use crate::pb::*;
use crate::pb::repository_service_client::RepositoryServiceClient;

use super::{GitksService, git_cmd, into_status, repository_maint, remote_endpoint};

async fn remote_repository_client(
    svc: &GitksService,
    header: Option<&RepositoryHeader>,
) -> Result<Option<RepositoryServiceClient<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 repository rpc");
    let endpoint = remote_endpoint(&route.grpc_addr).await?;
    let client = RepositoryServiceClient::connect(endpoint)
        .await
        .map_err(|e| tonic::Status::unavailable(e.to_string()))?;
    Ok(Some(client))
}

fn default_branch_name(gb: &crate::bare::GitBare) -> String {
    git_cmd(gb, &["symbolic-ref", "HEAD"])
        .ok()
        .and_then(|o| {
            String::from_utf8_lossy(&o.stdout)
                .trim()
                .strip_prefix("refs/heads/")
                .map(|b| b.to_string())
        })
        .unwrap_or_default()
}

#[tonic::async_trait]
impl repository_service_server::RepositoryService for GitksService {
    async fn get_repository(
        &self,
        request: tonic::Request<GetRepositoryRequest>,
    ) -> Result<tonic::Response<Repository>, tonic::Status> {
        let inner = request.into_inner();
        let repo = self.repo_label(inner.repository.as_ref());
        let span = tracing::info_span!("repo.get_repository", %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_repository_client(self, inner.repository.as_ref()).await? {
                    return client.get_repository(inner).await;
                }
                return Err(err);
            }
            Err(err) => return Err(err),
        };
        let bare = gb.bare_dir.join("HEAD").exists();
        let object_format = gb.object_format();
        Ok(tonic::Response::new(Repository {
            header: inner.repository,
            bare,
            object_format: object_format as i32,
            default_branch: default_branch_name(&gb),
            ..Default::default()
        }))
    }

    async fn init_repository(
        &self,
        request: tonic::Request<InitRepositoryRequest>,
    ) -> Result<tonic::Response<Repository>, tonic::Status> {
        let inner = request.into_inner();
        let repo = self.repo_label(inner.repository.as_ref());
        let span = tracing::info_span!("repo.init_repository", %repo);
        let _enter = span.enter();
        let bare_dir = self.resolve_for_init(inner.repository.as_ref())?;
        let gb = crate::bare::GitBare::new(bare_dir);
        gb.init_repository(inner.bare).map_err(into_status)?;
        tracing::info!(%repo, bare = inner.bare, "repository initialized");
        Ok(tonic::Response::new(Repository {
            header: inner.repository,
            bare: inner.bare,
            ..Default::default()
        }))
    }

    async fn delete_repository(
        &self,
        request: tonic::Request<DeleteRepositoryRequest>,
    ) -> Result<tonic::Response<()>, tonic::Status> {
        let inner = request.into_inner();
        let repo = self.repo_label(inner.repository.as_ref());
        let span = tracing::info_span!("repo.delete_repository", %repo);
        let _enter = span.enter();
        let bare_dir = self.resolve_for_init(inner.repository.as_ref())?;
        if !bare_dir.exists() {
            if let Some(mut client) = remote_repository_client(self, inner.repository.as_ref()).await? {
                return client.delete_repository(inner).await;
            }
        }
        tracing::warn!(%repo, path = %bare_dir.display(), "deleting repository");
        std::fs::remove_dir_all(&bare_dir).map_err(|e| tonic::Status::internal(e.to_string()))?;
        tracing::info!(%repo, "repository deleted");
        Ok(tonic::Response::new(()))
    }

    async fn repository_exists(
        &self,
        request: tonic::Request<RepositoryExistsRequest>,
    ) -> Result<tonic::Response<RepositoryExistsResponse>, tonic::Status> {
        let inner = request.into_inner();
        let repo = self.repo_label(inner.repository.as_ref());
        let span = tracing::info_span!("repo.repository_exists", %repo);
        let _enter = span.enter();
        let bare_dir = self.resolve_for_init(inner.repository.as_ref())?;
        let exists = bare_dir.exists() && bare_dir.is_dir() && bare_dir.join("HEAD").exists();
        if !exists {
            if let Some(mut client) = remote_repository_client(self, inner.repository.as_ref()).await? {
                return client.repository_exists(inner).await;
            }
        }
        Ok(tonic::Response::new(RepositoryExistsResponse { exists }))
    }

