#include <string.h>

#include "cmsis_os2.h"

#include "user_epd_impl.h"

#define BUSY_MAX_POLLING_TIME 30000 // 30s
#define SPI_MAX_TRANSFER_TIME 1000 // 1s

extern osSemaphoreId_t g_epd_busy_semphr;
extern osSemaphoreId_t g_spi2_semphr;

depg0213_ret_t _epd_reset_cb(void *handle) {
    SPI_HandleTypeDef *hspi = handle;
    if (hspi->Instance == SPI2) {
        HAL_GPIO_WritePin(SPI2_RES_GPIO_Port, SPI2_RES_Pin, GPIO_PIN_SET);
        HAL_Delay(1);
        HAL_GPIO_WritePin(SPI2_RES_GPIO_Port, SPI2_RES_Pin, GPIO_PIN_RESET);
        HAL_Delay(1);
        HAL_GPIO_WritePin(SPI2_RES_GPIO_Port, SPI2_RES_Pin, GPIO_PIN_SET);
    }
    return DEPG0213_OK;
}

depg0213_ret_t _epd_poll_busy(void *handle) {
    SPI_HandleTypeDef *hspi = handle;
    if (hspi->Instance == SPI2) {
        if (osKernelGetState() != osKernelRunning) { // Kernel has not started, use flag polling instead.
            uint32_t tick_start = HAL_GetTick();
            while (HAL_GPIO_ReadPin(SPI2_BUSY_GPIO_Port, SPI2_BUSY_Pin) != GPIO_PIN_RESET) {
                if (HAL_GetTick() - tick_start > BUSY_MAX_POLLING_TIME) {
                    return DEPG0213_ERROR;
                }
            }
        } else { // Kernel has started, use semaphore.
            if(osSemaphoreAcquire(g_epd_busy_semphr, BUSY_MAX_POLLING_TIME) != osOK) {
                return DEPG0213_ERROR;
            }
        }
    }
    return DEPG0213_OK;
}

depg0213_ret_t _epd_write_cmd_cb(void *handle, uint8_t *cmd, uint8_t len) {
    SPI_HandleTypeDef *hspi = handle;

    HAL_StatusTypeDef ret = HAL_OK;

    if (hspi->Instance == SPI2) {
        HAL_GPIO_WritePin(SPI2_DC_GPIO_Port, SPI2_DC_Pin, GPIO_PIN_RESET);
        if(osKernelGetState() == osKernelRunning) {
            ret = HAL_SPI_Transmit_IT(hspi, cmd, 0x01);
            if(osSemaphoreAcquire(g_spi2_semphr, SPI_MAX_TRANSFER_TIME) != osOK) {
                return DEPG0213_ERROR;
            }
        }
        else {
            ret = HAL_SPI_Transmit(hspi, cmd, 0x01, SPI_MAX_TRANSFER_TIME);
        }
        if (len > 1) {
            HAL_GPIO_WritePin(SPI2_DC_GPIO_Port, SPI2_DC_Pin, GPIO_PIN_SET);
            if(osKernelGetState() == osKernelRunning) {
                ret = HAL_SPI_Transmit_IT(hspi, &cmd[1], len - 1);
                if(osSemaphoreAcquire(g_spi2_semphr, SPI_MAX_TRANSFER_TIME) != osOK) {
                    return DEPG0213_ERROR;
                }
            }
            else {
                ret = HAL_SPI_Transmit(hspi, &cmd[1], len - 1, SPI_MAX_TRANSFER_TIME);
            }
        }
    }
    if (ret != HAL_OK) return DEPG0213_ERROR;
    return DEPG0213_OK;
}

depg0213_ret_t _epd_write_data_cb(void *handle, uint8_t *data, uint16_t len) {
    SPI_HandleTypeDef *hspi = handle;

    HAL_StatusTypeDef ret = HAL_OK;

    if (hspi->Instance == SPI2) {
        HAL_GPIO_WritePin(SPI2_DC_GPIO_Port, SPI2_DC_Pin, GPIO_PIN_SET);
        if(osKernelGetState() == osKernelRunning) {
            ret = HAL_SPI_Transmit_IT(hspi, data, len);
            if(osSemaphoreAcquire(g_spi2_semphr, SPI_MAX_TRANSFER_TIME) != osOK) {
                return DEPG0213_ERROR;
            }
        }
        else {
            ret = HAL_SPI_Transmit(hspi, data, len, SPI_MAX_TRANSFER_TIME);
        }
    }
    if (ret != HAL_OK) return DEPG0213_ERROR;
    return DEPG0213_OK;
}