#ifndef CST_PROVIDER_SWITCH_H
#define CST_PROVIDER_SWITCH_H

/* Model lists, API keys and provider switches, shared by the TUI and the
 * WebUI so both front ends validate and persist the same way.
 *
 * A key is checked with GET /models: a 401/403 (CST_MODELS_AUTH) rejects
 * it, any other failure (offline, no /models route) lets it through
 * unverified. A key that passes is saved to <config>/credentials. Keys are
 * never copied into err. */

#include "cst_agent.h"
#include "cst_models.h"

#ifdef __cplusplus
extern "C" {
#endif

#define CST_PS_MAX_MODELS 512
#define CST_PS_UNKNOWN (-1)   /* no such provider */
#define CST_PS_NEED_KEY (-10) /* no key given, none saved or in the env */
/* Non-negative results are flags: */
#define CST_PS_UNVERIFIED 1 /* /models failed for another reason; err says */
#define CST_PS_UNSAVED 2    /* the credentials file could not be written */

typedef struct {
  char id[128];
  int api; /* listed by the provider's /models (else built-in only) */
  cst_model_info_t info;
} cst_ps_model_t;

/* GET /models; a good answer refreshes models-cache/<provider>.json. The
 * count, CST_MODELS_AUTH, or another negative value with err set. */
int cst_ps_fetch(const char *provider, const char *api_base, const char *key,
                 char ids[][128], int max, char *err, size_t err_sz);
/* The cached list: count, or -1; *fresh when younger than the TTL. */
int cst_ps_cached(const char *provider, char ids[][128], int max, int *fresh);

/* Base URL for provider: cfg's own when it is the current provider (it may
 * be overridden), else the preset's; "" when unknown. */
const char *cst_ps_base(const cst_agent_config_t *cfg, const char *provider);

/* The model picker list for cfg's provider: the API's ids (the cache while
 * it is fresh, else a fetch; refresh always fetches) followed by the
 * built-in names it did not list. *api_rc gets the fetch result (count,
 * CST_MODELS_AUTH, -1 with err) or the cached count. Returns the count. */
int cst_ps_models(const cst_agent_config_t *cfg, int refresh,
                  cst_ps_model_t *out, int max, int *api_rc, char *err,
                  size_t err_sz);

/* Checks key against /models and saves it: CST_MODELS_AUTH (err set), or
 * the CST_PS_* flags. When ids is given it gets the fetched list and *nids
 * the raw fetch result. */
int cst_ps_verify_save(const char *provider, const char *api_base,
                       const char *key, char ids[][128], int max, int *nids,
                       char *err, size_t err_sz);

/* Point cfg at provider p with key: base URL, the remembered model (else
 * the preset's), settings saved. */
void cst_ps_apply_provider(cst_agent_config_t *cfg, const cst_provider_t *p,
                           const char *key);

/* The whole switch without a prompt: key NULL/"" uses the saved or env
 * key (else CST_PS_NEED_KEY); a given key is verified and saved first. A
 * preset with no model takes the first one the API lists. The CST_PS_*
 * flags, or CST_PS_UNKNOWN / CST_PS_NEED_KEY / CST_MODELS_AUTH. */
int cst_ps_switch_provider(cst_agent_config_t *cfg, const char *name,
                           const char *key, char *err, size_t err_sz);

/* Replace the current provider's key: verified, saved, put in cfg. Same
 * results as cst_ps_verify_save. */
int cst_ps_set_key(cst_agent_config_t *cfg, const char *key, char *err,
                   size_t err_sz);

#ifdef __cplusplus
}
#endif

#endif