/*
  $ avr-gcc -Werror -mmcu=atmega162 -Os -o test_lcd.elf -DF_CPU=1000000 -Wall -Waddr-space-convert -include $AVRTEST/avrtest.h test_lcd.c $AVRTEST/exit-atmega162.o
  $ avr-objdump -h -d -S -r -j .text -j .data -j .rodata -j .eeprom -j .boot test_lcd.elf > test_lcd.lst
  $ avr-objdump -P mem-usage test_lcd.elf

test_lcd.elf:     file format elf32-avr
AVR Memory Usage
----------------
Device: atmega162

Program:    2512 bytes (15.3% Full)
(.text + .data + .rodata + .bootloader)

Data:         38 bytes (3.7% Full)
(.data + .bss + .noinit)

  $ avrtest -mmcu=avr5 test_lcd.elf
gestartet

lcd_clrscr()
@LCD(0,0): 0 Testzeile 1
@LCD(0,1): 0 Testzeile 2
@LCD(0,2): 0 Testzeile 3
@LCD(0,3): 0 Testzeile 4anzeige_version()
lcd_clrscr()
@LCD(0,0): 1 Testzeile 1
@LCD(0,1): 1 Testzeile 2
@LCD(0,2): 1 Testzeile 3
@LCD(0,3): 1 Testzeile 4eingabe_betrieb()
lcd_clrscr()
@LCD(0,0): 1 Testzeile 1
@LCD(0,1): 1 Testzeile 2
@LCD(0,2): 1 Testzeile 3
@LCD(0,3): 1 Testzeile 4eingabe_betrieb()
lcd_clrscr()
@LCD(0,0): 1 Testzeile 1
@LCD(0,1): 1 Testzeile 2
@LCD(0,2): 1 Testzeile 3
@LCD(0,3): 1 Testzeile 4eingabe_betrieb()
lcd_clrscr()
@LCD(0,0): 1 Testzeile 1
@LCD(0,1): 1 Testzeile 2
@LCD(0,2): 1 Testzeile 3
@LCD(0,3): 1 Testzeile 4eingabe_betrieb()
 exit status: EXIT
      reason: exit 0 function called
     program: test_lcd.elf
exit address: 0009b0
total cycles: 10015462
total instr.: 8009073
*/

#include <stdlib.h>
#include <avr/io.h>
#include <stdbool.h>
#include <avr/interrupt.h>
#include <util/delay.h>
#include <stdio.h>

#ifdef AVRTEST_H
#include <avr/pgmspace.h> // PSTR
#include <ctype.h>
#endif

#define UART_BAUD_RATE   9600      // 9600 baud

#define NEXT_STATE      1
#define PREVIOUS_STATE  0

#define LCD_LINES           4
#define LCD_DISP_LENGTH     20
#define LCD_IO_DATA         0xC000
// A15=1, A14=0 ==> Instruction Register
#define LCD_IO_FUNCTION     0x8000

static int8_t anzeige_version(void)
{
#ifdef AVRTEST_H
    LOG_PSTR (PSTR("anzeige_version()"));
#endif

    _delay_ms(2000);
    return NEXT_STATE;
}

static int8_t eingabe_betrieb(void)
{
#ifdef AVRTEST_H
    LOG_PSTR (PSTR("eingabe_betrieb()"));
#endif

    _delay_ms(2000);
    return NEXT_STATE;
}

#define FLIT(X) ((const __flash char[]) { X } ) // AVR-LibC v2.3

typedef struct menu
{
    const __flash char *texte[LCD_LINES];
    const int8_t previous;
    const int8_t next;
    int8_t (*fp) (void);
} t_menu;

const __flash t_menu main_menu[] =
{
    {
        {
            FLIT(" 0 Testzeile 1"),
            FLIT(" 0 Testzeile 2"),
            FLIT(" 0 Testzeile 3"),
            FLIT(" 0 Testzeile 4")
        }, 0, 1, anzeige_version
    },
    {
        {
            FLIT(" 1 Testzeile 1"),
            FLIT(" 1 Testzeile 2"),
            FLIT(" 1 Testzeile 3"),
            FLIT(" 1 Testzeile 4")
        }, 1, 1, eingabe_betrieb
    }
};

static inline
void lcd_write (uint8_t d, bool rs)
{
#ifdef AVRTEST_H
    LOG_PFMT_U8 (isprint (d) ? PSTR("%c") : PSTR("{0x%02x}"), d);
#endif
    if (rs)
        *(volatile uint8_t*)(LCD_IO_DATA) = d;
    else
        *(volatile uint8_t*)(LCD_IO_FUNCTION) = d;
}

void lcd_putc (char c)
{
    lcd_write (c, 1);
}

void lcd_puts_p (const __flash char *pstr)
// print string from program memory on lcd (no auto linefeed)
{
    char c;

    while ((c = *pstr++))
    {
        lcd_putc (c);
    }
}

void lcd_clrscr (void)
{
#ifdef AVRTEST_H
    LOG_PSTR (PSTR ("\nlcd_clrscr()"));
#endif
}

void lcd_gotoxy (uint8_t x, uint8_t y)
{
#ifdef AVRTEST_H
    LOG_PFMT_U8 (PSTR ("\n@LCD(%u,"), x);
    LOG_PFMT_U8 (PSTR ("%u):"), y);
#endif
}


void show_display_lines (const __flash t_menu *menu)
{
    lcd_clrscr();
    
    const __flash char *const __flash *texte = & menu->texte[0];
    for (int i = 0; i < LCD_LINES; i++)
    {
        lcd_gotoxy (0, i);
        lcd_puts_p (*texte++);
    }
}

int main(void)
{
    int index, new_index;
    
    DDRB |= (1 << PB3) | (1 << PB2) | (1 << PB1) | (1 << PB0);
    PORTB = (1 << PB3) | (1 << PB2) | (1 << PB1) | (1 << PB0);

    PORTB ^= (1 << PB0);
    PORTB ^= (1 << PB1);

    printf_P (PSTR("gestartet\n"));

    index = 0;
    for (;;)
    {
        for (;;)
        {
            const __flash t_menu *menu = &main_menu[index];
            show_display_lines (menu);
            new_index = menu->fp();
            if (new_index == 0)
                index = menu->previous;
            else
                index = menu->next;

#ifdef AVRTEST_H
            static int count;
            if (++count > 4)
                return 0;
#endif
        }
    }
}