                                     substitutions[current_path_index - 2]);
                }
            }
          else if (path_index > 1)
            {
              full_name  = substitutions[path_index - 2];
              full_name += CmtSystem::file_separator ();
            }
          
          full_name += header_file;
          
          deps.push_back (full_name);
        }
    }
}


//--------------------------------------------------
static char* at_start_action (char* ptr,
                              state_def& state,
                              const cmt_string& dir_name,
                              int current_path_index,
                              const CmtSystem::cmt_string_vector& include_paths,
                              const CmtSystem::cmt_string_vector& substitutions,
                              CmtSystem::cmt_string_vector& all_deps,
                              CmtSystem::cmt_string_vector& deps)
{

  char term = 0;
  // To ignore leading spaces and tabs 
  while ( (*ptr == ' ') || (*ptr == '\t'))
    {
      ptr++;
    }

  if (*ptr == '#')
    {
      ptr++;

      // skip spaces 
      while ((*ptr == ' ') || (*ptr == '\t')) ptr++;

      if (!strncmp (ptr, "include", 7))
        {
	  // We have a #include statement

          ptr += 7;

          while ((*ptr == ' ') || (*ptr == '\t')) ptr++;
          
          if (*ptr == '<')
            {
              term = '>';
              ptr++;
            }
          else if (*ptr == '"')
            {
              term = '"';
              ptr++;
            }
          else
            {
	      // empty #include statement??
              state = in_line;
              ptr += strlen (ptr);
              return (ptr);
            }
        }
      else
        {
	  // ignore other pre-processor statements

          state = in_line;
          ptr += strlen (ptr);
          return (ptr);
        }
    }
  else if (!strncmp (ptr, "      include", 13))
    {
      // fortran include statement

      ptr += 13;

      while ((*ptr == ' ') || (*ptr == '\t')) ptr++;

      if (*ptr == '\'')
        {
          term = '\'';
          ptr++;
        }
      else
        {
          state = in_line;
          return (ptr);
        }
    }
  else if (!strncmp (ptr, "\tinclude", 8))
    {
      // fortran include statement

      ptr += 8;

      while ((*ptr == ' ') || (*ptr == '\t')) ptr++;

      if (*ptr == '\'')
        {
          term = '\'';
          ptr++;
        }
      else
        {
          state = in_line;
          return (ptr);
        }
    }
  else
    {
      state = in_line;
      return (ptr);
    }

  // At this point we do have to include a header file.

  char* end;

  end = strchr (ptr, term);
  if (end != 0)
    {
      *end = 0;
    }
  
  const char* header_file = ptr;
  
  header_file_action (header_file,
                      dir_name,
                      current_path_index,
                      include_paths,
                      substitutions,
                      all_deps,
                      deps);
  
  if (end != 0)
    {
      *end = term;
    }

  state = in_line;
  ptr += strlen (ptr);
  
  return (ptr);
}

/**
   Any line with no header inclusion
   step through comments and strings
*/
static char* in_line_action (char* ptr, state_def& state)
{
  char* pattern = ptr + strlen (ptr);
  int length = 0;

  /*
    search for the first occurrence of 
    {single-quote double-quote open-comment open-line-comment}

    Must exclude escaped quotes \' and \"
  */

  char* pos = strchr (ptr, '"');
  if ((pos != 0) && (pos < pattern) && (pos > ptr) && (*(pos-1) != '\\'))
    {
      state = in_string;
      pattern = pos;
      length = 1;
    }

  pos = strchr (ptr, '\'');
  if ((pos != 0) && (pos < pattern) && (pos > ptr) && (*(pos-1) != '\\'))
    {
      state = in_char;
      pattern = pos;
      length = 1;
    }

  pos = strstr (ptr, "/*");   //*/
  if ((pos != 0) && (pos < pattern))
    {
      state = in_comment;
      pattern = pos;
      length = 2;
    }

  pos = strstr (ptr, "//");
  if ((pos != 0) && (pos < pattern))
    {
      state = in_line_comment;
      pattern = pos;
      length = 2;
    }

  ptr = pattern + length;

  return (ptr);
}

//--------------------------------------------------
static char* in_string_action (char* ptr, state_def& state)
{
  // we exclusively look for a double quote

  char* pos = strchr (ptr, '"');
  if (pos == 0)
    {
      // This string is not finished till the end of the line..
      // we expect it to continue to the next line...
      // thus we leave the state as it is
      ptr += strlen (ptr);
    }
  else
    {
      if ((pos > ptr) && (*(pos - 1) == '\\'))
        {
          ptr = pos + 1;
        }
      else
        {
          ptr = pos + 1;
          state = in_line;
        }
    }

