/** \file wildcard.c

Fish needs it's own globbing implementation to support
tab-expansion of globbed parameters. Also provides recursive
wildcards using **.

*/

#include "config.h"

#include <stdlib.h>
#include <stdio.h>
#include <limits.h>
#include <wchar.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <dirent.h>
#include <errno.h>


#include "fallback.h"
#include "util.h"

#include "wutil.h"
#include "complete.h"
#include "common.h"
#include "wildcard.h"
#include "complete.h"
#include "reader.h"
#include "expand.h"


/**
   This flag is set in the flags parameter of wildcard_expand if the
   call is part of a recursiv wildcard search. It is used to make sure
   that the contents of subdirectories are only searched once.
*/
#define WILDCARD_RECURSIVE 64

/**
   The maximum length of a filename token. This is a fallback value,
   an attempt to find the true value using patchconf is always made. 
*/
#define MAX_FILE_LENGTH 1024

/**
   Push the specified argument to the list if an identical string is
   not already in the list. This function iterates over the list,
   which is quite slow if the list is large. It might make sense to
   use a hashtable for this.
*/
static void al_push_check( array_list_t *l, const wchar_t *new )
{
	int i;

	for( i = 0; i < al_get_count(l); i++ ) 
	{
		if( !wcscmp( al_get(l, i), new ) ) 
		{
			free( (void *)new );
			return;
		}
	}

	al_push( l, new );
}


int wildcard_has( const wchar_t *str, int internal )
{
	wchar_t prev=0;
	if( !str )
	{
		debug( 2, L"Got null string on line %d of file %s", __LINE__, __FILE__ );
		return 0;		
	}

	if( internal )
	{
		for( ; *str; str++ )
		{
			if( ( *str == ANY_CHAR ) || (*str == ANY_STRING) || (*str == ANY_STRING_RECURSIVE) )
				return 1;
			prev = *str;
		}
	}
	else
	{
		for( ; *str; str++ )
		{
			if( ( (*str == L'*' ) || (*str == L'?' ) ) && (prev != L'\\') )
				return 1;
			prev = *str;
		}
	}
	
	return 0;
}

/**
   Check whether the string str matches the wildcard string wc.
  
   \param str String to be matched.
   \param wc The wildcard.
   \param is_first Whether files beginning with dots should not be matched against wildcards. 
*/
static int wildcard_match2( const wchar_t *str, 
							const wchar_t *wc, 
							int is_first )
{
	
	if( *str == 0 && *wc==0 )
		return 1;
	
	if( *wc == ANY_STRING || *wc == ANY_STRING_RECURSIVE)
	{		
		/* Ignore hidden file */
		if( is_first && *str == L'.' )
		{
			return 0;
		}
		
		/* Try all submatches */
		do
		{
			if( wildcard_match2( str, wc+1, 0 ) )
				return 1;
		}
		while( *(str++) != 0 );
		return 0;
	}
	else if( *str == 0 )
	{
		/*
		  End of string, but not end of wildcard, and the next wildcard
		  element is not a '*', so this is not a match.
		*/
		return 0;
	}

	if( *wc == ANY_CHAR )
	{
		if( is_first && *str == L'.' )
		{
			return 0;
		}
		
		return wildcard_match2( str+1, wc+1, 0 );
	}
	
	if( *wc == *str )
		return wildcard_match2( str+1, wc+1, 0 );

	return 0;
}

/**
   Matches the string against the wildcard, and if the wildcard is a
   possible completion of the string, the remainder of the string is
   inserted into the array_list_t.
*/
static int wildcard_complete_internal( const wchar_t *orig, 
									   const wchar_t *str, 
									   const wchar_t *wc, 
									   int is_first,
									   const wchar_t *desc,
									   const wchar_t *(*desc_func)(const wchar_t *),
									   array_list_t *out )
{
	if( !wc || !str || !orig)
	{
		debug( 2, L"Got null string on line %d of file %s", __LINE__, __FILE__ );
		return 0;		
	}

	if( *wc == 0 &&
		( ( *str != L'.') || (!is_first)) )
	{
		wchar_t *new;
		if( !out )
		{
			return 1;
		}
			
		if( wcschr( str, PROG_COMPLETE_SEP ) )
		{
			/*
			  This completion has an embedded description, du not use the generic description
			*/
			wchar_t *sep;
			
			new = wcsdup( str );
			sep = wcschr(new, PROG_COMPLETE_SEP );
			*sep = COMPLETE_SEP;			
		}
		else
		{
			const wchar_t *this_desc = desc;
			
			if( desc_func )
			{
				/*
				  A descripton generating function is specified, call
				  it. If it returns something, use that as the
				  description.
				*/
				const wchar_t *func_desc = desc_func( orig );
				if( func_desc )
					this_desc = func_desc;
			}
			
