#include "GDM1602K.h"
#include <avr/io.h>
#include <stdbool.h>
#include <util/delay.h>

void lcd_4bit_init() {
    LCD_DATA_DDR  = 0xFF;
    LCD_DATA_PORT = (1 << LCD_DB5);
    LCD_DATA_PORT &= ~(1 << LCD_RS_PIN);
    _delay_us(1);
    LCD_DATA_PORT |= (1 << LCD_EN_PIN);
    _delay_us(1);
    LCD_DATA_PORT &= ~(1 << LCD_EN_PIN);
    _delay_us(1);
    LCD_DATA_PORT &= ~(1 << LCD_DB5);
    _delay_us(1);
}

void lcd_send(bool rs, uint8_t data) {
    LCD_DATA_DDR  = 0xFF;
    LCD_DATA_PORT = 0x00;

    LCD_DATA_PORT |= (data >> 4) << 3;
    _delay_us(1);

    // If rs (actual text data), set RS pin high
    if (rs == true)
        LCD_DATA_PORT |= (1 << LCD_RS_PIN);

    // Pulse enable
    _delay_ms(2);
    LCD_DATA_PORT |= (1 << LCD_EN_PIN);

    _delay_us(1);
    LCD_DATA_PORT &= ~(1 << LCD_EN_PIN);

    //_delay_us(1);

    // Clear data pins
    LCD_DATA_PORT &= ~(0x0F << 3);

    // Mask the lower bits and shift accordingly
    LCD_DATA_PORT |= (data & 0x0F) << 3;
    _delay_us(1);

    // Pulse enable
    LCD_DATA_PORT |= (1 << LCD_EN_PIN);
    _delay_us(1);
    LCD_DATA_PORT &= ~(1 << LCD_EN_PIN);
    _delay_us(1);
    LCD_DATA_PORT &= ~(0x0F << 3);

    LCD_DATA_PORT &= ~(1 << LCD_RS_PIN); // RS Low
}

void lcd_init() {
    _delay_ms(100);
    lcd_4bit_init();

    // lcd_send(1, 0b01111000);
    lcd_send(0, 0x01);       // Clear screen
    lcd_send(0, 0x02);       // Return home
    lcd_send(0, 0b00001100); // Display on, no cursor
    lcd_send(0, 0b00101000);
}

void lcd_clear() { lcd_send(0, 0x01); }

void test_leds() {
    DDRB |= 0xFF;
    PORTB = (1 << LCD_DB4);
    _delay_us(1);
    PORTB = (1 << LCD_DB5);
    _delay_us(1);
    PORTB = (1 << LCD_DB6);
    _delay_us(1);
    PORTB = (1 << LCD_DB7);
    _delay_us(1);

    PORTB = (1 << LCD_EN_PIN);
    _delay_us(1);
    PORTB = (1 << LCD_RS_PIN);
    _delay_us(1);
    PORTB = 0x00;
}

void lcd_set_cursor(uint8_t row, uint8_t col) {
    uint8_t position = 0x80;

    if (row == 1)
        position += 0x40;

    position += col;
    lcd_send(0, position);
}

// Takes a string and splits it over two lines if needed. Max length is 32
// characters.
void lcd_write_string(const char *string) {
    uint8_t i = 0;
    while (string[i]) {
        if (i == 16) {
            lcd_set_cursor(1, 0);
            while (string[i] == ' ') i++; // Skip leading spaces on the new line
        }
        lcd_send(1, string[i]);
        i++;
    }
}

// Takes two separate strings and prints them on their corresponding row
void lcd_write_strings(const char *top, const char *bottom) {
    uint8_t i = 0;

    while (top[i]) {
        lcd_send(1, top[i]);
        i++;
    }

    i = 0;
    lcd_set_cursor(1, 0);
    while (bottom[i]) {
        lcd_send(1, bottom[i]);
        i++;
    }
}