#ifndef BT_UART_H
#define BT_UART_H

/*
 * bt_uart — DX-BT24 Bluetooth module UART driver
 *
 * The DX-BT24 is a UART-transparent BLE module.  Whatever is written to the
 * serial port is forwarded verbatim over BLE to the connected iOS/Android app.
 *
 * Usage (normal operation — module already at 115200):
 *   bt_uart_init("/dev/ttyS1", 0)   — do_at_probe=0: skip AT commands
 *   bt_uart_send_json(json_str)     — every event, thread-safe
 *   bt_uart_close()                 — shutdown (optional)
 *
 * First-time / factory-reset setup (module at factory default 9600):
 *   bt_uart_init("/dev/ttyS1", 1)   — do_at_probe=1: negotiate baud via AT
 *   After success, set bt_at_probe = 0 in INI — never probe again.
 */

/* Open and configure the UART to the BT module.
 * dev:          device path, e.g. "/dev/ttyS1"  (NULL or "" = disabled).
 * do_at_probe:  0 = open directly at 115200 (normal operation, no AT sent).
 *               1 = run AT baud negotiation first (one-time setup only).
 * Returns 0 on success, -1 on failure / disabled. */
int  bt_uart_init(const char *dev, int do_at_probe);

/* Write JSON bytes to the BT module (no CRLF added). Thread-safe. No-op if not init'd. */
void bt_uart_send_json(const char *json);

/* Close the UART fd and release resources. */
void bt_uart_close(void);

#endif /* BT_UART_H */