/** \file builtin_set.c Functions defining the set builtin

Functions used for implementing the set builtin. 

*/
#include <stdlib.h>
#include <stdio.h>
#include <wchar.h>
#include <wctype.h>
#include <sys/types.h>
#include <termios.h>
#include <signal.h>

#include "config.h"

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

#include "wutil.h"
#include "builtin.h"
#include "env.h"
#include "expand.h"
#include "common.h"
#include "wgetopt.h"
#include "proc.h"
#include "parser.h"
#include "translate.h"

#define BUILTIN_SET_PATH_ERROR L"%ls: Could not add component %ls to %ls.\n"
#define BUILTIN_SET_PATH_HINT L"%ls: Did you mean 'set %ls $%ls %ls'?\n"
#define BUILTIN_SET_ARG_COUNT L"%ls: The number of variable indexes does not match the number of values\n"

static int is_path_variable( const wchar_t *env )
{
	return contains_str( env,
						 L"PATH",
						 L"CDPATH",
						 (void *)0 );
}

/**
   Call env_set. If this is a path variable, e.g. PATH, validate the
   elements. On error, print a description of the problem to stderr.
*/
static int my_env_set( const wchar_t *key, array_list_t *val, int scope )
{
	string_buffer_t sb;
	int i;
	int retcode = 0;
	wchar_t *val_str=0;
		
	if( is_path_variable( key ) )
	{
		int error = 0;
		
		for( i=0; i<al_get_count( val ); i++ )
		{
			int show_perror = 0;
			int show_hint = 0;
			
			struct stat buff;
			wchar_t *dir = (wchar_t *)al_get( val, i );
			
			if( wstat( dir, &buff ) )
			{
				error = 1;
				show_perror = 1;
			}

			if( !( S_IFDIR & buff.st_mode ) )
			{
				error = 1;
				
			}
			
			if( error )
			{
				wchar_t *colon;
				
				sb_printf( sb_err, 
						   _(BUILTIN_SET_PATH_ERROR),
						   L"set", 
						   dir, 
						   key );
				colon = wcschr( dir, L':' );
				
				if( colon && *(colon+1) ) 
				{
					show_hint = 1;
				}

			}
			
			if( show_perror )
			{
				builtin_wperror( L"set" );
			}
			
			if( show_hint )
			{
				sb_printf( sb_err, 
						   _(BUILTIN_SET_PATH_HINT),
						   L"set",
						   key,
						   key,
						   wcschr( dir, L':' )+1);
			}
			
			if( error )
			{
				break;
			}
			
		}

		if( error )
		{
			return 1;
		}
		
	}

	sb_init( &sb );

	if( al_get_count( val ) )
	{
		for( i=0; i<al_get_count( val ); i++ )
		{
			sb_append( &sb, (wchar_t *)al_get( val, i ) );
			if( i<al_get_count( val )-1 )
			{
				sb_append( &sb, ARRAY_SEP_STR );
			}
		}
		val_str = (wchar_t *)sb.buff;
		
	}
	
	switch( env_set( key, val_str, scope | ENV_USER ) )
	{
		case ENV_PERM:
		{
			sb_printf( sb_err, _(L"%ls: Tried to change the read-only variable '%ls'\n"), L"set", key );
			retcode=1;
			break;
		}
	}

	sb_destroy( &sb );

	return retcode;
}

/** 
	Extract indexes from a destination argument of the form name[index1 index2...]

