/**
 * @file shell_modbus.c
 * @brief Provides shell commands for Modbus and valve configuration.
 *
 * This file implements a set of commands for the Zephyr shell to allow
 * runtime configuration of the Modbus server (baudrate, slave ID) and the
 * valve (max opening/closing times). The settings are persisted to non-volatile
 * storage.
 */

#include <zephyr/shell/shell.h>
#include <lib/modbus_server.h>
#include <stdlib.h>

/**
 * @brief Shell command to set the Modbus baudrate.
 *
 * @param sh The shell instance.
 * @param argc Argument count.
 * @param argv Argument values.
 * @return 0 on success, -EINVAL on error.
 */
static int cmd_modbus_setb(const struct shell *sh, size_t argc, char **argv)
{
	if (argc != 2) {
		shell_error(sh, "Usage: setb <baudrate>");
		return -EINVAL;
	}

	uint32_t new_baud = (uint32_t)strtoul(argv[1], NULL, 10);
	const uint32_t valid_baud_rates[] = {1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200};
	bool is_valid = false;

	for (int i = 0; i < ARRAY_SIZE(valid_baud_rates); i++) {
		if (new_baud == valid_baud_rates[i]) {
			is_valid = true;
			break;
		}
	}

	if (!is_valid) {
		char error_msg[128];
		int offset =
		    snprintf(error_msg, sizeof(error_msg), "Invalid baudrate. Valid rates are: ");
		for (int i = 0; i < ARRAY_SIZE(valid_baud_rates); i++) {
			offset += snprintf(error_msg + offset,
			    sizeof(error_msg) - offset,
			    "%u ",
			    valid_baud_rates[i]);
		}
		shell_error(sh, "%s", error_msg);
		return -EINVAL;
	}

	if (modbus_reconfigure(new_baud, modbus_get_unit_id()) != 0) {
		shell_error(sh, "Failed to apply new baudrate");
	} else {
		shell_print(sh, "Modbus baudrate set to: %u (and saved)", new_baud);
	}

	return 0;
}

/**
 * @brief Shell command to set the Modbus slave ID.
 *
 * @param sh The shell instance.
 * @param argc Argument count.
 * @param argv Argument values.
 * @return 0 on success, -EINVAL on error.
 */
static int cmd_modbus_setid(const struct shell *sh, size_t argc, char **argv)
{
	if (argc != 2) {
		shell_error(sh, "Usage: setid <slave_id>");
		return -EINVAL;
	}

	uint32_t new_id_u32 = (uint32_t)strtoul(argv[1], NULL, 10);
	if (new_id_u32 == 0 || new_id_u32 > 247) {
		shell_error(sh, "Invalid slave ID: %s. Must be between 1 and 247.", argv[1]);
		return -EINVAL;
	}
	uint8_t new_id = (uint8_t)new_id_u32;

	if (modbus_reconfigure(modbus_get_baudrate(), new_id) != 0) {
		shell_error(sh, "Failed to apply new slave ID");
	} else {
		shell_print(sh, "Modbus slave ID set to: %u (and saved)", new_id);
	}

	return 0;
}

/**
 * @brief Shell command to show the current Modbus configuration.
 *
 * @param sh The shell instance.
 * @param argc Argument count.
 * @param argv Argument values.
 * @return 0 on success.
 */
static int cmd_modbus_show(const struct shell *sh, size_t argc, char **argv)
{
	const int label_width = 15;

	shell_print(sh, "Modbus Settings:");
	shell_print(sh, "%*s %u", label_width, "Baudrate:", modbus_get_baudrate());
	shell_print(sh, "%*s %u", label_width, "Slave ID:", modbus_get_unit_id());
	return 0;
}

SHELL_STATIC_SUBCMD_SET_CREATE(sub_modbus_cmds,
    SHELL_CMD(setb, NULL, "Set Modbus baudrate", cmd_modbus_setb),
    SHELL_CMD(setid, NULL, "Set Modbus slave ID", cmd_modbus_setid),
    SHELL_CMD(show, NULL, "Show Modbus configuration", cmd_modbus_show),
    SHELL_SUBCMD_SET_END);

SHELL_CMD_REGISTER(modbus, &sub_modbus_cmds, "Modbus commands", NULL);