#![allow(unused_imports)]
// Copyright 2024 RustFS Team
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#![allow(unused_variables)]

use crate::bucket::metadata::BucketMetadata;
// use crate::event::name::EventName;
use crate::event::targetlist::TargetList;
use crate::store::ECStore;
use crate::store_api::ObjectInfo;
use std::collections::HashMap;
use std::sync::Arc;
use std::sync::OnceLock;
use std::sync::atomic::Ordering;
use tokio::sync::RwLock;
use tracing::warn;

pub struct EventNotifier {
    target_list: TargetList,
    //bucket_rules_map: HashMap<String , HashMap<EventName, Rules>>,
}

impl EventNotifier {
    pub fn new() -> Arc<RwLock<Self>> {
        Arc::new(RwLock::new(Self {
            target_list: TargetList::new(),
            //bucket_rules_map: HashMap::new(),
        }))
    }

    fn get_arn_list(&self) -> Vec<String> {
        warn!(
            event_count = self.target_list.total_events.load(Ordering::Relaxed),
            "event notifier arn list requested but not implemented in this build"
        );
        Vec::new()
    }

    fn set(&self, bucket: &str, meta: BucketMetadata) {
        warn!(bucket = bucket, "event notifier set() called but currently no-op in this build");
    }

    fn init_bucket_targets(&self, _api: ECStore) -> Result<(), std::io::Error> {
        /*if err := self.target_list.Add(globalNotifyTargetList.Targets()...); err != nil {
          return err
        }
        self.target_list = self.target_list.Init(runtime.GOMAXPROCS(0)) // TODO: make this configurable (y4m4)
        nil*/
        warn!("init_bucket_targets called but currently no-op in this build");
        Ok(())
    }

    fn send(&self, args: EventArgs) {
        warn!(
            event_name = args.event_name,
            bucket = args.bucket_name,
            "event send() called but notifier is not fully implemented in this build"
        );
    }
}

#[derive(Debug, Default)]
pub struct EventArgs {
    pub event_name: String,
    pub bucket_name: String,
    pub object: ObjectInfo,
    pub req_params: HashMap<String, String>,
    pub resp_elements: HashMap<String, String>,
    pub host: String,
    pub user_agent: String,
}

impl EventArgs {}

type EventDispatchHook = Arc<dyn Fn(EventArgs) + Send + Sync + 'static>;

static EVENT_DISPATCH_HOOK: OnceLock<EventDispatchHook> = OnceLock::new();

pub fn register_event_dispatch_hook<F>(hook: F) -> bool
where
    F: Fn(EventArgs) + Send + Sync + 'static,
{
    EVENT_DISPATCH_HOOK.set(Arc::new(hook)).is_ok()
}

pub fn send_event(args: EventArgs) {
    if let Some(hook) = EVENT_DISPATCH_HOOK.get() {
        hook(args);
        return;
    }

    warn!(
        event_name = args.event_name,
        bucket = args.bucket_name,
        "event send() dropped because no event dispatch hook is registered"
    );
}

#[cfg(test)]
mod tests {
    use super::*;
    use std::sync::atomic::{AtomicUsize, Ordering};

    static DISPATCH_COUNT: AtomicUsize = AtomicUsize::new(0);

    #[test]
    fn send_event_dispatches_to_registered_hook() {
        let _ = register_event_dispatch_hook(|_args| {
            DISPATCH_COUNT.fetch_add(1, Ordering::Relaxed);
        });
        let before = DISPATCH_COUNT.load(Ordering::Relaxed);

        send_event(EventArgs {
            event_name: "s3:ObjectCreated:Put".to_string(),
            bucket_name: "demo".to_string(),
            ..Default::default()
        });

        assert_eq!(DISPATCH_COUNT.load(Ordering::Relaxed), before + 1);
    }
}
