use eyre::{Context as EyreContext, Result};
use tonic::Code;
use tonic::transport::{Channel, Endpoint, Uri};
use tower::service_fn;

use hyper_util::rt::TokioIo;

#[cfg(unix)]
use tokio::net::UnixStream;

use crate::aclient::{history::History, settings::Settings};
use crate::generated;
use crate::{
    events::DaemonEvent,
    generated::{
        control::{
            ForceSyncEvent, HistoryDeletedEvent, HistoryPrunedEvent, HistoryRebuiltEvent,
            SendEventRequest, SettingsReloadedEvent, ShutdownEvent,
            control_client::ControlClient as ControlServiceClient,
        },
        history::{
            EndHistoryReply, EndHistoryRequest, ShutdownRequest, StartHistoryReply,
            StartHistoryRequest, StatusReply, StatusRequest, TailHistoryReply, TailHistoryRequest,
            history_client::HistoryClient as HistoryServiceClient,
        },
        semantic::{
            CommandCapture, RecordCommandsReply,
            semantic_client::SemanticClient as SemanticServiceClient,
        },
    },
};

pub struct HistoryClient {
    client: HistoryServiceClient<Channel>,
}

#[derive(Clone, Copy, Debug, Eq, PartialEq)]
pub enum DaemonClientErrorKind {
    Connect,
    Unavailable,
    Unimplemented,
    Other,
}

#[must_use]
pub fn classify_error(error: &eyre::Report) -> DaemonClientErrorKind {
    for cause in error.chain() {
        if cause.downcast_ref::<tonic::transport::Error>().is_some() {
            return DaemonClientErrorKind::Connect;
        }

        if let Some(status) = cause.downcast_ref::<tonic::Status>() {
            return match status.code() {
                Code::Unavailable => DaemonClientErrorKind::Unavailable,
                Code::Unimplemented => DaemonClientErrorKind::Unimplemented,
                _ => DaemonClientErrorKind::Other,
            };
        }
    }

    DaemonClientErrorKind::Other
}

// Wrap the grpc client
impl HistoryClient {
    #[cfg(unix)]
    pub async fn new(path: String) -> Result<Self> {
        use eyre::Context;

        let log_path = path.clone();
        let channel = Endpoint::try_from("http://atuin_local_daemon:0")?
            .connect_with_connector(service_fn(move |_: Uri| {
                let path = path.clone();

                async move {
                    Ok::<_, std::io::Error>(TokioIo::new(UnixStream::connect(path.clone()).await?))
                }
            }))
            .await
            .wrap_err_with(|| {
                format!(
                    "failed to connect to local atuin daemon at {}. Is it running?",
                    &log_path
                )
            })?;

        let client = HistoryServiceClient::new(channel);

        Ok(Self { client })
    }

    pub async fn start_history(&mut self, h: History) -> Result<StartHistoryReply> {
        let req = StartHistoryRequest {
            command: h.command,
            cwd: h.cwd,
            hostname: h.hostname,
            session: h.session,
            timestamp: h.timestamp.unix_timestamp_nanos() as u64,
            author: h.author,
            intent: h.intent.unwrap_or_default(),
        };

        Ok(self.client.start_history(req).await?.into_inner())
    }

    pub async fn end_history(
        &mut self,
        id: String,
        duration: u64,
        exit: i64,
    ) -> Result<EndHistoryReply> {
        let req = EndHistoryRequest { id, exit, duration };

        Ok(self.client.end_history(req).await?.into_inner())
    }

    pub async fn status(&mut self) -> Result<StatusReply> {
        Ok(self.client.status(StatusRequest {}).await?.into_inner())
    }

    pub(crate) async fn tail_history(&mut self) -> Result<tonic::Streaming<TailHistoryReply>> {
        Ok(self
            .client
            .tail_history(TailHistoryRequest {})
            .await?
            .into_inner())
    }

    pub async fn shutdown(&mut self) -> Result<bool> {
        let resp = self.client.shutdown(ShutdownRequest {}).await?.into_inner();
        Ok(resp.accepted)
    }
}

