#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include "pig_latin.h"

static int is_vowel(char c) {
    return c=='a' || c=='e' || c=='i' || c=='o' || c=='u';
}

static int is_consonant(char c) {
    return c >= 'a' && c <= 'z' && !is_vowel(c);
}

static void translate_word(const char *word, char *buf) {
    int len = (int)strlen(word);

    if (is_vowel(word[0]) ||
        (len >= 2 && word[0]=='x' && word[1]=='r') ||
        (len >= 2 && word[0]=='y' && word[1]=='t')) {
        sprintf(buf, "%say", word);
        return;
    }

    int i = 0;
    while (i < len && is_consonant(word[i]) && word[i] != 'y') {
        if (word[i] == 'q' && i + 1 < len && word[i+1] == 'u') break;
        i++;
    }

    int split;

    if (i < len - 1 && word[i] == 'q' && word[i+1] == 'u') {
        split = i + 2;
    }
    else if (i > 0 && i < len && word[i] == 'y') {
        split = i;
    }
    else {
        split = i > 0 ? i : 1;
    }

    strncpy(buf, word + split, len - split);
    buf[len - split] = '\0';
    strncat(buf, word, split);
    strcat(buf, "ay");
}

char *translate(const char *phrase) {
    if (!phrase) return NULL;

    int plen = (int)strlen(phrase);
    char *result = malloc(plen * 2 + 16);
    if (!result) return NULL;
    result[0] = '\0';

    char *copy = malloc(plen + 1);
    strcpy(copy, phrase);
    
    char word_buf[512];
    int first = 1;
    char *token = strtok(copy, " ");
    while (token != NULL) {
        translate_word(token, word_buf);
        if (!first) strcat(result, " ");
        strcat(result, word_buf);
        first = 0;
        token = strtok(NULL, " ");
    }

    free(copy);
    return result;
}