  return (ptr);
}

//--------------------------------------------------
static char* in_char_action (char* ptr, state_def& state)
{
  // we exclusively look for a single quote

  char* pos = strchr (ptr, '\'');
  if (pos == 0)
    {
      // This string is not finished till the end of the line..
      // we expect it continues to the nex line...
      // thus we leave the state as it is
      ptr += strlen (ptr);
    }
  else
    {
      if ((pos > ptr) && (*(pos - 1) == '\\'))
        {
          ptr = pos + 1;
        }
      else
        {
          ptr = pos + 1;
          state = in_line;
        }
    }

  return (ptr);
}

//--------------------------------------------------
static char* in_comment_action (char* ptr, state_def& state)
{
  char* pattern = ptr + strlen (ptr);
  int length    = 0;
  char* pos;
  

  /*
    Even if we are inside a comment, we must detect strings since comment markers may 
    be written inside them.
  
    pos = strchr (ptr, '"');
  
    if ((pos != 0) && (pos < pattern) && (pos > ptr) && (*(pos-1) != '\\'))
    {
    state = in_string_comment;
    pattern = pos;
    length = 1;
    }

    pos = strchr (ptr, '\'');
    if ((pos != 0) && (pos < pattern) && (pos > ptr) && (*(pos-1) != '\\'))
    {
    state = in_char_comment;
    pattern = pos;
    length = 1;
    }
  */
  pos = strstr (ptr, "*/");
  if ((pos != 0) && (pos < pattern))
    {
      state   = in_line;
      pattern = pos;
      length  = 2;
    }

  ptr = pattern + length;

  return (ptr);
}

//--------------------------------------------------
static char* in_string_comment_action (char* ptr, state_def& state)
{
  char* pos = strchr (ptr, '"');
  if (pos == 0)
    {
      // This string is not finished till the end of the line..
      // we expect it continues to the nex line...
      ptr += strlen (ptr);
    }
  else
    {
      if ((pos > ptr) && (*(pos - 1) == '\\'))
        {
          ptr = pos + 1;
        }
      else
        {
          ptr = pos + 1;
          state = in_comment;
        }
    }

  return (ptr);
}

//--------------------------------------------------
static char* in_char_comment_action (char* ptr, state_def& state)
{
  char* pos = strchr (ptr, '\'');
  if (pos == 0)
    {
      // This string is not finished till the end of the line..
      // we expect it continues to the nex line...
      ptr += strlen (ptr);
    }
  else
    {
      if ((pos > ptr) && (*(pos - 1) == '\\'))
        {
          ptr = pos + 1;
        }
      else
        {
          ptr = pos + 1;
          state = in_comment;
        }
      pos--;
    }

  return (ptr);
}

//--------------------------------------------------
static char* in_line_comment_action (char* ptr, state_def& state)
{
  char * pos = strchr (ptr, '\\');  
  /* Extend this part to deal with continuation character */  
  if ( (pos == NULL) || ( (ptr + strlen(ptr)-1)!=pos ))
    {
      state = in_line;
    }
  
  ptr    += strlen (ptr);
  
  return (ptr);
}

//--------------------------------------------------
static void build_deps_text (char* text,
			     const cmt_string& dir_name,
			     int current_path_index,
			     const CmtSystem::cmt_string_vector& include_paths,
			     const CmtSystem::cmt_string_vector& substitutions,
			     CmtSystem::cmt_string_vector& all_deps,
			     CmtSystem::cmt_string_vector& deps)
{
  Log;

  int pos;
  int max_pos;
  int line_number = 1;

  log << "CMT> build_deps_text dir_name="
      << dir_name << log_endl;


  // erase of continuation character
  pos = 0;
  max_pos = strlen (text);
  char* current = text;
  char* last = text + max_pos;
  while (current < last)
    {
   
      char* crnl = strstr (current, "\r\n");
      char* nl   = strstr (current, "\n");
      
      if ( (crnl==0) && (nl ==0)) break;
      
      int length = 0;
            
      char * ptr = 0;
      if (nl==0)  //crnl > 0
	{
	  length = 3;
	  ptr    = crnl; 
	}      
      else if (crnl==0) //nl > 0
	{
	  length = 2;                        
	  ptr    = nl; 
	}     
      else if (crnl < nl)
	{
	  length = 3;
	  ptr    = crnl;                 
	}
      else // (crnl > nl)
	{
	  length = 2;                        
	  ptr    = nl;         
	}
      strcpy (ptr, ptr+length);
      current = ptr;
      last -= length;
    } 
  
  pos = 0;
  max_pos = strlen (text);
  current = text;
  last = text + max_pos;

  state_def state = at_start;
  

  while (current < last)
    {
             
      char marker;
      char* marker_pos = 0;

