Resolve "Send details about why duel could not be created"

appapi.yaml

@@ -543,25 +543,42 @@ paths:
             application/json:
               schema:
                 $ref: '#/components/schemas/duel'
-        '200':
-          description: Query was correct but no new duel could not be created. Often due to no intersection in pool selections of players.
+        '409':
+          description: Did not create duel since the current user and the challenged user don't have common question pools.
           content:
-            text/plain:
+            application/json:
               schema:
-                type: string
-                description: Details on why no duel was created.
+                type: object
+                properties:
+                  pools:
+                    type: object
+                    required:
+                      - self
+                      - opponent
+                    properties:
+                      self:
+                        type: array
+                        items:
+                          type: integer
+                          format: uint32
+                          description: ID's of the requesting user's pools.
+                      opponent:
+                        type: array
+                        items:
+                          type: integer
+                          format: uint32
+                          description: ID's of the given user's pools.
+
         '401':
           description: Authentication failure.
           content:
             text/plain:
               schema:
                 type: string
-        '400':
-          description: Query was invalid.
+        '403':
+          description: There already is a running duel with the current and the challenged user.
         '404':
           description: User with `id` does not exist.
-        '500':
-          description: The server cannot deliver due to an internal error.
   '/duel/pool':
     get:
       summary: Get pools to choose from.

endpoint/duel/endpoint.go

@@ -11,6 +11,7 @@ import (
 
 	"firebase.google.com/go/messaging"
 
+	"gitlab.akamu.de/akamu/game-server-go/endpoint/pool"
 	"gitlab.akamu.de/akamu/game-server-go/endpoint/refreshjwt"
 
 	"github.com/getsentry/raven-go"
@@ -22,7 +23,7 @@ import (
 
 var errUserForbidsNotifications = errors.New("user does not want to receive notifications")
 
-func SetupDuelRoutes(group *gin.RouterGroup, repository DuelQuery, titleRepository title.TitleQuery, sessionRepository refreshjwt.RefreshJWTQuery) {
+func SetupDuelRoutes(group *gin.RouterGroup, repository DuelQuery, titleRepository title.TitleQuery, sessionRepository refreshjwt.RefreshJWTQuery, poolRepository pool.PoolQuery) {
 	group.OPTIONS("", func(ctx *gin.Context) {
 		ctx.Header("Allow", "GET,POST,PATCH,PUT,DELETE")
 		ctx.Status(200)
@@ -32,7 +33,7 @@ func SetupDuelRoutes(group *gin.RouterGroup, repository DuelQuery, titleReposito
 	group.GET("", getDuel(repository))
 
 	// Endpoint to create new duel
-	group.POST("", postDuel(repository, sessionRepository))
+	group.POST("", postDuel(repository, sessionRepository, poolRepository))
 
 	// Endpoint to fetch all playable pools
 	group.GET("/pool", getPools(repository))
@@ -96,7 +97,7 @@ func getDuel(repository DuelQuery) gin.HandlerFunc {
 	}
 }
 
-func postDuel(repository DuelQuery, sessionRepository refreshjwt.RefreshJWTQuery) gin.HandlerFunc {
+func postDuel(repository DuelQuery, sessionRepository refreshjwt.RefreshJWTQuery, poolRepository pool.PoolQuery) gin.HandlerFunc {
 	return func(ctx *gin.Context) {
 		// Fetch challenged user
 		var challenged struct {
@@ -123,7 +124,21 @@ func postDuel(repository DuelQuery, sessionRepository refreshjwt.RefreshJWTQuery
 			case ErrUserNotFound:
 				ctx.AbortWithError(http.StatusNotFound, err)
 			case ErrNoCommonPool:
-				ctx.AbortWithError(http.StatusConflict, err)
+				// Get pools of user and challenged user for the app
+				poolsChallenger, errPoolsChallenger := poolRepository.SelectUserPools(challenger)
+				poolsChallenged, errPoolsChallanged := poolRepository.SelectUserPools(challenged.ID)
+				if errPoolsChallenger != nil {
+					raven.CaptureError(errPoolsChallenger, nil)
+					ctx.AbortWithError(http.StatusConflict, errPoolsChallenger)
+					return
+				} else if errPoolsChallanged != nil {
+					raven.CaptureError(errPoolsChallanged, nil)
+					ctx.AbortWithError(http.StatusConflict, errPoolsChallanged)
+					return
+				}
+
+				ctx.AbortWithStatusJSON(http.StatusConflict, gin.H{"pools": gin.H{"self": poolsChallenger, "opponent": poolsChallenged}})
+
 			default:
 				raven.CaptureError(err, nil)
 				ctx.AbortWithError(http.StatusInternalServerError, err)

endpoint/duel/query.go

@@ -238,6 +238,8 @@ var ErrQuestionNotFound = errors.New("question not found")
 var ErrBadRequest = errors.New("The request was either formatted incorrectly or it was not allowed at the currect state of the database.")
 
