///\file proiect.c
///\brief C Text editor library
///
/// Created by Badea Elena-Delia
/// Implements functions for determinating if a word is present in a document, determinating the number of occurrences for a word in a document, replacing all instances of a word in a document with another given word, replacing specific instances of a word in a document with another given word, creating a sorted list of words by the number of occurrences in a document.

#include<stdlib.h>
#include<string.h>
#include<stdio.h>
#include<malloc.h>

///The variables ok and current_number are declared and initialized outside the functions
int ok = 0 ;
int current_number = 0;

int word(char given_word[256], char text_from_file[256])
{
    ///\fn word(char given_word[256], char text_from_file[256])
    ///\brief This function is used to determinate if a word is present in a document, but it also counts the number of occurences of that word
    ///\param given_word The word we are looking for
    ///\param text_from_file The text from our file

    char *cuv;

    ///We start by dividing the text into words, using the strtok function
    cuv = strtok(text_from_file, " ,.!?;");

    while(cuv)
    {
        if(strcmp(given_word, cuv)==0)
        {
            ///Every time we found the word, we increment the variable ok
            ok++;
        }
        cuv = strtok(NULL," ,.!?;" );
    }


    ///We return the number of appearences
    return ok;

}

char *replace(const char *s, const char *old, const char *new)
{
    ///\fn char *replace(const char *s, const char *old, const char *new)
    ///\brief This function is used to replace every all instances of a word in our file with another one
    ///\param s The text where we are looking for the word and we replace it
    ///\param old The word we want to be replaced
    ///\param new The word we want to replace with

    char *ret;
    int i, count = 0;
    ///The lenght of the new word
    size_t newlen = strlen(new);
    ///The lenght of the old word (the word we want to replace)
    size_t oldlen = strlen(old);

    for (i = 0; s[i] != '\0'; i++)
        {
            ///We go through the text and we are looking for our word
            if (strstr(&s[i], old) == &s[i])
                {
                    ///When we found the word, we increase the paramer count, used when we allocate memory for the new word
                    count++;
                    i += oldlen - 1;
                }
        }

    ///We allocate memory for the new word
    ret = malloc(i + count * (newlen - oldlen));

    if (ret == NULL)
    {
        exit(EXIT_FAILURE);
    }

    i = 0;
    while (*s)
    {
        if (strstr(s, old) == s)
        {
            ///Here, the replacing is made, using the function strcpy, as long as we found the word in the text
            strcpy(&ret[i], new);
            i += newlen;
            s += oldlen;
            }
            else
            {
                ret[i++] = *s++;
                }
    }

    ret[i] = '\0';

    return ret;
}

void new_word(FILE *f_2, char given_word[256], char rpwrd[256], char text_from_file[256])
{
    ///\fn new_word(FILE *f_2, char given_word[256], char rpwrd[256], char text_from_file[256])
    ///\brief In this function we call the function replace and we replace the given word with another word in our text
    ///To do this, first we copy the text from the file in a variable, named here text_2. We do this because our text suffers changes and it can produce some errord to other functions
    ///Then we copy, using strcpy, in the text_2, the new text (made by calling the function replace) and after that we printf it in the file.
    ///\param f_2 Pointer to the file where we print the new text
    ///\param given_word The word we want to be replace
    ///\param rpwrd The word that we want to replace the given_word with
    ///\param text_from_file The text from our file

    char text_2[256];

    strcpy(text_2, text_from_file);
    strcpy(text_2,replace(text_2, given_word, rpwrd) );
    fprintf(f_2, "%s" ,text_2);


