use std::path::Path;

use anyhow::Result;
use fjall::{Config, Keyspace, PartitionCreateOptions, PartitionHandle};

/// Contains the handles needed to reference key-value data.
///
/// This contains both the Keyspace and multiple PartitionHandle.
/// The Keyspace allows operational control and reporting at the top level,
/// while each PartitionHandle controls reading, writing, and removing from a
/// particular partition of the data.
///
/// All fields are public, because this is meant to be used internally as a
/// wrapper to pass everything around, instead of passing each handle around by
/// itself.
#[derive(Clone)]
pub struct KvHandle {
    pub keyspace: Keyspace,

    pub project: PartitionHandle,
    pub document: PartitionHandle,
    pub permissions: PartitionHandle,
}

impl KvHandle {
    pub fn open<P: AsRef<Path>>(p: P) -> Result<KvHandle> {
        // TODO: those should probably be configurable, or like, not just hard coded.
        let config = Config::new(p).flush_workers(4).compaction_workers(4);
        let keyspace = Keyspace::open(config)?;

        let project = keyspace.open_partition("project", PartitionCreateOptions::default())?;
        let document = keyspace.open_partition("document", PartitionCreateOptions::default())?;
        let permissions = keyspace.open_partition("permissions", PartitionCreateOptions::default())?;

        Ok(KvHandle {
            keyspace,
            project,
            document,
            permissions,
        })
    }
}