use std::sync::Arc;

use async_tungstenite::tungstenite::protocol::frame;
use async_tungstenite::tungstenite::{self, Utf8Bytes};
use async_tungstenite::{async_tls::client_async_tls, tungstenite::Message};
use bytes::Bytes;
use futures_util::{SinkExt, StreamExt};
use jacquard::{
    CloseCode, CloseFrame, StreamError, WebSocketClient, WebSocketConnection, WsMessage, WsSink,
    WsStream, WsText, client::BasicClient,
};
use smol::net::TcpStream;

#[derive(Debug, Clone, Default)]
pub struct AsyncTungsteniteClient;

impl WebSocketClient for AsyncTungsteniteClient {
    type Error = tungstenite::Error;

    async fn connect(
        &self,
        uri: jacquard::deps::fluent_uri::Uri<&str>,
    ) -> Result<WebSocketConnection, Self::Error> {
        let uri_str = uri.as_str();

        let authority = uri
            .authority()
            .ok_or_else(|| tungstenite::Error::Url(tungstenite::error::UrlError::NoHostName))?;

        let domain = authority.host();
        let default_port = if uri_str.starts_with("wss:") { 443 } else { 80 };
        let port = authority
            .port_to_u16()
            .ok()
            .flatten()
            .unwrap_or(default_port);

        let addr = format!("{domain}:{port}");

        let tcp_stream = TcpStream::connect(&addr)
            .await
            .map_err(tungstenite::Error::Io)?;

        let (ws_stream, _response) = client_async_tls(uri_str, tcp_stream).await?;

        let (sink, stream) = ws_stream.split();

        let rx_stream = stream.filter_map(|result| async move {
            match result {
                Ok(msg) => convert_to_ws_message(msg).map(Ok),
                Err(e) => Some(Err(StreamError::transport(e))),
            }
        });
        let rx = WsStream::new(rx_stream);

        let tx_sink = sink.with(|msg: WsMessage| async move {
            Ok::<_, tungstenite::Error>(convert_from_ws_message(msg))
        });
        let tx_sink_mapped = tx_sink.sink_map_err(StreamError::transport);
        let tx = WsSink::new(tx_sink_mapped);

        Ok(WebSocketConnection::new(tx, rx))
    }
}

fn convert_to_ws_message(msg: Message) -> Option<WsMessage> {
    match msg {
        Message::Text(utf8_bytes) => {
            // Both Utf8Bytes and WsText wrap Bytes with UTF-8 invariant — zero-copy
            let bytes: Bytes = utf8_bytes.into();
            // Safety: tungstenite already validated UTF-8
            Some(WsMessage::Text(unsafe {
                WsText::from_bytes_unchecked(bytes)
            }))
        }
        Message::Binary(data) => Some(WsMessage::Binary(data)),
        Message::Close(frame) => {
            let close_frame = frame.map(|f| {
                let code = convert_close_code(f.code);
                let reason_bytes: Bytes = f.reason.into();
                // Safety: CloseFrame reason was already UTF-8 validated by tungstenite
                let reason_str = unsafe { core::str::from_utf8_unchecked(&reason_bytes) };
                CloseFrame::new(code, reason_str.to_owned())
            });
            Some(WsMessage::Close(close_frame))
        }
        _ => None,
    }
}

fn convert_from_ws_message(msg: WsMessage) -> Message {
    match msg {
        WsMessage::Text(text) => {
            // WsText → Bytes → Utf8Bytes, both already UTF-8 validated
            let bytes = text.into_bytes();
            // Safety: WsText guarantees UTF-8
            Message::Text(unsafe { Utf8Bytes::from_bytes_unchecked(bytes) })
        }
        WsMessage::Binary(bytes) => Message::Binary(bytes),
        WsMessage::Close(frame) => {
            let close_frame = frame.map(|f| {
                let code: u16 = f.code.into();
                frame::CloseFrame {
                    code: code.into(),
                    reason: Utf8Bytes::from(f.reason.to_string()),
                }
            });
            Message::Close(close_frame)
        }
    }
}

fn convert_close_code(code: frame::coding::CloseCode) -> CloseCode {
    use frame::coding::CloseCode as TC;
    match code {
        TC::Normal => CloseCode::Normal,
        TC::Away => CloseCode::Away,
        TC::Protocol => CloseCode::Protocol,
        TC::Unsupported => CloseCode::Unsupported,
        TC::Invalid => CloseCode::Invalid,
        TC::Policy => CloseCode::Policy,
        TC::Size => CloseCode::Size,
        TC::Extension => CloseCode::Extension,
        TC::Error => CloseCode::Error,
        TC::Tls => CloseCode::Tls,
        other => {
            let raw: u16 = other.into();
            CloseCode::from(raw)
        }
    }
}

use bevy::prelude::*;

/// Shared AT Protocol client for XRPC calls.
#[derive(Resource, Clone)]
pub struct AtpClient(pub Arc<BasicClient>);

pub fn setup_atp_client(mut commands: Commands) {
    commands.insert_resource(AtpClient(Arc::new(BasicClient::unauthenticated())));
}