use super::*;
use crate::pull_requests::{Direction, ReviewFilter, SortField, SortRule};

struct Fixture(PathBuf);

impl Fixture {
    fn new() -> Self {
        let path = std::env::temp_dir().join(format!(
            "vamp-pr-preferences-{}-{}",
            std::process::id(),
            NEXT_TEMP.fetch_add(1, Ordering::Relaxed)
        ));
        fs::create_dir(&path).unwrap();
        Self(path)
    }

    fn path(&self) -> PathBuf {
        self.0.join("state/vamp/pull_requests.json")
    }
}

impl Drop for Fixture {
    fn drop(&mut self) {
        let _ = fs::remove_dir_all(&self.0);
    }
}

#[test]
fn paths_use_absolute_xdg_state_or_home_without_reading_environment() {
    assert_eq!(
        path_from(Some(OsStr::new("/state")), Some(OsStr::new("/home"))).unwrap(),
        PathBuf::from("/state/vamp/pull_requests.json")
    );
    for xdg in [None, Some(OsStr::new("")), Some(OsStr::new("relative"))] {
        assert_eq!(
            path_from(xdg, Some(OsStr::new("/home"))).unwrap(),
            PathBuf::from("/home/.local/state/vamp/pull_requests.json")
        );
    }
    assert!(path_from(None, None).is_err());
    assert!(path_from(None, Some(OsStr::new("relative"))).is_err());
}

#[test]
fn loading_is_lazy_and_applied_preferences_round_trip_atomically() {
    let fixture = Fixture::new();
    let path = fixture.path();
    let (store, mut preferences, notice) = Store::load(Ok(path.clone()));
    assert_eq!(preferences, Preferences::default());
    assert!(notice.is_none());
    assert!(!path.parent().unwrap().exists());
    preferences.filters = vec![ReviewFilter::Approved];
    preferences.sort.insert(
        SortField::UpdatedAt,
        SortRule {
            precedence: Some(1),
            direction: Direction::Asc,
        },
    );
    store.save(&preferences).unwrap();
    let (_, loaded, notice) = Store::load(Ok(path.clone()));
    assert_eq!(loaded.sort, preferences.sort);
    assert_eq!(loaded.filters, Preferences::default().filters);
    assert!(!fs::read_to_string(&path).unwrap().contains("filters"));
    assert!(notice.is_none());
    preferences.filters.clear();
    preferences.sort.clear();
    store.save(&preferences).unwrap();
    assert_eq!(Store::load(Ok(path)).1, Preferences::default());
    assert_eq!(
        fs::read_dir(fixture.0.join("state/vamp")).unwrap().count(),
        1
    );
}

#[test]
fn previously_saved_filters_are_ignored_without_changing_sort_or_file() {
    let fixture = Fixture::new();
    let path = fixture.path();
    fs::create_dir_all(path.parent().unwrap()).unwrap();
    for filters in [
        r#"[]"#,
        r#"["approved"]"#,
        r#"["unknown"]"#,
        r#"{"invalid":true}"#,
    ] {
        let bytes = format!(
            r#"{{"version":1,"preferences":{{"sort":{{"created_at":{{"precedence":1,"direction":"asc"}}}},"filters":{filters}}}}}"#
        );
        fs::write(&path, &bytes).unwrap();
        let (_, loaded, notice) = Store::load(Ok(path.clone()));
        assert!(notice.is_none());
        assert_eq!(loaded.filters, Preferences::default().filters);
        assert_eq!(loaded.sort[&SortField::CreatedAt].direction, Direction::Asc);
        assert_eq!(fs::read_to_string(&path).unwrap(), bytes);
    }
}

#[test]
fn corrupt_incompatible_and_invalid_data_is_preserved_even_after_apply() {
    let fixture = Fixture::new();
    let path = fixture.path();
    fs::create_dir_all(path.parent().unwrap()).unwrap();
    for bytes in [
        "not json",
        r#"{"version":2,"preferences":{}}"#,
        r#"{"version":1,"preferences":{"sort":{"unknown":{}}}}"#,
        r#"{"version":1,"preferences":{"sort":{"updated_at":{"direction":"up"}}}}"#,
        r#"{"version":1,"preferences":{"sort":{"updated_at":{"precedence":0}}}}"#,
        r#"{"version":1,"preferences":{"sort":{"updated_at":{"precedence":1},"created_at":{"precedence":1}}}}"#,
    ] {
        fs::write(&path, bytes).unwrap();
        let (store, loaded, notice) = Store::load(Ok(path.clone()));
        assert_eq!(loaded, Preferences::default());
        assert!(notice.unwrap().contains("session-only"));
        assert!(store.save(&loaded).unwrap_err().contains("preserved"));
        assert_eq!(fs::read_to_string(&path).unwrap(), bytes);
    }
}

#[test]
fn failed_writes_and_newly_incompatible_data_are_reported_without_replacement() {
    let fixture = Fixture::new();
    let path = fixture.path();
    let (store, preferences, _) = Store::load(Ok(path.clone()));
    fs::write(fixture.0.join("state"), "keep this file").unwrap();
    assert!(
        store
            .save(&preferences)
            .unwrap_err()
            .contains("session-only")
    );
    assert_eq!(
        fs::read_to_string(fixture.0.join("state")).unwrap(),
        "keep this file"
    );
    fs::remove_file(fixture.0.join("state")).unwrap();
    fs::create_dir_all(path.parent().unwrap()).unwrap();
    let incompatible = r#"{"version":9,"preferences":{}}"#;
    fs::write(&path, incompatible).unwrap();
    assert!(
        store
            .save(&preferences)
            .unwrap_err()
            .contains("unsupported")
    );
    assert_eq!(fs::read_to_string(path).unwrap(), incompatible);
}