#include "ws2812.h"

#define PWM_FREQ            800000UL                    /* Number in units of hertz */
#define PWM_1US             (1000000UL / PWM_FREQ)      /* Number of PWM pulses for 1 us */
#define RESET_LEN           100UL                       /* 50us pulse length */
#define RESET_BYTES_COUNT  (RESET_LEN * PWM_1US)        /* Number of reset pulses */

#define BYTES_PER_LED       24                          /* Number of bytes per led */

#define WS2812_LAST_SLOT_LEN    1                       /* Additional 1 byte at the end */
#define WS2812_1            (2 * TIM_PERIOD / 3)        /* Logical 1 value */
#define WS2812_0            (TIM_PERIOD / 3)            /* Logical 0 value */
#define WS2812_RST          0                           /* Reset value */

#define TIM_PRESCALER       0
#define TIM_PERIOD          44 //works

TIM_HandleTypeDef htim3;
DMA_HandleTypeDef hdma_tim3_ch1_trig;
uint32_t data[RESET_BYTES_COUNT + LED_COUNT * BYTES_PER_LED + WS2812_LAST_SLOT_LEN + RESET_BYTES_COUNT];

void WS_Init(void) {
    TIM_MasterConfigTypeDef sMasterConfig;
    TIM_OC_InitTypeDef sConfigOC;
    GPIO_InitTypeDef GPIO_InitStruct;

    /* DMA controller clock enable */
    __HAL_RCC_DMA1_CLK_ENABLE();
    __HAL_RCC_TIM3_CLK_ENABLE();
    __HAL_RCC_GPIOB_CLK_ENABLE();

    /* Init GPIO */
    GPIO_InitStruct.Pin = GPIO_PIN_4;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Pull = GPIO_PULLDOWN;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
    GPIO_InitStruct.Alternate = GPIO_AF2_TIM3;
    HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);

    /* Init timer */
    htim3.Instance = TIM3;
    htim3.Init.Prescaler = TIM_PRESCALER;
    htim3.Init.CounterMode = TIM_COUNTERMODE_UP;
    htim3.Init.Period = TIM_PERIOD;
    htim3.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
    HAL_TIM_PWM_Init(&htim3);

    sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
    sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
    HAL_TIMEx_MasterConfigSynchronization(&htim3, &sMasterConfig);

    /* Init PWM channel */
    sConfigOC.OCMode = TIM_OCMODE_PWM1;
    sConfigOC.Pulse = htim3.Init.Period / 2;
    sConfigOC.OCPolarity = TIM_OCPOLARITY_HIGH;
    sConfigOC.OCFastMode = TIM_OCFAST_DISABLE;
    HAL_TIM_PWM_ConfigChannel(&htim3, &sConfigOC, TIM_CHANNEL_1);

    hdma_tim3_ch1_trig.Instance = DMA1_Channel6;
    hdma_tim3_ch1_trig.Init.Direction = DMA_MEMORY_TO_PERIPH;
    hdma_tim3_ch1_trig.Init.PeriphInc = DMA_PINC_DISABLE;
    hdma_tim3_ch1_trig.Init.MemInc = DMA_MINC_ENABLE;
    hdma_tim3_ch1_trig.Init.PeriphDataAlignment = DMA_PDATAALIGN_HALFWORD;
    hdma_tim3_ch1_trig.Init.MemDataAlignment = DMA_MDATAALIGN_WORD;
    hdma_tim3_ch1_trig.Init.Mode = DMA_NORMAL;
    hdma_tim3_ch1_trig.Init.Priority = DMA_PRIORITY_LOW;
    HAL_DMA_Init(&hdma_tim3_ch1_trig);

    /* Several peripheral DMA handle pointers point to the same DMA handle.
    Be aware that there is only one channel to perform all the requested DMAs. */
    __HAL_LINKDMA(&htim3, hdma[TIM_DMA_ID_CC1], hdma_tim3_ch1_trig);
    __HAL_LINKDMA(&htim3, hdma[TIM_DMA_ID_TRIGGER], hdma_tim3_ch1_trig);

    /* DMA interrupt init */
    /* DMA1_Channel6_IRQn interrupt configuration */
    HAL_NVIC_SetPriority(DMA1_Channel6_IRQn, 0, 0);
    HAL_NVIC_EnableIRQ(DMA1_Channel6_IRQn);
}


void WS_Update(void) {
    HAL_TIM_PWM_Start_DMA(&htim3, TIM_CHANNEL_1, data, sizeof(data) / sizeof(data[0])); /* Start sending and don't wait for it */
    while (htim3.hdma[TIM_DMA_ID_CC1]->Instance->CNDTR > 0);    /* Check if anything to send */
}

void WS_SetColor(uint32_t ledIndex, uint8_t r, uint8_t g, uint8_t b, uint8_t update) {
    uint8_t i = 0;
    ledIndex = ledIndex % LED_COUNT;

    for (i = 0; i < 8; i++) {                           /* Set colors, order is green, red, blue */
        data[RESET_BYTES_COUNT + ledIndex * BYTES_PER_LED + 0 + i] = ((g << i) & 0x80) ? WS2812_1 : WS2812_0;
        data[RESET_BYTES_COUNT + ledIndex * BYTES_PER_LED + 8 + i] = ((r << i) & 0x80) ? WS2812_1 : WS2812_0;
        data[RESET_BYTES_COUNT + ledIndex * BYTES_PER_LED + 16 + i] = ((b << i) & 0x80) ? WS2812_1 : WS2812_0;
    }

    if (update) {                                       /* Update leds on demand */
        WS_Update();
    }
}

void WS_SetColorAll(uint8_t r, uint8_t g, uint8_t b, uint8_t update) {
    uint16_t ledIndex = 0;

    /* Set color for all leds */
    for (ledIndex = 0; ledIndex < LED_COUNT; ledIndex++) {
        WS_SetColor(ledIndex, r, g, b, 0);              /* Set colors without immediatelly update process */
    }

    if (update) {                                       /* Update leds on demand */
        WS_Update();
    }
}

void WS_ScrollForwardColor(uint8_t r, uint8_t g, uint8_t b) { ///It is red, green, blue
    uint8_t index;

    for (index = 0; index < LED_COUNT; index++) {
        WS_SetColorAll(0, 0, 0, 0);                     /* Set colors for all leds and don't update immediatelly */
        WS_SetColor(index, r, g, b, 1);                 /* Set color for specific led and update */
        HAL_Delay(50);                                 /* Little delay */
    }
}

/* Interrupt function service routine */
void DMA1_Channel6_IRQHandler(void) {
  HAL_DMA_IRQHandler(&hdma_tim3_ch1_trig);
}