#![allow(dead_code)]

use gdiist_rocksdb as rocksdb;
use rocksdb::{Error, Options, DB};
use std::path::{Path, PathBuf};

/// Temporary database path which calls DB::Destroy when DBPath is dropped.
pub struct DBPath {
    dir: tempfile::TempDir, // kept for cleaning up during drop
    path: PathBuf,
}

impl DBPath {
    /// Produces a fresh (non-existent) temporary path which will be DB::destroy'ed automatically.
    pub fn new(prefix: &str) -> DBPath {
        let dir = tempfile::Builder::new()
            .prefix(prefix)
            .tempdir()
            .expect("Failed to create temporary path for db.");
        let path = dir.path().join("db");

        DBPath { dir, path }
    }
}

impl Drop for DBPath {
    fn drop(&mut self) {
        let opts = Options::default();
        DB::destroy(&opts, &self.path).expect("Failed to destroy temporary DB");
    }
}

/// Convert a DBPath ref to a Path ref.
/// We don't implement this for DBPath values because we want them to
/// exist until the end of their scope, not get passed in to functions and
/// dropped early.
impl AsRef<Path> for &DBPath {
    fn as_ref(&self) -> &Path {
        &self.path
    }
}

type Pair = (Box<[u8]>, Box<[u8]>);

pub fn pair(left: &[u8], right: &[u8]) -> Pair {
    (Box::from(left), Box::from(right))
}

#[track_caller]
pub fn assert_iter(iter: impl Iterator<Item = Result<Pair, Error>>, want: &[Pair]) {
    let got = iter.collect::<Result<Vec<_>, _>>().unwrap();
    assert_eq!(got.as_slice(), want);
}

#[track_caller]
pub fn assert_iter_reversed(iter: impl Iterator<Item = Result<Pair, Error>>, want: &[Pair]) {
    let mut got = iter.collect::<Result<Vec<_>, _>>().unwrap();
    got.reverse();
    assert_eq!(got.as_slice(), want);
}