syntax = "proto3";

package chatto.api.v1;

import "buf/validate/validate.proto";
import "chatto/api/v1/permissions.proto";
import "chatto/api/v1/pagination.proto";
import "chatto/api/v1/rooms.proto";
import "google/protobuf/timestamp.proto";

// Viewer-specific state and permission decisions for one room.
message RoomViewerState {
  // True when the current user is an effective room member.
  bool is_member = 1;
  // True when the room has neutral Badge attention for the current user.
  // This state is independent of the user's last-read message cursor.
  bool has_unread = 2;
  // Effective room-scoped permission decisions after room state constraints.
  repeated PermissionGrant permissions = 3;
  // Earliest time the current user may create another message. Absent when
  // slow mode is disabled, expired, or bypassed by moderation permissions.
  google.protobuf.Timestamp slow_mode_next_post_at = 4;
}

// Room kinds to include in directory responses.
enum RoomDirectoryScope {
  // Include visible channel rooms and the caller's DM rooms.
  ROOM_DIRECTORY_SCOPE_UNSPECIFIED = 0;
  // Include visible channel rooms and the caller's DM rooms.
  ROOM_DIRECTORY_SCOPE_ALL = 1;
  // Include visible channel rooms only.
  ROOM_DIRECTORY_SCOPE_CHANNELS = 2;
  // Include the caller's DM rooms only.
  ROOM_DIRECTORY_SCOPE_DMS = 3;
}

// Archive state to include in room directory responses.
enum RoomArchiveFilter {
  // Include active rooms only.
  ROOM_ARCHIVE_FILTER_UNSPECIFIED = 0;
  // Include active rooms only.
  ROOM_ARCHIVE_FILTER_ACTIVE = 1;
  // Include archived rooms only.
  ROOM_ARCHIVE_FILTER_ARCHIVED = 2;
  // Include both active and archived rooms.
  ROOM_ARCHIVE_FILTER_ALL = 3;
}

// Room metadata plus state and capabilities resolved for the authenticated
// viewer.
message RoomWithViewerState {
  reserved 2 to 13;
  reserved "is_member", "has_unread", "can_list_room", "can_join_room", "can_post_message", "can_post_in_thread", "can_attach", "can_react", "can_echo_message", "can_manage_others_message", "can_manage_room", "can_ban_room_members";

  // Public room metadata.
  Room room = 1;
  // State and permission decisions resolved for the current user.
  RoomViewerState viewer_state = 14;
  // Complete participant user IDs for a DM. Empty for channel rooms.
  repeated string member_user_ids = 15;
  // Whether this DM has received a root message. Absent for channel rooms.
  optional bool has_message_history = 16;
}

// Sidebar link metadata for room group navigation.
message SidebarLink {
  // Stable sidebar link ID.
  string id = 1;
  // Display label.
  string label = 2;
  // Absolute http(s) URL or server-local path.
  string url = 3;
}

// One ordered item in a room group.
message RoomGroupItem {
  oneof item {
    // Visible room entry.
    RoomWithViewerState room = 1;
    // Sidebar link entry.
    SidebarLink sidebar_link = 2;
  }
}

// Viewer-specific state for one room group.
message RoomGroupViewerState {
  reserved 1;
  reserved "can_create_room";

  // Effective group-scoped permission decisions after group state constraints.
  repeated PermissionGrant permissions = 2;
}

// Ordered group of channel rooms and sidebar links.
message RoomGroup {
  reserved 4;
  reserved "rooms";

  // Stable room group ID.
  string id = 1;
  // Display name.
  string name = 2;
  // Public group description, when set.
  string description = 3;
  // Mixed room/sidebar-link entries in sidebar order.
  repeated RoomGroupItem items = 5;
  // State and permissions resolved for the current user.
  RoomGroupViewerState viewer_state = 6;
}

// Request for rooms visible to the current user.
message ListRoomsRequest {
  // Which room kinds to include. Defaults to all.
  RoomDirectoryScope scope = 1 [(buf.validate.field).enum.defined_only = true];
  // Archive state to include. Defaults to ACTIVE. Combined with scope; this
  // filter does not grant access to hidden rooms.
  RoomArchiveFilter archive_filter = 2 [(buf.validate.field).enum.defined_only = true];
  // Defaults to 50 rooms, capped at 100. Rooms are ordered by ID ascending.
  PageRequest page = 3;
}

