/* Dictionary.c
   Implementation of the Dictionary Class
*/

#include <assert.h>
#include <stdlib.h>
#include <string.h>

#include "Boolean.h"

struct dictionary {
  int count;
  int max_count;
  char **English;
  char **Foreign;
  };

#include "Dictionary.h"

#define VALID_WORD(w)  assert(w!=NULL);assert(strlen(w)>0);

Dictionary ConsDictionary( int max_words ) {
/* Construct a new dictionary.
   Pre-cond: max_words > 0
   Post-cond: returns a newly constructed Dictionary 
               or
              NULL if insufficient memory
*/
  Dictionary d;
  assert( max_words > 0 );
  d = (Dictionary)malloc( sizeof( struct dictionary ) );
  if ( d != NULL ) {
    d->max_count = max_words;
    d->count = 0;
    d->English = (char **)malloc( max_words*sizeof( char * ) );
    d->Foreign = (char **)malloc( max_words*sizeof( char * ) );
    }
  else {
    printf("ConsDictionary: insuff space\n");
    }
  return d;
  }

int DeleteDictionary( Dictionary d ) {
/* Delete a dictionary.
   Pre-cond: d is a valid Dictionary
   Post-cond: space used by d has been freed
              returns TRUE if no errors, FALSE on error
*/
  assert( d != NULL );
  assert( d->English != NULL );
  assert( d->Foreign != NULL );
  free( d->English );
  free( d->Foreign );
  free( d );
  }

int WordCount( Dictionary d ) {
/* Count words in the dictionary
   Pre-cond: d is a valid Dictionary
   Post-cond: returns count of words currently in Dictionary
*/
  assert( d != NULL );
  return d->count;
  }

int AddTranslation( Dictionary d, char *lang1, char *lang2 ) {
/* Add a new translation to the dictionary
   Neither lang1 nor lang2 may be in the dictionary already
   Pre-cond: d is a valid Dictionary and
             lang1 != NULL and strlen( lang1 ) > 0 and
             lang2 != NULL and strlen( lang2 ) > 0 and
             FindForeign( d, lang1 ) == NULL and
             FindEnglish( d, lang2 ) == NULL
   Post-cond: WordCount( d ) = old WordCount( d ) + 1 and
              strcmp( FindForeign( d, lang1 ), lang2 ) == 0 and
              strcmp( FindEnglish( d, lang2 ), lang1 ) == 0 
*/
  assert( d != NULL );
  VALID_WORD( lang1 );
  VALID_WORD( lang2 );
  assert( FindForeign( d, lang1 ) == NULL );
  assert( FindEnglish( d, lang2 ) == NULL );

  d->English[d->count] = strdup( lang1 );
  d->Foreign[d->count] = strdup( lang2 );
  d->count++;
  return TRUE;
  }
   
int ReplaceTranslation( Dictionary d, char *lang1, char *lang2 ) {
/* Replace an existing translation in the dictionary
   lang1 must be in the dictionary already
   lang2 must not be in the dictionary already
   Pre-cond: d is a valid Dictionary and
             lang1 != NULL and strlen( lang1 ) > 0 and
             lang2 != NULL and strlen( lang2 ) > 0 and
             FindForeign( d, lang1 ) != NULL and
             FindEnglish( d, lang2 ) == NULL
   Post-cond: WordCount( d ) = old WordCount( d ) + 1 and
              strcmp( FindForeign( d, lang1 ), lang2 ) == 0 and
              strcmp( FindEnglish( d, lang2 ), lang1 ) == 0 
*/
  int i;
  assert( d != NULL );
  VALID_WORD( lang1 );
  VALID_WORD( lang2 );
  assert( FindForeign( d, lang1 ) != NULL );
  assert( FindEnglish( d, lang2 ) == NULL );
  for( i=0; i<d->count; i++ ) {
    if ( strcmp( d->English[i], lang1 ) == 0 ) {
      free( d->English[i] );
      d->English[i] = strdup( lang1 );
      return TRUE;
      }
    }
  return FALSE;
  }

char *FindForeign( Dictionary d, char *word ) {
  int i;
  assert( d != NULL );
  VALID_WORD( word );
  for( i=0; i<d->count; i++ ) {
    if ( strcmp( d->English[i], word ) == 0 ) {
      return d->Foreign[i];
      }
    }
  return NULL;
  }

char *FindEnglish( Dictionary d, char *word ) {
  int i;
  assert( d != NULL );
  VALID_WORD( word );
  for( i=0; i<d->count; i++ ) {
    if ( strcmp( d->Foreign[i], word ) == 0 ) {
      return d->English[i];
      }
    }
  return NULL;
  }