      char* crnl = strstr (current, "\r\n");
      char* nl = strchr (current, '\n');

      char* first = nl;
      int length = 1;

      char* ptr = 0;

      if (crnl != 0)
        {
	  // cr+nl has been found

          if (nl == 0)
            {
	      // cr but no nl ??
              first = crnl;
              length = 2;
            }
          else
            {
	      // both cr+nl and nl found
              first = (nl < crnl) ? nl : crnl;
              length = (nl < crnl) ? 1 : 2;
            }
        }
      else
	{
	  // no cr+nl but nl alone found
	  first = nl;
	  length = 1;
	}

      ptr = current;

      if (first == 0)
        {
    	  // neither nl nor cr+nl found => this is the last line
	  marker_pos = 0;
        }
      else
        {
    	  marker_pos = first;
	  marker = *marker_pos;
	  *marker_pos = 0;
        }

      log << "CMT> build_deps_text2 line=[" 
	  << current << "]" << log_endl;
      
      while (strlen (ptr) > 0)
	{
	  switch (state)
	    {
	    case at_start:
	      ptr = at_start_action (ptr,
				     state,
				     dir_name,
				     current_path_index,
				     include_paths,
				     substitutions,
				     all_deps,
				     deps);
	      break;
	    case in_line:
	      ptr = in_line_action (ptr, state);
	      break;
	    case in_string:
	      ptr = in_string_action (ptr, state);
	      break;
	    case in_char:
	      ptr = in_char_action (ptr, state);
	      break;
	    case in_comment:
	      ptr = in_comment_action (ptr, state);
	      break;
	    case in_string_comment:
	      ptr = in_string_comment_action (ptr, state);
	      break;
	    case in_char_comment:
	      ptr = in_char_comment_action (ptr, state);
	      break;
	    case in_line_comment:
	      ptr = in_line_comment_action (ptr, state);
	      break;
	    }
	}

      if (state == in_line) state = at_start;
      line_number++;

      if (marker_pos != 0)
	{
	  *marker_pos = marker;
	  current = marker_pos + length;
	}
      else
	{
	  break;
	}
    }
            
}

//--------------------------------------------------
static int build_deps (const cmt_string& name,
                       const cmt_string& dir_name,
                       int current_path_index,
                       const CmtSystem::cmt_string_vector& include_paths,
                       const CmtSystem::cmt_string_vector& substitutions,
                       CmtSystem::cmt_string_vector& all_deps,
                       CmtSystem::cmt_string_vector& deps)
{
  Log;

  int result = -1;
  cmt_string new_dir;

  log << "CMT> build_deps name=" << name << " dir_name=" 
      << dir_name << log_endl;

  //
  // Return 0 when the file is found in the current directory
  //
  if (CmtSystem::test_file (name))
    {
      cmt_string text;

      text.read (name);

      char* ptr = &text[0];
      CmtSystem::dirname (name, new_dir);

      build_deps_text (ptr, new_dir, current_path_index,
		       include_paths, substitutions,
		       all_deps, deps);
      return (0);
    }

  cmt_string full_name;

  full_name = dir_name;
  full_name += CmtSystem::file_separator ();
  full_name += name;

  //
  // Return 1 when the file is found in the directory of the
  // upper level source file
  //
  if (CmtSystem::test_file (full_name))
    {
      cmt_string text;

      text.read (full_name);

      char* ptr = &text[0];
      CmtSystem::dirname (full_name, new_dir);

      build_deps_text (ptr, new_dir, current_path_index,
		       include_paths, substitutions,
		       all_deps, deps);
      return (1);
    }

  int path_index = -1;

  //
  // Return [path_index + 2] when the include file is found at one of
  // the include_paths
  //
  for (path_index = 0; path_index < include_paths.size (); path_index++)
    {
      full_name  = include_paths[path_index];
      full_name += CmtSystem::file_separator ();
      full_name += name;

      log << "CMT> build_deps2 full_name=" << full_name << log_endl;

      if (CmtSystem::test_file (full_name))
        {
	  cmt_string text;

	  text.read (full_name);

	  char* ptr = &text[0];
	  CmtSystem::dirname (full_name, new_dir);

	  log << "CMT> build_deps3 new_dir=" << new_dir << log_endl;

	  build_deps_text (ptr,
			   new_dir,
			   path_index + 2,
			   include_paths,
			   substitutions,
			   all_deps,
			   deps);

	  return (path_index + 2);
        }
    }

  log << "CMT> build_deps3" << log_endl;

  return (-1);
}

//--------------------------------------------------------------------------
void DepsBuilder::clear ()
{
  m_include_paths.clear ();
  m_substitutions.clear ();
}

