# Copyright 2018 New Vector 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 Federation Events API"
  version: "1.0.0"
host: localhost:8448
schemes:
  - https
basePath: /_matrix/federation/v1
consumes:
  - application/json
produces:
  - application/json
securityDefinitions:
  $ref: definitions/security.yaml
paths:
  "/backfill/{roomId}":
    get:
      summary: Retrieves the events which precede the given event
      description: |-
        Retrieves a sliding-window history of previous PDUs that occurred in the given room.
        Starting from the PDU ID(s) given in the ``v`` argument, the PDUs that preceded it
        are retrieved, up to the total number given by the ``limit``.
      operationId: backfillRoom
      security:
        - signedRequest: []
      parameters:
        - in: path
          name: roomId
          type: string
          description: The room ID to backfill.
          required: true
          x-example: "!SomeRoom:matrix.org"
        - in: query
          name: v
          type: array
          items:
            type: string
          description: The event IDs to backfill from.
          required: true
          x-example: ["$abc123:matrix.org"]
        - in: query
          name: limit
          type: integer
          description: The maximum number of PDUs to retrieve, including the given events.
          required: true
          x-example: 2
      responses:
        200:
          description: |-
            A transaction containing the PDUs that preceded the given event(s), including the given
            event(s), up to the given limit.
          schema:
            $ref: "definitions/transaction.yaml"
  "/get_missing_events/{roomId}":
    post:
      summary: Retrieves events that the sender is missing
      description: |-
        Retrieves previous events that the sender is missing. This is done by doing a breadth-first
        walk of the ``prev_events`` for the ``latest_events``, ignoring any events in ``earliest_events``
        and stopping at the ``limit``.
      operationId: getMissingPreviousEvents
      security:
        - signedRequest: []
      parameters:
        - in: path
          name: roomId
          type: string
          description: The room ID to search in.
          required: true
          x-example: "!SomeRoom:matrix.org"
        - in: body
          name: body
          schema:
            type: object
            properties:
              limit:
                type: integer
                description: The maximum number of events to retrieve. Defaults to 10.
                example: 10
              min_depth:
                type: integer
                description: The minimum depth of events to retrieve. Defaults to 0.
                example: 0
              earliest_events:
                type: array
                description: |-
                  The latest event IDs that the sender already has. These are skipped when retrieving
                  the previous events of ``latest_events``.
                items:
                  type: string
                example: ["$missing_event:example.org"]
              latest_events:
                type: array
                description: The event IDs to retrieve the previous events for.
                items:
                  type: string
                example: ["$event_that_has_the_missing_event_as_a_previous_event:example.org"]
            required: ['earliest_events', 'latest_events']
      responses:
        200:
          description: |-
            The previous events for ``latest_events``, excluding any ``earliest_events``, up to the
            provided ``limit``.
          schema:
            type: object
            properties:
              events:
                type: array
                description: |-
                  The missing events. The event format varies depending on the room version - check
                  the `room version specification`_ for precise event formats.
                items:
                  type: object
                  title: PDU
            required: ['events']
          examples:
            application/json: {
              "events": [
                {"see_room_version_spec": "The event format changes depending on the room version."}
              ]
            }