//! Benchmark the generation of a large database with values of varying sizes for each (a)db variant
//! that supports variable-size values.

use crate::variable::{
    gen_random_kv, get_any_ordered, get_any_unordered, get_current_ordered, get_current_unordered,
    Digest, Variant, VARIANTS,
};
use commonware_runtime::{
    benchmarks::{context, tokio},
    tokio::{Config, Context},
};
use commonware_storage::qmdb::{any::traits::DbAny, store::LogStore, Error};
use criterion::{criterion_group, Criterion};
use std::time::{Duration, Instant};

const NUM_ELEMENTS: u64 = 1_000;
const NUM_OPERATIONS: u64 = 10_000;
const COMMITS_PER_ITERATION: u64 = 100;

/// Benchmark the generation of a large randomly generated any db.
fn bench_variable_generate(c: &mut Criterion) {
    let cfg = Config::default();
    let runner = tokio::Runner::new(cfg);
    for elements in [NUM_ELEMENTS, NUM_ELEMENTS * 10] {
        for operations in [NUM_OPERATIONS, NUM_OPERATIONS * 10] {
            for variant in VARIANTS {
                c.bench_function(
                    &format!(
                        "{}/variant={} elements={} operations={}",
                        module_path!(),
                        variant.name(),
                        elements,
                        operations,
                    ),
                    |b| {
                        b.to_async(&runner).iter_custom(|iters| async move {
                            let ctx = context::get::<Context>();
                            let mut total_elapsed = Duration::ZERO;
                            for _ in 0..iters {
                                let commit_frequency = (operations / COMMITS_PER_ITERATION) as u32;
                                let elapsed = match variant {
                                    Variant::AnyUnordered => {
                                        let db = get_any_unordered(ctx.clone()).await;
                                        test_db(db, elements, operations, commit_frequency)
                                            .await
                                            .unwrap()
                                    }
                                    Variant::AnyOrdered => {
                                        let db = get_any_ordered(ctx.clone()).await;
                                        test_db(db, elements, operations, commit_frequency)
                                            .await
                                            .unwrap()
                                    }
                                    Variant::CurrentUnordered => {
                                        let db = get_current_unordered(ctx.clone()).await;
                                        test_db(db, elements, operations, commit_frequency)
                                            .await
                                            .unwrap()
                                    }
                                    Variant::CurrentOrdered => {
                                        let db = get_current_ordered(ctx.clone()).await;
                                        test_db(db, elements, operations, commit_frequency)
                                            .await
                                            .unwrap()
                                    }
                                };
                                total_elapsed += elapsed;
                            }
                            total_elapsed
                        });
                    },
                );
            }
        }
    }
}

/// Test the database generation and cleanup.
///
/// Generates data, prunes, and destroys.
async fn test_db<C>(
    mut db: C,
    elements: u64,
    operations: u64,
    commit_frequency: u32,
) -> Result<Duration, Error>
where
    C: DbAny<Key = Digest> + LogStore<Value = Vec<u8>>,
{
    let start = Instant::now();

    // Generate random operations
    gen_random_kv(&mut db, elements, operations, commit_frequency).await;
    db.prune(db.inactivity_floor_loc().await).await?;
    db.sync().await?;

    let elapsed = start.elapsed();
    db.destroy().await?; // don't time destroy

    Ok(elapsed)
}

criterion_group! {
    name = benches;
    config = Criterion::default().sample_size(10);
    targets = bench_variable_generate
}