use std::{cmp::Ordering, path::Path};

use cuddle_clusters::{process::ProcessOpts, ConcreteComponent, IntoComponent};
use walkdir::DirEntry;

pub(crate) async fn run_test_with_components(
    name: &str,
    components: Vec<impl IntoComponent>,
) -> anyhow::Result<()> {
    let _ = tracing_subscriber::fmt::try_init();

    println!("running for: {name}");

    let current_dir = std::env::current_dir()?;

    let test_folder = current_dir.join("tests").join(name);

    let actual = test_folder.join("actual");
    tokio::fs::create_dir_all(&actual).await?;
    let expected = test_folder.join("expected");
    tokio::fs::create_dir_all(&expected).await?;

    let components: Vec<_> = components.into_iter().map(|p| p.into_component()).collect();

    cuddle_clusters::process_opts(
        components.clone(),
        ProcessOpts {
            path: test_folder.clone(),
            output: actual.clone(),
        },
    )
    .await?;

    if std::env::var("TEST_OVERRIDE") == Ok("true".to_string()) {
        cuddle_clusters::process_opts(
            components,
            ProcessOpts {
                path: test_folder,
                output: expected.clone(),
            },
        )
        .await?;
    }

    compare(&expected, &actual).await?;

    Ok(())
}

pub(crate) async fn run_test(name: &str) -> anyhow::Result<()> {
    run_test_with_components(name, Vec::<ConcreteComponent>::new()).await
}

async fn compare(expected: &Path, actual: &Path) -> anyhow::Result<()> {
    let mut exp = walk_dir(expected)?;
    let mut act = walk_dir(actual)?;

    for (exp, act) in (&mut exp).zip(&mut act) {
        let exp = exp?;
        let act = act?;

        if exp.depth() != act.depth() {
            return Err(anyhow::anyhow!(
                "path(different depth): expected {} is different from actual: {}",
                exp.path().display(),
                act.path().display()
            ));
        }

        if exp.file_type() != act.file_type() {
            return Err(anyhow::anyhow!(
                "path(different filetype): expected {} is different from actual: {}",
                exp.path().display(),
                act.path().display()
            ));
        }

        if exp.file_name() != act.file_name() {
            return Err(anyhow::anyhow!(
                "path(different filename): expected {} is different from actual: {}",
                exp.path().display(),
                act.path().display()
            ));
        }

        if exp.metadata()?.is_file() {
            let exp_file = tokio::fs::read_to_string(exp.path()).await?;
            let act_file = tokio::fs::read_to_string(act.path()).await?;

            similar_asserts::assert_eq!(exp_file, act_file);
        }
    }

    if exp.next().is_some() || act.next().is_some() {
        return Err(anyhow::anyhow!(
            "path(uneven amount of items): expected: {}, actual: {}",
            exp.next()
                .map(|o| match o {
                    Ok(o) => o.path().display().to_string(),
                    Err(_) => "expected: not-found".to_string(),
                })
                .unwrap_or("expected: not-found".into()),
            act.next()
                .map(|o| match o {
                    Ok(o) => o.path().display().to_string(),
                    Err(_) => "actual: not-found".to_string(),
                })
                .unwrap_or("actual: not-found".into()),
        ));
    }

    Ok(())
}

fn walk_dir(path: &Path) -> anyhow::Result<walkdir::IntoIter> {
    let mut walkdir = walkdir::WalkDir::new(path)
        .sort_by(compare_by_file_name)
        .into_iter();
    if let Some(Err(e)) = walkdir.next() {
        Err(e.into())
    } else {
        Ok(walkdir)
    }
}

fn compare_by_file_name(a: &DirEntry, b: &DirEntry) -> Ordering {
    a.file_name().cmp(b.file_name())
}