/* This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */
/** STM32F1 BusVoodoo application
 *  @file application.c
 *  @author King Kévin <kingkevin@cuvoodoo.info>
 *  @date 2016-2017
 */

/* standard libraries */
#include <stdint.h> // standard integer types
#include <string.h> // string utilities

/* STM32 (including CM3) libraries */
#include <libopencmsis/core_cm3.h> // Cortex M3 utilities
#include <libopencm3/stm32/gpio.h> // general purpose input output library
#include <libopencm3/stm32/rcc.h> // real-time control clock library
#include <libopencm3/stm32/dbgmcu.h> // debug utilities

/* own libraries */
#include "global.h" // board definitions
#include "print.h" // printing utilities
#include "uart.h" // USART utilities
#include "usb_cdcacm.h" // USB CDC ACM utilities
#include "terminal.h" // handle the terminal interface
#include "menu.h" // menu utilities
#include "busvoodoo_global.h" // BusVoodoo definitions
#include "busvoodoo_oled.h" // OLED utilities
#include "busvoodoo_hiz.h" // BusVoodoo HiZ mode
#include "busvoodoo_uart.h" // BusVoodoo UART mode

/** all supported BusVoodoo modes */
static struct busvoodoo_mode_t* busvoodoo_modes[] = {
	&busvoodoo_hiz_mode,
	&busvoodoo_uart_mode,
};

/** current BusVoodoo mode */
static struct busvoodoo_mode_t* busvoodoo_mode = NULL;
/** is mode setup complete */
static bool busvoodoo_mode_complete = false;

size_t putc(char c)
{
	size_t length = 0; // number of characters printed
	static char last_c = 0; // to remember on which character we last sent
	if ('\n' == c) { // send carriage return (CR) + line feed (LF) newline for each LF
		if ('\r' != last_c) { // CR has not already been sent
			uart_putchar_nonblocking('\r'); // send CR over USART
			usb_cdcacm_putchar('\r'); // send CR over USB
			length++; // remember we printed 1 character
		}
	}
	uart_putchar_nonblocking(c); // send byte over USART
	usb_cdcacm_putchar(c); // send byte over USB
	length++; // remember we printed 1 character
	last_c = c; // remember last character
	return length; // return number of characters printed   
}

/** switch BusVoddoo mode
 *  @param[in] mode mode to switch to
 */
static void switch_mode(struct busvoodoo_mode_t* mode)
{
	if (busvoodoo_mode) {
		(*busvoodoo_mode->exit)(); // exit current mode
	}
	// reset pinout
	for (uint8_t i=0; i<LENGTH(busvoodoo_global_pinout_rscan); i++) {
		busvoodoo_global_pinout_rscan[i] = NULL;
	}
	for (uint8_t i=0; i<LENGTH(busvoodoo_global_pinout_io); i++) {
		busvoodoo_global_pinout_io[i] = NULL;
	}
	// reset OLED
	busvoodoo_safe_state(); // return to safe state
	busvoodoo_oled_clear(); // clear OLED display buffer
	busvoodoo_oled_update(); // update OLED display
	if (NULL==mode) { // no mode provided
		busvoodoo_mode = &busvoodoo_hiz_mode; // use default mode
	} else { // mode provided
		busvoodoo_mode = mode; // set provided mode a current mode
	}
	busvoodoo_mode_complete = (*busvoodoo_mode->setup)(&terminal_prefix, NULL); // start setup
	terminal_send(0); // update the terminal prompt
}

/** command to show help
 *  @param[in] argument no argument required
 */
static void command_help(void* argument);
/** command to select mode
 *  @param[in] argument mode to select
 */
static void command_mode(void* argument);
/** command to quit current BusVoodoo mode
 *  @param[in] argument no argument required
 */
static void command_quit(void* argument);
/** command to reset board
 *  @param[in] argument no argument required
 */
static void command_reset(void* argument);
/** command to reboot into bootloader
 *  @param[in] argument no argument required
 */
static void command_bootloader(void* argument);
/** command to show version
 *  @param[in] argument no argument required
 */
static void command_version(void* argument);

/** list of all supported commands */
static const struct menu_command_t menu_commands[] = {
	{
		'm',
		"mode",
		"select mode",
		MENU_ARGUMENT_STRING,
		"[mode]",
		&command_mode,
	},
	{
		'q',
		"quit",
		"quit current mode",
		MENU_ARGUMENT_NONE,
		NULL,
		&command_quit,
	},
	{
		'r',
		"reset",
		"reset board",
		MENU_ARGUMENT_NONE,
		NULL,
		&command_reset,
	},
	{
		'b',
		"bootloader",
		"reboot into DFU bootloader",
		MENU_ARGUMENT_NONE,
		NULL,
		&command_bootloader,
	},
	{
		'v',
		"version",
		"show hardware and firmware version",
		MENU_ARGUMENT_NONE,
		NULL,
		&command_version,
	},
	{
		'h',
		"help",
		"display help",
		MENU_ARGUMENT_NONE,
		NULL,
		&command_help,
	},
};

static void command_help(void* argument)
{
	(void)argument; // we won't use the argument
	printf("available commands:\n");
	menu_print_commands(menu_commands, LENGTH(menu_commands)); // print global commands
	menu_print_commands(busvoodoo_global_commands, LENGTH(busvoodoo_global_commands)); // print BusVoodoo global commands
	menu_print_commands(busvoodoo_mode->commands, busvoodoo_mode->commands_nb); // print BusVoodoo mode commands
}

