syntax = "proto3";

package chatto.api.v1;

import "buf/validate/validate.proto";
import "chatto/api/v1/message_types.proto";
import "chatto/api/v1/pagination.proto";

// Request to add the current user's reaction to a message.
//
// When `message_event_id` names a channel echo of a thread reply, the server
// treats it as an alias for the original thread reply and stores the reaction
// on that original event. The server returns `RESOURCE_EXHAUSTED` when the
// current user already has 20 distinct emoji reactions on the canonical
// message; adding an emoji that already exists remains an idempotent success.
message AddReactionRequest {
  // Required. Room containing the message event.
  string room_id = 1 [(buf.validate.field).string.min_len = 1];
  // Required. Event ID of the message being reacted to, or a channel echo of
  // the message.
  string message_event_id = 2 [(buf.validate.field).string.min_len = 1];
  // Required. Emoji shortcode name, such as "thumbsup" or "heart".
  string emoji = 3 [(buf.validate.field).string.min_len = 1];
}

// Result of adding a reaction.
message AddReactionResponse {
  // True when the reaction was newly added, false when it already existed.
  bool added = 1;
  // Updated aggregate reaction state for this emoji.
  MessageReaction reaction = 2;
}

// Request to remove the current user's reaction from a message.
//
// When `message_event_id` names a channel echo of a thread reply, the server
// treats it as an alias for the original thread reply and removes the reaction
// from that original event.
message RemoveReactionRequest {
  // Required. Room containing the message event.
  string room_id = 1 [(buf.validate.field).string.min_len = 1];
  // Required. Event ID of the message whose reaction should be removed, or a
  // channel echo of the message.
  string message_event_id = 2 [(buf.validate.field).string.min_len = 1];
  // Required. Emoji shortcode name, such as "thumbsup" or "heart".
  string emoji = 3 [(buf.validate.field).string.min_len = 1];
}

// Result of removing a reaction.
message RemoveReactionResponse {
  // True when the reaction was removed, false when it did not exist.
  bool removed = 1;
  // Updated aggregate reaction state for this emoji. Empty when no reactions for
  // the emoji remain.
  MessageReaction reaction = 2;
}

// Request all users with one emoji reaction on a message. Echo IDs resolve to
// the original message. Users are ordered by user ID ascending.
message ListReactionUsersRequest {
  // Room containing the message.
  string room_id = 1 [(buf.validate.field).string.min_len = 1];
  // Message or channel echo ID.
  string message_event_id = 2 [(buf.validate.field).string.min_len = 1];
  // Emoji shortcode, such as "thumbsup".
  string emoji = 3 [(buf.validate.field).string.min_len = 1];
  // Defaults to 50 results. Maximum: 100. Zero uses the default.
  PageRequest page = 4;
}

// Complete reaction membership is available by paging this collection.
message ListReactionUsersResponse {
  // User IDs in this page. Use UserService.BatchGetUsers for profiles.
  repeated string user_ids = 1;
  // Count and continuation for the matching reaction users.
  PageInfo page = 2;
}