mod archive;
mod blame;
mod branch;
mod cache;
mod commit;
mod diff;
mod merge;
mod pack;
mod repository;
mod repository_maint;
mod tag;
mod tree;

use std::path::{Path, PathBuf};
use gix::discover::is_git;
use ractor::{ActorCell, ActorRef};
use tokio_stream::wrappers::ReceiverStream;

use crate::actor::message::{GitNodeMessage, RouteDecision};
use crate::bare::GitBare;
use crate::error::{GitError, GitResult};
use crate::pb::{
    archive_service_server, blame_service_server, branch_service_server, commit_service_server,
    diff_service_server, merge_service_server, pack_service_server, repository_service_server,
    tag_service_server, tree_service_server,
};

#[derive(Clone)]
pub struct GitksService {
    pub repo_prefix: PathBuf,
    pub node_actor: Option<ActorRef<GitNodeMessage>>,
}

impl GitksService {
    pub fn new(repo_prefix: PathBuf) -> Self {
        Self { repo_prefix, node_actor: None }
    }

    pub fn with_actor(mut self, node_actor: ActorRef<GitNodeMessage>) -> Self {
        self.node_actor = Some(node_actor);
        self
    }

    pub fn scan_all_repo(&self) -> GitResult<Vec<String>> {
        let root = self.repo_prefix.as_ref();
        let mut repos = Vec::new();
        if is_bare_git_repo(root) {
            repos.push(root.to_path_buf());
        } else {
            scan_bare_repos_recursively(root, &mut repos)?;
        }
        Ok(repos
            .into_iter()
            .filter_map(|path| path.to_str().map(str::to_owned))
            .collect())
    }
    pub async fn route_repository(
        &self,
        header: &crate::pb::RepositoryHeader,
    ) -> Result<Option<RouteDecision>, tonic::Status> {
        let members = ractor::pg::get_members(&"gitks_nodes".to_string());
        let local = self.node_actor.as_ref().map(|actor| actor.get_cell());
        for member in members {
            if local.as_ref().is_some_and(|actor| actor == &member) {
                continue;
            }
            if let Some(decision) = query_route(member, header.clone()).await? {
                if decision.found && !decision.grpc_addr.is_empty() {
                    return Ok(Some(decision));
                }
            }
        }
        Ok(None)
    }

    fn repo_label(&self, header: Option<&crate::pb::RepositoryHeader>) -> String {
        header
            .and_then(|h| {
                if h.relative_path.is_empty() {
                    None
                } else {
                    Some(h.relative_path.clone())
                }
            })
            .unwrap_or_else(|| "unknown".into())
    }

    pub(crate) fn resolve(
        &self,
        header: Option<&crate::pb::RepositoryHeader>,
    ) -> Result<GitBare, tonic::Status> {
        let header =
            header.ok_or_else(|| tonic::Status::invalid_argument("repository is required"))?;
        let header = self.prefixed_header(header);
        let gb = GitBare::from_repository_header(&header).map_err(into_status)?;
        tracing::debug!(
            repo = %gb.bare_dir.display(),
            "resolved repository"
        );
        Ok(gb)
    }

    pub(crate) fn resolve_for_init(
        &self,
        header: Option<&crate::pb::RepositoryHeader>,
    ) -> Result<PathBuf, tonic::Status> {
        let header =
            header.ok_or_else(|| tonic::Status::invalid_argument("repository is required"))?;
        let relative_path = header.relative_path.trim();
        if relative_path.is_empty() {
            return Err(tonic::Status::invalid_argument("relative_path is required"));
        }
        let candidate = self.repo_prefix.join(relative_path);
        // Path traversal check
        let canonical = candidate
            .canonicalize()
            .unwrap_or_else(|_| candidate.clone());
        let prefix_canon = self
            .repo_prefix
            .canonicalize()
            .unwrap_or_else(|_| self.repo_prefix.clone());
        if !canonical.starts_with(&prefix_canon) {
            return Err(tonic::Status::invalid_argument(
                "path traversal detected: relative_path escapes repo prefix",
            ));
        }
        Ok(canonical)
    }

    /// Inject repo_prefix as storage_path into the client-provided header
    fn prefixed_header(&self, header: &crate::pb::RepositoryHeader) -> crate::pb::RepositoryHeader {
        crate::pb::RepositoryHeader {
            storage_path: self.repo_prefix.to_string_lossy().into_owned(),
            relative_path: header.relative_path.clone(),
            storage_name: header.storage_name.clone(),
        }
    }
}



pub(super) async fn remote_endpoint(addr: &str) -> Result<tonic::transport::Endpoint, tonic::Status> {
    let uri: tonic::codegen::http::Uri = addr
        .parse()
        .map_err(|e| tonic::Status::invalid_argument(format!("invalid URI: {e}")))?;
    tonic::transport::Endpoint::new(uri)
        .map_err(|e| tonic::Status::internal(e.to_string()))
}

