use heed::types::ByteSlice;
use heed::Result as ZResult;
use std::sync::Arc;

#[derive(Copy, Clone)]
pub struct Synonyms {
    pub(crate) synonyms: heed::Database<ByteSlice, ByteSlice>,
}

impl Synonyms {
    pub fn put_synonyms(
        self,
        writer: &mut heed::RwTxn,
        word: &[u8],
        synonyms: &fst::Set,
    ) -> ZResult<()> {
        let bytes = synonyms.as_fst().as_bytes();
        self.synonyms.put(writer, word, bytes)
    }

    pub fn del_synonyms(self, writer: &mut heed::RwTxn, word: &[u8]) -> ZResult<bool> {
        self.synonyms.delete(writer, word)
    }

    pub fn clear(self, writer: &mut heed::RwTxn) -> ZResult<()> {
        self.synonyms.clear(writer)
    }

    pub fn synonyms(self, reader: &heed::RoTxn, word: &[u8]) -> ZResult<Option<fst::Set>> {
        match self.synonyms.get(reader, word)? {
            Some(bytes) => {
                let len = bytes.len();
                let bytes = Arc::new(bytes.to_owned());
                let fst = fst::raw::Fst::from_shared_bytes(bytes, 0, len).unwrap();
                Ok(Some(fst::Set::from(fst)))
            }
            None => Ok(None),
        }
    }
}