use crate::{
    cursor::{DbCursorRO, DbCursorRW, DbDupCursorRO, DbDupCursorRW},
    table::{DupSort, Table},
    DatabaseError,
};

/// Read only transaction
pub trait DbTx: Send + Sync {
    /// Cursor type for this read-only transaction
    type Cursor<T: Table>: DbCursorRO<T> + Send + Sync;
    /// `DupCursor` type for this read-only transaction
    type DupCursor<T: DupSort>: DbDupCursorRO<T> + DbCursorRO<T> + Send + Sync;

    /// Get value
    fn get<T: Table>(&self, key: T::Key) -> Result<Option<T::Value>, DatabaseError>;
    /// Commit for read only transaction will consume and free transaction and allows
    /// freeing of memory pages
    fn commit(self) -> Result<bool, DatabaseError>;
    /// Aborts transaction
    fn abort(self);
    /// Iterate over read only values in table.
    fn cursor_read<T: Table>(&self) -> Result<Self::Cursor<T>, DatabaseError>;
    /// Iterate over read only values in dup sorted table.
    fn cursor_dup_read<T: DupSort>(&self) -> Result<Self::DupCursor<T>, DatabaseError>;
    /// Returns number of entries in the table.
    fn entries<T: Table>(&self) -> Result<usize, DatabaseError>;
    /// Disables long-lived read transaction safety guarantees.
    fn disable_long_read_transaction_safety(&mut self);
}

/// Read write transaction that allows writing to database
pub trait DbTxMut: Send + Sync {
    /// Read-Write Cursor type
    type CursorMut<T: Table>: DbCursorRW<T> + DbCursorRO<T> + Send + Sync;
    /// Read-Write `DupCursor` type
    type DupCursorMut<T: DupSort>: DbDupCursorRW<T>
        + DbCursorRW<T>
        + DbDupCursorRO<T>
        + DbCursorRO<T>
        + Send
        + Sync;

    /// Put value to database
    fn put<T: Table>(&self, key: T::Key, value: T::Value) -> Result<(), DatabaseError>;
    /// Delete value from database
    fn delete<T: Table>(&self, key: T::Key, value: Option<T::Value>)
        -> Result<bool, DatabaseError>;
    /// Clears database.
    fn clear<T: Table>(&self) -> Result<(), DatabaseError>;
    /// Cursor mut
    fn cursor_write<T: Table>(&self) -> Result<Self::CursorMut<T>, DatabaseError>;
    /// `DupCursor` mut.
    fn cursor_dup_write<T: DupSort>(&self) -> Result<Self::DupCursorMut<T>, DatabaseError>;
}
