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

#include "memory.h"
#include "object.h"
#include "table.h"
#include "value.h"
#include "vm.h"

#define ALLOCATE_OBJ(type, objectType) \
(type*)allocateObject(sizeof(type), objectType)

static Obj* allocateObject(size_t size, ObjType type) {
  Obj* object = (Obj*) reallocate(NULL, 0, size);
  object->type = type;

  object->next = vm.objects;
  vm.objects = object;
  return object;
}

static ObjString* allocateString(char* chars, int length, uint32_t hash) {
  ObjString* string = ALLOCATE_OBJ(ObjString, OBJ_STRING);
  string->length = length;
  string->chars = chars;
  string->hash = hash;

  tableSet(&vm.strings, OBJ_VAL(string), NIL_VAL);

  return string;
}

static uint32_t hashString(const char* key, int length) {
  uint32_t hash = 2166136261u;

  for (int i = 0; i < length; i++) {
    hash ^= key[i];
    hash *= 16777619;
  }

  return hash;
}

ObjArray* takeArray(ValueArray* valArray) {
  ObjArray* array = ALLOCATE_OBJ(ObjArray, OBJ_ARRAY);
  array->array = valArray;
  return array;
}

ObjHash* takeHash(Table* hashTable) {
  ObjHash* hash = ALLOCATE_OBJ(ObjHash, OBJ_HASH);
  hash->hashTable = hashTable;
  return hash;
}


ObjString* takeString(char* chars, int length) {
  uint32_t hash = hashString(chars, length);
  return allocateString(chars, length, hash);
}

ObjString* copyString(const char* chars, int length) {
  uint32_t hash = hashString(chars, length);
  ObjString* interned = tableFindString(&vm.strings, chars, length, hash);
  if (interned != NULL) return interned;

  char* heapChars = ALLOCATE(char, length + 1);
  memcpy(heapChars, chars, length);
  heapChars[length] = '\0';

  return allocateString(heapChars, length, hash);
}

void printObject(Value value) {
  switch (OBJ_TYPE(value)) {
  case OBJ_STRING:
    printf("%s", AS_CSTRING(value));
    break;
  case OBJ_ARRAY:
    printf("[");
    ValueArray* array=AS_VARRAY(value);
    for (int i=0;i<array->count;i++) {
      printValue(array->values[i]);
      if (i<(array->count-1)) {
        printf(", ");
      }
    }
    printf("]");
    break;
  case OBJ_HASH:
    printf("{");
    Table* hash=AS_HASH(value);
    Entry** entries=getEntries(hash);
    for (int i=0;entries[i]!=NULL;i++) {
      Entry* entry=entries[i];
      printValue(entry->key);
      printf("=>");
      printValue(entry->value);
      if (entries[i+1]!=NULL) {
        printf(", ");
      }
    }
    printf("}");
    break;
  }
}