// Copyright 2022 Christopher Courtney, aka Drashna Jael're  (@drashna) <drashna@live.com>
// SPDX-License-Identifier: GPL-2.0-or-later

/*
 * scan matrix
 */
#include "matrix.h"
#include <string.h>
#include "atomic_util.h"
#include "wait.h"
#include "debug.h"
#include "util.h"
#include "debounce.h"

/* matrix state(1:on, 0:off) */
extern matrix_row_t matrix[MATRIX_ROWS];     // debounced values
extern matrix_row_t raw_matrix[MATRIX_ROWS]; // raw values

static const pin_t row_pins[MATRIX_ROWS] = MATRIX_ROW_PINS;
static const pin_t col_pins[MATRIX_COLS] = MATRIX_COL_PINS;
#define MATRIX_ROW_SHIFTER ((matrix_row_t)1)

static inline void setPinOutput_writeLow(pin_t pin) {
    ATOMIC_BLOCK_FORCEON {
        gpio_set_pin_output(pin);
        gpio_write_pin_low(pin);
    }
}

static inline void setPinOutput_writeHigh(pin_t pin) {
    ATOMIC_BLOCK_FORCEON {
        gpio_set_pin_output(pin);
        gpio_write_pin_high(pin);
    }
}

static inline void setPinInputHigh_atomic(pin_t pin) {
    ATOMIC_BLOCK_FORCEON {
        gpio_set_pin_input_high(pin);
    }
}

static inline uint8_t readMatrixPin(pin_t pin) {
    if (pin != NO_PIN) {
        return gpio_read_pin(pin);
    } else {
        return 1;
    }
}

static bool select_row(uint8_t row) {
    pin_t pin = row_pins[row];
    if (pin != NO_PIN) {
        setPinOutput_writeLow(pin);
        return true;
    }
    return false;
}

static void unselect_row(uint8_t row) {
    pin_t pin = row_pins[row];
    if (pin != NO_PIN) {
        setPinInputHigh_atomic(pin);
    }
}

static void unselect_rows(void) {
    for (uint8_t x = 0; x < MATRIX_ROWS; x++) {
        unselect_row(x);
    }
}

__attribute__((weak)) void matrix_init_custom(void) {
    unselect_rows();
    for (uint8_t x = 0; x < MATRIX_COLS; x++) {
        if (col_pins[x] != NO_PIN) {
            setPinInputHigh_atomic(col_pins[x]);
        }
    }
    setPinInputHigh_atomic(F7);
    setPinInputHigh_atomic(F0);
}

void matrix_read_cols_on_row(matrix_row_t current_matrix[], uint8_t current_row) {
    // Start with a clear matrix row
    matrix_row_t current_row_value = 0;

    if (!select_row(current_row)) { // Select row
        return;                     // skip NO_PIN row
    }
    matrix_output_select_delay();

    // For each col...
    matrix_row_t row_shifter = MATRIX_ROW_SHIFTER;
    for (uint8_t col_index = 0; col_index < MATRIX_COLS; col_index++, row_shifter <<= 1) {
        uint8_t pin_state = 0;
        if (current_row == 3 && col_index == 0) {
            pin_state = !readMatrixPin(F7);
        } else if (current_row == 3 && col_index == 3) {
            pin_state = !readMatrixPin(F0);
        } else {
            pin_state = readMatrixPin(col_pins[col_index]);
        }
        // Populate the matrix row with the state of the col pin
        current_row_value |= pin_state ? 0 : row_shifter;
    }

    // Unselect row
    unselect_row(current_row);
    matrix_output_unselect_delay(current_row, current_row_value != 0); // wait for all Col signals to go HIGH

    // Update the matrix
    current_matrix[current_row] = current_row_value;
}

bool matrix_scan_custom(matrix_row_t current_matrix[]) {
    static matrix_row_t temp_matrix[MATRIX_ROWS] = {0};

    for (uint8_t current_row = 0; current_row < MATRIX_ROWS; current_row++) {
        matrix_read_cols_on_row(temp_matrix, current_row);
    }

    bool changed = memcmp(current_matrix, temp_matrix, sizeof(temp_matrix)) != 0;
    if (changed) {
        memcpy(current_matrix, temp_matrix, sizeof(temp_matrix));
    }
    return changed;
}