use crate::FBError;
use base64::prelude::{BASE64_STANDARD, Engine};
use bincode::{Options, DefaultOptions};

pub struct FBKey {
	pub(crate) indices: Vec<Vec<(usize, usize)>>,
}

impl FBKey {

	pub fn export(&self) -> String {
		let binc = DefaultOptions::new();
		let indice_bytes = binc.serialize(&self.indices)
			.unwrap();

		BASE64_STANDARD.encode(&indice_bytes)
	}

	pub fn import(key_str: &str) -> Result<FBKey, FBError> {
		let binc = DefaultOptions::new();
		let indice_bytes = BASE64_STANDARD.decode(key_str)
			.map_err(|_| FBError::DecodeError)?;
		let indices: Vec<_> = binc.deserialize(&indice_bytes)
			.map_err(|_| FBError::DecodeError)?;
		if indices.len() < 2 {
			return Err(FBError::DecodeError);
		}

		Ok (FBKey {indices})
	}
}