			/*
			  Append description to item, if a description exists
			*/
			if( this_desc && wcslen(this_desc) )
			{
				/*
				  Check if the description already contains a separator character, if not, prepend it
				*/
				if( wcschr( this_desc, COMPLETE_SEP ) )
					new = wcsdupcat2( str, this_desc, (void *)0 );
				else
					new = wcsdupcat2( str, COMPLETE_SEP_STR, this_desc, (void *)0 );
			}
			else
				new = wcsdup( str );
		}

		if( new )
		{
			al_push( out, new );
		}
		return 1;
	}
	
	
	if( *wc == ANY_STRING )
	{		
		int res=0;
		
		/* Ignore hidden file */
		if( is_first && str[0] == L'.' )
			return 0;
		
		/* Try all submatches */
		do
		{
			res |= wildcard_complete_internal( orig, str, wc+1, 0, desc, desc_func, out );
			if( res && !out )
				break;
		}
		while( *str++ != 0 );
		return res;
		
	}
	else if( *wc == ANY_CHAR )
	{
		return wildcard_complete_internal( orig, str+1, wc+1, 0, desc, desc_func, out );
	}	
	else if( *wc == *str )
	{
		return wildcard_complete_internal( orig, str+1, wc+1, 0, desc, desc_func, out );
	}
	return 0;	
}

int wildcard_complete( const wchar_t *str,
					   const wchar_t *wc,
					   const wchar_t *desc,						
					   const wchar_t *(*desc_func)(const wchar_t *),
					   array_list_t *out )
{
	return wildcard_complete_internal( str, str, wc, 1, desc, desc_func, out );	
}


int wildcard_match( const wchar_t *str, const wchar_t *wc )
{
	return wildcard_match2( str, wc, 1 );	
}

/**
   Creates a path from the specified directory and filename. 
*/
static wchar_t *make_path( const wchar_t *base_dir, const wchar_t *name )
{
	
	wchar_t *long_name;
	int base_len = wcslen( base_dir );
	if( !(long_name= malloc( sizeof(wchar_t)*(base_len+wcslen(name)+1) )))
	{
		DIE_MEM();
	}					
	wcscpy( long_name, base_dir );
	wcscpy(&long_name[base_len], name );
	return long_name;
}

/**
   Get the description of the specified filename. If this is a regular file, append the filesize to the description.
*/
static void get_desc( wchar_t *fn, string_buffer_t *sb, int is_cmd )
{
	const wchar_t *desc;
	
	struct stat buf;
	off_t sz;
	wchar_t *sz_name[]=
		{
			L"kB", L"MB", L"GB", L"TB", L"PB", L"EB", L"ZB", L"YB", 0
		}
	;
	
	if( !fn || !sb )
	{
		debug( 2, L"Got null string on line %d of file %s", __LINE__, __FILE__ );
		return;		
	}
	
	sb_clear( sb );
	
	if( wstat( fn, &buf ) )
	{
		sz=-1;
	}
	else
	{
		sz = buf.st_size;
	}
						
	desc = complete_get_desc( fn );

	if( wcschr( desc, COMPLETE_SEP )==0 )
	{
		sb_append( sb, COMPLETE_SEP_STR );
	}
		
	if( sz >= 0 && S_ISDIR(buf.st_mode) )
	{
		sb_append( sb, desc );
	}
	else
	{							
		sb_append2( sb, desc, L", ", (void *)0 );
		if( sz < 0 )
		{
			sb_append( sb, L"unknown" );
		}
		else if( sz < 1 )
		{
			sb_append( sb, _( L"empty" ) );
		}
		else if( sz < 1024 )
		{
			sb_printf( sb, L"%lldB", sz );
		}
		else
		{
			int i;
			
			for( i=0; sz_name[i]; i++ )
			{
				if( sz < (1024*1024) || !sz_name[i+1] )
				{
					int isz = sz/1024;
					if( isz > 9 )
						sb_printf( sb, L"%d%ls", isz, sz_name[i] );
					else
						sb_printf( sb, L"%.1f%ls", (double)sz/1024, sz_name[i] );
					
					break;
				}
				sz /= 1024;

