Collab_RPG/src/events.c

#include <stdlib.h>
#include <string.h>
#include "events.h"

void events_init_handler(EventHandler *handler) {
    handler->vars = 0;
}

int events_bind_variable(EventHandler *handler, int *var, char *name) {
    if(handler->vars < MAX_VARIABLES){
        handler->variables[handler->vars] = var;
        handler->var_names[handler->vars++] = name;
    }else{
        return 1;
    }
    return 0;
}

char op_chars[OP_AMOUNT+1] = " =+-/*%";

int _op_null(int a, int b) {
    return 0;
}

int _op_set(int a, int b) {
    return b;
}

int _op_add(int a, int b) {
    return a+b;
}

int _op_sub(int a, int b) {
    return a-b;
}

int _op_div(int a, int b) {
    if(b == 0) return 0;
    return a/b;
}

int _op_mul(int a, int b) {
    return a*b;
}

int _op_mod(int a, int b) {
    if(b == 0) return 0;
    return a%b;
}

int (*_operations[OP_AMOUNT])(int, int) = {
    _op_null,
    _op_set,
    _op_add,
    _op_sub,
    _op_div,
    _op_mul,
    _op_mod
};

char _message_buffer[MESSAGE_BUFFER_SZ];
char *events_parse_string(EventHandler *handler, char *message) {
    char *message_ptr = _message_buffer;
    char in_op = message[0] == '`';
    char *token;
    int *var;
    unsigned int n, i;
    size_t len;
    char *sign;
    size_t left;
    size_t size;
    if(!strlen(message)) return message;
    for(token=strtok(message,"`");token!=NULL;in_op=!in_op,
                                              token=strtok(NULL,"`")){
        len = strlen(token);
        if(in_op && len){
            sign = NULL;
            for(n=0;sign==NULL&&n<OP_AMOUNT;n++,sign=strchr(token,op_chars[n]));
            if(sign != NULL){
                var = NULL;
                for(i=0;i<handler->vars;i++){
                    if(!strncmp(token+1, handler->var_names[i], sign-token-1)){
                        var = handler->variables[i];
                        break;
                    }
                }
                if(var){
                    *var = _operations[n](*var, atoi(sign+1));
                }
            }
        }else{
            left = (_message_buffer+MESSAGE_BUFFER_SZ)-message_ptr;
            size = len < left ? len : left;
            memcpy(message_ptr, token, size);
            message_ptr += size;
        }
    }
    *message_ptr = '\0';
    return _message_buffer;
}