    async fn get_object_format(
        &self,
        request: tonic::Request<RepositoryObjectFormatRequest>,
    ) -> Result<tonic::Response<RepositoryObjectFormatResponse>, tonic::Status> {
        let inner = request.into_inner();
        let repo = self.repo_label(inner.repository.as_ref());
        let span = tracing::info_span!("repo.get_object_format", %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_repository_client(self, inner.repository.as_ref()).await? {
                    return client.get_object_format(inner).await;
                }
                return Err(err);
            }
            Err(err) => return Err(err),
        };
        Ok(tonic::Response::new(RepositoryObjectFormatResponse {
            object_format: gb.object_format() as i32,
        }))
    }

    async fn get_default_branch(
        &self,
        request: tonic::Request<GetDefaultBranchRequest>,
    ) -> Result<tonic::Response<GetDefaultBranchResponse>, tonic::Status> {
        let inner = request.into_inner();
        let repo = self.repo_label(inner.repository.as_ref());
        let span = tracing::info_span!("repo.get_default_branch", %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_repository_client(self, inner.repository.as_ref()).await? {
                    return client.get_default_branch(inner).await;
                }
                return Err(err);
            }
            Err(err) => return Err(err),
        };
        Ok(tonic::Response::new(GetDefaultBranchResponse {
            name: default_branch_name(&gb),
        }))
    }

    async fn set_default_branch(
        &self,
        request: tonic::Request<SetDefaultBranchRequest>,
    ) -> 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!("repo.set_default_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_repository_client(self, inner.repository.as_ref()).await? {
                    return client.set_default_branch(inner).await;
                }
                return Err(err);
            }
            Err(err) => return Err(err),
        };
        let refname = format!("refs/heads/{}", inner.name);
        let out = git_cmd(&gb, &["symbolic-ref", "HEAD", &refname])?;
        if !out.status.success() {
            return Err(tonic::Status::internal(
                String::from_utf8_lossy(&out.stderr).trim().to_string(),
            ));
        }
        tracing::info!(%repo, %name, "default branch set");
        Ok(tonic::Response::new(()))
    }

    async fn get_repository_config(
        &self,
        request: tonic::Request<GetRepositoryConfigRequest>,
    ) -> Result<tonic::Response<GetRepositoryConfigResponse>, tonic::Status> {
        let inner = request.into_inner();
        let repo = self.repo_label(inner.repository.as_ref());
        let span = tracing::info_span!("repo.get_repository_config", %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_repository_client(self, inner.repository.as_ref()).await? {
                    return client.get_repository_config(inner).await;
                }
                return Err(err);
            }
            Err(err) => return Err(err),
        };
        let mut entries = Vec::new();
        if inner.keys.is_empty() {
            let out = git_cmd(&gb, &["config", "--list"])?;
            if !out.status.success() {
                return Err(tonic::Status::internal(
                    String::from_utf8_lossy(&out.stderr).trim().to_string(),
                ));
            }
            for line in String::from_utf8_lossy(&out.stdout).lines() {
                if let Some((k, v)) = line.split_once('=') {
                    entries.push(RepositoryConfigEntry {
                        key: k.trim().to_string(),
                        values: vec![v.trim().to_string()],
                    });
                }
            }
        } else {
            for key in &inner.keys {
                let out = git_cmd(&gb, &["config", "--get-all", key])?;
                if out.status.success() {
                    let vals: Vec<String> = String::from_utf8_lossy(&out.stdout)
                        .lines()
                        .map(|l| l.trim().to_string())
                        .filter(|l| !l.is_empty())
                        .collect();
                    if !vals.is_empty() {
                        entries.push(RepositoryConfigEntry {
                            key: key.clone(),
                            values: vals,
                        });
                    }
                }
            }
        }
        Ok(tonic::Response::new(GetRepositoryConfigResponse {
            entries,
        }))
    }

