use crate::pb::*;
use crate::pb::branch_service_client::BranchServiceClient;

use super::{GitksService, into_status};

async fn remote_branch_client(
    svc: &GitksService,
    header: Option<&RepositoryHeader>,
    is_write: bool,
) -> Result<Option<BranchServiceClient<tonic::transport::Channel>>, tonic::Status> {
    let header = match header {
        Some(h) => h,
        None => return Ok(None),
    };
    let Some(route) = svc.route_repository(header, is_write).await? else {
        return Ok(None);
    };
    tracing::info!(storage_name = %route.storage_name, relative_path = %route.relative_path, actor_name = %route.actor_name, grpc_addr = %route.grpc_addr, "forwarding branch rpc");
    let endpoint = super::remote_endpoint(&route.grpc_addr).await?;
    let client = BranchServiceClient::connect(endpoint)
        .await
        .map_err(|e| tonic::Status::unavailable(e.to_string()))?;
    Ok(Some(client))
}

#[tonic::async_trait]
impl branch_service_server::BranchService for GitksService {
    async fn list_branches(
        &self,
        request: tonic::Request<ListBranchesRequest>,
    ) -> Result<tonic::Response<ListBranchesResponse>, tonic::Status> {
        let inner = request.into_inner();
        let repo = self.repo_label(inner.repository.as_ref());
        let span = tracing::info_span!("branch.list_branches", %repo);
        let _enter = span.enter();
        let gb = match self.resolve(inner.repository.as_ref()) {
            Ok(gb) => gb,
            Err(err) if err.code() == tonic::Code::NotFound => {
                if let Some(mut client) = remote_branch_client(self, inner.repository.as_ref(), false).await? {
                    return client.list_branches(inner).await;
                }
                return Err(err);
            }
            Err(err) => return Err(err),
        };
        let resp = gb.list_branches(inner).map_err(into_status)?;
        tracing::info!(%repo, count = resp.branches.len(), "list_branches done");
        Ok(tonic::Response::new(resp))
    }

    async fn get_branch(
        &self,
        request: tonic::Request<GetBranchRequest>,
    ) -> Result<tonic::Response<Branch>, tonic::Status> {
        let inner = request.into_inner();
        let repo = self.repo_label(inner.repository.as_ref());
        let name = inner.name.clone();
        let span = tracing::info_span!("branch.get_branch", %repo, %name);
        let _enter = span.enter();
        let gb = match self.resolve(inner.repository.as_ref()) {
            Ok(gb) => gb,
            Err(err) if err.code() == tonic::Code::NotFound => {
                if let Some(mut client) = remote_branch_client(self, inner.repository.as_ref(), false).await? {
                    return client.get_branch(inner).await;
                }
                return Err(err);
            }
            Err(err) => return Err(err),
        };
        let resp = gb.get_branch(inner).map_err(into_status)?;
        Ok(tonic::Response::new(resp))
    }

    async fn create_branch(
        &self,
        request: tonic::Request<CreateBranchRequest>,
    ) -> Result<tonic::Response<Branch>, tonic::Status> {
        let inner = request.into_inner();
        let repo = self.repo_label(inner.repository.as_ref());
        let name = inner.name.clone();
        let span = tracing::info_span!("branch.create_branch", %repo, %name);
        let _enter = span.enter();
        let gb = match self.resolve(inner.repository.as_ref()) {
            Ok(gb) => gb,
            Err(err) if err.code() == tonic::Code::NotFound => {
                if let Some(mut client) = remote_branch_client(self, inner.repository.as_ref(), true).await? {
                    return client.create_branch(inner).await;
                }
                return Err(err);
            }
            Err(err) => return Err(err),
        };
        let resp = gb.create_branch(inner).map_err(into_status)?;
        tracing::info!(%repo, %name, "branch created");
        self.notify_ref_update(&repo, &format!("refs/heads/{}", name), "", "");
        Ok(tonic::Response::new(resp))
    }

    async fn delete_branch(
        &self,
        request: tonic::Request<DeleteBranchRequest>,
    ) -> Result<tonic::Response<()>, tonic::Status> {
        let inner = request.into_inner();
        let repo = self.repo_label(inner.repository.as_ref());
        let name = inner.name.clone();
        let span = tracing::info_span!("branch.delete_branch", %repo, %name);
        let _enter = span.enter();
        let gb = match self.resolve(inner.repository.as_ref()) {
            Ok(gb) => gb,
            Err(err) if err.code() == tonic::Code::NotFound => {
                if let Some(mut client) = remote_branch_client(self, inner.repository.as_ref(), true).await? {
                    return client.delete_branch(inner).await;
                }
                return Err(err);
            }
            Err(err) => return Err(err),
        };
        gb.delete_branch(inner).map_err(into_status)?;
        tracing::info!(%repo, %name, "branch deleted");
        self.notify_ref_update(&repo, &format!("refs/heads/{}", name), "", "");
        Ok(tonic::Response::new(()))
    }

