pub use crate::{
    buffer::Buffer, node::Node, BoxedNodeSend, Message, NodeData, Pass, Processor, Sum2,
};
use hashbrown::HashMap;
use petgraph::{graph::NodeIndex, prelude::EdgeIndex};

/// The builder to build `AudioContext`
pub struct AudioContextBuilder<const N: usize> {
    sr: usize,
    channels: usize,
    // stablegraph: bool,
    max_nodes: usize,
    max_edges: usize,
}

impl<const N: usize> Default for AudioContextBuilder<N> {
    fn default() -> Self {
        Self::new()
    }
}

impl<const N: usize> AudioContextBuilder<N> {
    pub fn new() -> Self {
        Self {
            sr: 44100,
            channels: 2,
            // stablegraph: false,
            max_nodes: 1024,
            max_edges: 1024,
        }
    }

    pub fn sr(self, sr: usize) -> Self {
        Self { sr, ..self }
    }

    pub fn channels(self, channels: usize) -> Self {
        Self { channels, ..self }
    }

    pub fn max_nodes(self, max_nodes: usize) -> Self {
        Self { max_nodes, ..self }
    }

    pub fn max_edges(self, max_edges: usize) -> Self {
        Self { max_edges, ..self }
    }

    pub fn build(self) -> AudioContext<N> {
        AudioContext::new(AudioContextConfig {
            sr: self.sr,
            channels: self.channels,
            max_nodes: self.max_nodes,
            max_edges: self.max_edges,
        })
    }
}

/// Another option for building `AudioContext`
pub struct AudioContextConfig {
    pub sr: usize,
    pub channels: usize,
    // pub stablegraph: bool,
    pub max_nodes: usize,
    pub max_edges: usize,
}

impl std::default::Default for AudioContextConfig {
    fn default() -> Self {
        Self {
            sr: 44100,
            channels: 2,
            max_nodes: 1024,
            max_edges: 1024,
        }
    }
}

#[macro_export]
macro_rules! audiocontext {
    ($size:expr, {$($para: ident: $data:expr),*}) => {
        (
            AudioContextBuilder::<$size>::new()$(.$para($data))*.build()
        )
    }
}

pub type GlicolNodeData<const N: usize> = NodeData<BoxedNodeSend<N>, N>;
pub type GlicolGraph<const N: usize> = petgraph::stable_graph::StableGraph<GlicolNodeData<N>, ()>;
pub type GlicolProcessor<const N: usize> = Processor<GlicolGraph<N>, N>;

/// The audio context that holds a destination and the graph connection
pub struct AudioContext<const N: usize> {
    pub input: NodeIndex,
    pub destination: NodeIndex,
    pub tags: HashMap<&'static str, NodeIndex>,
    pub graph: GlicolGraph<N>,
    pub processor: GlicolProcessor<N>,
    config: AudioContextConfig,
}

impl<const N: usize> AudioContext<N> {
    pub fn new(config: AudioContextConfig) -> Self {
        let mut graph = GlicolGraph::<N>::with_capacity(config.max_nodes, config.max_edges);
        let destination = graph.add_node(NodeData::multi_chan_node(
            config.channels,
            BoxedNodeSend::<N>::new(Sum2),
        ));
        let input = graph.add_node(NodeData::multi_chan_node(
            config.channels,
            BoxedNodeSend::<N>::new(Pass),
        ));
        Self {
            graph,
            destination,
            input,
            tags: HashMap::new(),
            processor: GlicolProcessor::<N>::with_capacity(config.max_nodes),
            config,
        }
    }

    pub fn reset(&mut self) {
        // self.graph.clear_edges();
        self.graph.clear();
        self.destination = self.graph.add_node(NodeData::multi_chan_node(
            self.config.channels,
            BoxedNodeSend::<N>::new(Sum2),
        ));
        self.input = self.graph.add_node(NodeData::multi_chan_node(
            self.config.channels,
            BoxedNodeSend::<N>::new(Pass),
        ));
    }

