/**
 * @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 <stdlib.h>
#include <lib/modbus_server.h>
#include <lib/valve.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_set_baud(const struct shell *sh, size_t argc, char **argv)
{
	if (argc != 2) {
		shell_error(sh, "Usage: set_baud <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_set_id(const struct shell *sh, size_t argc, char **argv)
{
	if (argc != 2) {
		shell_error(sh, "Usage: set_id <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 set the valve's maximum opening time.
 *
 * @param sh The shell instance.
 * @param argc Argument count.
 * @param argv Argument values.
 * @return 0 on success, -EINVAL on error.
 */
static int cmd_valve_set_open_time(const struct shell *sh, size_t argc, char **argv)
{
    if (argc != 2) {
        shell_error(sh, "Usage: set_open_time <seconds>");
        return -EINVAL;
    }

    uint16_t seconds = (uint16_t)strtoul(argv[1], NULL, 10);
    valve_set_max_open_time(seconds);
    shell_print(sh, "Max opening time set to: %u seconds (and saved)", seconds);

    return 0;
}

/**
 * @brief Shell command to set the valve's maximum closing time.
 *
 * @param sh The shell instance.
 * @param argc Argument count.
 * @param argv Argument values.
 * @return 0 on success, -EINVAL on error.
 */
static int cmd_valve_set_close_time(const struct shell *sh, size_t argc, char **argv)
{
    if (argc != 2) {
        shell_error(sh, "Usage: set_close_time <seconds>");
        return -EINVAL;
    }

    uint16_t seconds = (uint16_t)strtoul(argv[1], NULL, 10);
    valve_set_max_close_time(seconds);
    shell_print(sh, "Max closing time set to: %u seconds (and saved)", seconds);

    return 0;
}

/**
 * @brief Shell command to show the current configuration.
 *
 * @param sh The shell instance.
 * @param argc Argument count.
 * @param argv Argument values.
 * @return 0 on success.
 */
static int cmd_config_show(const struct shell *sh, size_t argc, char **argv)
{
	shell_print(sh, "Current Modbus Configuration:");
	shell_print(sh, "  Baudrate: %u", modbus_get_baudrate());
	shell_print(sh, "  Slave ID: %u", modbus_get_unit_id());
    shell_print(sh, "Current Valve Configuration:");
    shell_print(sh, "  Max Opening Time: %u s", valve_get_max_open_time());
    shell_print(sh, "  Max Closing Time: %u s", valve_get_max_close_time());
	return 0;
}

SHELL_STATIC_SUBCMD_SET_CREATE(sub_modbus_cmds,
	SHELL_CMD(set_baud, NULL, "Set Modbus baudrate", cmd_modbus_set_baud),
	SHELL_CMD(set_id,   NULL, "Set Modbus slave ID", cmd_modbus_set_id),
	SHELL_SUBCMD_SET_END
);

SHELL_STATIC_SUBCMD_SET_CREATE(sub_valve_cmds,
    SHELL_CMD(set_open_time, NULL, "Set max valve opening time", cmd_valve_set_open_time),
    SHELL_CMD(set_close_time, NULL, "Set max valve closing time", cmd_valve_set_close_time),
    SHELL_SUBCMD_SET_END
);

SHELL_CMD_REGISTER(modbus, &sub_modbus_cmds, "Modbus configuration", NULL);
SHELL_CMD_REGISTER(valve, &sub_valve_cmds, "Valve configuration", NULL);
SHELL_CMD_REGISTER(show_config, NULL, "Show all configurations", cmd_config_show);