use crate::pb::*;
use crate::pb::commit_service_client::CommitServiceClient;

use super::{GitksService, cache, into_status};

async fn remote_commit_client(
    svc: &GitksService,
    header: Option<&RepositoryHeader>,
) -> Result<Option<CommitServiceClient<tonic::transport::Channel>>, tonic::Status> {
    let header = match header {
        Some(h) => h,
        None => return Ok(None),
    };
    let Some(route) = svc.route_repository(header).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 commit rpc");
    let endpoint = super::remote_endpoint(&route.grpc_addr).await?;
    let client = CommitServiceClient::connect(endpoint)
        .await
        .map_err(|e| tonic::Status::unavailable(e.to_string()))?;
    Ok(Some(client))
}

#[tonic::async_trait]
impl commit_service_server::CommitService for GitksService {
    async fn list_commits(
        &self,
        request: tonic::Request<ListCommitsRequest>,
    ) -> Result<tonic::Response<ListCommitsResponse>, tonic::Status> {
        let inner = request.into_inner();
        let repo = self.repo_label(inner.repository.as_ref());
        let span = tracing::info_span!("commit.list_commits", %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_commit_client(self, inner.repository.as_ref()).await? {
                    return client.list_commits(inner).await;
                }
                return Err(err);
            }
            Err(err) => return Err(err),
        };
        let resp = if !inner.all && cache::selector_is_oid(&inner.revision) {
            cache::cached_response("commit.list_commits", &inner, || {
                gb.list_commits(inner.clone()).map_err(into_status)
            })?
        } else {
            gb.list_commits(inner).map_err(into_status)?
        };
        tracing::info!(%repo, count = resp.commits.len(), total = resp.page_info.as_ref().map(|p| p.total_count).unwrap_or(0), "list_commits done");
        Ok(tonic::Response::new(resp))
    }

    async fn get_commit(
        &self,
        request: tonic::Request<GetCommitRequest>,
    ) -> Result<tonic::Response<Commit>, tonic::Status> {
        let inner = request.into_inner();
        let repo = self.repo_label(inner.repository.as_ref());
        let span = tracing::info_span!("commit.get_commit", %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_commit_client(self, inner.repository.as_ref()).await? {
                    return client.get_commit(inner).await;
                }
                return Err(err);
            }
            Err(err) => return Err(err),
        };
        let resp = if cache::selector_is_oid(&inner.revision) {
            cache::cached_response("commit.get_commit", &inner, || {
                gb.get_commit(inner.clone()).map_err(into_status)
            })?
        } else {
            gb.get_commit(inner).map_err(into_status)?
        };
        Ok(tonic::Response::new(resp))
    }

    async fn get_commit_ancestors(
        &self,
        request: tonic::Request<GetCommitAncestorsRequest>,
    ) -> Result<tonic::Response<GetCommitAncestorsResponse>, tonic::Status> {
        let inner = request.into_inner();
        let repo = self.repo_label(inner.repository.as_ref());
        let span = tracing::info_span!("commit.get_commit_ancestors", %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_commit_client(self, inner.repository.as_ref()).await? {
                    return client.get_commit_ancestors(inner).await;
                }
                return Err(err);
            }
            Err(err) => return Err(err),
        };
        let resp = if cache::selector_is_oid(&inner.revision) {
            cache::cached_response("commit.get_commit_ancestors", &inner, || {
                gb.get_commit_ancestors(inner.clone()).map_err(into_status)
            })?
        } else {
            gb.get_commit_ancestors(inner).map_err(into_status)?
        };
        tracing::info!(%repo, count = resp.commits.len(), "get_commit_ancestors done");
        Ok(tonic::Response::new(resp))
    }

    async fn create_commit(
        &self,
        request: tonic::Request<CreateCommitRequest>,
    ) -> Result<tonic::Response<CreateCommitResponse>, tonic::Status> {
        let inner = request.into_inner();
        let repo = self.repo_label(inner.repository.as_ref());
        let branch = inner.branch.clone();
        let span = tracing::info_span!("commit.create_commit", %repo, %branch);
        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_commit_client(self, inner.repository.as_ref()).await? {
                    return client.create_commit(inner).await;
                }
                return Err(err);
            }
            Err(err) => return Err(err),
        };
        let resp = gb.create_commit(inner).map_err(into_status)?;
        let commit_hex = resp.commit.as_ref()
            .and_then(|c| c.oid.as_ref().map(|o| o.hex.as_str()).or(Some("?")))
            .unwrap_or("?");
        tracing::info!(%repo, %branch, %commit_hex, "commit created");
        Ok(tonic::Response::new(resp))
    }

    async fn revert_commit(
        &self,
        request: tonic::Request<RevertCommitRequest>,
    ) -> Result<tonic::Response<CreateCommitResponse>, tonic::Status> {
        let inner = request.into_inner();
        let repo = self.repo_label(inner.repository.as_ref());
        let branch = inner.branch.clone();
        let span = tracing::info_span!("commit.revert_commit", %repo, %branch);
        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_commit_client(self, inner.repository.as_ref()).await? {
                    return client.revert_commit(inner).await;
                }
                return Err(err);
            }
            Err(err) => return Err(err),
        };
        let resp = gb.revert_commit(inner).map_err(into_status)?;
        tracing::info!(%repo, %branch, "commit reverted");
        Ok(tonic::Response::new(resp))
    }

    async fn cherry_pick_commit(
        &self,
        request: tonic::Request<CherryPickCommitRequest>,
    ) -> Result<tonic::Response<CreateCommitResponse>, tonic::Status> {
        let inner = request.into_inner();
        let repo = self.repo_label(inner.repository.as_ref());
        let branch = inner.branch.clone();
        let span = tracing::info_span!("commit.cherry_pick_commit", %repo, %branch);
        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_commit_client(self, inner.repository.as_ref()).await? {
                    return client.cherry_pick_commit(inner).await;
                }
                return Err(err);
            }
            Err(err) => return Err(err),
        };
        let resp = gb.cherry_pick_commit(inner).map_err(into_status)?;
        tracing::info!(%repo, %branch, "commit cherry-picked");
        Ok(tonic::Response::new(resp))
    }

    async fn compare_commits(
        &self,
        request: tonic::Request<CompareCommitsRequest>,
    ) -> Result<tonic::Response<CompareCommitsResponse>, tonic::Status> {
        let inner = request.into_inner();
        let repo = self.repo_label(inner.repository.as_ref());
        let span = tracing::info_span!("commit.compare_commits", %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_commit_client(self, inner.repository.as_ref()).await? {
                    return client.compare_commits(inner).await;
                }
                return Err(err);
            }
            Err(err) => return Err(err),
        };
        let resp = if cache::selectors_are_oid(&inner.base, &inner.head) {
            cache::cached_response("commit.compare_commits", &inner, || {
                gb.compare_commits(inner.clone()).map_err(into_status)
            })?
        } else {
            gb.compare_commits(inner).map_err(into_status)?
        };
        tracing::info!(%repo, count = resp.commits.len(), "compare_commits done");
        Ok(tonic::Response::new(resp))
    }
}