syntax = "proto3";

package mstore.v1;

// ── Object Storage Service ────────────────────────────────────────────────────
//
// Küçük dosya (< 4 MB): PutObject / GetObject — tek mesaj, düşük latency
// Büyük dosya (>= 4 MB): PutObjectStream / GetObjectStream — chunk streaming
//
// C# tarafında `MStoreClient` wrapper bu seçimi otomatik yapar.
// Uygulama kodu sadece Put(path, data) / Get(path) çağırır.

service ObjectStorage {
  // ── Küçük objeler (< 4 MB) ────────────────────────────────────────────────
  rpc PutObject       (PutObjectRequest)    returns (PutObjectResponse);
  rpc GetObject       (GetObjectRequest)    returns (GetObjectResponse);
  rpc HeadObject      (HeadObjectRequest)   returns (ObjectInfo);
  rpc DeleteObject    (DeleteObjectRequest) returns (DeleteObjectResponse);
  rpc ListObjects     (ListObjectsRequest)  returns (ListObjectsResponse);

  // ── Büyük objeler: streaming (>= 4 MB) ───────────────────────────────────
  // Client → Server: N adet DataChunk gönderir, son chunk'ta is_last=true
  rpc PutObjectStream (stream PutChunk)     returns (PutObjectResponse);
  // Server → Client: N adet DataChunk gönderir
  rpc GetObjectStream (GetObjectRequest)    returns (stream GetChunk);

  // ── Multipart (>= 4 MB, internal — PutObjectStream'in altında kullanılır) ─
  rpc CreateMultipartUpload  (CreateMultipartRequest)   returns (CreateMultipartResponse);
  rpc UploadPart             (stream UploadPartChunk)   returns (UploadPartResponse);
  rpc CompleteMultipartUpload(CompleteMultipartRequest) returns (PutObjectResponse);
  rpc AbortMultipartUpload   (AbortMultipartRequest)    returns (Empty);

  // ── Batch operations ───────────────────────────────────────────────────
  rpc DeleteObjects (DeleteObjectsRequest)   returns (DeleteObjectsResponse);
  rpc PutObjects    (stream PutObjectsChunk) returns (stream PutObjectResult);
  rpc GetObjects    (GetObjectsRequest)      returns (stream GetObjectResult);

  // ── Bucket ────────────────────────────────────────────────────────────────
  rpc CreateBucket (CreateBucketRequest) returns (Empty);
  rpc DeleteBucket (DeleteBucketRequest) returns (Empty);
  rpc ListBuckets  (ListBucketsRequest)  returns (ListBucketsResponse);
  rpc HeadBucket   (HeadBucketRequest)   returns (BucketInfo);
}

// ── Common ────────────────────────────────────────────────────────────────────

message Empty {}

// ── Put (small) ───────────────────────────────────────────────────────────────

message PutObjectRequest {
  string bucket              = 1;
  string key                 = 2;
  bytes  data                = 3;  // Entire object, <= 4 MB
  string content_type        = 4;
  string storage_class       = 5;  // STANDARD | REDUCED_REDUNDANCY
  map<string, string> metadata = 6;
  // Optional client-side BLAKE3 checksum for integrity verification
  bytes  checksum_blake3     = 7;
}

message PutObjectResponse {
  string version_id  = 1;  // UUID v7
  string etag        = 2;  // Hex-encoded BLAKE3
  string request_id  = 3;
  string loc_token   = 4;  // X-MStore-Loc: zero-lookup token for fast GET (empty for inline objects)
}

// ── Put (streaming) ───────────────────────────────────────────────────────────
// First chunk carries object metadata in the `meta` field.
// Subsequent chunks carry only `data`.

message PutChunk {
  oneof payload {
    PutChunkMeta meta = 1;  // First message only
    bytes        data = 2;  // Subsequent messages
  }
}

message PutChunkMeta {
  string bucket              = 1;
  string key                 = 2;
  int64  total_size          = 3;  // Total object size in bytes (for pre-allocation)
  string content_type        = 4;
  string storage_class       = 5;
  map<string, string> metadata = 6;
  bytes  checksum_blake3     = 7;  // Full-object BLAKE3 (verified after last chunk)
}

// ── Get (small) ───────────────────────────────────────────────────────────────

message GetObjectRequest {
  string bucket     = 1;
  string key        = 2;
  string version_id = 3;  // Empty = latest
  int64  range_start = 4; // 0 = from beginning
  int64  range_end   = 5; // 0 = to end
  string loc_token   = 6; // X-MStore-Loc: if set, skip metadata lookup for zero-latency GET
}

message GetObjectResponse {
  bytes  data           = 1;
  string version_id     = 2;
  string etag           = 3;
  string content_type   = 4;
  int64  content_length = 5;
  int64  last_modified  = 6;  // Unix timestamp seconds
  map<string, string> metadata = 7;
}

// ── Get (streaming) ───────────────────────────────────────────────────────────
// First chunk contains ObjectMeta, subsequent chunks contain raw data.

message GetChunk {
  oneof payload {
    GetChunkMeta meta = 1;
    bytes        data = 2;
  }
}

message GetChunkMeta {
  string version_id     = 1;
  string etag           = 2;
  string content_type   = 3;
  int64  total_size     = 4;
  int64  last_modified  = 5;
  map<string, string> metadata = 6;
}

