use redis::AsyncCommands as _;
use redis::Client;
use redis_lock::LockAcrossOptions;
use serial_test::serial;
use std::error::Error;
use std::process::Stdio;

// Run the redis container with
// ```
// docker run -d --name my-redis-stack -p 6379:6379  redis/redis-stack-server:latest
// ```

#[cfg(feature = "sync")]
use redis::Commands as _;

#[cfg(feature = "sync")]
const ONE: &str = env!("CARGO_BIN_EXE_one");
#[cfg(feature = "sync")]
const TWO: &str = env!("CARGO_BIN_EXE_two");
const THREE: &str = env!("CARGO_BIN_EXE_three");
const FOUR: &str = env!("CARGO_BIN_EXE_four");
const FIVE: &str = env!("CARGO_BIN_EXE_five");

const REDIS_URL: &str = "redis://127.0.0.1/";

#[expect(
    clippy::panic_in_result_fn,
    reason = "It's annoying to handle the error here."
)]
#[expect(
    clippy::tests_outside_test_module,
    reason = "`#[serial]` break this lint"
)] // TODO Fix this.
#[test]
#[serial]
fn two() -> Result<(), Box<dyn Error>> {
    tokio::runtime::Runtime::new()?.block_on(async {
        const N: usize = 10;
        let client = Client::open(REDIS_URL)?;
        let mut conn = client.get_multiplexed_async_connection().await?;
        // Initialize account balances.
        redis::cmd("FLUSHALL").exec_async(&mut conn).await?;
        conn.set::<_, _, ()>("account1", 1000i32).await?;
        conn.set::<_, _, ()>("account2", 1000i32).await?;
        conn.set::<_, _, ()>("account3", 1000i32).await?;
        // Loads functions.
        redis_lock::setup(&client).await?;
        // Executes multiple instances of `one.rs` and `two.rs`.
        let threes = (0..N)
            .map(|_| {
                tokio::process::Command::new(THREE)
                    .stdout(Stdio::piped())
                    .stderr(Stdio::piped())
                    .spawn()
            })
            .collect::<Result<Vec<_>, _>>()?;
        let fours = (0..N)
            .map(|_| {
                tokio::process::Command::new(FOUR)
                    .stdout(Stdio::piped())
                    .stderr(Stdio::piped())
                    .spawn()
            })
            .collect::<Result<Vec<_>, _>>()?;
        let fives = (0..N)
            .map(|_| {
                tokio::process::Command::new(FIVE)
                    .stdout(Stdio::piped())
                    .stderr(Stdio::piped())
                    .spawn()
            })
            .collect::<Result<Vec<_>, _>>()?;

        // Waits for all instances to finish.
        for three in threes {
            let output = three.wait_with_output().await?;
            assert!(output.status.success());
            assert!(output.stderr.is_empty());
        }
        for four in fours {
            let output = four.wait_with_output().await?;
            assert!(output.status.success());
            assert!(output.stderr.is_empty());
        }
        for five in fives {
            let output = five.wait_with_output().await?;
            assert!(output.status.success());
            assert!(output.stderr.is_empty());
        }

        let balance1: i64 = conn.get("account1").await?;
        let balance2: i64 = conn.get("account2").await?;
        let balance3: i64 = conn.get("account3").await?;
        let total_balance = balance1
            .checked_add(balance2)
            .ok_or("overflow")?
            .checked_add(balance3)
            .ok_or("overflow")?;
        if total_balance == 3000 {
            Ok(())
        } else {
            Err("Total balance is not 3000".into())
        }
    })
}

// https://www.perplexity.ai/search/is-it-possibly-to-implement-di-PXg_TYNAQ5GfBStsVB1qAw
#[expect(clippy::tests_outside_test_module, reason = "`#[serial]` breaks it")] // TODO Fix this.
#[cfg(feature = "sync")]
#[test]
#[serial]
fn one() -> Result<(), Box<dyn Error>> {
    const N: usize = 10;
    let client = Client::open(REDIS_URL)?;
    let mut conn = client.get_connection()?;
    // Initialize account balances.
    redis::cmd("FLUSHALL").exec(&mut conn)?;
    conn.set::<_, _, ()>("account1", 1000i32)?;
    conn.set::<_, _, ()>("account2", 1000i32)?;
    conn.set::<_, _, ()>("account3", 1000i32)?;
    // Loads functions.
    redis_lock::sync::setup(&client)?;
    // Executes multiple instances of `one.rs` and `two.rs`.
    let ones = (0..N)
        .map(|_| {
            std::process::Command::new(ONE)
                .stdout(Stdio::piped())
                .stderr(Stdio::piped())
                .spawn()
        })
        .collect::<Result<Vec<_>, _>>()?;
    let twos = (0..N)
        .map(|_| {
            std::process::Command::new(TWO)
                .stdout(Stdio::piped())
                .stderr(Stdio::piped())
                .spawn()
        })
        .collect::<Result<Vec<_>, _>>()?;
    // Waits for all instances to finish.
    for one in ones {
        let _output = one.wait_with_output()?;
    }
    for two in twos {
        let _output = two.wait_with_output()?;
    }

    let balance1: i64 = conn.get("account1")?;
    let balance2: i64 = conn.get("account2")?;
    let balance3: i64 = conn.get("account3")?;
    let total_balance = balance1
        .checked_add(balance2)
        .ok_or("overflow")?
        .checked_add(balance3)
        .ok_or("overflow")?;
    if total_balance == 3000 {
        Ok(())
    } else {
        Err("Total balance is not 3000".into())
    }
}

#[expect(
    clippy::panic_in_result_fn,
    reason = "It's annoying to handle the error here."
)]
#[expect(
    clippy::tests_outside_test_module,
    reason = "`#[serial]` break this lint"
)] // TODO Fix this.
#[test]
#[serial]
fn single() -> Result<(), Box<dyn Error>> {
    tokio::runtime::Runtime::new()?.block_on(async {
        tracing_subscriber::fmt::fmt()
            .with_max_level(tracing::level_filters::LevelFilter::WARN)
            .init();
        const N: usize = 100;
        let client = Client::open(REDIS_URL)?;
        let connection = std::sync::Arc::new(tokio::sync::Mutex::new(
            client.get_multiplexed_async_connection().await?,
        ));
        // Reset database.
        redis::cmd("FLUSHALL")
            .exec_async(&mut *connection.lock().await)
            .await?;
        // Set state.
        let mut x: usize = 0;
        let ptr = std::ptr::from_mut::<usize>(&mut x) as usize;
        // Execute racy functions with lock.

        let futures = (0..N)
            .map(|_| {
                let cconnection = connection.clone();
                tokio::task::spawn(async move {
                    let _ = redis_lock::lock_across(
                        &[cconnection],
                        "resource",
                        async move {
                            let x: &mut usize = unsafe { &mut *(ptr as *mut usize) };
                            *x += 1;
                            tokio::time::sleep(std::time::Duration::from_millis(500)).await;
                        },
                        LockAcrossOptions::default(),
                    )
                    .await;
                })
            })
            .collect::<Vec<_>>();
        // let bar = indicatif::ProgressBar::new(N as u64);
        for future in futures {
            future.await?;
            // bar.inc(1);
        }
        // bar.finish();
        // Assert state.
        assert_eq!(x, N);
        Ok(())
    })
}