			}
		}		
	}
}

/**
  Test if the file specified by the given filename matches the
  expansion flags specified. flags can be a combination of
  EXECUTABLES_ONLY and DIRECTORIES_ONLY.
*/
static int test_flags( wchar_t *filename,
					   int flags )
{
	if( !(flags & EXECUTABLES_ONLY) && !(flags & DIRECTORIES_ONLY) )
		return 1;
	
	struct stat buf;
	if( wstat( filename, &buf ) == -1 )
	{
		return 0;
	}
		
	if( S_ISDIR( buf.st_mode ) )
		return 1;
	
	if( flags & EXECUTABLES_ONLY )
		return ( waccess( filename, X_OK ) == 0);

	return 0;
}


int wildcard_expand( const wchar_t *wc, 
					 const wchar_t *base_dir,
					 int flags,
					 array_list_t *out )
{
	
	/* Points to the end of the current wildcard segment */
	wchar_t *wc_end;

	/* Variables for traversing a directory */
	struct wdirent *next;
	DIR *dir;
	
	/* The result returned */
	int res = 0;
	
	/* Length of the directory to search in */
	int base_len;

	/* Variables for testing for presense of recursive wildcards */
	wchar_t *wc_recursive;
	int is_recursive;

	/* Sligtly mangled version of base_dir */
	const wchar_t *dir_string;

	/* Description for completions */
	string_buffer_t sb_desc;
	
	//	debug( 3, L"WILDCARD_EXPAND %ls in %ls", wc, base_dir );

	if( !wc || !base_dir || !out)
	{
		debug( 2, L"Got null string on line %d of file %s", __LINE__, __FILE__ );
		return 0;		
	}

	if( flags & ACCEPT_INCOMPLETE )
	{	
		/* 
		   Avoid excessive number of returned matches for wc ending with a * 
		*/
		int len = wcslen(wc);
		if( len && (wc[len-1]==ANY_STRING) )
		{
			wchar_t * foo = wcsdup( wc );
			foo[len-1]=0;
			int res = wildcard_expand( foo, base_dir, flags, out );
			free( foo );
			return res;			
		}
	}

	/*
	  Initialize various variables
	*/

	dir_string = base_dir[0]==L'\0'?L".":base_dir;
	
	if( !(dir = wopendir( dir_string )))
	{
		return 0;
	}

	wc_end = wcschr(wc,L'/');
	base_len = wcslen( base_dir );

	/*
	  Test for recursive match string in current segment
	*/	
	wc_recursive = wcschr( wc, ANY_STRING_RECURSIVE );
	is_recursive = ( wc_recursive && (!wc_end || wc_recursive < wc_end));

	/*
	  This makes sure that the base
	  directory of the recursive search is
	  also searched for matching files.
	*/
	if( is_recursive && (wc_end==(wc+1)) && !(flags & WILDCARD_RECURSIVE ) )
	{
		wildcard_expand( wc_end + 1,
						 base_dir,
						 flags,
						 out );
	}
	
	if( flags & ACCEPT_INCOMPLETE )
		sb_init( &sb_desc );

	/*
	  Is this segment of the wildcard the last?
	*/
	if( !wc_end && !is_recursive )
	{
		/*
		  Wildcard segment is the last segment,

		  Insert all matching files/directories
		*/
		if( wc[0]=='\0' )
		{
			/*
			  The last wildcard segment is empty. Insert everything if
			  completing, the directory itself otherwise.
			*/
			if( flags & ACCEPT_INCOMPLETE )
			{
				while( (next=wreaddir(dir))!=0 )
				{
					if( next->d_name[0] != L'.' )
					{
						wchar_t *name = next->d_name;
						wchar_t *long_name = make_path( base_dir, name );
						
						if( test_flags( long_name, flags ) )
						{
							get_desc( long_name,
									  &sb_desc,
									  flags & EXECUTABLES_ONLY );
							al_push( out,
									 wcsdupcat(name, (wchar_t *)sb_desc.buff) );
						}
						
						free( long_name );
					}					
				}
			}
			else
			{								
				res = 1;
				al_push_check( out, wcsdup( base_dir ) );
			}							
		}
		else
		{
			/*
			  This is the last wildcard segment, and it is not empty. Match files/directories.
			*/
			while( (next=wreaddir(dir))!=0 )
			{
				wchar_t *name = next->d_name;
				
				if( flags & ACCEPT_INCOMPLETE )
				{
					
					wchar_t *long_name = make_path( base_dir, name );

