//#define FOUND 0

//#define 3

//#define 4

/*

lookup value (key, value)

add pair (key, value)

change value (key, value)

remove pair (key)

*/

#include "db.h"

//--------------------------------------------------

//

// GET VALUE FROM GENERAL DATABASE

//

// inputs

// key, value

//

// returns

// 0 if ,

//

// 1) opens the database

// 2) gets a line

// 3) extracts the key

// 4) checks the value to see if it's the one we're looking for

int db_lookup(char*target_key, char*db_value){

FILE *general;

int linepos;

char *status;

char line[80];

char db_key[60];

// open general knowlege database

general = fopen("general.txt","r");

if(general == NULL) return CANT_OPEN_FILE;

// search for key

while(1){

// get a line

status = fgets(line,80,general);

if (status==0){

fclose(general);

return NOT_FOUND;

}

// get the key

linepos = copy_to_delimiter(line, db_key, ':');

// is it the key we're looking for?

// if not, get another line

if(strcmp(target_key, db_key) != 0) continue;

break;

} // end of key search

// get value

db_copy_word(line, linepos, db_value);

fclose(general);

return FOUND; // (found)

}

//-------------------------------------------------------------------

//

// example: db_add_pair("grass > color","green");

//

//

int db_add_pair(char*key, char*value){

FILE *general;

//open

general = fopen("general.txt","a");

if(general == NULL) {printf("fopen failed while trying to open general.txt");}

//add key and value

fprintf(general, "%s:%s\n", key, value);

// close

fclose(general);

return 1;

}

//--------------------------------

// returns

// 0 if not found

// id number if found

//

int db_get_id(char* firstname)

{

int i;

char id_string[20];

char db_name[20];

char string[20];

char key[80];

int result;

for(i=1; i<100; i++)

{

// look up name, retreive id

// make id_string

// strcpy(id_string,"#");

// itoa(i, string,10); // integer to string. integer, string, base

// strcat(id_string, string );

sprintf(clipboard, "#%d", i); // make id string

//printf("D119");

// make key

sprintf(key, "%s > firstname", clipboard);

//printf("D122");

result = db_lookup(key, db_name);

//printf("D124");

if(result == 0)continue;

if(strcmp(db_name, firstname) == 0){

return i;

}

}

return 0; // not in the database

}

//--------------------------------------------------------

//

// looks for the specified key and changes its value

//

//

int db_change_value(char*key, char*value){

FILE *general;

FILE *temp;

char *status;

char line[80];

char db_key[60];

//open files

general = fopen("general.txt","r");

if(general == NULL) {

printf("DB: can't open general.txt");

return 2;

}

temp = fopen("temp.txt","w");

if(temp == NULL) {

printf("DB: can't open temp.txt");

fclose(general);

return 2;

}

// search for a key, copy each line

while(1){

// get a line

status = fgets(line,80,general);

if (status==0){

fclose(general);

fclose(temp);

return 1; //(key not found)

}

db_copy_word(line,1, db_key);

// is it the key we're looking for?

// if not, get another line

if(strcmp(key, db_key)==0) {

fprintf(temp, "%s", line); // copy line to temp file

break;

}

} // end of subject search

//add key and value

fprintf(temp, "%s: %s\n", key, value);

// copy remainder of file

// fprintf(temp, "%s", line); // copy line to temp file

while(1){

// get another line

status = fgets(line,80,general);

if (status==0) break;

fprintf(temp, "%s", line); // copy line to temp file

}

// close

fclose(general);

fclose(temp);

if(remove("general.txt") != 0) {printf("oops, file error ""%s"" \n", strerror(1));}

if(rename("temp.txt","general.txt") != 0) {printf("file error ""%s"" \n", strerror(1));}

return 0; // (success)

}

//--------------------------------------------------------

int db_next_available_id(void){

int i;

char value[20];

char string[20];

int result;

char key[20];

char id_string[20];

for(i=1; i<100; i++){

// look for id, first_name

//printf("I: %d", i);

//strcpy(clipboard, "#"); printf("N220");

//itoa(i, string,10);

//strcat(clipboard, string);

sprintf(clipboard, "#%d", i); // make id string

strcpy(key, clipboard);

strcat(key, " > class");

//strcpy(key,"#");

//strcat(key, id_string);

//strcat(key, " > class");

result = db_lookup(key,value);

if(result != FOUND){

// printf("%d, %s ", i, id_string);

//sscanf(id_string, "%d", i);

//strcpy();

//printf(" S: %s", id_string);

return i;

}

// printf("N245");

}

printf("error in function DNAI");

return 0;

}

//----------------------------------------------------------

//

//

//

//

//

int db_copy_word(char* line, int position, char* value)

{

int i;

for(i=0; i<MAX_LETTERS-2; i++)

{

//skip over leading spaces and tabs

if(line[position]==' ') position++;

if(line[position]==' ') position++;

if(line[position]==' ') position++;

if(line[position]=='\t') position++;

if(line[position]=='\t') position++;

if(line[position]=='\t') position++;

if ((isalpha(line[position])==0) && (isdigit(line[position])==0))

{

value[i]=0;

return position;

}

else

{

value[i]=line[position];

position++;

}

}

return position;

}

//------------------------------

//

// COPIES A STRING UP TO THE DELIMITER

//

// parameters: from, to

//

// returns: the position after the delimiter

//

// usualy the copy then gets compared to a key that's being searched for

//

int copy_to_delimiter(char* from, char* to, char delimiter){

int i;

for(i=0; i<80; i++){

if (from[i] == delimiter){

to[i] = NULL; //

return i + 1;

}

else{

to[i] = from[i];

//i++;

}

}

return i;

}

//-----------------------------------------------------------------------

//

// ex: is cat a creature?

// db_root_check("cat", "creature");

//

int db_root_check(char* startingwith, char* lookingfor){

// animal creature

int result;

int n;

char subject[60];

char key[60];

char value[20];

strcpy(subject, startingwith);

for(n=0; n<5; n++){

strcpy(key, subject); // prepare to lookup

strcat(key," > class"); // prepare to lookup

result = db_lookup(key, value); // lookup

//printf("\nSW:%s LF:%s SUB:%s K:%s V:%s R:%d ", startingwith, lookingfor, subject, key, value, result);

if(result == NOT_FOUND) return NOT_FOUND; // if not in database at all, exit

if(strcmp(value,lookingfor)==0)return FOUND; // is it what we're looking for?

// if(strcmp(value,"root")==0)return FOUND; // has it reached root?

if(strcmp(value,"root")==0)break; // has it reached root?

strcpy(subject,value); // if no luck so far, the value becomes the subject

}

return NOT_FOUND; // not found

}