wifi_saved.h

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/*******************************************************************************
 * File: wifi_saved.h
 *
 * Description:
 *   Saved WiFi networks module — stores up to 6 network credentials in
 *   OPTIGA Trust M NVM via existing TESAIoT CRED_READ/WRITE/ERASE IPC.
 *
 *   Each saved network (106 bytes) is stored in one OPTIGA Type 3 data
 *   object (140 bytes max). Uses slots 5, 6, 8, 9, 10, 11 (skipping
 *   slot 4=reserved and slot 7=API_KEY).
 *
 *   LRU eviction: When all 6 slots are full, the entry with the
 *   smallest last_used timestamp is overwritten.
 *
 *   NVRAM fallback: When OPTIGA is not connected, entries are stored
 *   in a RAM cache (persists within session, lost on reboot).
 *
 ******************************************************************************/
 
#ifndef WIFI_SAVED_H
#define WIFI_SAVED_H
 
#include <stdint.h>
#include <stdbool.h>
 
#define WIFI_SAVED_MAX          6
 
/* Per-slot binary format: 106 bytes packed */
typedef struct __attribute__((packed)) {
    char     ssid[33];       /* null-terminated, max 32 chars */
    char     password[65];   /* null-terminated, max 63 chars (WPA2 standard) */
    uint8_t  security;       /* 0=open, 1=WEP, 2=WPA, 3=WPA2, 4=WPA3 */
    uint8_t  flags;          /* bit0 = auto_connect */
    uint16_t reserved;       /* alignment padding */
    uint32_t last_used;      /* epoch seconds (from RTC/NTP) for LRU eviction */
} wifi_saved_entry_t;        /* exactly 106 bytes */
 
/*******************************************************************************
 * Public API
 ******************************************************************************/

bool wifi_saved_load(int index, wifi_saved_entry_t *out);

bool wifi_saved_store(int index, const wifi_saved_entry_t *entry);

bool wifi_saved_erase(int index);

int wifi_saved_find(const char *ssid);

bool wifi_saved_add(const char *ssid, const char *password, uint8_t security);

int wifi_saved_count(void);

int wifi_saved_load_all(wifi_saved_entry_t *entries);
 
/*******************************************************************************
 * Non-blocking OPTIGA probe API — use from LVGL callbacks to avoid blocking.
 *
 * Usage:
 *   1. wifi_saved_probe_start()   → send IPC probe, return immediately
 *   2. wifi_saved_probe_ready()   → poll periodically (100ms timer)
 *   3. wifi_saved_probe_finish()  → set OPTIGA state based on response
 *   4. After probe, wifi_saved_load() skips probe (already done)
 ******************************************************************************/
bool wifi_saved_probe_start(void);
bool wifi_saved_probe_ready(void);
void wifi_saved_probe_finish(void);
 
/*******************************************************************************
 * Non-blocking slot read API — async IPC send + poll for individual slots.
 *
 * Usage:
 *   1. wifi_saved_read_start(index)  → send IPC or instant (RAM fallback)
 *   2. wifi_saved_read_ready()       → poll periodically
 *   3. wifi_saved_read_result(out)   → get entry after ready==true
 ******************************************************************************/
bool wifi_saved_read_start(int index);
bool wifi_saved_read_ready(void);
bool wifi_saved_read_result(wifi_saved_entry_t *out);
 
#endif /* WIFI_SAVED_H */