/*
Copyright 2022, Savanni D'Gerinel <savanni@luminescent-dreams.com>

This file is part of Savanni's AVR library.

This AVR library 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 AVR library 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 AVR library. If not, see <https://www.gnu.org/licenses/>.
*/

#include <dio.h>
#include <stdio.h>
#include <stdlib.h>
#include <util/delay.h>

#include "display.h"

#define ENABLE   _BV(5)
#define CHARCODE _BV(4)

void ping(dio_t *light) {
    dio_set(light, 1);
    _delay_ms(100);
    dio_set(light, 0);
    _delay_ms(100);
}


void send_half_code(display_t *disp, uint8_t reg, uint8_t data) {
    sr_send_msb(&disp->reg, (reg ? CHARCODE : 0) | data << 2);
    _delay_us(1);
    sr_send_msb(&disp->reg, (ENABLE | (reg ? CHARCODE : 0) | data) << 2);
    _delay_us(1);
    sr_send_msb(&disp->reg, ((reg ? CHARCODE : 0) | data) << 2);
    _delay_us(1);
}


void send_code(display_t *disp, uint8_t reg, uint8_t data) {
    send_half_code(disp, reg, data >> 4);
    send_half_code(disp, reg, data & 0xf);
}

void write_instruction(display_t *disp, uint8_t bitcode) {
    send_code(disp, 0, bitcode);
}

void write_char(display_t *disp, uint8_t bitcode) {
    send_code(disp, 1, bitcode);
    _delay_us(100);
}

void display_init(display_t *disp) {
    sr_initialize(&disp->reg);

    /* Initializing for 4-bit channel */
    send_half_code(disp, 0, 0b0011);
    _delay_ms(5);
    send_half_code(disp, 0, 0b0011);
    _delay_us(150);
    send_half_code(disp, 0, 0b0011);
    _delay_us(100);
    send_half_code(disp, 0, 0b0010);
    _delay_us(100);

    /* Function set, 4-bit channel, two lines, 5x10 dots */
    write_instruction(disp, 0b00101000);
    _delay_us(100);

    /* display off */
    write_instruction(disp, 0b00001000);
    _delay_us(100);

    /* display clear */
    write_instruction(disp, 0b00000001);
    _delay_ms(3);

    /* set entry mode */
    write_instruction(disp, 0b00000110);
    _delay_us(100);

    /* display on */
    write_instruction(disp, 0b00001100);
    _delay_us(100);
}

void display_clear(display_t *disp) {
    write_instruction(disp, 0b00000001);
    _delay_us(100);
    write_instruction(disp, 0b00000010);
    _delay_us(100);

}

void display_enable(display_t *disp) {
    write_instruction(disp, _BV(5));
    _delay_us(100);
    write_instruction(disp, _BV(5) | _BV(3));
    _delay_us(100);
}

void display_set_location(display_t *disp, size_t row, size_t column) {
    size_t addr = row * 40 + column;
    write_instruction(disp, 0b10000000 | addr);
    _delay_us(100);
}

void display_write_message(display_t *disp, const char *msg) {
    for (size_t i = 0; msg[i] != 0; i++) {
        write_char(disp, msg[i]);
    }
}

void display_write_bit_pattern(display_t *disp, const uint8_t pattern) {
    char msg[16];
    sprintf(msg, "* ");
    for (int i = 7; i >= 0; i--) {
        if (pattern & _BV(i)) {
            display_write_message(disp, "1");
        } else {
            display_write_message(disp, "0");
        }
    }
}