// ── Head ──────────────────────────────────────────────────────────────────────

message HeadObjectRequest {
  string bucket     = 1;
  string key        = 2;
  string version_id = 3;
}

message ObjectInfo {
  string bucket        = 1;
  string key           = 2;
  string version_id    = 3;
  string etag          = 4;
  int64  size          = 5;
  string content_type  = 6;
  int64  last_modified = 7;
  string storage_class = 8;
  map<string, string> metadata = 9;
  bool   is_delete_marker = 10;
}

// ── Delete ────────────────────────────────────────────────────────────────────

message DeleteObjectRequest {
  string bucket     = 1;
  string key        = 2;
  string version_id = 3;  // Empty = create delete marker
}

message DeleteObjectResponse {
  bool   delete_marker    = 1;
  string delete_marker_id = 2;
  string request_id       = 3;
}

// ── List ──────────────────────────────────────────────────────────────────────

message ListObjectsRequest {
  string bucket     = 1;
  string prefix     = 2;
  string delimiter  = 3;
  int32  max_keys   = 4;  // Default 1000, max 1000
  string page_token = 5;
}

message ListObjectsResponse {
  repeated ObjectInfo objects         = 1;
  repeated string     common_prefixes = 2;
  string              next_page_token = 3;
  bool                is_truncated    = 4;
  string              request_id      = 5;
}

// ── Multipart ─────────────────────────────────────────────────────────────────

message CreateMultipartRequest {
  string bucket              = 1;
  string key                 = 2;
  string content_type        = 3;
  string storage_class       = 4;
  map<string, string> metadata = 5;
}

message CreateMultipartResponse {
  string upload_id = 1;
}

message UploadPartChunk {
  oneof payload {
    UploadPartMeta meta = 1;
    bytes          data = 2;
  }
}

message UploadPartMeta {
  string bucket      = 1;
  string key         = 2;
  string upload_id   = 3;
  int32  part_number = 4;
  int64  part_size   = 5;
}

message UploadPartResponse {
  string etag        = 1;
  int32  part_number = 2;
}

message CompleteMultipartRequest {
  string bucket    = 1;
  string key       = 2;
  string upload_id = 3;
  repeated CompletedPart parts = 4;
}

message CompletedPart {
  int32  part_number = 1;
  string etag        = 2;
}

message AbortMultipartRequest {
  string bucket    = 1;
  string key       = 2;
  string upload_id = 3;
}

// ── Bucket ────────────────────────────────────────────────────────────────────

message CreateBucketRequest {
  string bucket = 1;
  string region = 2;  // Optional hint for geo-pinning
}

message DeleteBucketRequest {
  string bucket      = 1;
  bool   force_empty = 2;  // If true, delete even if not empty
}

message ListBucketsRequest {}

message ListBucketsResponse {
  repeated BucketInfo buckets = 1;
}

message HeadBucketRequest {
  string bucket = 1;
}

message BucketInfo {
  string bucket     = 1;
  int64  created_at = 2;  // Unix timestamp seconds
}

// ── Batch Delete ─────────────────────────────────────────────────────────

message DeleteObjectsRequest {
  string bucket = 1;
  repeated DeleteObjectId objects = 2;
}

message DeleteObjectId {
  string key        = 1;
  string version_id = 2;
}

message DeleteObjectsResponse {
  repeated DeletedObject deleted = 1;
  repeated DeleteError   errors  = 2;
  string request_id = 3;
}

message DeletedObject {
  string key              = 1;
  string version_id       = 2;
  bool   delete_marker    = 3;
  string delete_marker_id = 4;
}

message DeleteError {
  string key     = 1;
  string code    = 2;
  string message = 3;
}

// ── Batch Put (bidirectional streaming) ──────────────────────────────────
// Client sends a stream of objects (one PutObjectsItem per object with inline data).
// Server responds with one PutObjectResult per completed object.

message PutObjectsChunk {
  oneof payload {
    PutObjectsItem item = 1;   // Start of a new object (carries inline data)
    bytes          data = 2;   // Reserved for future large-object streaming
  }
}

message PutObjectsItem {
  string bucket              = 1;
  string key                 = 2;
  bytes  data                = 3;   // Inline data (entire object for V1)
  string content_type        = 4;
  string storage_class       = 5;
  map<string, string> metadata = 6;
  bytes  checksum_blake3     = 7;
}

message PutObjectResult {
  string key        = 1;
  string version_id = 2;
  string etag       = 3;
  string loc_token  = 4;
  string error_code = 5;   // Non-empty on failure
  string error_msg  = 6;
}

// ── Batch Get (server streaming) ─────────────────────────────────────────
// Client sends a list of keys, server streams back objects sequentially.
// Each object: one GetObjectResultMeta, then zero or more data chunks.

message GetObjectsRequest {
  string bucket = 1;
  repeated GetObjectsKey keys = 2;
}

message GetObjectsKey {
  string key        = 1;
  string version_id = 2;
  string loc_token  = 3;
}

message GetObjectResult {
  oneof payload {
    GetObjectResultMeta meta = 1;  // First message per object
    bytes               data = 2;  // Subsequent data chunks
  }
}

message GetObjectResultMeta {
  string key            = 1;
  string version_id     = 2;
  string etag           = 3;
  string content_type   = 4;
  int64  content_length = 5;
  int64  last_modified  = 6;
  map<string, string> metadata = 7;
  string error_code     = 8;   // Non-empty = skip this object
  string error_msg      = 9;
}