#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <time.h>
#include <unistd.h>

typedef struct {
    char *content;
    double *weights;
} Node;

int main(int argc, char *argv[]) {
    // Count number of characters
    char cchar;
    int size = 0;
    FILE *fptr = fopen(argv[1], "r");
    if (fptr == NULL) {
        perror("Error opening file");
        return EXIT_FAILURE;
    }

    while ((cchar = fgetc(fptr)) != EOF) {
        size++;
    }
    fseek(fptr, 0, SEEK_SET); // Reset file pointer to the beginning

    // Load file
    char *raw_file = malloc(size + 1); // <\0>
    if (raw_file == NULL) {
        perror("Memory allocation failed");
        fclose(fptr);
        return EXIT_FAILURE;
    }

    fread(raw_file, 1, size, fptr);
    raw_file[size] = '\0';
    fclose(fptr);

    //for (int i = 0; i < size; i++) {
    //    if (ispunct((unsigned char) raw_file[i]) && !(raw_file[i] == '\'')) {
    //        raw_file[i] = ' ';
    //    }
    //}

    // Get nb of words
    int nb_words = 0;
    int longest = 0;
    int c_size = 0;

    for (int i = 0; i < size; i++) {
        if (isspace((unsigned char) raw_file[i]) || raw_file[i] == '\0') {
            if (c_size > 0) {
                nb_words++;
                if (c_size > longest) {
                    longest = c_size;
                }
                c_size = 0;
            }
        } else {
            c_size++;
        }
    }

    // Load words
    char **words = malloc(nb_words * sizeof(char *));
    if (words == NULL) {
        perror("Memory allocation failed");
        free(raw_file);
        return EXIT_FAILURE;
    }

    int word_index = 0;
    char *token = strtok(raw_file, " \n");
    while (token != NULL) {
        words[word_index] = malloc(strlen(token) + 1);
        if (words[word_index] == NULL) {
            perror("Memory allocation failed");
            free(raw_file);
            for (int j = 0; j < word_index; j++) {
                free(words[j]);
            }
            free(words);
            return EXIT_FAILURE;
        }
        strcpy(words[word_index], token);
        word_index++;
        token = strtok(NULL, " \n");
    }

    // Count unique words
    int *uni_i = calloc(nb_words, sizeof(int));
    if (uni_i == NULL) {
        perror("Memory allocation failed");
        free(raw_file);
        for (int j = 0; j < word_index; j++) {
            free(words[j]);
        }
        free(words);
        return EXIT_FAILURE;
    }

    int uni_word = 0;
    for (int i = 0; i < nb_words; i++) {
        if (uni_i[i] == 0) {
            uni_word++;
            uni_i[i] = uni_word;
            for (int l = i + 1; l < nb_words; l++) {
                if (strcmp(words[i], words[l]) == 0) {
                    uni_i[l] = uni_word;
                }
            }
        }
    }

    // Init nodes
    Node *nodes = malloc(uni_word * sizeof(Node));
    if (nodes == NULL) {
        perror("Memory allocation failed");
        free(raw_file);
        for (int j = 0; j < word_index; j++) {
            free(words[j]);
        }
        free(words);
        free(uni_i);
        return EXIT_FAILURE;
    }

    // Initialize nodes
    for (int i = 0; i < uni_word; i++) {
        nodes[i].content = NULL;
        nodes[i].weights = calloc(uni_word, sizeof(double));
        if (nodes[i].weights == NULL) {
            perror("Memory allocation failed");
            free(raw_file);
            for (int j = 0; j < word_index; j++) {
                free(words[j]);
            }
            free(words);
            free(uni_i);
            free(nodes);
            return EXIT_FAILURE;
        }
    }

    // Assign words to nodes
    for (int i = 0; i < nb_words - 1; i++) {
        int index = uni_i[i] - 1;
        if (nodes[index].content == NULL) {
            nodes[index].content = words[i];
        }
        nodes[index].weights[uni_i[i + 1] - 1]++;
    }

    for (int i = 0; i < uni_word; i++) {
        double total = 0;
        for (int l = 0; l < uni_word; l++) {
            total += nodes[i].weights[l];
        }
        if (total > 0) {
            for (int l = 0; l < uni_word; l++) {
                nodes[i].weights[l] /= total;
            }
        }
    }

    int stop = 0;
    unsigned int next_words;
    getentropy(&next_words, sizeof(next_words));
    next_words = (next_words % uni_word);
    printf("Starting node: %d\n", next_words);
    double *working_memory = malloc(uni_word * sizeof(double));
    int *context = malloc(50 * sizeof(int));

    if (working_memory == NULL || context == NULL) {
        fprintf(stderr, "Memory allocation failed\n");
        return EXIT_FAILURE;
    }

    printf("Total words: %d\n", nb_words);
    printf("Unique words: %d\n", uni_word);
    printf("Longest word length: %d\n", longest);

    while (stop < 100) {
        for (int i = 0; i < uni_word; i++) {
            working_memory[i] = 1.0;
        }

        context[stop] = next_words;
        printf("%s ", nodes[next_words].content);

        for (int i = 0; i <= stop; i++) {
            for (int l = 0; l < uni_word; l++) {
                working_memory[l] += nodes[context[i]].weights[l];
                if (context[i] == l){
                    working_memory[l] /= uni_word;
                }
            }
        }

        int max = 0;
        for (int i = 1; i < uni_word; i++) {
            if (working_memory[i] > working_memory[max]) {
                max = i;
            }
        }

        if(working_memory[max] <= 0.0){
            break;
        }
        next_words = max;
        stop++;
    }

    printf("\n");

    return 0;
}