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


#if (MATRIX_COLS > 16)
#   error "MATRIX_COLS must not exceed 16"
#endif
#if (MATRIX_ROWS > 255)
#   error "MATRIX_ROWS must not exceed 255"
#endif


static bool _matrix_is_modified = false;

// matrix state buffer(1:on, 0:off)
#if (MATRIX_COLS <= 8)
static uint8_t *matrix;
static uint8_t _matrix0[MATRIX_ROWS];
#else
static uint16_t *matrix;
static uint16_t _matrix0[MATRIX_ROWS];
#endif

#ifdef MATRIX_HAS_GHOST
static bool matrix_has_ghost_in_row(uint8_t row);
#endif
static void _register_key(uint8_t key);


inline
uint8_t matrix_rows(void)
{
    return MATRIX_ROWS;
}

inline
uint8_t matrix_cols(void)
{
    return MATRIX_COLS;
}

void matrix_init(void)
{
    adb_host_init();

    // initialize matrix state: all keys off
    for (uint8_t i=0; i < MATRIX_ROWS; i++) _matrix0[i] = 0x00;
    matrix = _matrix0;

    print_enable = true;
    debug_enable = true;
    debug_matrix = true;
    debug_keyboard = true;
    debug_mouse = true;
    print("debug enabled.\n");
    return;
}

uint8_t matrix_scan(void)
{
    uint16_t codes;
    uint8_t key0, key1;

    _matrix_is_modified = false;

    codes = adb_host_kbd_recv();
    key0 = codes>>8;
    key1 = codes&0xFF;

    if (codes == 0) {                           // no keys
        return 0;
    } else if (key0 == 0xFF && key1 != 0xFF) {  // error
        return codes&0xFF;
    } else {
        _matrix_is_modified = true;
        _register_key(key0);
        if (key1 != 0xFF)       // key1 is 0xFF when no second key.
            _register_key(key1);
    }

    if (debug_matrix && matrix_is_modified()) {
        print("adb_host_kbd_recv: "); phex16(codes); print("\n");
    }
    return 1;
}

bool matrix_is_modified(void)
{
    return _matrix_is_modified;
}

inline
bool matrix_has_ghost(void)
{
#ifdef MATRIX_HAS_GHOST
    for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
        if (matrix_has_ghost_in_row(i))
            return true;
    }
#endif
    return false;
}

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

inline
#if (MATRIX_COLS <= 8)
uint8_t matrix_get_row(uint8_t row)
#else
uint16_t matrix_get_row(uint8_t row)
#endif
{
    return matrix[row];
}

void matrix_print(void)
{
#if (MATRIX_COLS <= 8)
    print("\nr/c 01234567\n");
#else
    print("\nr/c 0123456789ABCDEF\n");
#endif
    for (uint8_t row = 0; row < matrix_rows(); row++) {
        phex(row); print(": ");
#if (MATRIX_COLS <= 8)
        pbin_reverse(matrix_get_row(row));
#else
        pbin_reverse16(matrix_get_row(row));
#endif
#ifdef MATRIX_HAS_GHOST
        if (matrix_has_ghost_in_row(row)) {
            print(" <ghost");
        }
#endif
        print("\n");
    }
}

uint8_t matrix_key_count(void)
{
    uint8_t count = 0;
    for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
#if (MATRIX_COLS <= 8)
        count += bitpop(matrix[i]);
#else
        count += bitpop16(matrix[i]);
#endif
    }
    return count;
}

#ifdef MATRIX_HAS_GHOST
inline
static bool matrix_has_ghost_in_row(uint8_t row)
{
    // no ghost exists in case less than 2 keys on
    if (((matrix[row] - 1) & matrix[row]) == 0)
        return false;

    // ghost exists in case same state as other row
    for (uint8_t i=0; i < MATRIX_ROWS; i++) {
        if (i != row && (matrix[i] & matrix[row]) == matrix[row])
            return true;
    }
    return false;
}
#endif

inline
static void _register_key(uint8_t key)
{
    uint8_t col, row;
    col = key&0x07;
    row = (key>>3)&0x0F;
    if (key&0x80) {
        matrix[row] &= ~(1<<col);
    } else {
        matrix[row] |=  (1<<col);
    }
}