    async fn rename_branch(
        &self,
        request: tonic::Request<RenameBranchRequest>,
    ) -> Result<tonic::Response<Branch>, tonic::Status> {
        let inner = request.into_inner();
        let repo = self.repo_label(inner.repository.as_ref());
        let old = inner.old_name.clone();
        let new = inner.new_name.clone();
        let span = tracing::info_span!("branch.rename_branch", %repo, %old, %new);
        let _enter = span.enter();
        let gb = match self.resolve(inner.repository.as_ref()) {
            Ok(gb) => gb,
            Err(err) if err.code() == tonic::Code::NotFound => {
                if let Some(mut client) = remote_branch_client(self, inner.repository.as_ref(), true).await? {
                    return client.rename_branch(inner).await;
                }
                return Err(err);
            }
            Err(err) => return Err(err),
        };
        let resp = gb.rename_branch(inner).map_err(into_status)?;
        tracing::info!(%repo, old = %old, new = %new, "branch renamed");
        self.notify_ref_update(&repo, &format!("refs/heads/{}", new), "", "");
        Ok(tonic::Response::new(resp))
    }

    async fn update_branch_target(
        &self,
        request: tonic::Request<UpdateBranchTargetRequest>,
    ) -> Result<tonic::Response<Branch>, tonic::Status> {
        let inner = request.into_inner();
        let repo = self.repo_label(inner.repository.as_ref());
        let name = inner.name.clone();
        let span = tracing::info_span!("branch.update_branch_target", %repo, %name);
        let _enter = span.enter();
        let gb = match self.resolve(inner.repository.as_ref()) {
            Ok(gb) => gb,
            Err(err) if err.code() == tonic::Code::NotFound => {
                if let Some(mut client) = remote_branch_client(self, inner.repository.as_ref(), true).await? {
                    return client.update_branch_target(inner).await;
                }
                return Err(err);
            }
            Err(err) => return Err(err),
        };
        let resp = gb.update_branch_target(inner).map_err(into_status)?;
        tracing::info!(%repo, %name, "branch target updated");
        self.notify_ref_update(&repo, &format!("refs/heads/{}", name), "", "");
        Ok(tonic::Response::new(resp))
    }

    async fn set_branch_upstream(
        &self,
        request: tonic::Request<SetBranchUpstreamRequest>,
    ) -> Result<tonic::Response<Branch>, tonic::Status> {
        let inner = request.into_inner();
        let repo = self.repo_label(inner.repository.as_ref());
        let name = inner.name.clone();
        let span = tracing::info_span!("branch.set_branch_upstream", %repo, %name);
        let _enter = span.enter();
        let gb = match self.resolve(inner.repository.as_ref()) {
            Ok(gb) => gb,
            Err(err) if err.code() == tonic::Code::NotFound => {
                if let Some(mut client) = remote_branch_client(self, inner.repository.as_ref(), true).await? {
                    return client.set_branch_upstream(inner).await;
                }
                return Err(err);
            }
            Err(err) => return Err(err),
        };
        let resp = gb.set_branch_upstream(inner).map_err(into_status)?;
        tracing::info!(%repo, %name, "branch upstream set");
        self.notify_ref_update(&repo, &format!("refs/heads/{}", name), "", "");
        Ok(tonic::Response::new(resp))
    }

    async fn compare_branch(
        &self,
        request: tonic::Request<CompareBranchRequest>,
    ) -> Result<tonic::Response<CompareBranchResponse>, tonic::Status> {
        let inner = request.into_inner();
        let repo = self.repo_label(inner.repository.as_ref());
        let source = inner.source_branch.clone();
        let target = inner.target_branch.clone();
        let span = tracing::info_span!("branch.compare_branch", %repo, %source, %target);
        let _enter = span.enter();
        let gb = match self.resolve(inner.repository.as_ref()) {
            Ok(gb) => gb,
            Err(err) if err.code() == tonic::Code::NotFound => {
                if let Some(mut client) = remote_branch_client(self, inner.repository.as_ref(), false).await? {
                    return client.compare_branch(inner).await;
                }
                return Err(err);
            }
            Err(err) => return Err(err),
        };
        let resp = gb.compare_branch(inner).map_err(into_status)?;
        tracing::info!(%repo, %source, %target, ahead = resp.ahead_by, behind = resp.behind_by, "branch compared");
        Ok(tonic::Response::new(resp))
    }
}