	\param indexes the list to insert the new indexes into
	\param src the source string to parse
	\param name the name of the element. Return null if the name in \c src does not match this name

	\return the number of indexes parsed, or -1 on error
*/
static int parse_index( array_list_t *indexes,
						const wchar_t *src,
						const wchar_t *name )
{
	int len;
	
	int count = 0;
	const wchar_t *src_orig = src;
	
	if (src == 0)
	{
		return 0;
	}
	
	while (*src != L'\0' && (iswalnum(*src) || *src == L'_'))
	{
		src++;
	}
	
	if (*src != L'[')
	{
		sb_printf( sb_err, _(BUILTIN_SET_ARG_COUNT), L"set" );					
		return 0;
	}

	len = src-src_orig;
	
	if( (wcsncmp( src_orig, name, len )!=0) || (wcslen(name) != (len)) )
	{
		sb_printf( sb_err, 
				   _(L"%ls: Multiple variable names specified in single call (%ls and %.*ls)\n"),
				   L"set", 
				   name,
				   len,
				   src_orig);
		return 0;
	}

	src++;	

	while (iswspace(*src)) 
	{
		src++;
	}
	
	while (*src != L']') 
	{
		wchar_t *end;
		long l_ind = wcstol(src, &end, 10);
		if (end == src) 
		{
			sb_printf(sb_err, _(L"%ls: Invalid index starting at '%ls'\n"), L"set", src);
			return 0;
		}
		
		int *ind = (int *) calloc(1, sizeof(int));
		*ind = (int) l_ind;
		al_push(indexes, ind);
		src = end;
		count++;
		while (iswspace(*src)) src++;
	}

	return count;
}


/**
   Update a list \c list by writing copies (using wcsdup) of the
   values specified by \c values to the indexes specified by \c
   indexes. The previous entries at the specidied position will be
   free'd.

   \return The number of elements in the list after the modifications have been made
*/
static int update_values( array_list_t *list, 
						  array_list_t *indexes,
						  array_list_t *values ) 
{
	int i;

	/* Replace values where needed */
	for( i = 0; i < al_get_count(indexes); i++ ) 
	{
		int ind = *(int *) al_get(indexes, i) - 1;
		void *new = (void *) al_get(values, i);
		free((void *) al_get(list, ind));
		al_set(list, ind, new != 0 ? wcsdup(new) : wcsdup(L""));
	}
  
	return al_get_count(list);
}


/**
   Return 1 if an array list of int* pointers contains the specified
   value, 0 otherwise
*/
static int al_contains_int( array_list_t *list,
							int val)
{
	int i;

	for (i = 0; i < al_get_count(list); i++) 
	{
		int *current = (int *) al_get(list, i);
		if (current != 0 && *current == val) 
		{
			return 1;
		}
	}
	
	return 0;
}


/**
   Erase from a list values at specified indexes 
*/
static void erase_values(array_list_t *list, array_list_t *indexes) 
{
	int i;
	array_list_t result;

	al_init(&result);

	for (i = 0; i < al_get_count(list); i++) 
	{
		if (!al_contains_int(indexes, i + 1)) 
		{
			al_push(&result, al_get(list, i));
		}
		else 
		{
			free((void *) al_get(list, i));
		}
	}
	
	al_truncate(list,0);	
	al_push_all( list, &result );
	al_destroy(&result);
}


/**
   Fill a string buffer with values from a list, using ARRAY_SEP_STR to separate them 
*/
static int fill_buffer_from_list(string_buffer_t *sb, array_list_t *list) 
{
	int i;

	for (i = 0; i < al_get_count(list); i++) 
	{
		wchar_t *v = (wchar_t *) al_get(list, i);
		if (v != 0) 
		{
			sb_append(sb, v);
		}    
		if (i < al_get_count(list) - 1)
			sb_append(sb, ARRAY_SEP_STR);
	}
	return al_get_count(list);
}


/**
   Print the names of all environment variables in the scope, with or without values,
   with or without escaping
*/
static void print_variables(int include_values, int esc, int scope) 
{
	array_list_t names;
	int i;
	
	al_init( &names );
	env_get_names( &names, scope );
	
	sort_list( &names );
	
	for( i = 0; i < al_get_count(&names); i++ )
	{
		wchar_t *key = (wchar_t *)al_get( &names, i );
		wchar_t *e_key = esc ? escape(key, 1) : wcsdup(key);

		sb_append(sb_out, e_key);
		
