use crate::{settings_store::SettingsStore, Settings};
use fs::Fs;
use futures::{channel::mpsc, StreamExt};
use gpui::{App, BackgroundExecutor, ReadGlobal};
use std::{path::PathBuf, sync::Arc, time::Duration};

pub const EMPTY_THEME_NAME: &str = "empty-theme";

#[cfg(any(test, feature = "test-support"))]
pub fn test_settings() -> String {
    let mut value = crate::settings_store::parse_json_with_comments::<serde_json::Value>(
        crate::default_settings().as_ref(),
    )
    .unwrap();
    #[cfg(not(target_os = "windows"))]
    util::merge_non_null_json_value_into(
        serde_json::json!({
            "ui_font_family": "Courier",
            "ui_font_features": {},
            "ui_font_size": 14,
            "ui_font_fallback": [],
            "buffer_font_family": "Courier",
            "buffer_font_features": {},
            "buffer_font_size": 14,
            "buffer_font_fallback": [],
            "theme": EMPTY_THEME_NAME,
        }),
        &mut value,
    );
    #[cfg(target_os = "windows")]
    util::merge_non_null_json_value_into(
        serde_json::json!({
            "ui_font_family": "Courier New",
            "ui_font_features": {},
            "ui_font_size": 14,
            "ui_font_fallback": [],
            "buffer_font_family": "Courier New",
            "buffer_font_features": {},
            "buffer_font_size": 14,
            "buffer_font_fallback": [],
            "theme": EMPTY_THEME_NAME,
        }),
        &mut value,
    );
    value.as_object_mut().unwrap().remove("languages");
    serde_json::to_string(&value).unwrap()
}

pub fn watch_config_file(
    executor: &BackgroundExecutor,
    fs: Arc<dyn Fs>,
    path: PathBuf,
) -> mpsc::UnboundedReceiver<String> {
    let (tx, rx) = mpsc::unbounded();
    executor
        .spawn(async move {
            let (events, _) = fs.watch(&path, Duration::from_millis(100)).await;
            futures::pin_mut!(events);

            let contents = fs.load(&path).await.unwrap_or_default();
            if tx.unbounded_send(contents).is_err() {
                return;
            }

            loop {
                if events.next().await.is_none() {
                    break;
                }

                if let Ok(contents) = fs.load(&path).await {
                    if tx.unbounded_send(contents).is_err() {
                        break;
                    }
                }
            }
        })
        .detach();
    rx
}

pub fn update_settings_file<T: Settings>(
    fs: Arc<dyn Fs>,
    cx: &App,
    update: impl 'static + Send + FnOnce(&mut T::FileContent, &App),
) {
    SettingsStore::global(cx).update_settings_file::<T>(fs, update);
}