					/*
					  Test for matches before stating file, so as to minimize the number of calls to the much slower stat function 
					*/
					if( wildcard_complete( name,
										   wc,
										   L"",
										   0,
										   0 ) )
					{
						if( test_flags( long_name, flags ) )
						{
							get_desc( long_name,
									  &sb_desc, 
									  flags & EXECUTABLES_ONLY );
							
							wildcard_complete( name,
											   wc,
											   (wchar_t *)sb_desc.buff,
											   0,
											   out );
						}
					}
					
					free( long_name );
					
				}
				else
				{
					if( wildcard_match2( name, wc, 1 ) )
					{
						wchar_t *long_name = make_path( base_dir, name );
						
						al_push_check( out, long_name );
						res = 1;
					}
				}
			}
		}
	}
	else
	{
		/*
		  Wilcard segment is not the last segment.  Recursively call
		  wildcard_expand for all matching subdirectories.
		*/
		
		/*
		  wc_str is the part of the wildcarded string from the
		  beginning to the first slash
		*/
		wchar_t *wc_str;

		/*
		  new_dir is a scratch area containing the full path to a
		  file/directory we are iterating over
		*/
		wchar_t *new_dir;

		/*
		  The maximum length of a file element
		*/
		long ln=MAX_FILE_LENGTH;
		char * narrow_dir_string = wcs2str( dir_string );
		
		if( narrow_dir_string )
		{
			/* 
			   Find out how long the filename can be in a worst case
			   scenario
			*/
			ln = pathconf( narrow_dir_string, _PC_NAME_MAX ); 

			/*
			  If not specified, use som large number as fallback
			*/
			if( ln < 0 )
				ln = MAX_FILE_LENGTH;		
			free( narrow_dir_string );
		}
		new_dir= malloc( sizeof(wchar_t)*(base_len+ln+2)  );

		wc_str = wc_end?wcsndup(wc, wc_end-wc):wcsdup(wc);

		if( (!new_dir) || (!wc_str) )
		{
			DIE_MEM();
		}

		wcscpy( new_dir, base_dir );
		
		while( (next=wreaddir(dir))!=0 )
		{
			wchar_t *name = next->d_name;
			
			/*
			  Test if the file/directory name matches the whole
			  wildcard element, i.e. regular matching.
			*/
			int whole_match = wildcard_match2( name, wc_str, 1 );
			int partial_match = 0;
			
			/* 
			   If we are doing recursive matching, also check if this
			   directory matches the part up to the recusrive
			   wildcard, if so, then we can search all subdirectories
			   for matches.
			*/
			if( is_recursive )
			{
				wchar_t *end = wcschr( wc, ANY_STRING_RECURSIVE );
				wchar_t *wc_sub = wcsndup( wc, end-wc+1);
				partial_match = wildcard_match2( name, wc_sub, 1 );
				free( wc_sub );
			}			

			if( whole_match || partial_match )
			{
				int new_len;
				struct stat buf;			
				char *dir_str;
				int stat_res;

				wcscpy(&new_dir[base_len], name );
				dir_str = wcs2str( new_dir );
				
				if( dir_str )
				{
					stat_res = stat( dir_str, &buf );
					free( dir_str );
					
					if( !stat_res )
					{
						if( S_ISDIR(buf.st_mode) )
						{
							new_len = wcslen( new_dir );
							new_dir[new_len] = L'/';
							new_dir[new_len+1] = L'\0';
							
							/*
							  Regular matching
							*/
							if( whole_match )
							{
								wchar_t *new_wc = L"";
								if( wc_end )
								{
									new_wc=wc_end+1;
									/*
									  Accept multiple '/' as a single direcotry separator
									*/
									while(*new_wc==L'/')
									{
										new_wc++;
									}
								}
								
								res |= wildcard_expand( new_wc,
														new_dir, 
														flags, 
														out );
							}
							
							/*
							  Recursive matching
							*/
							if( partial_match )
							{
								res |= wildcard_expand( wcschr( wc, ANY_STRING_RECURSIVE ), 
														new_dir,
														flags | WILDCARD_RECURSIVE, 
														out );
							}
						}								
					}
				}
			}
		}
		
		free( wc_str );
		free( new_dir );
	}
	closedir( dir );
	
	if( flags & ACCEPT_INCOMPLETE )
	{
		sb_destroy( &sb_desc );
	}

	return res;
}