/*
Copyright 2012 Jun Wako <wakojun@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/>.
*/

/*
 * scan matrix
 */
#include <stdint.h>
#include <stdbool.h>
#include <avr/io.h>
#include <util/delay.h>
#include "action_layer.h"
#include "print.h"
#include "debug.h"
#include "util.h"
#include "matrix.h"
#include "analog.h"


#ifndef DEBOUNCE
#   define DEBOUNCE	10
#endif
static uint8_t debouncing = DEBOUNCE;

/* matrix state(1:on, 0:off) */
static matrix_row_t matrix[MATRIX_ROWS];
static matrix_row_t matrix_debouncing[MATRIX_ROWS];

static matrix_row_t read_cols(void);
static void init_cols(void);
static void init_encoder(void);
static void init_pot(void);
static void unselect_rows(void);
static void select_row(uint8_t row);
int16_t analogRead(uint8_t pin);
uint8_t state;
int32_t position;
int16_t value;

inline
uint8_t matrix_rows(void)
{
    return MATRIX_ROWS;
}

inline
uint8_t matrix_cols(void)
{
    return MATRIX_COLS;
}

void matrix_init(void)
{
    // initialize row and col
    unselect_rows();
    init_cols();
    init_encoder();
    init_pot();

    // initialize matrix state: all keys off
    for (uint8_t i=0; i < MATRIX_ROWS; i++) {
        matrix[i] = 0;
        matrix_debouncing[i] = 0;
    }
}

static void init_encoder(void)
{
    DDRC &= ~(1<<6 | 1<<7);
    PORTC |=  (1<<6 | 1<<7);

    uint8_t s = 0;
    _delay_ms(1);
    if (PINC&(1<<6)) s |= 1;
    if (PINC&(1<<7)) s |= 2;
    state = s;
    position = 0;
}

void read_encoder(void)
{
    uint8_t s = state & 3;
    if (PINC&(1<<6)) s |= 4;
    if (PINC&(1<<7)) s |= 8;
    state = (s >> 2);
    switch (s) {
        case 1: case 7: case 8: case 14:
            position++; 
            break;
        case 2: case 4: case 11: case 13:
            position--; 
            break;
        case 3: case 12:
            position += 2; 
            break;
        case 6: case 9:
            position -= 2; 
            break;
    }
}

#define HEX(n) (((n) < 10) ? ((n) + '0') : ((n) + 'A' - 10))

static void init_pot(void)
{
    // DDRD &= ~(1<<4);
    // PORTD |=  (1<<4);
    // DIDR2 = (1<<0);
}

uint8_t matrix_scan(void)
{
    for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
        select_row(i);
        _delay_us(30);  // without this wait read unstable value.
        matrix_row_t cols = read_cols();
        if (matrix_debouncing[i] != cols) {
            matrix_debouncing[i] = cols;
            if (debouncing) {
                debug("bounce!: "); debug_hex(debouncing); debug("\n");
            }
            debouncing = DEBOUNCE;
        }
        unselect_rows();
    }

    if (debouncing) {
        if (--debouncing) {
            _delay_ms(1);
        } else {
            for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
                matrix[i] = matrix_debouncing[i];
            }
        }
    }

    read_encoder();
    if (position >= 2) {
        register_code(KC_AUDIO_VOL_UP);
        unregister_code(KC_AUDIO_VOL_UP);
        position = 0;
    } else if (position <= -2) {
        register_code(KC_AUDIO_VOL_DOWN);
        unregister_code(KC_AUDIO_VOL_DOWN);
        position = 0;
    }

    uint16_t val = analogRead(11);

    debug("analogRead: "); debug_hex(val); debug("\n");

    return 1;
}

bool matrix_is_modified(void)
{
    if (debouncing) return false;
    return true;
}

inline
bool matrix_is_on(uint8_t row, uint8_t col)
{
    return (matrix[row] & ((matrix_row_t)1<<col));
}

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++) {
        phex(row); print(": ");
        pbin_reverse16(matrix_get_row(row));
        print("\n");
    }
}

uint8_t matrix_key_count(void)
{
    uint8_t count = 0;
    for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
        count += bitpop16(matrix[i]);
    }
    return count;
}

/* Column pin configuration
 * col: 0  1  2  3  4  5  6  7  8  9  10 11
 * pin: F0 F1 F4 F5 F6 F7 B6 B5 B4 D7 D5 D4
 */

static void init_cols(void)
{
    DDRF  &= ~(1<<0 | 1<<1 | 1<<4 | 1<<5 | 1<<6 | 1<<7);
    PORTF |=  (1<<0 | 1<<1 | 1<<4 | 1<<5 | 1<<6 | 1<<7);
    DDRD  &= ~(1<<0);
    PORTD |=  (1<<0);
    DDRB  &= ~(1<<0 | 1<<1 | 1<<2 | 1<<3 | 1<<7);
    PORTB |=  (1<<0 | 1<<1 | 1<<2 | 1<<3 | 1<<7);
}

static matrix_row_t read_cols(void)
{
    return (PINB&(1<<0) ? 0 : (1<< 0)) |
           (PINB&(1<<1) ? 0 : (1<< 1)) |
           (PINB&(1<<2) ? 0 : (1<< 2)) |
           (PINB&(1<<3) ? 0 : (1<< 3)) |
           (PINB&(1<<7) ? 0 : (1<< 4)) |
           (PIND&(1<<0) ? 0 : (1<< 5)) |
           (PINF&(1<<7) ? 0 : (1<< 6)) |
           (PINF&(1<<6) ? 0 : (1<< 7)) |
           (PINF&(1<<5) ? 0 : (1<< 8)) |
           (PINF&(1<<4) ? 0 : (1<< 9)) |
           (PINF&(1<<1) ? 0 : (1<<10)) |
           (PINF&(1<<0) ? 0 : (1<<11));
}

/* Row pin configuration
 * row: 0  1  2  3
 * pin: B0 B1 B2 B3
 */
static void unselect_rows(void)
{
    // Hi-Z(DDR:0, PORT:0) to unselect
    DDRB  &= ~0b01110000;
    PORTB &= ~0b01110000;
    DDRD  &= ~0b10000000;
    PORTD &= ~0b10000000;
}

static void select_row(uint8_t row)
{
    switch (row) {
        case 0:
            DDRB  |= (1<<6);
            PORTB &= ~(1<<6);
            break;
        case 1:
            DDRB  |= (1<<5);
            PORTB &= ~(1<<5);
            break;
        case 2:
            DDRB  |= (1<<4);
            PORTB &= ~(1<<4);
            break;
        case 3:
            DDRD  |= (1<<7);
            PORTD &= ~(1<<7);
            break;
    }
}