    async fn set_repository_config(
        &self,
        request: tonic::Request<SetRepositoryConfigRequest>,
    ) -> Result<tonic::Response<()>, tonic::Status> {
        let inner = request.into_inner();
        let repo = self.repo_label(inner.repository.as_ref());
        let span = tracing::info_span!("repo.set_repository_config", %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_repository_client(self, inner.repository.as_ref()).await? {
                    return client.set_repository_config(inner).await;
                }
                return Err(err);
            }
            Err(err) => return Err(err),
        };
        for entry in &inner.entries {
            if entry.values.is_empty() {
                git_cmd(&gb, &["config", "--unset-all", &entry.key])?;
            } else {
                let _ = git_cmd(
                    &gb,
                    &["config", "--replace-all", &entry.key, &entry.values[0]],
                );
                for v in entry.values.iter().skip(1) {
                    let _ = git_cmd(&gb, &["config", "--add", &entry.key, v]);
                }
            }
        }
        Ok(tonic::Response::new(()))
    }

    async fn get_repository_statistics(
        &self,
        request: tonic::Request<RepositoryStatisticsRequest>,
    ) -> Result<tonic::Response<RepositoryStatistics>, tonic::Status> {
        let inner = request.into_inner();
        let repo = self.repo_label(inner.repository.as_ref());
        let span = tracing::info_span!("repo.get_repository_statistics", %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_repository_client(self, inner.repository.as_ref()).await? {
                    return client.get_repository_statistics(inner).await;
                }
                return Err(err);
            }
            Err(err) => return Err(err),
        };
        Ok(tonic::Response::new(repository_maint::get_statistics(&gb)))
    }

    async fn check_repository_health(
        &self,
        request: tonic::Request<RepositoryHealthRequest>,
    ) -> Result<tonic::Response<RepositoryHealthResponse>, tonic::Status> {
        let inner = request.into_inner();
        let repo = self.repo_label(inner.repository.as_ref());
        let span = tracing::info_span!("repo.check_repository_health", %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_repository_client(self, inner.repository.as_ref()).await? {
                    return client.check_repository_health(inner).await;
                }
                return Err(err);
            }
            Err(err) => return Err(err),
        };
        let resp = repository_maint::check_health(&gb, inner.connectivity_only)?;
        tracing::info!(%repo, ok = resp.ok, errors = resp.errors.len(), warnings = resp.warnings.len(), "health check done");
        Ok(tonic::Response::new(resp))
    }

    async fn garbage_collect(
        &self,
        request: tonic::Request<GarbageCollectRequest>,
    ) -> Result<tonic::Response<RepositoryMaintenanceResponse>, tonic::Status> {
        let inner = request.into_inner();
        let repo = self.repo_label(inner.repository.as_ref());
        let span = tracing::info_span!("repo.garbage_collect", %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_repository_client(self, inner.repository.as_ref()).await? {
                    return client.garbage_collect(inner).await;
                }
                return Err(err);
            }
            Err(err) => return Err(err),
        };
        let resp = repository_maint::run_gc(&gb, inner.prune, inner.aggressive)?;
        tracing::info!(%repo, ok = resp.ok, "gc done");
        Ok(tonic::Response::new(resp))
    }

    async fn repack(
        &self,
        request: tonic::Request<RepackRequest>,
    ) -> Result<tonic::Response<RepositoryMaintenanceResponse>, tonic::Status> {
        let inner = request.into_inner();
        let repo = self.repo_label(inner.repository.as_ref());
        let span = tracing::info_span!("repo.repack", %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_repository_client(self, inner.repository.as_ref()).await? {
                    return client.repack(inner).await;
                }
                return Err(err);
            }
            Err(err) => return Err(err),
        };
        let resp = repository_maint::run_repack(
            &gb,
            inner.full,
            inner.write_bitmaps,
            inner.write_multi_pack_index,
        )?;
        tracing::info!(%repo, ok = resp.ok, "repack done");
        Ok(tonic::Response::new(resp))
    }

    async fn write_commit_graph(
        &self,
        request: tonic::Request<WriteCommitGraphRequest>,
    ) -> Result<tonic::Response<RepositoryMaintenanceResponse>, tonic::Status> {
        let inner = request.into_inner();
        let repo = self.repo_label(inner.repository.as_ref());
        let span = tracing::info_span!("repo.write_commit_graph", %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_repository_client(self, inner.repository.as_ref()).await? {
                    return client.write_commit_graph(inner).await;
                }
                return Err(err);
            }
            Err(err) => return Err(err),
        };
        let resp = repository_maint::run_commit_graph_write(&gb, inner.split, inner.replace)?;
        tracing::info!(%repo, ok = resp.ok, "commit-graph write done");
        Ok(tonic::Response::new(resp))
    }
}