shardline-server 1.0.0

use axum::body::Bytes;
#[cfg(test)]
use shardline_index::FileRecord;
use shardline_protocol::{ByteRange, RepositoryScope};
use shardline_storage::ObjectStore;
use tokio::task;

use super::LocalBackend;
use crate::{
    ServerError, ShardMetadataLimits,
    model::UploadFileResponse,
    object_store::{read_full_object, reconstruct_file_record_bytes},
    upload_ingest::RequestBodyReader,
    validation::validate_identifier,
    xet_adapter::{FileReconstructionResponse, ShardUploadResponse, build_reconstruction_response},
};

impl LocalBackend {
    /// Stores a file version as deduplicated content chunks.
    ///
    /// # Errors
    ///
    /// Returns [`ServerError`] when file identifier validation, chunk persistence, or
    /// metadata persistence fails.
    pub async fn upload_file(
        &self,
        file_id: &str,
        body: Bytes,
        repository_scope: Option<&RepositoryScope>,
    ) -> Result<UploadFileResponse, ServerError> {
        self.upload_file_stream(
            file_id,
            RequestBodyReader::from_bytes(body),
            repository_scope,
            None,
        )
        .await
    }

    /// Stores a streamed file version as deduplicated content chunks.
    ///
    /// # Errors
    ///
    /// Returns [`ServerError`] when request streaming, file identifier validation,
    /// chunk persistence, source digest validation, or metadata persistence fails.
    pub(crate) async fn upload_file_stream(
        &self,
        file_id: &str,
        mut body: RequestBodyReader,
        repository_scope: Option<&RepositoryScope>,
        expected_sha256: Option<&str>,
    ) -> Result<UploadFileResponse, ServerError> {
        validate_identifier(file_id)?;

        let object_store = self.object_store();
        let mut ingestor = crate::upload_ingest::FileUploadIngestor::new_with_parallelism(
            self.chunk_size,
            expected_sha256.is_some(),
            self.upload_max_in_flight_chunks,
        );
        while let Some(bytes) = body.next_bytes().await? {
            ingestor.ingest_body_chunk(&object_store, &bytes).await?;
        }

        let (record, response) = ingestor
            .finish(&object_store, file_id, repository_scope, expected_sha256)
            .await?;
        self.record_store
            .commit_file_version_metadata(&record)
            .await?;

        Ok(response)
    }

    /// Stores a bounded native Xet shard and indexes the contained file reconstructions.
    ///
    /// # Errors
    ///
    /// Returns [`ServerError`] when request streaming, shard validation, referenced xorb
    /// validation, or metadata persistence fails.
    pub(crate) async fn upload_shard_stream(
        &self,
        mut body: RequestBodyReader,
        repository_scope: Option<&RepositoryScope>,
        shard_metadata_limits: ShardMetadataLimits,
    ) -> Result<ShardUploadResponse, ServerError> {
        let uploaded_body = crate::upload_ingest::read_body_to_bytes(&mut body).await?;
        let record_store = self.record_store.clone();
        let object_store = self.object_store();
        crate::xet_adapter::register_uploaded_shard_bytes(
            &object_store,
            &uploaded_body,
            repository_scope,
            shard_metadata_limits,
            move |records, mappings| async move {
                record_store
                    .commit_native_shard_metadata(&records, &mappings)
                    .await?;
                Ok(())
            },
        )
        .await
        .map_err(ServerError::from)
    }

    /// Loads reconstruction metadata for a file.
    ///
    /// # Errors
    ///
    /// Returns [`ServerError`] when the file identifier is invalid or the record is
    /// missing or unreadable.
    pub async fn reconstruction(
        &self,
        file_id: &str,
        content_hash: Option<&str>,
        requested_range: Option<ByteRange>,
        repository_scope: Option<&RepositoryScope>,
    ) -> Result<FileReconstructionResponse, ServerError> {
        let record = self
            .read_record(file_id, content_hash, repository_scope)
            .await?;
        Ok(build_reconstruction_response(
            self.public_base_url(),
            &record,
            requested_range,
        )?)
    }

