use crate::messages::{EngineMessage::*, SyncedEngineMessage::*, UnsyncedEngineMessage::*, *};

use queues::*;

#[derive(PartialEq)]

pub enum QueueChatStrategy {

    NetworkGame,

    LocalGame,

}

pub struct MessagesQueue {

    strategy: QueueChatStrategy,

    hi_ticks: u32,

    unordered: Queue<EngineMessage>,

    ordered: Queue<EngineMessage>,

}

impl MessagesQueue {

    pub fn new(strategy: QueueChatStrategy) -> Self {

        MessagesQueue {

            strategy,

            hi_ticks: 0,

            unordered: queue![],

            ordered: queue![],

        }

    }

    fn is_unordered(&self, message: &EngineMessage) -> bool {

        match message {

            Unordered(_) => true,

            Unsynced(HogSay(_)) | Unsynced(ChatMessage(_)) | Unsynced(TeamMessage(_)) => {

                self.strategy == QueueChatStrategy::NetworkGame

            }

            _ => false,

        }

    }

    pub fn push(&mut self, engine_message: EngineMessage) {

        if self.is_unordered(&engine_message) {

            self.unordered.add(engine_message).unwrap();

        } else if let Synced(TimeWrap, timestamp) = engine_message {

            self.ordered

                .add(Synced(TimeWrap, timestamp + self.hi_ticks))

                .unwrap();

            self.hi_ticks += 65536;

        } else if let Synced(message, timestamp) = engine_message {

            self.ordered

                .add(Synced(message, timestamp + self.hi_ticks))

                .unwrap();

        } else {

            self.ordered.add(engine_message).unwrap();

        }

    }

    pub fn pop(&mut self, timestamp: u32) -> Option<EngineMessage> {

        if let Ok(message) = self.unordered.remove() {

            Some(message)

        } else if let Ok(Synced(_, message_timestamp)) = self.ordered.peek() {

            if message_timestamp == timestamp {

                self.ordered.remove().ok()

            } else {

                None

            }

        } else {

            self.ordered.remove().ok()

        }

    }

    pub fn iter(&mut self, timestamp: u32) -> MessagesQueueIterator {

        MessagesQueueIterator {

            timestamp,

            queue: self,

        }

    }

}

pub struct MessagesQueueIterator<'a> {

    timestamp: u32,

    queue: &'a mut MessagesQueue,

}

impl<'a> Iterator for MessagesQueueIterator<'a> {

    type Item = EngineMessage;

    fn next(&mut self) -> Option<EngineMessage> {

        self.queue.pop(self.timestamp)

    }

}

#[test]

fn queue_order() {

    use crate::messages::UnorderedEngineMessage::*;

    let mut queue = MessagesQueue::new(QueueChatStrategy::LocalGame);

    queue.push(Synced(Skip, 1));

    queue.push(Unsynced(ChatMessage("hi".to_string())));

    queue.push(Synced(TimeWrap, 65535));

    queue.push(Unordered(Ping));

    queue.push(Synced(Skip, 2));

    let zero_tick: Vec<EngineMessage> = queue.iter(0).collect();

    assert_eq!(zero_tick, vec![Unordered(Ping)]);

    assert_eq!(queue.pop(1), Some(Synced(Skip, 1)));

    assert_eq!(queue.pop(1), Some(Unsynced(ChatMessage("hi".to_string()))));

    assert_eq!(queue.pop(1), None);

    assert_eq!(queue.pop(2), None);

    assert_eq!(queue.pop(65535), Some(Synced(TimeWrap, 65535)));

    assert_eq!(queue.pop(65535), None);

    assert_eq!(queue.pop(65538), Some(Synced(Skip, 65538)));

    assert_eq!(queue.pop(65538), None);

    assert_eq!(queue.pop(65539), None);

}