//--------------------------------------------------------------------------
void DepsBuilder::add (const cmt_string& path, const cmt_string& substitution)
{
  if (path[path.size () - 1] == CmtSystem::file_separator ())
    {
      cmt_string p = path;
      p.erase (path.size () - 1);
      m_include_paths.push_back (p);
    }
  else
    {
      m_include_paths.push_back (path);
    }

  m_substitutions.push_back (substitution);
}

//--------------------------------------------------------------------------
void DepsBuilder::add_includes (const Use& use)
{
  Log;

  const Include::IncludeVector& includes = use.includes;
  int include_number;

  for (include_number = 0;
       include_number < includes.size ();
       include_number++)
    {
      const Include& include = includes[include_number];

      cmt_string temp = include.name;
      cmt_string pattern;
      cmt_string name;
      char end_pattern;

      int start = 0;

      for (;;)
        {
          int begin;

          begin = temp.find (start, "${");
          if (begin != cmt_string::npos)
            {
              end_pattern = '}';
            }
          else
            {
              begin = temp.find (start, "$(");
              if (begin != cmt_string::npos)
                {
                  end_pattern = ')';
                }
              else
                {
                  break;
                }
            }

          start = begin + 2;

          int end;
          end = temp.find (start, end_pattern);
          if (end == cmt_string::npos) break;
          if (end < begin) break;
          start = end + 1;

          temp.substr (begin, end - begin + 1, pattern);
          temp.substr (begin + 2, end - begin - 2, name);

          Symbol* macro = Symbol::find (name);
          if (macro != 0)
            {
              cmt_string value = macro->resolve_macro_value ();
              value += CmtSystem::file_separator ();
              temp.replace_all (pattern, value);
            }
          else
            {
              cmt_string value = CmtSystem::getenv (name);
              value += CmtSystem::file_separator ();
              temp.replace_all (pattern, value);
            }
        }

      log << "include = " << temp << log_endl;

      add (temp, include.name);
    }
}

//--------------------------------------------------------------------------
CmtSystem::cmt_string_vector& DepsBuilder::run (const cmt_string& file_name)
{
  Log;

  log << "Starting deps builder on " << file_name << log_endl;


  m_deps.clear ();
  m_all_deps.clear ();

  cmt_string preprocessor;
  Symbol* macro = Symbol::find ("preprocessor_command");
  if (macro != 0)
    {
      preprocessor = macro->resolve_macro_value ();
    }

  if (preprocessor == "")
    {
      //
      //   Since no preprocessor command is defined,
      // we use the internal mechanism provided here.
      //
      cmt_string new_dir;

      CmtSystem::dirname (file_name, new_dir);

      build_deps (file_name,
                  new_dir,
                  0,
                  m_include_paths,
                  m_substitutions,
                  m_all_deps,
                  m_deps);
    }
  else
    {
      //
      //  An external preprocessor command is defined. We expect it
      // to follow a "standard" syntax for its output, ie:
      //   o It starts with:
      //       <module>.o: ...
      //   o There may be many lines with trailing back-slashes
      //   o All entries are space-separated
      //   o One of the entries is the source file name itself
      //
      //  The preprocessor command expects the list of -I options
      // (resolved from the "includes" macro) and the list of 
      // -D/-U options (resolved from the "*_pp_*flags" macros)
      //

      //
      // Building the complete command (still the pp_*flags are
      // missing)
      //
      preprocessor += " ";
      macro = Symbol::find ("includes");
      preprocessor += macro->resolve_macro_value ();
      preprocessor += " ";
      preprocessor += file_name;
      
      cmt_string output;
      
      CmtSystem::execute (preprocessor, output);

      //
      // Make the output as one single big line.
      //

      output.replace_all ("\n", " ");
      output.replace_all ("\\ ", " ");
      
      CmtSystem::cmt_string_vector files;
      
      CmtSystem::split (output, " \t", files);

      //
      // Analyze each entry
      //
      
      for (int i = 1; i < files.size (); i++)
        {
          const cmt_string& file = files[i];
          if (file == file_name) continue;
          
          cmt_string dir;
          cmt_string name;
          cmt_string full_name;
          
          CmtSystem::dirname (file, dir);

	  //
	  // Only declared include_paths will be taken into account
	  // Others are considered as system include paths.
	  //
          
          for (int j = 0; j < m_include_paths.size (); j++)
            {
              const cmt_string& p = m_include_paths[j];
              if (dir == p)
                {
                  CmtSystem::basename (file, name);
                  full_name = m_substitutions[j];
                  full_name += name;

		  //
		  // We add in the "m_deps" list the symbolic form
		  // of the path rather that the expanded one.
		  //
                  
                  m_deps.push_back (full_name);
                  
                  break;
                }
            }
        }
    }

  return (m_deps);
}