pub(super) fn bridge_server_stream<T: Send + 'static>(
    mut remote: tonic::Streaming<T>,
) -> tokio_stream::wrappers::ReceiverStream<Result<T, tonic::Status>> {
    let (tx, rx) = tokio::sync::mpsc::channel(16);
    tokio::spawn(async move {
        use tokio_stream::StreamExt;
        while let Some(item) = remote.next().await {
            if tx.send(item).await.is_err() {
                break;
            }
        }
    });
    tokio_stream::wrappers::ReceiverStream::new(rx)
}

async fn query_route(
    member: ActorCell,
    header: crate::pb::RepositoryHeader,
) -> Result<Option<RouteDecision>, tonic::Status> {
    let actor_ref: ActorRef<GitNodeMessage> = member.into();
    match ractor::call_t!(actor_ref, GitNodeMessage::RouteRepository, 500, header) {
        Ok(decision) => Ok(Some(decision)),
        Err(err) => {
            tracing::warn!(error = %err, "repository route query failed");
            Ok(None)
        }
    }
}

fn scan_bare_repos_recursively(dir: &Path, repos: &mut Vec<PathBuf>) -> GitResult<()> {
    for entry in std::fs::read_dir(dir)? {
        let entry = entry?;
        let path = entry.path();

        if is_bare_git_repo(&path) {
            repos.push(path);
            continue;
        }

        if path.is_dir() {
            scan_bare_repos_recursively(&path, repos)?;
        }
    }

    Ok(())
}

fn is_bare_git_repo(path: &Path) -> bool {
    match is_git(path) {
        Ok(repo) => repo.is_bare(),
        Err(_) => false,
    }
}

pub(crate) fn into_status(e: GitError) -> tonic::Status {
    match &e {
        GitError::NotFound(_)
        | GitError::ObjectNotFound(_)
        | GitError::RefNotFound(_)
        | GitError::RepoNotFound => tonic::Status::not_found(e.to_string()),
        GitError::InvalidArgument(_) => tonic::Status::invalid_argument(e.to_string()),
        GitError::PermissionDenied(_) => tonic::Status::permission_denied(e.to_string()),
        GitError::Locked(_) => tonic::Status::failed_precondition(e.to_string()),
        GitError::AuthFailed(_) => tonic::Status::unauthenticated(e.to_string()),
        GitError::NotBareRepository => tonic::Status::failed_precondition(e.to_string()),
        _ => tonic::Status::internal(e.to_string()),
    }
}

impl From<GitError> for tonic::Status {
    fn from(e: GitError) -> Self {
        into_status(e)
    }
}

pub(crate) fn into_stream<T: Send + 'static>(
    items: Vec<T>,
) -> ReceiverStream<Result<T, tonic::Status>> {
    let (tx, rx) = tokio::sync::mpsc::channel(items.len().max(1));
    for item in items {
        let _ = tx.try_send(Ok(item));
    }
    ReceiverStream::new(rx)
}

pub(crate) fn git_cmd(gb: &GitBare, args: &[&str]) -> Result<std::process::Output, tonic::Status> {
    let mut full_args: Vec<String> = vec![
        "--git-dir".into(),
        gb.bare_dir.to_string_lossy().into_owned(),
    ];
    full_args.extend(args.iter().map(|s| s.to_string()));
    tracing::debug!(
        repo = %gb.bare_dir.display(),
        args = %full_args.iter().skip(2).cloned().collect::<Vec<_>>().join(" "),
        "spawning git subprocess"
    );
    let result = std::process::Command::new("git")
        .args(&full_args)
        .output()
        .map_err(|e| {
            tracing::error!(
                repo = %gb.bare_dir.display(),
                error = %e,
                "failed to spawn git subprocess"
            );
            tonic::Status::internal(e.to_string())
        })?;
    if !result.status.success() {
        let stderr = String::from_utf8_lossy(&result.stderr);
        tracing::warn!(
            repo = %gb.bare_dir.display(),
            status = ?result.status.code(),
            stderr = %stderr.trim(),
            "git subprocess exited with non-zero status"
        );
    }
    Ok(result)
}

pub async fn serve(
    addr: std::net::SocketAddr,
    svc: GitksService,
) -> Result<(), tonic::transport::Error> {
    let span = tracing::info_span!("gitks.server", %addr);
    let _enter = span.enter();
    tracing::info!("registering gRPC services");
    let server = tonic::transport::Server::builder()
        .add_service(repository_service_server::RepositoryServiceServer::new(
            svc.clone(),
        ))
        .add_service(archive_service_server::ArchiveServiceServer::new(
            svc.clone(),
        ))
        .add_service(blame_service_server::BlameServiceServer::new(svc.clone()))
        .add_service(branch_service_server::BranchServiceServer::new(svc.clone()))
        .add_service(commit_service_server::CommitServiceServer::new(svc.clone()))
        .add_service(diff_service_server::DiffServiceServer::new(svc.clone()))
        .add_service(merge_service_server::MergeServiceServer::new(svc.clone()))
        .add_service(pack_service_server::PackServiceServer::new(svc.clone()))
        .add_service(tag_service_server::TagServiceServer::new(svc.clone()))
        .add_service(tree_service_server::TreeServiceServer::new(svc));
    tracing::info!("server ready, starting to accept connections");
    server.serve(addr).await
}