feat: condition pagination (#215)

go.mod

@@ -52,7 +52,6 @@ require (
 	cloud.google.com/go/trace v1.8.0 // indirect
 	contrib.go.opencensus.io/exporter/stackdriver v0.13.11 // indirect
 	firebase.google.com/go v3.13.0+incompatible // indirect
-	github.com/766b/go-outliner v0.0.0-20180511142203-fc6edecdadd7 // indirect
 	github.com/agnivade/levenshtein v1.1.1 // indirect
 	github.com/aws/aws-sdk-go v1.44.208 // indirect
 	github.com/bytedance/sonic v1.8.3 // indirect

go.sum

@@ -82,8 +82,6 @@ contrib.go.opencensus.io/exporter/stackdriver v0.13.11/go.mod h1:I5htMbyta491eUx
 dmitri.shuralyov.com/gpu/mtl v0.0.0-20190408044501-666a987793e9/go.mod h1:H6x//7gZCb22OMCxBHrMx7a5I7Hp++hsVxbQ4BYO7hU=
 firebase.google.com/go v3.13.0+incompatible h1:3TdYC3DDi6aHn20qoRkxwGqNgdjtblwVAyRLQwGn/+4=
 firebase.google.com/go v3.13.0+incompatible/go.mod h1:xlah6XbEyW6tbfSklcfe5FHJIwjt8toICdV5Wh9ptHs=
-github.com/766b/go-outliner v0.0.0-20180511142203-fc6edecdadd7 h1:cJXisB2yAM61AzMutv7X+KM8F3xVLxGH99S8VmaSlps=
-github.com/766b/go-outliner v0.0.0-20180511142203-fc6edecdadd7/go.mod h1:1SzhThoS5lcKfE4IFOLQJ04WCmFpaAiPe8H9yqXyYSU=
 github.com/99designs/gqlgen v0.13.0/go.mod h1:NV130r6f4tpRWuAI+zsrSdooO/eWUv+Gyyoi3rEfXIk=
 github.com/99designs/gqlgen v0.17.26 h1:fxgSTbPf1G30uWAWSoHd+9gSNMagmP04k58ThJ1/ikQ=
 github.com/99designs/gqlgen v0.17.26/go.mod h1:i4rEatMrzzu6RXaHydq1nmEPZkb3bKQsnxNRHS4DQB4=

pkg/clinical/application/dto/condition_output.go

@@ -0,0 +1,53 @@
+package dto
+
+import "github.com/savannahghi/scalarutils"
+
+// Condition represents a FHIR condition
+type Condition struct {
+	ID     string          `json:"id"`
+	Status ConditionStatus `json:"status"`
+	Name   string          `json:"condition"`
+	Code   string          `json:"code"`
+	System string          `json:"system"`
+
+	OnsetDate    scalarutils.Date `json:"onsetDate"`
+	RecordedDate scalarutils.Date `json:"recordedDate"`
+
+	Note string `json:"note"`
+
+	PatientID   string `json:"patientID"`
+	EncounterID string `json:"encounterID"`
+}
+
+// ConditionEdge is a condition edge
+type ConditionEdge struct {
+	Node   Condition
+	Cursor string
+}
+
+// ConditionConnection  is a Condition Connection Type
+type ConditionConnection struct {
+	TotalCount int
+	Edges      []ConditionEdge
+	PageInfo   PageInfo
+}
+
+// CreateConditionConnection creates a connection that follows the GraphQl Cursor Connection Specification
+func CreateConditionConnection(conditions []Condition, pageInfo PageInfo, total int) ConditionConnection {
+	connection := ConditionConnection{
+		TotalCount: total,
+		Edges:      []ConditionEdge{},
+		PageInfo:   pageInfo,
+	}
+
+	for _, condition := range conditions {
+		edge := ConditionEdge{
+			Node:   condition,
+			Cursor: condition.ID,
+		}
+
+		connection.Edges = append(connection.Edges, edge)
+	}
+
+	return connection
+}

pkg/clinical/application/dto/output.go

@@ -118,23 +118,6 @@ type Patient struct {
 	BirthDate   scalarutils.Date `json:"birthDate"`
 }
 
