#include "fwu.h"
#include <zephyr/kernel.h>
#include <zephyr/sys/crc.h>
#include <zephyr/sys/byteorder.h>
#include <zephyr/logging/log.h>

LOG_MODULE_REGISTER(fwu, LOG_LEVEL_INF);

#define FWU_BUFFER_SIZE 256
static uint8_t fwu_buffer[FWU_BUFFER_SIZE];
static uint32_t fwu_chunk_offset = 0;
static uint16_t fwu_chunk_size = 0;
static uint16_t fwu_last_chunk_crc = 0;

void fwu_init(void) {}

void fwu_handler(uint16_t addr, uint16_t reg)
{
    // This is a simplified handler. In a real scenario, you would have a proper mapping
    // between register addresses and actions.
    if (addr == 0x0100) { // FWU_COMMAND
        if (reg == 1) { LOG_INF("FWU: Chunk at offset %u (size %u) verified.", fwu_chunk_offset, fwu_chunk_size); }
        else if (reg == 2) { LOG_INF("FWU: Finalize command received. Rebooting (simulated)."); }
    } else if (addr == 0x0101) { // FWU_CHUNK_OFFSET_LOW
        fwu_chunk_offset = (fwu_chunk_offset & 0xFFFF0000) | reg;
    } else if (addr == 0x0102) { // FWU_CHUNK_OFFSET_HIGH
        fwu_chunk_offset = (fwu_chunk_offset & 0x0000FFFF) | ((uint32_t)reg << 16);
    } else if (addr == 0x0103) { // FWU_CHUNK_SIZE
        fwu_chunk_size = (reg > FWU_BUFFER_SIZE) ? FWU_BUFFER_SIZE : reg;
    } else if (addr >= 0x0180 && addr < (0x0180 + (FWU_BUFFER_SIZE / 2))) {
        uint16_t index = (addr - 0x0180) * 2;
        if (index < sizeof(fwu_buffer)) {
            sys_put_be16(reg, &fwu_buffer[index]);
            if (index + 2 >= fwu_chunk_size) {
                fwu_last_chunk_crc = crc16_ccitt(0xffff, fwu_buffer, fwu_chunk_size);
                LOG_INF("FWU: Chunk received, CRC is 0x%04X", fwu_last_chunk_crc);
            }
        }
    }
}

uint16_t fwu_get_last_chunk_crc(void)
{
    return fwu_last_chunk_crc;
}