#include "lib/lib.h"
#include "lib/vec.h"
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

DECL_VEC(CharVec, char);

CharVec readStdinToNewline() {
    CharVec cvec = CharVec_new(2);
    int ch;
    while (EOF != (ch = fgetc(stdin)) && ch != '\n') {
        CharVec_push(&cvec, ch);
    }
    return cvec;
}

bool pairedBraces(char open_brace, char close_brace) {
    if (open_brace == '\0')
        return true;

    int asciiDiff = 2;
    if (open_brace == '(' || open_brace == ')') {
        asciiDiff = 1;
    }
    return ((int)open_brace - ((int)close_brace - asciiDiff)) == 0;
}

bool checkCharVecBalance(CharVec *cvec) {
    int balance = 0;
    CharVec braceStack = CharVec_new(cvec->elem_count);
    char lastOpenBrace = '\0';
    while (cvec->elem_count != 0) {
        char val = CharVec_first(cvec);
        switch (val) {
        case '(':
        case '[':
        case '{':
            CharVec_push(&braceStack, val);
            balance++;
            break;
        case ')':
        case ']':
        case '}':
            if (!pairedBraces(CharVec_pop(&braceStack), val))
                return 0;
            balance--;
            break;
        }
    }
    if (balance == 0) {
        return -1;
    } else {
        return cvec->elem_count;
    }
}

int main() {
    print_header();
    printf("Enter Expression: ");
    CharVec cvec = readStdinToNewline();
    char *input = malloc(cvec.elem_count + 1);
    strcpy(input, cvec.data);

    if (checkCharVecBalance(&cvec)) {
        printf("It's balanced (^_^)\n");
        return EXIT_SUCCESS;
    } else {
        printf("It's Not Balanced (0_0)\n");
        return EXIT_FAILURE;
    }
}