#ifndef ENV_H

#define ENV_H

#include "value.h"

/* Forward-declare Env so EnvEntry can hold an Env* pointer. */

typedef struct Env Env;

typedef struct EnvEntry {

char *name;

DeclType decl_type;

int decl_base; // 0 = parent int/float, 2..64 = named base

Value schema; // NEW: map schema value, .type==VAL_NULL if none

Value value;

bool initialized;

bool frozen;

bool permafrozen;

// If non-NULL, this entry is an alias to another binding name in the environment

char *alias_target;

// If non-NULL, indicates the Env where alias_target should be resolved.

// This allows aliasing to bindings that live in a different Env tree

// (for example, caller environments when binding pointer arguments).

Env *alias_target_env;

} EnvEntry;

typedef struct Env {

struct Env *parent;

EnvEntry *entries;

size_t count;

size_t capacity;

int refcount;

EnvEntry **ht_slots;

size_t ht_capacity;

size_t ht_count;

} Env;

Env *env_create(Env *parent);

// Kept to make extension development easier.

void env_retain(Env *env);

void env_free(Env *env);

bool env_define(Env *env, const char *name, DeclType type, int base, Value schema);

bool env_assign(Env *env, const char *name, Value value, DeclType type, int type_base, bool declare_if_missing);

bool env_get(Env *env, const char *name, Value *out_value, DeclType *out_type, int *out_base, bool *out_initialized);

bool env_delete(Env *env, const char *name);

// Kept to make extension development easier.

bool env_exists(Env *env, const char *name);

// Return a per-thread snapshot of the EnvEntry for the given name, searching parents.

// The snapshot is safe to read after the function returns even when the

// namespace buffer is active (it does not point into Env storage).

// Caller must not free the returned pointer.

// Returns NULL if not found.

EnvEntry *env_get_entry(Env *env, const char *name);

// Local lookup helper (O(1) with hash table, falls back to linear scan).

EnvEntry *env_find_local(Env *env, const char *name);

// Create or update an alias (pointer) binding: `name` will become an alias to `target_name`.

// If declare_if_missing is true, `name` will be defined if absent. Returns true on success.

bool env_set_alias(Env *env, const char *name, const char *target_name, DeclType type, int type_base,

bool declare_if_missing);

// Create or update an alias where the alias target should be resolved in a

// specific environment (target_env). This supports pointer args binding

// where the pointed-to symbol is visible in the caller's environment.

bool env_set_alias_cross(Env *env, const char *name, Env *target_env, const char *target_name, DeclType type,

int type_base, bool declare_if_missing);

// Symbol freezing API

// Returns 0 on success, -1 if the identifier was not found.

// Kept to make extension development easier.

int env_freeze(Env *env, const char *name);

// Returns 0 on success, -1 if not found, -2 if identifier is permanently frozen

// Kept to make extension development easier.

int env_thaw(Env *env, const char *name);

// Returns 0 on success, -1 if not found

// Kept to make extension development easier.

int env_permafreeze(Env *env, const char *name);

// Returns -1 if permanently frozen, 1 if frozen, 0 if not frozen or not found

// Kept to make extension development easier.

int env_frozen_state(Env *env, const char *name);

// Returns 1 if permanently frozen, 0 otherwise (or not found)

// Kept to make extension development easier.

int env_permafrozen(Env *env, const char *name);

// ---- Direct (unbuffered) entry points used by the namespace buffer ----

// These perform the actual work and must not be called from outside

// env.c / ns_buffer.c. Public callers should use the non-_direct

// versions above, which route through the write buffer when active.

bool env_define_direct(Env *env, const char *name, DeclType type, int base, Value schema);

bool env_assign_direct(Env *env, const char *name, Value value, DeclType type, int type_base, bool declare_if_missing);

bool env_delete_direct(Env *env, const char *name);

bool env_set_alias_direct(Env *env, const char *name, const char *target_name, DeclType type, int type_base,

bool declare_if_missing);

int env_freeze_direct(Env *env, const char *name);

int env_thaw_direct(Env *env, const char *name);

int env_permafreeze_direct(Env *env, const char *name);

// Restore or overwrite a local entry's declared type and value. This will

// update the local entry (creating it if absent) to have `type` and, if

// `initialized` is true, set its value to a copy of `value` and mark it

// initialized; otherwise leave it uninitialized. Returns true on success.

bool env_restore_local(Env *env, const char *name, Value value, DeclType type, int type_base, bool initialized);

bool env_restore_local_direct(Env *env, const char *name, Value value, DeclType type, int type_base, bool initialized);

#endif // ENV_H