# Copyright 2016 OpenMarket Ltd
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
swagger: '2.0'
info:
  title: "Matrix Client-Server Event Context API"
  version: "1.0.0"
host: localhost:8008
schemes:
  - https
  - http
basePath: /_matrix/client/v3
consumes:
  - application/json
produces:
  - application/json
securityDefinitions:
  $ref: definitions/security.yaml
paths:
  "/rooms/{roomId}/context/{eventId}":
    get:
      summary: Get events and state around the specified event.
      description: |-
        This API returns a number of events that happened just before and
        after the specified event. This allows clients to get the context
        surrounding an event.

        *Note*: This endpoint supports lazy-loading of room member events. See
        [Lazy-loading room members](/client-server-api/#lazy-loading-room-members) for more information.
      operationId: getEventContext
      security:
        - accessToken: []
      parameters:
        - in: path
          type: string
          name: roomId
          description: The room to get events from.
          required: true
          x-example: "!636q39766251:example.com"
        - in: path
          type: string
          name: eventId
          description: The event to get context around.
          required: true
          x-example: "$f3h4d129462ha:example.com"
        - in: query
          type: integer
          name: limit
          description: |-
            The maximum number of events to return. Default: 10.
          x-example: 3
        - in: query
          name: filter
          type: string
          description: |-
            A JSON `RoomEventFilter` to filter the returned events with. The
            filter is only applied to `events_before`, `events_after`, and
            `state`. It is not applied to the `event` itself. The filter may
            be applied before or/and after the `limit` parameter - whichever the
            homeserver prefers.

            See [Filtering](/client-server-api/#filtering) for more information.
          x-example: "66696p746572"
      responses:
        200:
          description: The events and state surrounding the requested event.
          schema:
            type: object
            description: The events and state surrounding the requested event.
            properties:
              start:
                type: string
                description: |-
                  A token that can be used to paginate backwards with.
              end:
                type: string
                description: |-
                  A token that can be used to paginate forwards with.
              events_before:
                type: array
                description: |-
                  A list of room events that happened just before the
                  requested event, in reverse-chronological order.
                items:
                  allOf:
                    - "$ref": "../../event-schemas/schema/core-event-schema/room_event.yaml"
              event:
                description: |-
                  Details of the requested event.
                allOf:
                  - "$ref": "../../event-schemas/schema/core-event-schema/room_event.yaml"
              events_after:
                type: array
                description: |-
                  A list of room events that happened just after the
                  requested event, in chronological order.
                items:
                  allOf:
                    - "$ref": "../../event-schemas/schema/core-event-schema/room_event.yaml"
              state:
                type: array
                description: |-
                  The state of the room at the last event returned.
                items:
                  allOf:
                    - "$ref": "../../event-schemas/schema/core-event-schema/state_event.yaml"
          examples:
            application/json: {
              "end": "t29-57_2_0_2",
              "events_after": [
                {
                  "room_id": "!636q39766251:example.com",
                  "$ref": "../../event-schemas/examples/m.room.message$m.text.yaml"
                }
              ],
              "event": {
                "event_id": "$f3h4d129462ha:example.com",
                "room_id": "!636q39766251:example.com",
                "$ref": "../../event-schemas/examples/m.room.message$m.image.yaml"
              },
              "events_before": [
                {
                  "room_id": "!636q39766251:example.com",
                  "$ref": "../../event-schemas/examples/m.room.message$m.file.yaml"
                }
              ],
              "start": "t27-54_2_0_2",
              "state": [
                {
                  "room_id": "!636q39766251:example.com",
                  "$ref": "../../event-schemas/examples/m.room.create.yaml"
                },
                {
                  "room_id": "!636q39766251:example.com",
                  "$ref": "../../event-schemas/examples/m.room.member.yaml"
                }
              ]
            }
      tags:
        - Room participation
