#pragma once

#include <stm32f1xx_hal.h>

#include <string_view>

/*
 * small uart wrapper
 * assumes USART1 with default pins/port
 */

template <uint16_t PinTX, uint16_t PinRX, uint32_t Port, uint32_t UsartBase>
struct uart_handler {
  static void enable_clocks() {
    __HAL_RCC_USART1_CLK_ENABLE();
    __HAL_RCC_GPIOA_CLK_ENABLE();
    __HAL_RCC_AFIO_CLK_ENABLE();
  }

  static void init_gpio() {
    GPIO_InitTypeDef ua_tx;
    GPIO_InitTypeDef ua_rx;

    ua_tx.Pin = pin_tx;
    ua_tx.Mode = GPIO_MODE_AF_PP;
    ua_tx.Speed = GPIO_SPEED_HIGH;

    ua_rx.Pin = pin_rx;
    ua_rx.Mode = GPIO_MODE_INPUT;
    ua_rx.Speed = GPIO_SPEED_HIGH;

    HAL_GPIO_Init(reinterpret_cast<GPIO_TypeDef*>(port), &ua_tx);
    HAL_GPIO_Init(reinterpret_cast<GPIO_TypeDef*>(port), &ua_rx);
  }

  static bool enable_oscillators() {
    RCC_OscInitTypeDef RCC_OscInitStruct = {0};
    RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

    /** Initializes the RCC Oscillators according to the specified parameters
     * in the RCC_OscInitTypeDef structure.
     */
    RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
    RCC_OscInitStruct.HSIState = RCC_HSI_ON;
    RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
    RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
    if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK) {
      return false;
    }

    /** Initializes the CPU, AHB and APB buses clocks
     */
    RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_SYSCLK |
                                  RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2;
    RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSI;
    RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
    RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
    RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;

    if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0) != HAL_OK) {
      return false;
    }

    return true;
  }

  static bool init_uart_handle() {
    s_UARTHandle.Instance = reinterpret_cast<USART_TypeDef*>(usart_base);
    s_UARTHandle.Init.BaudRate = 9600;
    s_UARTHandle.Init.WordLength = UART_WORDLENGTH_8B;
    s_UARTHandle.Init.StopBits = UART_STOPBITS_1;
    s_UARTHandle.Init.Parity = UART_PARITY_NONE;
    s_UARTHandle.Init.Mode = UART_MODE_TX_RX;
    s_UARTHandle.Init.HwFlowCtl = UART_HWCONTROL_NONE;

    auto result = HAL_UART_Init(&s_UARTHandle);

    return result == HAL_OK;
  }

  static bool init() {
    enable_clocks();
    init_gpio();

    if (!enable_oscillators()) {
      return false;
    }

    return init_uart_handle();
  }

  static HAL_StatusTypeDef write(const std::string_view& message,
                                 uint32_t timeout = HAL_MAX_DELAY) {
    constexpr std::string_view carriage_return{"\r\n"};

    write(reinterpret_cast<uint8_t*>(const_cast<char*>(message.data())),
          message.size(), timeout);

    return write(
        reinterpret_cast<uint8_t*>(const_cast<char*>(carriage_return.data())),
        carriage_return.size(), timeout);
  }

  static HAL_StatusTypeDef write(uint8_t* buf, uint16_t size,
                                 uint32_t timeout = HAL_MAX_DELAY) {
    return HAL_UART_Transmit(&s_UARTHandle, buf, size, timeout);
  }

  static UART_HandleTypeDef s_UARTHandle;

 private:
  static constexpr auto pin_tx = PinTX;
  static constexpr auto pin_rx = PinRX;
  static constexpr auto port = Port;
  static constexpr auto usart_base = UsartBase;
};

template <uint16_t PinTX, uint16_t PinRX, uint32_t Port, uint32_t UsartBase>
UART_HandleTypeDef uart_handler<PinTX, PinRX, Port, UsartBase>::s_UARTHandle =
    UART_HandleTypeDef();