		if( include_values ) 
		{
			wchar_t *value = env_get(key);
			wchar_t *e_value;
			e_value = esc ? expand_escape_variable(value) : wcsdup(value);
			sb_append2(sb_out, L" ", e_value, (void *)0);
			free(e_value);
		}
		
		sb_append(sb_out, L"\n");
		free(e_key);
	}
  	al_destroy(&names);
}



/**
   The set builtin. Creates, updates and erases environment variables and environemnt variable arrays. 
*/

int builtin_set( wchar_t **argv ) 
{
	
	/**
	   Variables used for parsing the argument list
	*/
	const static struct woption
		long_options[] = 
		{
			{ 
				L"export", no_argument, 0, 'x' 
			},
			{ 
				L"global", no_argument, 0, 'g' 
			},
			{ 
				L"local", no_argument, 0, 'l'  
			},
			{ 
				L"erase", no_argument, 0, 'e'  
			},
			{ 
				L"names", no_argument, 0, 'n' 
			} ,
			{ 
				L"unexport", no_argument, 0, 'u' 
			} ,
			{ 
				L"universal", no_argument, 0, 'U' 
			} ,
			{ 
				L"query", no_argument, 0, 'q' 
			} ,
			{ 
				0, 0, 0, 0 
			}
		}
	;
	
	const wchar_t *short_options = L"+xglenuUq";

	int argc = builtin_count_args(argv);

	/*
	  Flags to set the work mode
	*/
	int local = 0, global = 0, export = 0;
	int erase = 0, list = 0, unexport=0;
	int universal = 0, query=0;
	

	/*
	  Variables used for performing the actual work
	*/
	wchar_t *dest = 0;
	int retcode=0;
	int scope;
	int slice=0;
	int i;
	
	
	/* Parse options to obtain the requested operation and the modifiers */
	woptind = 0;
	while (1) 
	{
		int c = wgetopt_long(argc, argv, short_options, long_options, 0);

		if (c == -1) 
		{
			break;
		}
    
		switch(c) 
		{
			case 0:
				break;
			case 'e':
				erase = 1;
				break;
			case 'n':
				list = 1;
				break;
			case 'x':
				export = 1;
				break;
			case 'l':
				local = 1;
				break;
			case 'g':
				global = 1;
				break;
			case 'u':
				unexport = 1;
				break;
			case 'U':
				universal = 1;
				break;
			case 'q':
				query = 1;
				break;
			case '?':
				return 1;
			default:
				break;
		}
	}

	/*
	  Ok, all arguments have been parsed, let's validate them
	*/

	/*
	  If we are checking the existance of a variable (-q) we can not
	  also specify scope
	*/

	if( query && (erase || list || global || local || universal || export || unexport ) )
	{
		sb_printf(sb_err,
				  BUILTIN_ERR_COMBO2,
				  argv[0],
				  parser_current_line() );
		
//		builtin_print_help( argv[0], sb_err );
		return 1;
	}
	

	/* We can't both list and erase varaibles */
	if( erase && list ) 
	{
		sb_printf(sb_err,
				  BUILTIN_ERR_COMBO2,
				  argv[0],
				  parser_current_line() );		

//		builtin_print_help( argv[0], sb_err );
		return 1;
	}

	/*
	  Variables can only have one scope
	*/
	if( local + global + universal > 1 ) 
	{
		sb_printf( sb_err,
				   BUILTIN_ERR_GLOCAL,
				   argv[0],
				   parser_current_line() );
//		builtin_print_help( argv[0], sb_err );
		return 1;
	}

	/*
	  Variables can only have one export status
	*/
	if( export && unexport ) 
	{
		sb_printf( sb_err,
				   BUILTIN_ERR_EXPUNEXP,
				   argv[0],
				   parser_current_line() );
//		builtin_print_help( argv[0], sb_err );
		return 1;
	}