// One live page of rooms visible to the current user. Changes between requests
// can shift offsets. Follow page.has_more to read the complete directory.
message ListRoomsResponse {
  // Visible rooms matching both the room-kind scope and archive filter.
  repeated RoomWithViewerState rooms = 1;
  // Count after visibility, scope, and archive filters, before pagination.
  PageInfo page = 2;
}

// Request for ordered room groups visible to the current user.
message ListRoomGroupsRequest {
  reserved 1;
  reserved "include_archived_rooms";
}

// Finite snapshot of ordered room groups visible to the current user.
message ListRoomGroupsResponse {
  // Channel room groups in sidebar order.
  repeated RoomGroup groups = 1;
}

// Request for one ordered room group visible to the current user.
message GetRoomGroupRequest {
  reserved 2;
  reserved "include_archived_rooms";

  // Required. Room group to resolve.
  string group_id = 1 [(buf.validate.field).string.min_len = 1];
}

// One ordered room group visible to the current user.
message GetRoomGroupResponse {
  // Resolved room group. Hidden and archived room entries are omitted.
  RoomGroup group = 1;
}

// Request visible room groups by stable group ID.
message BatchGetRoomGroupsRequest {
  reserved 2;
  reserved "include_archived_rooms";

  // Required room group IDs. Unknown groups are omitted from the response.
  repeated string group_ids = 1 [(buf.validate.field).repeated = {
    min_items: 1
    max_items: 100
    items: {
      string: {min_len: 1}
    }
  }];
}

// Visible room group batch response for direct group hydration.
message BatchGetRoomGroupsResponse {
  // Resolved room groups in first-seen request order.
  repeated RoomGroup groups = 1;
}

// Request for one room visible to the current user.
message GetRoomRequest {
  // Required. Room to resolve.
  string room_id = 1 [(buf.validate.field).string.min_len = 1];
}

// Room visible to the current user.
message GetRoomResponse {
  // Resolved room and viewer state.
  RoomWithViewerState room = 1;
}

// Request visible rooms by stable room ID.
message BatchGetRoomsRequest {
  // Required room IDs. Unknown rooms and rooms hidden from the caller are
  // omitted from the response. Archived rooms may be returned when the caller
  // can still refresh them directly.
  repeated string room_ids = 1 [(buf.validate.field).repeated = {
    min_items: 1
    max_items: 100
    items: {
      string: {min_len: 1}
    }
  }];
}

// Visible room batch response for direct room hydration.
message BatchGetRoomsResponse {
  // Resolved rooms in first-seen request order.
  repeated RoomWithViewerState rooms = 1;
}

// Reads room directory data.
service RoomDirectoryService {
  // Lists rooms visible to the current user. Defaults to active rooms; use
  // archive_filter to discover archived rooms or include both states. Channel
  // rooms require membership or room.list. DM membership exposes room and
  // participant metadata. Message-derived DM state also requires current
  // read permission. Accessible empty DMs are included. Returns up to 100 rooms
  // ordered by ID ascending; the default page size is 50.
  rpc ListRooms(ListRoomsRequest) returns (ListRoomsResponse);
  // Lists ordered channel room groups and sidebar items visible to the current
  // user as a finite navigation snapshot. Hidden room entries are omitted.
  // Archived room entries are omitted.
  rpc ListRoomGroups(ListRoomGroupsRequest) returns (ListRoomGroupsResponse);
  // Returns one ordered room group by ID. Hidden room entries are omitted.
  // Archived room entries are omitted.
  // Returns NOT_FOUND when the room group does not exist.
  rpc GetRoomGroup(GetRoomGroupRequest) returns (GetRoomGroupResponse);
  // Returns ordered room groups for a set of stable group IDs. Hidden room
  // entries are omitted. Archived room entries are omitted. Unknown groups are
  // omitted. Results preserve first-seen request order and repeated IDs are
  // de-duplicated.
  rpc BatchGetRoomGroups(BatchGetRoomGroupsRequest) returns (BatchGetRoomGroupsResponse);
  // Returns one visible room by ID. DM rooms require membership. Returns
  // NOT_FOUND when the room does not exist and PERMISSION_DENIED when the room
  // exists but is hidden from the caller.
  rpc GetRoom(GetRoomRequest) returns (GetRoomResponse);
  // Returns visible rooms for a set of stable room IDs. This is a direct
  // hydration API, so visible archived rooms may be returned. Unknown rooms and
  // rooms hidden from the caller are omitted. Results preserve first-seen
  // request order and repeated IDs are de-duplicated.
  rpc BatchGetRooms(BatchGetRoomsRequest) returns (BatchGetRoomsResponse);
}