/*
Copyright 2011 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/>.
*/

#include <stdint.h>
#include <stdbool.h>
#include <avr/io.h>
#include <util/delay.h>
#include "print.h"
#include "util.h"
#include "debug.h"
#include "ps2.h"
#include "matrix.h"


static void matrix_make(uint8_t code);
static void matrix_break(uint8_t code);
#ifdef MATRIX_HAS_GHOST
static bool matrix_has_ghost_in_row(uint8_t row);
#endif


/*
 * Matrix Array usage:
 * 'Scan Code Set 3' is assigned into 17x8 cell matrix.
 *
 *    8bit wide
 *   +---------+
 *  0|         |
 *  :|         | 0x00-0x87
 *  ;|         |
 * 17|         |
 *   +---------+
 */
static uint8_t matrix[MATRIX_ROWS];
#define ROW(code)      (code>>3)
#define COL(code)      (code&0x07)

static bool is_modified = false;


inline
uint8_t matrix_rows(void)
{
    return MATRIX_ROWS;
}

inline
uint8_t matrix_cols(void)
{
    return MATRIX_COLS;
}

void matrix_init(void)
{
    print_enable = true;
    debug_enable = true;
    //debug_matrix = true;
    //debug_keyboard = true;
    //debug_mouse = false;

    ps2_host_init();
    // Make and Break code without Typematic
    while (ps2_host_send(0xF8) != 0xFA) {
        debug("send F8: failed\n");
        _delay_ms(500);
    }
    debug("send F8: OK\n");


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

    return;
}

uint8_t matrix_scan(void)
{

    // scan code reading states
    static enum {
        INIT,
        F0,
    } state = INIT;


    is_modified = false;

    uint8_t code;
    while ((code = ps2_host_recv())) {
        debug_hex(code);
        switch (state) {
            case INIT:
                switch (code) {
                    case 0xF0:
                        state = F0;
                        debug(" ");
                        break;
                    default:    // normal key make
                        if (code < 0x88) {
                            matrix_make(code);
                        } else {
                            debug("unexpected scan code at INIT: "); debug_hex(code); debug("\n");
                        }
                        state = INIT;
                        debug("\n");
                }
                break;
            case F0:    // Break code
                switch (code) {
                    default:
                    if (code < 0x88) {
                        matrix_break(code);
                    } else {
                        debug("unexpected scan code at F0: "); debug_hex(code); debug("\n");
                    }
                    state = INIT;
                    debug("\n");
                }
                break;
        }
    }
    return 1;
}

bool matrix_is_modified(void)
{
    return 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
uint8_t matrix_get_row(uint8_t row)
{
    return matrix[row];
}

void matrix_print(void)
{
    print("\nr/c 01234567\n");
    for (uint8_t row = 0; row < matrix_rows(); row++) {
        phex(row); print(": ");
        pbin_reverse(matrix_get_row(row));
#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++) {
        count += bitpop(matrix[i]);
    }
    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 matrix_make(uint8_t code)
{
    if (!matrix_is_on(ROW(code), COL(code))) {
        matrix[ROW(code)] |= 1<<COL(code);
        is_modified = true;
    }
}

inline
static void matrix_break(uint8_t code)
{
    if (matrix_is_on(ROW(code), COL(code))) {
        matrix[ROW(code)] &= ~(1<<COL(code));
        is_modified = true;
    }
}