#include "OTA.h"
#include "gd32c10x_fmc.h"
#include <cstring>

extern CAN_transmiter CAN0_transmiter; // CAN初始化
extern "C" {
void canfd_rx_irq_handler(void);
}

OTAHandler::OTAHandler() : ota_active(false), received_size(0) {}

void OTAHandler::init() {
	// 初始化CANFD接收中断
	nvic_irq_enable(CAN0_RX0_IRQn, 1, 1);
}

void OTAHandler::process() {
	if (!ota_active)
		return;

	// 这里可以添加超时处理逻辑
	// 例如：10秒无数据则退出OTA模式
}

bool OTAHandler::validateApplication() {
	uint32_t *app_vector = (uint32_t *)APP_START_ADDR;
	uint32_t stack_ptr = app_vector[0];
	uint32_t reset_handler = app_vector[1];

	// 简单验证：检查栈指针是否在SRAM范围内
	return (stack_ptr >= 0x20000000 && stack_ptr < 0x20008000) &&
		   (reset_handler >= APP_START_ADDR &&
			reset_handler < (APP_START_ADDR + APP_MAX_SIZE));
}

void OTAHandler::jumpToApplication() {
	if (!validateApplication()) {
		// 无效APP，停留在bootloader
		return;
	}

	// 关闭所有中断
	__disable_irq();

	// 设置主栈指针
	uint32_t msp_value = *(__IO uint32_t *)APP_START_ADDR;
	__set_MSP(msp_value);

	// 获取复位地址
	uint32_t reset_handler = *(__IO uint32_t *)(APP_START_ADDR + 4);
	typedef void (*AppEntryFunc)(void);
	AppEntryFunc app_entry = (AppEntryFunc)reset_handler;

	// 跳转
	app_entry();
}

void OTAHandler::eraseApplicationArea() {
	// 擦除APP区域
	fmc_unlock();
	for (uint32_t addr = APP_START_ADDR; addr < (APP_START_ADDR + APP_MAX_SIZE);
		 addr += FMC_PAGE_SIZE) {
		fmc_page_erase(addr);
	}
	fmc_lock();
}

void OTAHandler::writeApplicationData(uint32_t offset, uint8_t *data,
									  uint32_t size) {
	fmc_unlock();
	uint32_t write_addr = APP_START_ADDR + offset;

	// 32位对齐写入
	for (uint32_t i = 0; i < size; i += 4) {
		uint32_t word = 0;
		memcpy(&word, &data[i], 4);
		fmc_word_program(write_addr + i, word);
	}

	fmc_lock();
}

void OTAHandler::handleOTAMessage(uint32_t id, uint8_t *data, uint8_t len) {
	if (id == CANFD_OTA_REQ_ID) {
		// OTA请求包
		uint32_t new_size = *(uint32_t *)data;
		if (new_size <= APP_MAX_SIZE) {
			expected_size = new_size;
			received_size = 0;
			eraseApplicationArea();
			ota_active = true;
			sendACK(0xFFFFFFFF); // 确认开始
		}
	} else if (id == CANFD_OTA_DATA_ID && ota_active) {
		// 数据包格式：[4字节包序号][实际数据]
		if (len >= 4) {
			uint32_t packet_num = *(uint32_t *)data;
			uint32_t offset = packet_num * (len - 4);

			if (offset < expected_size) {
				writeApplicationData(offset, &data[4], len - 4);
				received_size += (len - 4);
				sendACK(packet_num);

				// 检查是否完成
				if (received_size >= expected_size) {
					ota_active = false;
					// 跳转前延时让ACK发出
					for (volatile int i = 0; i < 100000; i++)
						;
					jumpToApplication();
				}
			}
		}
	}
}

void OTAHandler::sendACK(uint32_t packet_num) {
	CAN0_transmiter.sendACK(CANFD_OTA_ACK_ID, packet_num);
}