#include "cppmain.h"
#include "init.h"
#include "usbd_cdc_if.h"
//#include "usb_device.h"
//#include "cmsis_os.h"
#include <cmath>
#include "limits"

const double pi{ std::acos(-1) };
#define BUFFER_SIZE 512

namespace Heck {
    // Serial Logging
    // --------------
    void log(std::string msg)
    {
        std::string out{ msg };
        out.append("\r\n");
        CDC_Transmit_FS((uint8_t *)out.data(), out.size());
    }


    // DAC
    // ---
    u32 audio_buffer[BUFFER_SIZE];

    void dac1_set(u32 val)
    {
        HAL_DAC_SetValue(&hdac1, DAC_CHANNEL_1, DAC_ALIGN_12B_R, val);
    }

    void dac1_toggle()
    {
        static bool dac_state{ 0 };
        dac_state = !dac_state;
        if (dac_state) {
            dac1_set(0b0000111111111111);
        } else {
            dac1_set(0b0000000000000000);
        }
    }

    void dac_start_dma()
    {
        HAL_DAC_Start_DMA(&hdac1, DAC_CHANNEL_1, (u32 *)audio_buffer, BUFFER_SIZE, DAC_ALIGN_12B_R);
    }

    void dac_stop_dma()
    {
        HAL_DAC_Stop_DMA(&hdac1, DAC_CHANNEL_1);
    }

    // LED
    // ---

    void led_green_toggle()
    {
        HAL_GPIO_TogglePin(GPIOD, GPIO_PIN_12);
    }

    void led_green_on()
    {
        HAL_GPIO_WritePin(GPIOD, GPIO_PIN_12, GPIO_PIN_SET);
    }

    void led_green_off()
    {
        HAL_GPIO_WritePin(GPIOD, GPIO_PIN_12, GPIO_PIN_RESET);
    }


    // CALLBACKS
    void irq1_cb()
    {
        if (!is_running) {
            is_running = true;
            return;
        }
    }

    void timer2_cb()
    {
        led_green_toggle();
    }

    void timer7_cb() {}

    // dont forget to start the DAC
    // HAL_DAC_Start(&hdac, DAC_CHANNEL_1);
    void bytebeat()
    {
        long t{ 0 };
        while (true) {
            unsigned char res = t * ((t >> 12 | t >> 8) & 63 & t >> 4);
            dac1_set((res % 256) * 100);
            for (int g = 0; g < 60000; g++) {}
            t++;
            t %= (std::numeric_limits<long>::max() - 1);
        }
    }

    u32 random(u32 max)
    {
        u32 ret{ 0 };
        HAL_RNG_GenerateRandomNumber(&hrng, &ret);
        ret %= max;
        return ret;
    }

    void buffer_init_noise()
    {
        log("buffer_init_noise()");
        for (int i = 0; i < BUFFER_SIZE; i++) {
            u32 val = random(4096);
            audio_buffer[i] = val;
            log(std::to_string(val));
        }
    }

    void buffer_init_sin()
    {
        log("buffer_init_sin()");
        for (int i = 0; i < BUFFER_SIZE; i++) {
            float p = float(i) / (float)BUFFER_SIZE - 0.5;
            u32 val = sin(p) * 4096;
            audio_buffer[i] = val;
            log(std::to_string(val));
        }
    }

    void buffer_div(int div)
    {
        log("init_scale()");
        for (int i = 0; i < BUFFER_SIZE; i++) {
            u32 val = audio_buffer[i] / div;
            audio_buffer[i] = val;
            log(std::to_string(val));
        }
    }

    void buffer_randomize(int max)
    {
        log("buffer_randomize()");
        u32 buf_index = random(BUFFER_SIZE);
        u32 buf_val = random(max);
        audio_buffer[buf_index] = buf_val;
        log("i:" + std::to_string(buf_index) + " v:" + std::to_string(buf_val));
    }

    void main()
    {
        while (!is_running) {
            HAL_Delay(1);
        }
        log("Starting...");

        dac_start_dma();

        HAL_TIM_Base_Start_IT(&htim2);
        HAL_TIM_Base_Start_IT(&htim7);
        HAL_TIM_Base_Start(&htim6);

        //                init_buffer_noise();
        buffer_init_sin();
        buffer_div(10);
        log("Entering MainLoop...");
        while (true) {
            //            buffer_randomize(400);
            HAL_Delay(10);
        }
    }

} // namespace Heck


// ----------------------------------------------------------------------------------------------
// C Linkage (Bridging)
// ----------------------------------------------------------------------------------------------

extern "C" void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin)
{
    if (GPIO_Pin == GPIO_PIN_0) {
        Heck::irq1_cb();
    } else {
        __NOP(); // why NOP? i dont know! was from an example
    }
}

extern "C" void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim)
{
    if (htim->Instance == TIM2) {
        Heck::log(
            "TIM2 timer: instance: " + std::to_string(reinterpret_cast<u32>(htim->Instance)) +
            " channel: " + std::to_string(htim->Channel));
        Heck::timer2_cb();
    } else if (htim->Instance == TIM6) {
        Heck::log(
            "TIM6 timer: instance: " + std::to_string(reinterpret_cast<u32>(htim->Instance)) +
            " channel: " + std::to_string(htim->Channel));
    } else if (htim->Instance == TIM7) {
        Heck::log(
            "TIM7 timer: instance: " + std::to_string(reinterpret_cast<u32>(htim->Instance)) +
            " channel: " + std::to_string(htim->Channel));
        Heck::timer7_cb();
    } else {
        Heck::log(
            "UNKNOWN timer: instance: " + std::to_string(reinterpret_cast<u32>(htim->Instance)) +
            " channel: " + std::to_string(htim->Channel));
    }
}


extern "C" void HAL_DAC_ConvCpltCallbackCh1(DAC_HandleTypeDef *hdac)
{
    Heck::dac_start_dma();
}

extern "C" void heck_log(char *msg)
{
    Heck::log(std::string(msg));
}

extern "C" void heck_cppmain(void)
{
    Heck::main();
}

/**
  * @brief  Reports the name of the source file and the source line number
  *         where the assert_param error has occurred.
  * @param  file: pointer to the source file name
  * @param  line: assert_param error line source number
  * @retval None
  */
extern "C" void assert_failed(uint8_t *file, uint32_t line)
{
    /* User can add his own implementation to report the file name and line number,
     ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
    int str_size = 1024;
    char str[str_size];
    snprintf(str, str_size, "assert failed: %s:%d");
    heck_log(str);
}

extern "C" void Error_Handler(void)
{
    heck_log("Error_Handler StR1keZ!");
    __disable_irq();
    while (1) {}
}