Add event join service and api endpoint

Signed-off-by: Asai Neko <sugar@sne.moe>

docs/swagger.yaml

@@ -100,6 +100,17 @@ definitions:
       checkin_code:
         type: string
     type: object
+  service_event.EventJoinData:
+    properties:
+      event_id:
+        type: string
+      role:
+        type: string
+      state:
+        type: string
+      user_id:
+        type: string
+    type: object
   service_user.UserInfoData:
     properties:
       allow_public:
@@ -636,6 +647,63 @@ paths:
       summary: Get Event Information
       tags:
       - Event
+  /event/join:
+    post:
+      consumes:
+      - application/json
+      description: Allows an authenticated user to join an event by providing the
+        event ID. The user's role and state are initialized by the service.
+      parameters:
+      - description: Event Join Details (UserId and EventId are required)
+        in: body
+        name: request
+        required: true
+        schema:
+          $ref: '#/definitions/service_event.EventJoinData'
+      produces:
+      - application/json
+      responses:
+        "200":
+          description: Successfully joined the event
+          schema:
+            allOf:
+            - $ref: '#/definitions/utils.RespStatus'
+            - properties:
+                data:
+                  type: object
+              type: object
+        "400":
+          description: Invalid Input or UUID Parse Failed
+          schema:
+            allOf:
+            - $ref: '#/definitions/utils.RespStatus'
+            - properties:
+                data:
+                  type: object
+              type: object
+        "403":
+          description: Unauthorized / Missing User ID
+          schema:
+            allOf:
+            - $ref: '#/definitions/utils.RespStatus'
+            - properties:
+                data:
+                  type: object
+              type: object
+        "500":
+          description: Internal Server Error / Database Error
+          schema:
+            allOf:
+            - $ref: '#/definitions/utils.RespStatus'
+            - properties:
+                data:
+                  type: object
+              type: object
+      security:
+      - ApiKeyAuth: []
+      summary: Join an Event
+      tags:
+      - Event
   /event/list:
     get:
       consumes: