/*
 * Copyright (c) 2024 Yishai Jaffe <yishai1999@gmail.com>
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include <zephyr/drivers/uart.h>
#include <zephyr/shell/shell.h>
#include <stdlib.h>

#include <zephyr/logging/log.h>
LOG_MODULE_REGISTER(uart_shell, CONFIG_LOG_DEFAULT_LEVEL);

static bool device_is_uart(const struct device *dev)
{
	return DEVICE_API_IS(uart, dev);
}

static int cmd_uart_write(const struct shell *sh, size_t argc, char **argv)
{
	char *s_dev_name = argv[1];
	const struct device *dev = shell_device_get_binding(s_dev_name);

	if (!dev || !device_is_uart(dev)) {
		shell_error(sh, "UART: Device driver %s not found.", s_dev_name);
		return -ENODEV;
	}

	char *buf = argv[2];
	int msg_len = strlen(buf);

	for (int i = 0; i < msg_len; i++) {
		uart_poll_out(dev, buf[i]);
	}

	return 0;
}


static int cmd_uart_read(const struct shell *sh, size_t argc, char **argv)
{
	char *s_dev_name = argv[1];
	const struct device *dev = shell_device_get_binding(s_dev_name);
	int ret = 0;
	char chr;
	k_timepoint_t end;
	uint64_t seconds;

	if (!dev || !device_is_uart(dev)) {
		shell_error(sh, "UART: Device driver %s not found.", s_dev_name);
		return -ENODEV;
	}

	seconds = shell_strtoul(argv[2], 10, &ret);
	if (ret != 0) {
		shell_help(sh);
		return SHELL_CMD_HELP_PRINTED;
	}
	if (seconds < 1) {
		return -EINVAL;
	}
	shell_info(sh, "UART: Read for %lli seconds from %s.", seconds, s_dev_name);

	end = sys_timepoint_calc(K_SECONDS(seconds));
	while (!sys_timepoint_expired(end)) {
		ret = uart_poll_in(dev, &chr);
		if (ret == 0) {
			shell_fprintf_normal(sh, "%c", chr);
		}
		if (ret != 0 && ret != -1) {
			shell_error(sh, "Failed to read from UART (%d)", ret);
			return ret;
		}
	}

	shell_fprintf_normal(sh, "\n");

	return 0;
}


static int cmd_uart_baudrate(const struct shell *sh, size_t argc, char **argv)
{
	char *s_dev_name = argv[1];
	const struct device *dev;
	struct uart_config cfg;
	uint32_t baudrate;
	int ret = 0;

	dev = shell_device_get_binding(s_dev_name);
	if (!dev || !device_is_uart(dev)) {
		shell_error(sh, "UART: Device driver %s not found.", s_dev_name);
		return -ENODEV;
	}

	baudrate = shell_strtoul(argv[2], 10, &ret);
	if (ret != 0) {
		shell_help(sh);
		return SHELL_CMD_HELP_PRINTED;
	}
	ret = uart_config_get(dev, &cfg);
	if (ret < 0) {
		shell_error(sh, "UART: Failed to get current configuration: %d", ret);
		return ret;
	}
	cfg.baudrate = baudrate;

	ret = uart_configure(dev, &cfg);
	if (ret < 0) {
		shell_error(sh, "UART: Failed to configure device: %d", ret);
		return ret;
	}
	return 0;
}

static int cmd_uart_flow_control(const struct shell *sh, size_t argc, char **argv)
{
	char *s_dev_name = argv[1];
	const struct device *dev;
	struct uart_config cfg;
	uint8_t flow_control;
	int ret;

	dev = shell_device_get_binding(s_dev_name);
	if (!dev || !device_is_uart(dev)) {
		shell_error(sh, "UART: Device driver %s not found.", s_dev_name);
		return -ENODEV;
	}

	if (!strcmp(argv[2], "none")) {
		flow_control = UART_CFG_FLOW_CTRL_NONE;
	} else if (!strcmp(argv[2], "rtscts")) {
		flow_control = UART_CFG_FLOW_CTRL_RTS_CTS;
	} else if (!strcmp(argv[2], "dtrdsr")) {
		flow_control = UART_CFG_FLOW_CTRL_DTR_DSR;
	} else if (!strcmp(argv[2], "rs485")) {
		flow_control = UART_CFG_FLOW_CTRL_RS485;
	} else {
		shell_error(sh, "Unknown: '%s'", argv[2]);
		shell_help(sh);
		return SHELL_CMD_HELP_PRINTED;
	}

	ret = uart_config_get(dev, &cfg);
	if (ret < 0) {
		shell_error(sh, "UART: Failed to get current configuration: %d", ret);
		return ret;
	}
	cfg.flow_ctrl = flow_control;

	ret = uart_configure(dev, &cfg);
	if (ret < 0) {
		shell_error(sh, "UART: Failed to configure device: %d", ret);
		return ret;
	}
	return 0;
}

static void device_name_get(size_t idx, struct shell_static_entry *entry)
{
	const struct device *dev = shell_device_filter(idx, device_is_uart);

	entry->syntax = (dev != NULL) ? dev->name : NULL;
	entry->handler = NULL;
	entry->help = NULL;
	entry->subcmd = NULL;
}

SHELL_DYNAMIC_CMD_CREATE(dsub_device_name, device_name_get);

SHELL_STATIC_SUBCMD_SET_CREATE(sub_uart_cmds,
	SHELL_CMD_ARG(write, &dsub_device_name,
		      SHELL_HELP("Write data to the UART device",
				 "<device> <data>"),
		      cmd_uart_write, 3, 0),
	SHELL_CMD_ARG(read, &dsub_device_name,
		      SHELL_HELP("Read data from the UART device",
				 "<device> <duration in secs>"),
		      cmd_uart_read, 3, 0),
	SHELL_CMD_ARG(baudrate, &dsub_device_name,
		      SHELL_HELP("Configure the UART device baudrate",
				 "<device> <baudrate>"),
		      cmd_uart_baudrate, 3, 0),
	SHELL_CMD_ARG(fc, &dsub_device_name,
		      SHELL_HELP("Configure the UART device flow control",
				 "<device> <none|rtscts|dtrdsr|rs485>"),
		      cmd_uart_flow_control, 3, 0),
	SHELL_SUBCMD_SET_END     /* Array terminated. */
);

SHELL_CMD_REGISTER(uart, &sub_uart_cmds, "UART commands", NULL);