pub(crate) struct SemanticClient {
    client: SemanticServiceClient<Channel>,
}

impl SemanticClient {
    #[cfg(unix)]
    pub(crate) async fn new(path: String) -> Result<Self> {
        let log_path = path.clone();
        let channel = Endpoint::try_from("http://atuin_local_daemon:0")?
            .connect_with_connector(service_fn(move |_: Uri| {
                let path = path.clone();

                async move {
                    Ok::<_, std::io::Error>(TokioIo::new(UnixStream::connect(path.clone()).await?))
                }
            }))
            .await
            .wrap_err_with(|| {
                format!(
                    "failed to connect to local atuin daemon at {}. Is it running?",
                    &log_path
                )
            })?;

        let client = SemanticServiceClient::new(channel);

        Ok(Self { client })
    }

    #[cfg(unix)]
    pub(crate) async fn from_settings(settings: &Settings) -> Result<Self> {
        Self::new(settings.daemon.socket_path.clone()).await
    }

    pub(crate) async fn record_commands(
        &mut self,
        captures: Vec<CommandCapture>,
    ) -> Result<RecordCommandsReply> {
        let stream = tokio_stream::iter(captures);
        Ok(self.client.record_commands(stream).await?.into_inner())
    }
}

// ============================================================================
// Control Client
// ============================================================================

/// Client for the Control gRPC service.
///
/// Used to inject events into a running daemon from external processes.
pub struct ControlClient {
    client: ControlServiceClient<Channel>,
}

impl ControlClient {
    /// Connect to the daemon's control service.
    #[cfg(unix)]
    pub(crate) async fn new(path: String) -> Result<Self> {
        let log_path = path.clone();
        let channel = Endpoint::try_from("http://atuin_local_daemon:0")?
            .connect_with_connector(service_fn(move |_: Uri| {
                let path = path.clone();

                async move {
                    Ok::<_, std::io::Error>(TokioIo::new(UnixStream::connect(path.clone()).await?))
                }
            }))
            .await
            .wrap_err_with(|| {
                format!(
                    "failed to connect to local atuin daemon at {}. Is it running?",
                    &log_path
                )
            })?;

        let client = ControlServiceClient::new(channel);

        Ok(Self { client })
    }

    /// Connect using settings.
    #[cfg(unix)]
    pub async fn from_settings(settings: &Settings) -> Result<Self> {
        Self::new(settings.daemon.socket_path.clone()).await
    }

    /// Send an event to the daemon.
    pub async fn send_event(&mut self, event: DaemonEvent) -> Result<()> {
        let proto_event = daemon_event_to_proto(event);
        let request = SendEventRequest {
            event: Some(proto_event),
        };
        self.client.send_event(request).await?;
        Ok(())
    }
}

/// Convert a daemon event to its proto representation.
fn daemon_event_to_proto(event: DaemonEvent) -> generated::control::send_event_request::Event {
    use generated::control::send_event_request::Event;

    match event {
        DaemonEvent::HistoryPruned => Event::HistoryPruned(HistoryPrunedEvent {}),
        DaemonEvent::HistoryRebuilt => Event::HistoryRebuilt(HistoryRebuiltEvent {}),
        DaemonEvent::HistoryDeleted { ids } => Event::HistoryDeleted(HistoryDeletedEvent {
            ids: ids.into_iter().map(|id| id.0).collect(),
        }),
        DaemonEvent::ForceSync => Event::ForceSync(ForceSyncEvent {}),
        DaemonEvent::SettingsReloaded => Event::SettingsReloaded(SettingsReloadedEvent {}),
        DaemonEvent::ShutdownRequested => Event::Shutdown(ShutdownEvent {}),
        // These events are internal and not sent via the control service
        DaemonEvent::HistoryStarted(_)
        | DaemonEvent::HistoryEnded(_)
        | DaemonEvent::RecordsAdded(_)
        | DaemonEvent::SyncCompleted { .. }
        | DaemonEvent::SyncFailed { .. } => {
            // Use shutdown as a fallback, though this shouldn't happen
            tracing::warn!("attempted to send internal event via control service");
            Event::Shutdown(ShutdownEvent {})
        }
    }
}