#include <stdio.h>  // printf()
#include <stdlib.h> // malloc() free()
#include <string.h> // memset()

#include "../defines.h"
#include "../logger/logger.h"
#include "zone.h"

typedef struct ZoneHeader {
  u64 capacity;
  u64 cur_size;
} ZoneHeader;

Zone *zoneCreate(size_t sizeBytes) {
  // First we need to get a block of memory from the OS
  // This block needs to include the size of what we want to store
  // plus the size of our ZoneHeader
  void *mem_block = malloc(sizeBytes + sizeof(ZoneHeader));

  // Now that we have the block let's get the addresses
  // for where the header is, and the offset where the data starts
  ZoneHeader *zone_header = (ZoneHeader *)mem_block;
  Zone *zone_addr = (Zone *)(zone_header + sizeof(ZoneHeader));

  // Initialize the values of the header
  zone_header->capacity = sizeBytes;
  zone_header->cur_size = 0;

  return zone_addr;
}

void *zoneAlloc(Zone *zone, size_t sizeBytes) {
  ZoneHeader *zone_header = (ZoneHeader *)zone - sizeof(ZoneHeader);

  if (zone_header->cur_size + sizeBytes > zone_header->capacity) {
    QERROR("Could not allocate, not enough space.");
    return NULL;
  }

  void *new_mem = (char *)zone + zone_header->cur_size;

  zone_header->cur_size += sizeBytes;

  printf("Zone Header Information:\n");
  printf("Current Size: %" PRIu64 "\n", zone_header->cur_size);
  printf("Total Capacity: %" PRIu64 "\n", zone_header->capacity);

  return new_mem;
}

void zoneFree(void *data, size_t dataSize) {
  // TODO: We want to eventually pass in a pointer to the zone so we can track
  // our free blocks

  // Lets first check to make sure we weren't given a NULL pointer
  if (data == NULL)
    return;

  // First we need to set the memory starting at `data` and going to `dataSize`
  // to 0
  memset(data, 0, dataSize);

  // Now we need to null the pointer
  data = NULL;

  // TODO: Add logic to alert that this space can now be used
}

void zoneClear(Zone *zone) {
  ZoneHeader *zone_header = (ZoneHeader *)zone - sizeof(ZoneHeader);

  zone_header->cur_size = 0;

  printf("Zone Header Information:\n");
  printf("Current Size: %" PRIu64 "\n", zone_header->cur_size);
  printf("Total Capacity: %" PRIu64 "\n", zone_header->capacity);
}

void zoneDestroy(Zone *zone) {
  // First we need to go back to the beginning of the header as we returned
  // an offset for the user to use
  void *del_mem = (ZoneHeader *)zone - sizeof(ZoneHeader);

  // Free the memory
  free(del_mem);
}