#include "ti_msp_dl_config.h"
#include <stdint.h>
#include <stdbool.h>

#define APP_BASE        0x00008000
#define TEMP_BASE       0x00058000
#define MAX_APP_SIZE    (300 * 1024)

volatile bool upgrade_mode = false;
volatile uint32_t write_address;
volatile uint32_t received_size = 0;

/* Forward declarations */
void jump_to_application(void);
void enter_upgrade_mode(void);
void erase_application_area(void);
void erase_temp_area(void);
void copy_temp_to_application(void);

int main(void)
{
    SYSCFG_DL_init();

    NVIC_EnableIRQ(GPIO_SWITCHES_INT_IRQN);
    NVIC_EnableIRQ(UART_0_INST_INT_IRQN);

    if (upgrade_mode)
    {
        enter_upgrade_mode();
    }

    jump_to_application();

    while(1);
}

/* --------- Jump to Application ---------- */
void jump_to_application(void)
{
    uint32_t sp = *(uint32_t *)APP_BASE;
    uint32_t reset = *(uint32_t *)(APP_BASE + 4);

    __disable_irq();
    SCB->VTOR = APP_BASE;
    __set_MSP(sp);
    ((void (*)(void))reset)();
}

/* --------- Enter Upgrade Mode ---------- */
void enter_upgrade_mode(void)
{
    erase_temp_area();

    write_address = TEMP_BASE;
    received_size = 0;

    while (received_size < MAX_APP_SIZE)
    {
        /* wait for UART interrupt to fill data */
    }

    erase_application_area();
    copy_temp_to_application();

    NVIC_SystemReset();
}
#define FLASH_WRITE_SIZE  8

uint8_t  uart_buffer[FLASH_WRITE_SIZE];
uint32_t uart_index = 0;
/* --------- UART Interrupt ---------- */
void UART_0_INST_IRQHandler(void)
{
    if (DL_UART_Main_getPendingInterrupt(UART_0_INST) ==
        DL_UART_MAIN_IIDX_RX)
    {
        uint8_t byte = DL_UART_Main_receiveData(UART_0_INST);

        uart_buffer[uart_index++] = byte;

        if (uart_index == 8)
        {
            __disable_irq();

            DL_FlashCTL_programMemoryFromRAM(
                FLASHCTL,
                write_address,
                (uint32_t *)uart_buffer,
                8,
                DL_FLASHCTL_REGION_SELECT_MAIN);

            __enable_irq();

            write_address += 8;
            received_size += 8;
            uart_index = 0;
        }
    }
}
/* --------- Button Interrupt ---------- */
void GROUP1_IRQHandler(void)
{
    if (DL_GPIO_getPendingInterrupt(GPIO_SWITCHES_PORT) ==
        GPIO_SWITCHES_USER_SWITCH_1_IIDX)
    {
        upgrade_mode = true;
    }
}

#define FLASH_SECTOR_SIZE   (8 * 1024)

void erase_application_area(void)
{
    for (uint32_t addr = APP_BASE;
         addr < TEMP_BASE;
         addr += FLASH_SECTOR_SIZE)
    {
        __disable_irq();

        DL_FlashCTL_eraseMemory(
            FLASHCTL,
            addr,
            DL_FLASHCTL_COMMAND_SIZE_SECTOR);

        __enable_irq();
    }
}

void erase_temp_area(void)
{
    for (uint32_t addr = TEMP_BASE;
         addr < 0x00080000;
         addr += FLASH_SECTOR_SIZE)
    {
        __disable_irq();

        DL_FlashCTL_eraseMemory(
            FLASHCTL,
            addr,
            DL_FLASHCTL_COMMAND_SIZE_SECTOR);

        __enable_irq();
    }
}
/* --------- Copy TEMP → APP ---------- */
void copy_temp_to_application(void)
{
    uint32_t offset = 0;
    uint8_t buffer[8];

    while (offset < received_size)
    {
        for (uint32_t i = 0; i < 8; i++)
        {
            buffer[i] = *(uint8_t *)(TEMP_BASE + offset + i);
        }

        __disable_irq();

        DL_FlashCTL_programMemoryFromRAM(
            FLASHCTL,
            APP_BASE + offset,
            (uint32_t *)buffer,
            8,
            DL_FLASHCTL_REGION_SELECT_MAIN);

        __enable_irq();

        offset += 8;
    }
}