	/*
	  Calculate the scope value for variable assignement
	*/
	scope = (local ? ENV_LOCAL : 0) | (global ? ENV_GLOBAL : 0) | (export ? ENV_EXPORT : 0) | (unexport ? ENV_UNEXPORT : 0) | (universal ? ENV_UNIVERSAL:0) | ENV_USER; 

	if( query )
	{
		/*
		  Query mode. Return the number variables that do not exist
		  out of the specified variables.
		*/
		int i;
		for( i=woptind; i<argc; i++ )
		{
			if( !env_exist( argv[i] ) )
			{
				retcode++;
			}
			
		}
		return retcode;
	}
	
	if( woptind == argc )
	{
		/*
		  Print values of variables
		*/

		if( erase ) 
		{
			sb_printf( sb_err,
					   _(L"%ls: Erase needs a variable name\n%ls\n"), 
					   argv[0],
					   parser_current_line() );
			
//			builtin_print_help( argv[0], sb_err );
			retcode = 1;
		}
		else
		{
			print_variables( 1, 1, scope );
		}
		
		return retcode;
	}

	if( list ) 
	{
		/* Maybe we should issue an error if there are any other arguments? */
		print_variables(0, 0, scope);
		return 0;
	} 
	
	if( !(dest = wcsdup(argv[woptind])))
	{
		die_mem();		
	}

	if( wcschr( dest, L'[' ) )
	{
		slice = 1;
		*wcschr( dest, L'[' )=0;
	}
	
	if( !wcslen( dest ) )
	{
		free( dest );
		sb_printf( sb_err, BUILTIN_ERR_VARNAME_ZERO, argv[0] );
		return 1;
	}

	
	/*
	  set assignment can work in two modes, either using slices or
	  using the whole array. We detect which mode is used here.
	*/
	
	if( slice )
	{

		/*
		  Slice mode
		*/
		int idx_count, val_count;
		array_list_t values;
		array_list_t indexes;
		
		al_init(&values);
		al_init(&indexes);
	
		for( ; woptind<argc; woptind++ )
		{			
			if( !parse_index( &indexes, argv[woptind], dest ) )
			{
				retcode = 1;
				break;
			}
			
			val_count = argc-woptind-1;
			idx_count = al_get_count( &indexes );

			if( !erase )
			{
				if( val_count < idx_count )
				{
					sb_printf( sb_err, _(BUILTIN_SET_ARG_COUNT), argv[0] );
					retcode=1;
					break;
				}
				if( val_count == idx_count )
				{
					woptind++;
					break;
				}
			}
		}		

		if( !retcode )
		{
			/*
			  Slice indexes have been calculated, do the actual work
			*/

			array_list_t result;
			al_init(&result);

			expand_variable_array( env_get(dest), &result );
			if( erase )
			{
				erase_values(&result, &indexes);
				my_env_set( dest, &result, scope);
			}
			else
			{
				array_list_t value;
				al_init(&value);

				while( woptind < argc ) 
				{
					al_push(&value, argv[woptind++]);
				}

				update_values( &result, 
							   &indexes,
							   &value );
				
				my_env_set(dest,
						   &result,
						   scope);
								
				al_destroy( &value );
								
			}			
			al_foreach( &result, (void (*)(const void *))&free );
			al_destroy( &result );
		}

		al_foreach( &indexes, (void (*)(const void *))&free );
		al_destroy(&indexes);
		al_destroy(&values);
		
	}
	else
	{
		woptind++;
		
		/*
		  No slicing
		*/
		if( erase )
		{
			if( woptind != argc )
			{
				sb_printf( sb_err, 
						   _(L"%ls: Values cannot be specfied with erase\n%ls\n"),
						   argv[0],
						   parser_current_line() );
				retcode=1;
			}
			else
			{
				env_remove( dest, ENV_USER );
			}
		}
		else
		{
			array_list_t val;
			al_init( &val );
			
			for( i=woptind; i<argc; i++ )
			{
				al_push( &val, argv[i] );
			}

			retcode = my_env_set( dest, &val, scope );
						
			al_destroy( &val );			
			
		}		
	}
	
	free( dest );
	
	return retcode;

}