#ifndef FZL_WALKER_H
#define FZL_WALKER_H

#include <common/fzl_opcodes.h>
#include <common/fzl_types.h>
#include <compiler/fzl_parser.h>
#include <compiler/utils/fzl_const_pool.h>
#include <compiler/utils/fzl_ctable.h>
#include <compiler/utils/fzl_symtable.h>
#include <stdbool.h>
#include <stddef.h>

// Type of context
typedef enum
{
  FZL_WALK_CTX_TYPE_GLOBAL,
  FZL_WALK_CTX_TYPE_FN,
  FZL_WALK_CTX_TYPE_CLASS,
  FZL_WALK_CTX_TYPE_ASSIGN
} fzl_walk_ctx_type_t;

// Internal walk function result
typedef struct
{
  fzl_type_t type;

  char *error_msg;
  bool error;

  char *classname;
} fzl_walk_res_t;

// Function context descriptor
typedef struct fzl_walk_ctx
{
  fzl_walk_ctx_type_t type;
  struct fzl_walk_ctx *parent;

  fzl_node_t *fn;
  size_t initial_env_lvl;
} fzl_walk_ctx_t;

// Walker descriptor
typedef struct
{
  fzl_node_t *root;
  fzl_const_hash_pool_t *consts;

  uint64_t *ops;
  size_t op_count;
  size_t op_remainder;

  fzl_symtable_t *syms[64];
  size_t sym_top;

  fzl_walk_ctx_t *ctx;

  fzl_ctable_t *classes[64];
  size_t classes_count;
} fzl_walker_t;

// Allocate new walker
fzl_walker_t *fzl_mkwalker(fzl_node_t *root);

// Walk throught the entire AST and build:
// 1. Constants table
// 2. Operations
int fzl_walk(fzl_walker_t *walker);

// Get last error message
char *fzl_walker_geterror();

// Free walker
void fzl_freewalker(fzl_walker_t *walker);

#endif // FZL_WALKER_H