/*

Copyright 2013 Oleg Kostyuk <cub.uanic@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 "matrix.h"
#include <stdint.h>
#include <stdbool.h>
#include <avr/io.h>
#include "wait.h"
#include "action_layer.h"
#include "print.h"
#include "debug.h"
#include "util.h"
#include "debounce.h"
#include "gergoplex.h"

#ifdef BALLER
#    include <avr/interrupt.h>
#    include "pointing_device.h"
#endif

#ifndef DEBOUNCE
#    define DEBOUNCE 5
#endif

// ATmega pin defs
#define COL1 (1 << 6)
#define COL2 (1 << 5)
#define COL3 (1 << 4)
#define COL4 (1 << 1)

/* matrix state(1:on, 0:off) */
static matrix_row_t matrix[MATRIX_ROWS];
/*
 * matrix state(1:on, 0:off)
 * contains the raw values without debounce filtering of the last read cycle.
 */
static matrix_row_t raw_matrix[MATRIX_ROWS];

static const pin_t col_pins[MATRIX_COLS] = MATRIX_COL_PINS;
// Right-hand side only pins, the left side is controlled my MCP
static const pin_t row_pins[MATRIX_ROWS_PER_SIDE] = MATRIX_ROW_PINS;

// Debouncing: store for each key the number of scans until it's eligible to
// change.  When scanning the matrix, ignore any changes in keys that have
// already changed in the last DEBOUNCE scans.

static matrix_row_t read_cols(uint8_t row);
static void         init_cols(void);
static void         unselect_rows(void);
static void         select_row(uint8_t row);

static uint8_t mcp23018_reset_loop;

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

void matrix_init(void) {
    // initialize row and col
    mcp23018_status = init_mcp23018();
    unselect_rows();
    init_cols();

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

    debounce_init(MATRIX_ROWS);
    matrix_init_kb();
}
void matrix_power_up(void) {
    mcp23018_status = init_mcp23018();

    unselect_rows();
    init_cols();

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

// Reads and stores a row, returning
// whether a change occurred.
static inline bool store_raw_matrix_row(uint8_t index) {
    matrix_row_t temp = read_cols(index);
    if (raw_matrix[index] != temp) {
        raw_matrix[index] = temp;
        return true;
    }
    return false;
}
uint8_t matrix_scan(void) {
    if (mcp23018_status) {  // if there was an error
        if (++mcp23018_reset_loop == 0) {
            // if (++mcp23018_reset_loop >= 1300) {
            // since mcp23018_reset_loop is 8 bit - we'll try to reset once in 255 matrix scans
            // this will be approx bit more frequent than once per second
            print("trying to reset mcp23018\n");
            mcp23018_status = init_mcp23018();
            if (mcp23018_status) {
                print("left side not responding\n");
            } else {
                print("left side attached\n");
            }
        }
    }

    bool changed = false;
    for (uint8_t i = 0; i < MATRIX_ROWS_PER_SIDE; i++) {
        // select rows from left and right hands
        uint8_t left_index  = i;
        uint8_t right_index = i + MATRIX_ROWS_PER_SIDE;
        select_row(left_index);
        select_row(right_index);

        // we don't need a 30us delay anymore, because selecting a
        // left-hand row requires more than 30us for i2c.

        changed |= store_raw_matrix_row(left_index);
        changed |= store_raw_matrix_row(right_index);

        unselect_rows();
    }

    debounce(raw_matrix, matrix, MATRIX_ROWS, changed);
    matrix_scan_kb();

#ifdef DEBUG_MATRIX
    for (uint8_t c = 0; c < MATRIX_COLS; c++)
        for (uint8_t r = 0; r < MATRIX_ROWS; r++)
            if (matrix_is_on(r, c)) xprintf("r:%d c:%d \n", r, c);
#endif

    return 1;
}

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++) {
        print_hex8(row);
        print(": ");
        print_bin_reverse16(matrix_get_row(row));
        print("\n");
    }
}

// Remember this means ROWS
static void init_cols(void) {
    for (uint8_t col = 0; col < MATRIX_COLS; col++) {
      setPinInputHigh(col_pins[col]);
    }
}

static matrix_row_t read_cols(uint8_t row) {
    if (row < 5) {
        if (mcp23018_status) {  // if there was an error
            return 0;
        } else {
            uint8_t data    = 0;
            mcp23018_status = i2c_start(I2C_ADDR_READ, I2C_TIMEOUT);
            if (mcp23018_status) goto out;
            mcp23018_status = i2c_read_nack(I2C_TIMEOUT);
            if (mcp23018_status < 0) goto out;
            data            = ~((uint8_t)mcp23018_status);
            mcp23018_status = I2C_STATUS_SUCCESS;
        out:
            i2c_stop();

#ifdef DEBUG_MATRIX
            if (data != 0x00) xprintf("I2C: %d\n", data);
#endif
            return data;
        }
    } else {
        return ~((((PINF & COL4) >> 1) | ((PINF & (COL1 | COL2 | COL3)) >> 3)) & 0xF);
    }
}

// Row pin configuration
static void unselect_rows(void) {
    // no need to unselect on mcp23018, because the select step sets all
    // the other row bits high, and it's not changing to a different direction

    for (uint8_t row = 0; row < MATRIX_ROWS_PER_SIDE; row++) {
      setPinInput(row_pins[row]);
      writePinLow(row_pins[row]);
    }
}

static void select_row(uint8_t row) {
    if (row < 5) {
        // select on mcp23018
        if (mcp23018_status) {  // do nothing on error
        } else {                // set active row low  : 0 // set other rows hi-Z : 1
            mcp23018_status = i2c_start(I2C_ADDR_WRITE, I2C_TIMEOUT);
            if (mcp23018_status) goto out;
            mcp23018_status = i2c_write(GPIOA, I2C_TIMEOUT);
            if (mcp23018_status) goto out;
            mcp23018_status = i2c_write(0xFF & ~(1 << (row + 1)), I2C_TIMEOUT);
            if (mcp23018_status) goto out;
        out:
            i2c_stop();
        }
    } else {
        setPinOutput(row_pins[row - MATRIX_ROWS_PER_SIDE]);
        writePinLow(row_pins[row - MATRIX_ROWS_PER_SIDE]);
    }
}