 const TotalRounds = 2
+
+// Must match the value in endpoints/pool/query.go
 const QuestionsPerRound = 2
 
 const queryDuelsByID = "SELECT `duel`.`idduel`, `duel`.`round_current`, `duel`.`round_max`, `duel`.`started_on`, `duel`.`modified_on`, `duel`.`finished_on`, `duel`.`running`, `duel`.`started`, `duel`.`next`, `duel_player_score`.`score`, `participant`.`iduser`, `participant`.`username`, idavatar, avatar.image, avatar.level, title.idtitle, title.name, subject.idsubject, subject.name, subject.shortform, subject.department, subject.description, title.unlock_score, title.unlock_win, `round`.`idround`, `round`.`number`, `round`.`started`, `pool`.`idpool`, `pool`.`name`, `pool`.`shortform`, `pool`.`image`" +

endpoint/pool/query.go

@@ -6,14 +6,17 @@ import (
 	"fmt"
 
 	"gitlab.akamu.de/akamu/game-server-go/dbhandler"
-	"gitlab.akamu.de/akamu/game-server-go/endpoint/duel"
 	"gitlab.akamu.de/akamu/game-server-go/schemas"
 )
 
 var ErrorInvalidPools = errors.New("The selection of pools was invalid.")
 
+// Must match the value in endpoint/duel/query.go
+const QuestionsPerRound = 2
+
 type PoolQuery interface {
 	Select(userID uint32) ([]schemas.PoolSchema, error)
+	SelectUserPools(userID uint32) ([]uint32, error)
 	PatchUserPools(userID uint32, selection []uint32) error
 }
 
@@ -36,7 +39,7 @@ func (m MySQLPoolQuery) Select(userID uint32) ([]schemas.PoolSchema, error) {
 	}
 
 	// Fetch pools from database
-	rows, errRows := db.Query(queryString, userID, duel.QuestionsPerRound)
+	rows, errRows := db.Query(queryString, userID, QuestionsPerRound)
 
 	// Check whether query failed
 	if errRows != nil {
@@ -76,6 +79,38 @@ func (m MySQLPoolQuery) Select(userID uint32) ([]schemas.PoolSchema, error) {
 	return pools, nil
 }
 
+// Select returns a list of all available playable pools.
+func (m MySQLPoolQuery) SelectUserPools(userID uint32) ([]uint32, error) {
+	db, err := dbhandler.GetDBConnection()
+	if err != nil {
+		return nil, fmt.Errorf("failed to get database instance: %v", err)
+	}
+
+	// Fetch pools from database
+	rows, err := db.Query("SELECT DISTINCT `pool` FROM `user_pool` WHERE `user`=? AND `pool` IN (SELECT `pool` FROM `pool_question` GROUP BY `pool` HAVING COUNT(DISTINCT `question`) >= ?)", userID, QuestionsPerRound)
+
+	// Check whether query failed
+	if err != nil {
+		return nil, fmt.Errorf("failed fetching pools from database: %v", err)
+	}
+
+	defer rows.Close()
+
+	// Generate output
+	var pools []uint32
+
+	for rows.Next() {
+		var pool uint32
+		if err := rows.Scan(&pool); err != nil {
+			return nil, fmt.Errorf("failed aggregating pools from database: %v", err)
+		}
+
+		pools = append(pools, pool)
+	}
+
+	return pools, nil
+}
+
 // PatchUserPools insert relations into user_pool for all pools in the array `selection`.
 // Relations to pools that are not in `selection` are deleted.
 func (m MySQLPoolQuery) PatchUserPools(userID uint32, selection []uint32) error {

setup/setup.go

@@ -313,7 +313,7 @@ func SetupRoutes(courseRepository course.CourseQuery, flashcardRepository flashc
 	pool.SetupPoolRoutes(authGroup.Group("/pool"), poolRepository)
 	friend.SetupFriendRoutes(authGroup.Group("/friend"), friendRepository)
 	avatar.SetupAvatarRoutes(authGroup.Group("/avatar"), avatarRepository)
-	duel.SetupDuelRoutes(authGroup.Group("/duel"), duelRepository, titleRepository, refreshjwtRepository)
+	duel.SetupDuelRoutes(authGroup.Group("/duel"), duelRepository, titleRepository, refreshjwtRepository, poolRepository)
 	resource.SetupResourceRoutes(authGroup.Group("/resource"), resourceRepository, resourceServerConfig)
 	refreshjwt.SetupRefreshJWTRoutes(authGroup.Group("/session"), refreshjwtRepository)
 

test/pool_test.go

@@ -21,6 +21,10 @@ func (p *mockPool) Select(userID uint32) ([]schemas.PoolSchema, error) {
 	return pools, nil
 }
 
+func (*mockPool) SelectUserPools(userId uint32) ([]uint32, error) {
+	return nil, nil
+}
+
 // just to match interface doesnt do anything actually
 func (p *mockPool) PatchUserPools(userID uint32, selection []uint32) error {
 	return nil