    /// an alternative to new() specify the estimated max node and edge numbers
    /// to avoid dynamic allocation
    // pub fn with_capacity(nodes: usize, edges: usize) -> Self {
    //     let mut graph = GlicolGraph::<N>::with_capacity(nodes, edges);
    //     let destination = graph.add_node( NodeData::new2( BoxedNodeSend::<N>::new( Sum)  ) );
    //     let input = graph.add_node( NodeData::multi_chan_node(config.channels, BoxedNodeSend::<N>::new(Pass) ) );
    //     Self {
    //         graph,
    //         destination,
    //         input,
    //         processor: GlicolProcessor::<N>::with_capacity(nodes),
    //     }
    // }

    pub fn add_mono_node<T>(&mut self, node: T) -> NodeIndex
    where
        T: Node<N> + Send + 'static,
    {
        self.graph.add_node(
            // channel?
            NodeData::new1(BoxedNodeSend::<N>::new(node)),
        )
    }

    pub fn add_stereo_node<T>(&mut self, node: T) -> NodeIndex
    where
        T: Node<N> + Send + 'static,
    {
        self.graph.add_node(
            // channel?
            NodeData::new2(BoxedNodeSend::<N>::new(node)),
        )
    }

    pub fn add_multi_chan_node<T>(&mut self, chan: usize, node: T) -> NodeIndex
    where
        T: Node<N> + Send + 'static,
    {
        self.graph.add_node(
            // channel?
            NodeData::multi_chan_node(chan, BoxedNodeSend::<N>::new(node)),
        )
    }

    pub fn connect(&mut self, from: NodeIndex, to: NodeIndex) -> EdgeIndex {
        let edge_index = self.graph.add_edge(from, to, ());
        self.graph[to].node.send_msg(Message::Index(from.index()));
        edge_index
    }

    pub fn connect_with_order(&mut self, from: NodeIndex, to: NodeIndex, pos: usize) -> EdgeIndex {
        let edge_index = self.graph.add_edge(from, to, ());
        self.graph[to]
            .node
            .send_msg(Message::IndexOrder(pos, from.index()));
        edge_index
    }

    pub fn chain(&mut self, chain: Vec<NodeIndex>) -> Vec<EdgeIndex> {
        chain.windows(2)
            .map(|pair| {
                let ret = self.graph.add_edge(pair[0], pair[1], ());
                self.graph[pair[1]]
                    .node
                    .send_msg(Message::Index(pair[0].index()));
                ret
            }).collect()
    }

    pub fn chain_boxed(
        &mut self,
        chain: Vec<GlicolNodeData<N>>,
    ) -> (Vec<NodeIndex>, Vec<EdgeIndex>) {
        let indices = chain.into_iter()
            .map(|node| self.graph.add_node(node))
            .collect::<Vec<_>>();

        let v = indices.windows(2)
            .map(|pair| {
                let ret = self.graph.add_edge(pair[0], pair[1], ());
                self.graph[pair[1]]
                    .node
                    .send_msg(Message::Index(pair[0].index()));
                ret
            }).collect();

        (indices, v)
    }

    pub fn add_node_chain(
        &mut self,
        chain: Vec<NodeData<BoxedNodeSend<N>, N>>,
    ) -> (Vec<NodeIndex>, Vec<EdgeIndex>) {
        let v = chain.into_iter()
            .map(|node| self.graph.add_node(node))
            .collect::<Vec<_>>();

        let j = v.windows(2)
            .map(|pair| self.graph.add_edge(pair[0], pair[1], ()))
            .collect();

        (v, j)
    }

    pub fn next_block(&mut self) -> &[Buffer<N>] {
        self.processor.process(&mut self.graph, self.destination);
        &self.graph[self.destination].buffers
    }

    pub fn send_msg(&mut self, index: NodeIndex, msg: Message) {
        self.graph[index].node.send_msg(msg);
    }

    pub fn send_msg_to_all(&mut self, msg: Message) {
        for nodedata in self.graph.node_weights_mut() {
            nodedata.node.send_msg(msg.clone());
        }
    }
}