syntax = "proto3";
package qpc.v1;

// Delivery service: enqueue, fetch, peek, ack, batch (6 methods).
// Method IDs: 200-205.

message Envelope {
  uint64 seq = 1;
  bytes data = 2;
}

message EnqueueRequest {
  bytes recipient_key = 1;
  bytes payload = 2;
  bytes channel_id = 3;
  uint32 ttl_secs = 4;
  // Client-generated idempotency key (16 bytes, UUID v7).
  // Server deduplicates enqueue requests with the same message_id within a TTL window.
  bytes message_id = 5;
}

message EnqueueResponse {
  uint64 seq = 1;
  bytes delivery_proof = 2;
  // True if this was a duplicate enqueue (message_id already seen).
  bool duplicate = 3;
}

message FetchRequest {
  bytes recipient_key = 1;
  bytes channel_id = 2;
  uint32 limit = 3;
  // Device ID for multi-device scoping. When set, the server builds
  // a composite queue key (identity_key + device_id). Empty = bare key.
  bytes device_id = 4;
}

message FetchResponse {
  repeated Envelope payloads = 1;
}

message FetchWaitRequest {
  bytes recipient_key = 1;
  bytes channel_id = 2;
  uint64 timeout_ms = 3;
  uint32 limit = 4;
  bytes device_id = 5;
}

message FetchWaitResponse {
  repeated Envelope payloads = 1;
}

message PeekRequest {
  bytes recipient_key = 1;
  bytes channel_id = 2;
  uint32 limit = 3;
  bytes device_id = 4;
}

message PeekResponse {
  repeated Envelope payloads = 1;
}

message AckRequest {
  bytes recipient_key = 1;
  bytes channel_id = 2;
  uint64 seq_up_to = 3;
  bytes device_id = 4;
}

message AckResponse {}

message BatchEnqueueRequest {
  repeated bytes recipient_keys = 1;
  bytes payload = 2;
  bytes channel_id = 3;
  uint32 ttl_secs = 4;
  // Client-generated idempotency key (16 bytes, UUID v7).
  bytes message_id = 5;
}

message BatchEnqueueResponse {
  repeated uint64 seqs = 1;
}