#include <pcre2.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "logger.h"
#include "utils.h"

int regex_match(const char *subject, str_array_t patterns,
                str_array_t *results) {
  pcre2_code *re;

  int errornumber;
  int rc = PCRE2_ERROR_NOMATCH;

  PCRE2_SIZE subject_len = strlen(subject);
  PCRE2_SIZE offset = 0, erroroffset;
  PCRE2_SIZE *ovector;

  pcre2_match_data *match_data;
  for (unsigned short i = 0; i < patterns.n; i++) {
    DEBUG_PRINT("Gets pattern: %s\n", patterns.str[i]);
    re = pcre2_compile((PCRE2_SPTR)patterns.str[i], PCRE2_ZERO_TERMINATED, 0,
                       &errornumber, &erroroffset, NULL);

    if (re == NULL) {
      PCRE2_UCHAR buffer[256];
      pcre2_get_error_message(errornumber, buffer, sizeof(buffer));
      LOG("PCRE2", "compilation failed at offset %d: %s\n", (int)erroroffset,
          buffer);
      return 1;
    }

    match_data = pcre2_match_data_create_from_pattern(re, NULL);

    unsigned char i = 0;
    while (offset < subject_len &&
           (rc = pcre2_match(re, (PCRE2_SPTR)subject, (PCRE2_SIZE)subject_len,
                             offset, 0, match_data, NULL)) > 0) {

      // results->str = realloc(results->str, sizeof(char *) * (rc +
      // results->n));
      resize_str_array(results, rc + i);

      ovector = pcre2_get_ovector_pointer(match_data);
      DEBUG_PRINT("Get %d captures.\n", rc - 1);
      DEBUG_PRINT("Match succeeded at offset %d.\n", (int)ovector[0]);

      for (unsigned short j = 1; j < rc; j++) {
        PCRE2_SIZE substring_length = ovector[2 * j + 1] - ovector[2 * j];
        PCRE2_SPTR substring = (PCRE2_SPTR)subject + ovector[2 * j];
        /* Here we need to manually control the str array,
         * as PCRE2_SPTR == const unsigned char
         * (which cannot be directly casted) */
        results->str[j] = malloc(substring_length + 1);
        sprintf(results->str[j], "%.*s", (int)substring_length, substring);
        DEBUG_PRINT("index: %2d, substring_length: %d\n", j,
                    (int)substring_length);
      }
      offset = ovector[1];
      DEBUG_PRINT("offset: %zu, subject_len: %zu\n", offset, subject_len);
      i++;
    }
    pcre2_match_data_free(match_data);
    pcre2_code_free(re);
    if (rc <= 0) {

      switch (rc) {
      case PCRE2_ERROR_NOMATCH:
        DEBUG_PRINT("No match found.\n");
        return 0;
        break;
      case 0:
        LOG("PCRE2",
            "ovector was not big enough for all the captured substrings\n");
        break;
      default:
        LOG("PCRE2", "Matching error %d\n", rc);
        return 1;
      }
    }
  }
  return 0;
}

int repchr(char *str, char t, char r) {
  int c = 0;
  for (size_t i = 0; str[i] != '\0'; i++) {
    if (str[i] == t) {
      str[i] = r;
      c++;
    }
  }
  return c;
}

generic_array_t create_array(size_t elem_size, size_t n) {
  generic_array_t array;
  array.data = n ? malloc(elem_size * n) : NULL;
  array.elem_size = elem_size;
  array.n = n;
  return array;
}

void free_array(generic_array_t *array) {
  free_and_nullify(array->data);
  array->n = 0;
}

void resize_array(generic_array_t *array, size_t new_size) {
  array->data = realloc(array->data, array->elem_size * new_size);
  array->n = new_size;
}

void *get_element(generic_array_t *array, size_t index) {
  if (index >= array->n) {
    return NULL; // Out of bounds
  }
  return (char *)array->data + index * array->elem_size;
}

/* A more specific impl, specially for string (char *) */

str_array_t create_str_array(size_t n) {
  str_array_t array;
  array.str = n ? malloc(n * sizeof(char *)) : NULL;
  array.n = n;
  for (size_t i = 0; i < n; i++) {
    array.str[i] = NULL;
  }
  return array;
}

void free_str_array(str_array_t *array) {
  for (size_t i = 0; i < array->n; i++) {
    free(array->str[i]);
  }
  free_and_nullify(array->str);
  array->n = 0;
}

void resize_str_array(str_array_t *array, size_t new_size) {
  array->str = realloc(array->str, sizeof(char *) * new_size);
  for (size_t i = array->n; i < new_size; i++) {
    array->str[i] = NULL;
  }
  array->n = new_size;
}

int set_str_element(str_array_t *array, size_t index, const char *value) {
  if (index >= array->n) {
    return 1; // Out of bounds
  }
  array->str[index] = malloc(strlen(value) + 1);
  strcpy(array->str[index], value);
  return 0;
}

const char *get_str_element(str_array_t *array, size_t index) {
  if (index >= array->n) {
    return NULL; // Out of bounds
  }
  return array->str[index];
}

queue_t create_queue(void) {
  queue_t queue;
  queue.front = queue.rear = NULL;
  return queue;
}

int is_empty_queue(queue_t *queue) { return queue->front == NULL; }

void enqueue(queue_t *queue, data_t data) {
  node_t *node = malloc(sizeof(node_t));
  node->data = data;
  node->next = NULL;
  if (queue->rear == NULL) {
    queue->rear = queue->front = node;
  } else {
    queue->rear->next = node;
    queue->rear = node;
  }
}

data_t dequeue(queue_t *queue) {
  if (is_empty_queue(queue)) {
    DEBUG_PRINT("Queue is empty.\n");
    return NULL;
  }

  node_t *temp = queue->front;
  data_t data = temp->data;
  queue->front = temp->next;
  free_and_nullify(temp);

  if (queue->front == NULL) {
    queue->rear = NULL;
  }

  return data;
}

void free_queue(queue_t *queue) {
  while (!is_empty_queue(queue)) {
    dequeue(queue);
  }
}

void free_and_nullify(void *p) {
  if (p) {
    free(p);
    p = NULL;
  }
}