/*
  Copyright 2014 Ralf Schmitt <ralf@bunkertor.net>
  Copyright 2016 Daniel Svensson <dsvensson@gmail.com>

  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 2 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/>.
*/

#include <stdint.h>
#include <stdbool.h>
#include <avr/io.h>
#include <util/delay.h>
#include "wait.h"
#include "print.h"
#include "debug.h"
#include "util.h"
#include "matrix.h"
#include "debounce.h"

static matrix_row_t matrix[MATRIX_ROWS];
static matrix_row_t matrix_debouncing[MATRIX_ROWS];

static matrix_row_t read_cols(void);
static void         select_row(uint8_t col);

// user-defined overridable functions

__attribute__((weak)) void matrix_init_kb(void) {
    matrix_init_user();
}

__attribute__((weak)) void matrix_scan_kb(void) {
    matrix_scan_user();
}

__attribute__((weak)) void matrix_init_user(void) {}

__attribute__((weak)) void matrix_scan_user(void) {}

// helper functions

inline uint8_t matrix_rows(void) {
    return MATRIX_ROWS;
}

inline uint8_t matrix_cols(void) {
    return MATRIX_COLS;
}

void matrix_init(void) {
    /* Column output pins */
    DDRD |= 0b01111011;
    /* Row input pins */
    DDRC &= ~0b10000000;
    DDRB &= ~0b01111111;
    PORTC |= 0b10000000;
    PORTB |= 0b01111111;

    for (uint8_t i = 0; i < matrix_rows(); i++) {
        matrix[i]            = 0;
        matrix_debouncing[i] = 0;
    }

    matrix_init_kb();
}

uint8_t matrix_scan(void) {
    bool changed = false;
    for (uint8_t col = 0; col < MATRIX_COLS; col++) {
        select_row(col);
        wait_us(30);
        matrix_row_t rows = read_cols();
        for (uint8_t row = 0; row < matrix_rows(); row++) {
            bool prev_bit = matrix_debouncing[row] & ((matrix_row_t)1 << col);
            bool curr_bit = rows & (1 << row);
            if ((changed |= prev_bit != curr_bit)) {
                matrix_debouncing[row] ^= (matrix_row_t)1 << col;
            }
        }
    }

    debounce(matrix_debouncing, matrix, changed);
    matrix_scan_kb();

    return (uint8_t)changed;
}

inline matrix_row_t matrix_get_row(uint8_t row) {
    return matrix[row];
}

void matrix_print(void) {
    print("\nr/c 0123456789ABCDEF\n");
    for (uint8_t row = 0; row < matrix_rows(); row++) {
        print_hex8(row);
        print(": ");
        print_bin_reverse16(matrix_get_row(row));
        print("\n");
    }
}

static matrix_row_t read_cols(void) {
    return (PINB & (1 << 5) ? 0 : ((matrix_row_t)1 << 0)) | (PINC & (1 << 7) ? 0 : ((matrix_row_t)1 << 1)) | (PINB & (1 << 4) ? 0 : ((matrix_row_t)1 << 2)) | (PINB & (1 << 6) ? 0 : ((matrix_row_t)1 << 3)) | (PINB & (1 << 1) ? 0 : ((matrix_row_t)1 << 4)) | (PINB & (1 << 2) ? 0 : ((matrix_row_t)1 << 5)) | (PINB & (1 << 3) ? 0 : ((matrix_row_t)1 << 6)) | (PINB & (1 << 0) ? 0 : ((matrix_row_t)1 << 7));
}

static void select_row(uint8_t col) {
    switch (col) {
        case 0:
            PORTD = (PORTD & ~0b01111011) | 0b00011011;
            break;
        case 1:
            PORTD = (PORTD & ~0b01111011) | 0b01000011;
            break;
        case 2:
            PORTD = (PORTD & ~0b01111011) | 0b01100000;
            break;
        case 3:
            PORTD = (PORTD & ~0b01111011) | 0b01111001;
            break;
        case 4:
            PORTD = (PORTD & ~0b01111011) | 0b01100010;
            break;
        case 5:
            PORTD = (PORTD & ~0b01111011) | 0b01101010;
            break;
        case 6:
            PORTD = (PORTD & ~0b01111011) | 0b01110001;
            break;
        case 7:
            PORTD = (PORTD & ~0b01111011) | 0b01101001;
            break;
        case 8:
            PORTD = (PORTD & ~0b01111011) | 0b01100001;
            break;
        case 9:
            PORTD = (PORTD & ~0b01111011) | 0b01111000;
            break;
        case 10:
            PORTD = (PORTD & ~0b01111011) | 0b00100011;
            break;
        case 11:
            PORTD = (PORTD & ~0b01111011) | 0b00101011;
            break;
        case 12:
            PORTD = (PORTD & ~0b01111011) | 0b00110011;
            break;
        case 13:
            PORTD = (PORTD & ~0b01111011) | 0b01110000;
            break;
        case 14:
            PORTD = (PORTD & ~0b01111011) | 0b00010011;
            break;
        case 15:
            PORTD = (PORTD & ~0b01111011) | 0b01101000;
            break;
        case 16:
            PORTD = (PORTD & ~0b01111011) | 0b00001011;
            break;
        case 17:
            PORTD = (PORTD & ~0b01111011) | 0b00111011;
            break;
    }
}