use criterion::{black_box, criterion_group, criterion_main, BenchmarkId, Criterion};
use limbo_core::{Database, PlatformIO, IO};
use pprof::criterion::{Output, PProfProfiler};
use std::sync::Arc;

fn rusqlite_open() -> rusqlite::Connection {
    let sqlite_conn = rusqlite::Connection::open("../testing/testing.db").unwrap();
    sqlite_conn
        .pragma_update(None, "locking_mode", "EXCLUSIVE")
        .unwrap();
    sqlite_conn
}

fn bench(criterion: &mut Criterion) {
    // https://github.com/tursodatabase/limbo/issues/174
    // The rusqlite benchmark crashes on Mac M1 when using the flamegraph features
    let enable_rusqlite = std::env::var("DISABLE_RUSQLITE_BENCHMARK").is_err();

    #[allow(clippy::arc_with_non_send_sync)]
    let io = Arc::new(PlatformIO::new().unwrap());
    let db = Database::open_file(io.clone(), "../testing/testing.db").unwrap();
    let limbo_conn = db.connect();

    let queries = [
        "SELECT 1",
        "SELECT * FROM users LIMIT 1",
        "SELECT first_name, count(1) FROM users GROUP BY first_name HAVING count(1) > 1 ORDER BY count(1)  LIMIT 1",
    ];

    for query in queries.iter() {
        let mut group = criterion.benchmark_group(format!("Prepare `{}`", query));

        group.bench_with_input(BenchmarkId::new("Limbo", query), query, |b, query| {
            b.iter(|| {
                limbo_conn.prepare(query).unwrap();
            });
        });

        if enable_rusqlite {
            let sqlite_conn = rusqlite_open();

            group.bench_with_input(BenchmarkId::new("Sqlite3", query), query, |b, query| {
                b.iter(|| {
                    sqlite_conn.prepare(query).unwrap();
                });
            });
        }

        group.finish();
    }

    let mut group = criterion.benchmark_group("Execute `SELECT * FROM users LIMIT ?`");

    for i in [1, 10, 50, 100] {
        group.bench_with_input(BenchmarkId::new("Limbo", i), &i, |b, i| {
            // TODO: LIMIT doesn't support query parameters.
            let mut stmt = limbo_conn
                .prepare(format!("SELECT * FROM users LIMIT {}", *i))
                .unwrap();
            let io = io.clone();
            b.iter(|| {
                loop {
                    match stmt.step().unwrap() {
                        limbo_core::StepResult::Row => {}
                        limbo_core::StepResult::IO => {
                            let _ = io.run_once();
                        }
                        limbo_core::StepResult::Done => {
                            break;
                        }
                        limbo_core::StepResult::Interrupt | limbo_core::StepResult::Busy => {
                            unreachable!();
                        }
                    }
                }
                stmt.reset();
            });
        });

        if enable_rusqlite {
            let sqlite_conn = rusqlite_open();

            group.bench_with_input(BenchmarkId::new("Sqlite3", i), &i, |b, i| {
                // TODO: Use parameters once we fix the above.
                let mut stmt = sqlite_conn
                    .prepare(&format!("SELECT * FROM users LIMIT {}", *i))
                    .unwrap();
                b.iter(|| {
                    let mut rows = stmt.raw_query();
                    while let Some(row) = rows.next().unwrap() {
                        black_box(row);
                    }
                });
            });
        }
    }

    group.finish();

    let mut group = criterion.benchmark_group("Execute `SELECT 1`");

    group.bench_function("Limbo", |b| {
        let mut stmt = limbo_conn.prepare("SELECT 1").unwrap();
        let io = io.clone();
        b.iter(|| {
            loop {
                match stmt.step().unwrap() {
                    limbo_core::StepResult::Row => {}
                    limbo_core::StepResult::IO => {
                        let _ = io.run_once();
                    }
                    limbo_core::StepResult::Done => {
                        break;
                    }
                    limbo_core::StepResult::Interrupt | limbo_core::StepResult::Busy => {
                        unreachable!();
                    }
                }
            }
            stmt.reset();
        });
    });

    if enable_rusqlite {
        let sqlite_conn = rusqlite_open();

        group.bench_function("Sqlite3", |b| {
            let mut stmt = sqlite_conn.prepare("SELECT 1").unwrap();
            b.iter(|| {
                let mut rows = stmt.raw_query();
                while let Some(row) = rows.next().unwrap() {
                    black_box(row);
                }
            });
        });
    }

    group.finish();
}

criterion_group! {
    name = benches;
    config = Criterion::default().with_profiler(PProfProfiler::new(100, Output::Flamegraph(None)));
    targets = bench
}
criterion_main!(benches);