use embedded_storage::nor_flash::NorFlash;
use embedded_storage::nor_flash::ReadNorFlash;
use esp_storage::{FlashStorage, FlashStorageError};

pub type StoreError = FlashStorageError;

const FLASH_ADDR: u32 = 0x9000;

const INITIALIZATION_SIZE: usize = 0x1004;
const FLASH_INITIALIZE_MAGIC: u32 = 0xde6de6de;

pub struct Store {
    pub storage: FlashStorage<'static>,
}

fn initialize_flash(storage: &mut FlashStorage) -> Result<(), StoreError> {
    let zeros: [u8; INITIALIZATION_SIZE] = [0; INITIALIZATION_SIZE];
    storage.write(FLASH_ADDR, &zeros)?;
    storage.write(FLASH_ADDR, &FLASH_INITIALIZE_MAGIC.to_ne_bytes())?;
    Ok(())
}

impl Store {
    pub fn new(flash: esp_hal::peripherals::FLASH<'static>) -> Result<Self, StoreError> {
        let mut storage = FlashStorage::new(flash);

        let mut magic: [u8; 4] = [0, 0, 0, 0];
        storage.read(FLASH_ADDR, &mut magic)?;

        if (u32::from_ne_bytes(magic)) != FLASH_INITIALIZE_MAGIC {
            initialize_flash(&mut storage)?;
        }

        Ok(Self { storage })
    }

    pub fn read(&mut self, offset: u32, bytes: &mut [u8]) -> Result<(), StoreError> {
        self.storage.read(FLASH_ADDR + offset, bytes)
    }

    pub fn write(&mut self, offset: u32, bytes: &mut [u8]) -> Result<(), StoreError> {
        self.storage.write(FLASH_ADDR + offset, bytes)
    }
}