#include <pgpl.h>
#include <stdlib.h>
#include <string.h>

/* TODO: Further test this file. */

struct PGPL_Vector {
  void *data;
  uint32_t data_size;
  uint32_t length;
  uint32_t allocated;
  void *last_delete;
};

#define pgpl_vector_internal_conditional_resize(vector)                        \
  if (vector->length > vector->allocated) {                                    \
    vector->allocated *= 2;                                                    \
    vector->data =                                                             \
        realloc(vector->data, vector->allocated * vector->data_size);          \
  }

#define pgpl_vector_internal_memcpy_offset(vector, i)                          \
  (char *)vector->data + (vector->data_size * (i))

PGPL_Vector *pgpl_vector_create(uint32_t data_size) {
  PGPL_Vector *vector = malloc(sizeof(*vector));
  vector->data_size = data_size;
  vector->allocated = 1;
  vector->length = 0;
  vector->last_delete = malloc(vector->data_size);
  vector->data = malloc(vector->allocated * vector->data_size);
  return vector;
}

void pgpl_vector_destroy(PGPL_Vector *vector) {
  free(vector->data);
  free(vector->last_delete);
  free(vector);
}

void pgpl_vector_push_back(PGPL_Vector *vector, void *data) {
  vector->length++;
  pgpl_vector_internal_conditional_resize(vector);
  memcpy(pgpl_vector_internal_memcpy_offset(vector, vector->length - 1), data,
         vector->data_size);
}

void pgpl_vector_push_front(PGPL_Vector *vector, void *data) {
  vector->length++;
  pgpl_vector_internal_conditional_resize(vector);
  memmove(pgpl_vector_internal_memcpy_offset(vector, 1), vector->data,
          vector->data_size * vector->length);
  memcpy(vector->data, data, vector->data_size);
}

void *pgpl_vector_pop_back(PGPL_Vector *vector) {
  memcpy(vector->last_delete,
         pgpl_vector_internal_memcpy_offset(vector, vector->length - 1),
         vector->data_size);

  vector->length--;

  return vector->last_delete;
}

void *pgpl_vector_pop_front(PGPL_Vector *vector) {
  memcpy(vector->last_delete, vector->data, vector->data_size);
  vector->length--;
  memmove(vector->data, pgpl_vector_internal_memcpy_offset(vector, 1),
          vector->data_size * vector->length);
  return vector->last_delete;
}

void *pgpl_vector_peek_back(PGPL_Vector *vector) {
  return pgpl_vector_internal_memcpy_offset(vector, vector->length - 1);
}

void *pgpl_vector_peek_front(PGPL_Vector *vector) { return vector->data; }

void *pgpl_vector_delete_index(PGPL_Vector *vector, uint32_t index) {
  memcpy(vector->last_delete, pgpl_vector_internal_memcpy_offset(vector, index),
         vector->data_size);
  memmove(pgpl_vector_internal_memcpy_offset(vector, index),
          pgpl_vector_internal_memcpy_offset(vector, index + 1),
          vector->data_size * (vector->length - index - 1));
  vector->length--;
  return vector->last_delete;
}

void pgpl_vector_insert_after_index(PGPL_Vector *vector, uint32_t index,
                                    void *data) {
  vector->length++;
  pgpl_vector_internal_conditional_resize(vector);
  memmove(pgpl_vector_internal_memcpy_offset(vector, index + 2),
          pgpl_vector_internal_memcpy_offset(vector, index + 1),
          vector->data_size * (vector->length - index - 2));
  memcpy(pgpl_vector_internal_memcpy_offset(vector, index + 1), data,
         vector->data_size);
}

void *pgpl_vector_get_index(PGPL_Vector *vector, uint32_t index) {
  return pgpl_vector_internal_memcpy_offset(vector, index);
}

uint32_t pgpl_vector_get_length(PGPL_Vector *vector) { return vector->length; }