}

char *replace_one_word(const char *s, const char *old, const char *new, int word_number)
{
    ///\fn char *replace_one_word(const char *s, const char *old, const char *new, int word_number)
    ///\brief This function is like the function replace, but here, we replace only a specific instances of a word with another given word
    ///To do this, we count the appearences of the word and we replace only the specific inatance
    ///\param s The text
    ///\param old The word we want to be replaced
    ///\param new The word we want to replace with
    ///\param word_number The number of the appearance of the word that we want to replace

    char *ret;
    int i, count = 0;

    size_t newlen = strlen(new);
    size_t oldlen = strlen(old);


    for (i = 0; s[i] != '\0'; i++)
        {
            if (strstr(&s[i], old) == &s[i])
                {
                    count++;
                    i += oldlen - 1;
                }
        }

    ret = malloc(i + (newlen - oldlen));

    if (ret == NULL)
    {
        exit(EXIT_FAILURE);
    }

    i = 0;
    while (*s)
    {
        if (strstr(s, old) == s )
        {
            current_number++;
            if(current_number == word_number)
            {
                ///We only replace the word when we are on the word_number-th appearence
                strcpy(&ret[i], new);
                i += newlen;
                s += oldlen;
            }
            else{ret[i++] = *s++;}

        }
            else
            {
                ret[i++] = *s++;
                }
    }

    ret[i] = '\0';

    return ret;
}

void replace_a_word(FILE *f, char given_word[256], char rpwrd[256], char text_from_file[256], int nr)
{
    ///\fn replace_a_word(FILE *f, char given_word[256], char rpwrd[256], char text_from_file[256], int nr)
    ///\brief This function is used to replace a specific instance of a word with another given one
    ///To do this, we copy, using the function strcpy, our text from the file in the variable text, and then, using the function replace_one_word, we copy in variable text the new text obtained by calling the function replace_one_word
    ///Then we print the new text in the file.
    ///\param f Pointer to the file
    ///\param given_word The word we want to be replace
    ///\param rpwrd The word that we want to replace the given_word with
    ///\param text_from_file The text from our file
    ///\param nr The number of the appearence of the word we want to replace

    char text[256];
    strcpy(text, text_from_file);
    strcpy(text,replace_one_word(text, given_word, rpwrd, nr) );
    fprintf(f, "%s" ,text);


}

void sort(int *a[100], int *b[100], int n)
{   ///\fn void sort(int a[100], char *b[100])
    ///\brief This function is used to sort the two arrays, based on array a
    ///\param a A random array
    ///\param b A random array of strings

    int i,j, aux_a, aux_b;

    for(i=0; i<n; i++)
    {
        for(j=0; j<n; j++)
        {
            if(a[i] > a[j])
            {
                aux_a = a[i]; ///Interchange in a
                a[i] = a[j];
                a[j] = aux_a;
                aux_b = b[i];
                b[i] = b[j];
                b[j] = aux_b;
            }
        }
    }
}


void cuv(FILE *f)
{   ///\fn void cuv(FILE *f)
    ///\brief This function is used to list the words from the file sorted by the number of their occurences in the text
    ///\param f File pointer
    int lenght = 0, occure[100], i , j, freq[100], k , ok;
    char *words, text[256], *words_array[256], *list[256];

    while(!(feof(f)))
    {
        fgets(text, sizeof(text),f);
        words = strtok(text, " ,.!?;\n\r\t");

        while(words)
        {
            words_array[lenght] =(char*)calloc(words, sizeof(words) + 1); ///store the words into an string array
            strcat(words_array[lenght], words);
            lenght++;
            words = strtok(NULL," ,.!?;\n\r\t" );
        }
    }
    for(i=0;i<lenght;i++)
    {   k=0;
        for(j=0;j<lenght;j++)
        {
            if(strcmp(words_array[i], words_array[j]) == 0)
            {
                occure[i] = k+1; ///count the appearences
                k++;
            }

        }
        freq[i] = i; ///memorize the position

    }

    sort(occure, freq, lenght);
    j = 0 ;
    printf("List of words: ");
    ok = 0;
    while(j<lenght)
    {
            printf("%s ", words_array[freq[j]]); ///We print the words sorted by their number of occurence
            j++;

    }
}