    /// Loads the logical byte length for a file version.
    ///
    /// # Errors
    ///
    /// Returns [`ServerError`] when the file identifier is invalid or the record is
    /// missing or unreadable.
    pub async fn file_total_bytes(
        &self,
        file_id: &str,
        content_hash: Option<&str>,
        repository_scope: Option<&RepositoryScope>,
    ) -> Result<u64, ServerError> {
        let record = self
            .read_record(file_id, content_hash, repository_scope)
            .await?;
        Ok(record.total_bytes)
    }

    /// Loads the file-version record used by streaming transfer paths.
    ///
    /// # Errors
    ///
    /// Returns [`ServerError`] when the file identifier is invalid or the record is
    /// missing or unreadable.
    #[cfg(test)]
    pub(crate) async fn file_record(
        &self,
        file_id: &str,
        content_hash: Option<&str>,
        repository_scope: Option<&RepositoryScope>,
    ) -> Result<FileRecord, ServerError> {
        self.read_record(file_id, content_hash, repository_scope)
            .await
    }

    /// Reconstructs a file into a contiguous byte vector.
    ///
    /// # Errors
    ///
    /// Returns [`ServerError`] when metadata or chunk bytes cannot be read.
    pub async fn download_file(
        &self,
        file_id: &str,
        content_hash: Option<&str>,
        repository_scope: Option<&RepositoryScope>,
    ) -> Result<Vec<u8>, ServerError> {
        let record = self
            .read_record(file_id, content_hash, repository_scope)
            .await?;
        let object_store = self.object_store();
        let server_frontends = self.server_frontends.clone();
        task::spawn_blocking(move || {
            reconstruct_file_record_bytes(&object_store, &server_frontends, &record)
        })
        .await
        .map_err(ServerError::BlockingTask)?
    }

    /// Reads a stored chunk by hash.
    ///
    /// # Errors
    ///
    /// Returns [`ServerError`] when the hash is invalid or the chunk is missing.
    pub async fn read_chunk(&self, hash_hex: &str) -> Result<Vec<u8>, ServerError> {
        let object_store = self.object_store();
        let object_key = crate::chunk_store::chunk_object_key(hash_hex)?;
        let metadata = object_store.metadata(&object_key)?;
        let Some(metadata) = metadata else {
            return Err(ServerError::NotFound);
        };

        task::spawn_blocking(move || {
            read_full_object(&object_store, &object_key, metadata.length())
        })
        .await
        .map_err(ServerError::BlockingTask)?
    }

    /// Reads a stored chunk only when it is reachable from a concrete file version.
    ///
    /// # Errors
    ///
    /// Returns [`ServerError`] when the hash, file identifier, or content hash are
    /// invalid, when the file version is missing, or when the chunk is not referenced
    /// by that version.
    pub async fn read_chunk_for_file_version(
        &self,
        hash_hex: &str,
        file_id: &str,
        content_hash: &str,
        repository_scope: Option<&RepositoryScope>,
    ) -> Result<Vec<u8>, ServerError> {
        let record = self
            .read_record(file_id, Some(content_hash), repository_scope)
            .await?;
        if !record.chunks.iter().any(|chunk| chunk.hash == hash_hex) {
            return Err(ServerError::NotFound);
        }

        self.read_chunk(hash_hex).await
    }

    /// Loads the stored byte length for a chunk object.
    ///
    /// # Errors
    ///
    /// Returns [`ServerError`] when the hash is invalid or the chunk is missing.
    pub async fn chunk_length(&self, hash_hex: &str) -> Result<u64, ServerError> {
        let object_store = self.object_store();
        let object_key = crate::chunk_store::chunk_object_key(hash_hex)?;
        let metadata = object_store.metadata(&object_key)?;
        let Some(metadata) = metadata else {
            return Err(ServerError::NotFound);
        };

        Ok(metadata.length())
    }
}