#pragma once
#include "llama.h"
#include "common.h"
#include <cstdint>
#include <vector>
enum common_reasoning_budget_state {
REASONING_BUDGET_IDLE, // waiting for start sequence
REASONING_BUDGET_COUNTING, // counting down tokens
REASONING_BUDGET_FORCING, // forcing budget message + end sequence
REASONING_BUDGET_WAITING_UTF8, // budget exhausted, waiting for UTF-8 completion
REASONING_BUDGET_DONE, // passthrough forever
};
// Creates a reasoning budget sampler that limits token generation inside a
// reasoning block (e.g. between <think> and </think>).
//
// State machine: IDLE -> COUNTING -> WAITING_UTF8 -> FORCING -> DONE
// IDLE: passthrough, watching for a start sequence
// COUNTING: counting down remaining tokens, watching for a natural end sequence
// WAITING_UTF8: budget exhausted, allowing tokens to complete a UTF-8 sequence
// FORCING: forces forced_tokens token-by-token (all other logits -> -inf)
// DONE: passthrough forever
//
// Parameters:
// vocab - vocabulary (used for UTF-8 boundary detection; can be nullptr)
// start_seqs - token sequences, any of which activates counting
// end_seqs - token sequences, any of which naturally deactivates
// forced_tokens - token sequence forced when budget expires
// budget - max tokens allowed in the reasoning block
// initial_state - initial state
//
struct llama_sampler * common_reasoning_budget_init(
const struct llama_vocab * vocab,
const std::vector<llama_tokens> & start_seqs,
const std::vector<llama_tokens> & end_seqs,
const llama_tokens & forced_tokens,
int32_t budget,
common_reasoning_budget_state initial_state = REASONING_BUDGET_IDLE);
common_reasoning_budget_state common_reasoning_budget_get_state(const struct llama_sampler * smpl);
// The end sequence that transitioned the sampler to DONE, or nullptr if none
// was recorded. Cleared when a new start sequence re-arms the sampler.
const llama_tokens * common_reasoning_budget_get_end_match(const struct llama_sampler * smpl);
// Manually transition the reasoning budget sampler into the FORCING state.
// Returns true if the transition occurred.
bool common_reasoning_budget_force(struct llama_sampler * smpl);