-// Condition represents a FHIR condition
-type Condition struct {
-	ID     string          `json:"id"`
-	Status ConditionStatus `json:"status"`
-	Name   string          `json:"condition"`
-	Code   string          `json:"code"`
-	System string          `json:"system"`
-
-	OnsetDate    scalarutils.Date `json:"onsetDate"`
-	RecordedDate scalarutils.Date `json:"recordedDate"`
-
-	Note string `json:"note"`
-
-	PatientID   string `json:"patientID"`
-	EncounterID string `json:"encounterID"`
-}
-
 // Terminology models the OCL terminology output
 type Terminology struct {
 	Code   string            `json:"code"`

pkg/clinical/application/dto/pagination.go

@@ -0,0 +1,54 @@
+package dto
+
+import "fmt"
+
+const defaultPageCount = 10
+
+// PageInfo is used to add pagination information to Relay edges.
+type PageInfo struct {
+	// Forward pagination
+	HasNextPage bool
+	EndCursor   *string
+
+	// Backward pagination
+	HasPreviousPage bool
+	StartCursor     *string
+}
+
+// Pagination represents paging parameters
+type Pagination struct {
+	// Forward pagination arguments
+	First *int   `json:"first"`
+	After string `json:"after"`
+
+	// Backward pagination arguments
+	Last   *int   `json:"last"`
+	Before string `json:"before"`
+}
+
+func (p *Pagination) Validate() error {
+	if p.First != nil && p.Last != nil {
+		return fmt.Errorf("cannot provide both first and last")
+	}
+
+	if p.First != nil {
+		first := *p.First
+		if first <= 0 {
+			return fmt.Errorf("first cannot be less than 0")
+		}
+	}
+
+	if p.Last != nil {
+		last := *p.Last
+		if last <= 0 {
+			return fmt.Errorf("last cannot be less than 0")
+		}
+	}
+
+	if p.First == nil && p.Last == nil {
+		limit := defaultPageCount
+		p.First = &limit
+	}
+
+	return nil
+}

pkg/clinical/domain/condition.go

@@ -1,7 +1,6 @@
 package domain
 
 import (
-	"github.com/savannahghi/firebasetools"
 	"github.com/savannahghi/scalarutils"
 )
 
@@ -236,17 +235,14 @@ type FHIRConditionStageInput struct {
 	Type *FHIRCodeableConceptInput `json:"type,omitempty"`
 }
 
-// FHIRConditionRelayConnection is a Relay connection for Condition
-type FHIRConditionRelayConnection struct {
-	Edges    []*FHIRConditionRelayEdge `json:"edges,omitempty"`
-	PageInfo *firebasetools.PageInfo   `json:"pageInfo,omitempty"`
-}
-
-// FHIRConditionRelayEdge is a Relay edge for Condition
-type FHIRConditionRelayEdge struct {
-	Cursor *string `json:"cursor,omitempty"`
-
-	Node *FHIRCondition `json:"node,omitempty"`
+// PagedFHIRCondition ...
+type PagedFHIRCondition struct {
+	Conditions      []FHIRCondition
+	HasNextPage     bool
+	NextCursor      string
+	HasPreviousPage bool
+	PreviousCursor  string
+	TotalCount      int
 }
 
 // FHIRConditionRelayPayload is used to return single instances of Condition

pkg/clinical/domain/models.go

@@ -502,3 +502,13 @@ func MaritalStatusDisplay(val MaritalStatus) string {
 		return "unknown"
 	}
 }
+
+// PagedFHIRResource is a universal model for fetching FHIR resources with PageInfo details
+type PagedFHIRResource struct {
+	Resources       []map[string]interface{}
+	HasNextPage     bool
+	NextCursor      string
+	HasPreviousPage bool
+	PreviousCursor  string
+	TotalCount      int
+}