static void command_mode(void* argument)
{
	if (NULL==argument || 0==strlen(argument)) { // no mode provided: list all modes
		printf("available modes:\n");
		for (uint8_t i=0; i<LENGTH(busvoodoo_modes); i++) { // go through all modes
			printf("%s\t%s\n", busvoodoo_modes[i]->name, busvoodoo_modes[i]->description); // display mode information
		}
	} else { // mode provided
		bool mode_found = false; // to know if we found the matching mode
		for (uint8_t i=0; i<LENGTH(busvoodoo_modes); i++) { // go through all modes
			if (0==strcmp(argument, busvoodoo_modes[i]->name)) { // check for corresponding mode
				(*busvoodoo_mode->exit)(); // exit current mode
				led_off(); // switch off LEDs
				busvoodoo_mode = busvoodoo_modes[i]; // set matching mode as current mode
				busvoodoo_mode_complete = (*busvoodoo_mode->setup)(&terminal_prefix, NULL); // start setup
				terminal_send(0); // update the terminal prompt
				mode_found = true; // remember we found the mode
				break; // stop searching for mode
			}
		}
		if (!mode_found) {
			printf("unknown mode: %s\n", argument);
		}
	}
}

static void command_quit(void* argument)
{
	(void)argument; // we won't use the argument
	switch_mode(NULL); // switch do default mode
}

static void command_reset(void* argument)
{
	(void)argument; // we won't use the argument
	scb_reset_system(); // reset device
	while (true); // wait for the reset to happen
}

static void command_bootloader(void* argument)
{
	(void)argument; // we won't use the argument
	RCC_CSR |= RCC_CSR_RMVF; // clear reset flags
	scb_reset_core(); // reset core (the bootloader will interpret it as starting into DFU)
	while (true); // wait for the reset to happen
}

static void command_version(void* argument)
{
	(void)argument; // we won't use the argument
	printf("BusVoodoo board: %s\n", busvoodoo_full ? "full" : "light");
	printf("hardware revision: ");
	if (busvoodoo_revision) {
		printf("%u", busvoodoo_revision);
	} else {
		printf("unknown");
	}
	printf("\n");
	printf("firmware date: %04u-%02u-%02u\n", BUILD_YEAR, BUILD_MONTH, BUILD_DAY);
	printf("board ID: %08x%08x%08x\n", DESIG_UNIQUE_ID0, DESIG_UNIQUE_ID1, DESIG_UNIQUE_ID2);
}

/** process user command
 *  @param[in] str user command string (\0 ended)
 */
static void process_command(char* str)
{
	// ensure actions are available
	if (NULL==menu_commands || 0==LENGTH(menu_commands)) {
		return;
	}
	// handle user input
	if (NULL==busvoodoo_mode) { // no mode set
		switch_mode(NULL); // set default mode
	}
	if (!busvoodoo_mode_complete) { // mode setup is not complete
		busvoodoo_mode_complete = (*busvoodoo_mode->setup)(&terminal_prefix, str); // continue setup
		terminal_send(0); // update the terminal prompt
	} else {
		// don't handle empty lines
		if (!str || 0==strlen(str)) {
			return;
		}
		if (!menu_handle_command(str, busvoodoo_mode->commands, busvoodoo_mode->commands_nb)) {
			if (!menu_handle_command(str, busvoodoo_global_commands, LENGTH(busvoodoo_global_commands))) {
				if (!menu_handle_command(str, menu_commands, LENGTH(menu_commands))) {
					printf("command not recognized. enter help to list commands\n");
				}
			}
		}
	}
}

/** program entry point
 *  this is the firmware function started by the micro-controller
 */
void main(void);
void main(void)
{	
	rcc_clock_setup_in_hse_8mhz_out_72mhz(); // use 8 MHz high speed external clock to generate 72 MHz internal clock

	// enable functionalities for easier debug
	DBGMCU_CR |= DBGMCU_CR_STANDBY; // allow debug also in standby mode (keep digital part and clock powered)
	DBGMCU_CR |= DBGMCU_CR_STOP; // allow debug also in stop mode (keep clock powered)
	DBGMCU_CR |= DBGMCU_CR_SLEEP; // allow debug also in sleep mode (keep clock powered)

	board_setup(); // setup board
	uart_setup(); // setup USART (for printing)
	usb_cdcacm_setup(); // setup USB CDC ACM (for printing)

	busvoodoo_setup(); // setup BusVoodoo board
	printf("\nwelcome to BusVoodoo ("); // print welcome message
	if (busvoodoo_full) {
		printf("full");
	} else {
		printf("light");
	}
	printf(" version)\n");

	// setup terminal
	terminal_prefix = "BV: "; // set default prefix
	terminal_process = &process_command; // set central function to process commands
	terminal_setup(); // start terminal

	// setup OLED display
	sleep_ms(10); // wait a bit until the display is ready
	busvoodoo_oled_setup(); // setup OLED display

	// setup default mode
	switch_mode(NULL);

	// main loop
	bool action = false; // if an action has been performed don't go to sleep
	button_flag = false; // reset button flag
	while (true) { // infinite loop
		while (user_input_available) { // user input received
			action = true; // action has been performed
			char c = user_input_get(); // get user input
			if (0x04==c) { // CTRL+D is used to quit the mode
				printf("quit\n"); // acknowledge quitting
				command_quit(NULL); // quit current mode
			} else {
				terminal_send(c); // send received character to terminal
			}
		}
		if (action) { // go to sleep if nothing had to be done, else recheck for activity
			action = false;
		} else {
			__WFI(); // go to sleep
		}
	} // main loop
}