/* Copyright 2021 Jasper Chan
 *           2023 Huckies <https://github.com/Huckies>
 *
 * 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 "aw20216s.h"
#include "wait.h"
#include "spi_master.h"

#define AW20216S_PWM_REGISTER_COUNT 216

#ifndef AW20216S_CONFIGURATION
#    define AW20216S_CONFIGURATION (AW20216S_CONFIGURATION_SWSEL_1_12 | AW20216S_CONFIGURATION_CHIPEN)
#endif

#ifndef AW20216S_MIX_FUNCTION
#    define AW20216S_MIX_FUNCTION (AW20216S_MIX_FUNCTION_LPEN)
#endif

#ifndef AW20216S_SCALING_MAX
#    define AW20216S_SCALING_MAX 150
#endif

#ifndef AW20216S_GLOBAL_CURRENT_MAX
#    define AW20216S_GLOBAL_CURRENT_MAX 150
#endif

#ifndef AW20216S_SPI_MODE
#    define AW20216S_SPI_MODE 0
#endif

#ifndef AW20216S_SPI_DIVISOR
#    define AW20216S_SPI_DIVISOR 4
#endif

typedef struct aw20216s_driver_t {
    uint8_t pwm_buffer[AW20216S_PWM_REGISTER_COUNT];
    bool    pwm_buffer_dirty;
} PACKED aw20216s_driver_t;

aw20216s_driver_t driver_buffers[AW20216S_DRIVER_COUNT] = {{
    .pwm_buffer       = {0},
    .pwm_buffer_dirty = false,
}};

bool aw20216s_write(pin_t cs_pin, uint8_t page, uint8_t reg, uint8_t* data, uint8_t len) {
    static uint8_t s_spi_transfer_buffer[2] = {0};

    if (!spi_start(cs_pin, false, AW20216S_SPI_MODE, AW20216S_SPI_DIVISOR)) {
        spi_stop();
        return false;
    }

    s_spi_transfer_buffer[0] = (AW20216S_ID | page | AW20216S_WRITE);
    s_spi_transfer_buffer[1] = reg;

    if (spi_transmit(s_spi_transfer_buffer, 2) != SPI_STATUS_SUCCESS) {
        spi_stop();
        return false;
    }

    if (spi_transmit(data, len) != SPI_STATUS_SUCCESS) {
        spi_stop();
        return false;
    }

    spi_stop();
    return true;
}

static inline bool aw20216s_write_register(pin_t cs_pin, uint8_t page, uint8_t reg, uint8_t value) {
    // Little wrapper so callers need not care about sending a buffer
    return aw20216s_write(cs_pin, page, reg, &value, 1);
}

void aw20216s_soft_reset(pin_t cs_pin) {
    aw20216s_write_register(cs_pin, AW20216S_PAGE_FUNCTION, AW20216S_FUNCTION_REG_RESET, AW20216S_RESET_MAGIC);
}

static void aw20216s_init_scaling(pin_t cs_pin) {
    // Set constant current to the max, control brightness with PWM
    for (uint8_t i = 0; i < AW20216S_PWM_REGISTER_COUNT; i++) {
        aw20216s_write_register(cs_pin, AW20216S_PAGE_SCALING, i, AW20216S_SCALING_MAX);
    }
}

static inline void aw20216s_init_current_limit(pin_t cs_pin) {
    // Push config
    aw20216s_write_register(cs_pin, AW20216S_PAGE_FUNCTION, AW20216S_FUNCTION_REG_GLOBAL_CURRENT, AW20216S_GLOBAL_CURRENT_MAX);
}

static inline void aw20216s_soft_enable(pin_t cs_pin) {
    // Push config
    aw20216s_write_register(cs_pin, AW20216S_PAGE_FUNCTION, AW20216S_FUNCTION_REG_CONFIGURATION, AW20216S_CONFIGURATION);
}

static inline void aw20216s_auto_lowpower(pin_t cs_pin) {
    aw20216s_write_register(cs_pin, AW20216S_PAGE_FUNCTION, AW20216S_FUNCTION_REG_MIX_FUNCTION, AW20216S_MIX_FUNCTION);
}

void aw20216s_init_drivers(void) {
    spi_init();

#if defined(AW20216S_EN_PIN)
    gpio_set_pin_output(AW20216S_EN_PIN);
    gpio_write_pin_high(AW20216S_EN_PIN);
#endif

    aw20216s_init(AW20216S_CS_PIN_1);
#if defined(AW20216S_CS_PIN_2)
    aw20216s_init(AW20216S_CS_PIN_2);
#endif
}

void aw20216s_init(pin_t cs_pin) {
    aw20216s_soft_reset(cs_pin);
    wait_ms(2);

    // Drivers should start with all scaling and PWM registers as off
    aw20216s_init_current_limit(cs_pin);
    aw20216s_init_scaling(cs_pin);

    aw20216s_soft_enable(cs_pin);
    aw20216s_auto_lowpower(cs_pin);
}

void aw20216s_set_color(int index, uint8_t red, uint8_t green, uint8_t blue) {
    aw20216s_led_t led;
    memcpy_P(&led, (&g_aw20216s_leds[index]), sizeof(led));

    if (driver_buffers[led.driver].pwm_buffer[led.r] == red && driver_buffers[led.driver].pwm_buffer[led.g] == green && driver_buffers[led.driver].pwm_buffer[led.b] == blue) {
        return;
    }

    driver_buffers[led.driver].pwm_buffer[led.r] = red;
    driver_buffers[led.driver].pwm_buffer[led.g] = green;
    driver_buffers[led.driver].pwm_buffer[led.b] = blue;
    driver_buffers[led.driver].pwm_buffer_dirty  = true;
}

void aw20216s_set_color_all(uint8_t red, uint8_t green, uint8_t blue) {
    for (uint8_t i = 0; i < AW20216S_LED_COUNT; i++) {
        aw20216s_set_color(i, red, green, blue);
    }
}

void aw20216s_update_pwm_buffers(pin_t cs_pin, uint8_t index) {
    if (driver_buffers[index].pwm_buffer_dirty) {
        aw20216s_write(cs_pin, AW20216S_PAGE_PWM, 0, driver_buffers[index].pwm_buffer, AW20216S_PWM_REGISTER_COUNT);
        driver_buffers[index].pwm_buffer_dirty = false;
    }
}

void aw20216s_flush(void) {
    aw20216s_update_pwm_buffers(AW20216S_CS_PIN_1, 0);
#if defined(AW20216S_CS_PIN_2)
    aw20216s_update_pwm_buffers(AW20216S_CS_PIN_2, 1);
#endif
}
