use crate::core::entities::EncodingResult;
use crate::core::errors::EncoderError;

use super::entities::{Dict, DictEntry};
use super::errors::RepositoryError;

/// The number value can be encoded as many word sets,
/// but decoded as one number. For partial values, we can use
/// u64, but for the whole decoded value that may be very long,
/// we need a string.
type DecodedValue = String;

pub trait SystemDecoder {
    fn decode(&self, word: &str) -> DecodedValue;
}

pub trait SystemEncoder {
    fn initialize(&self) -> Result<(), EncoderError>;
    fn encode(&self, word: &str) -> Result<EncodingResult, EncoderError>;
}

#[async_trait::async_trait]
pub trait DictRepository: Send + Sync {
    async fn create_dict(&self, name: &str) -> Result<(), RepositoryError>;

    /// "Upsert" logic:
    /// - If entry exists (by text), update metadata.
    /// - If not, insert new.
    /// - IDs are handled by the Database.
    async fn save_entries(
        &self,
        dict_name: &str,
        entries: &[DictEntry],
    ) -> Result<(), RepositoryError>;

    /// Fetch a page of entries.
    async fn fetch_many(
        &self,
        name: &str,
        limit: Option<u32>,
        offset: Option<u32>,
    ) -> Result<Dict, RepositoryError>;
}

pub trait DictSource {
    fn next_entry(&mut self) -> Option<Result<DictEntry, anyhow::Error>>;
}