[feature] Add paging via Link header for notifications and account statuses (#629)

* test link headers

* page get account statuses properly

* page get notifications

* add util func for packaging timeline responses

* return timelined stuff from accountstatusesget

* rename timeline response

* use new convenience function

* go fmt

internal/api/client/account/statuses.go

@@ -222,12 +222,15 @@ func (m *Module) AccountStatusesGETHandler(c *gin.Context) {
 		publicOnly = i
 	}
 
-	statuses, errWithCode := m.processor.AccountStatusesGet(c.Request.Context(), authed, targetAcctID, limit, excludeReplies, excludeReblogs, maxID, minID, pinnedOnly, mediaOnly, publicOnly)
+	resp, errWithCode := m.processor.AccountStatusesGet(c.Request.Context(), authed, targetAcctID, limit, excludeReplies, excludeReblogs, maxID, minID, pinnedOnly, mediaOnly, publicOnly)
 	if errWithCode != nil {
 		l.Debugf("error from processor account statuses get: %s", errWithCode)
 		c.JSON(errWithCode.Code(), gin.H{"error": errWithCode.Safe()})
 		return
 	}
 
-	c.JSON(http.StatusOK, statuses)
+	if resp.LinkHeader != "" {
+		c.Header("Link", resp.LinkHeader)
+	}
+	c.JSON(http.StatusOK, resp.Items)
 }

internal/api/client/account/statuses_test.go

@@ -37,7 +37,47 @@ type AccountStatusesTestSuite struct {
 	AccountStandardTestSuite
 }
 
-func (suite *AccountStatusesTestSuite) TestGetStatusesMediaOnly() {
+func (suite *AccountStatusesTestSuite) TestGetStatusesPublicOnly() {
+	// set up the request
+	// we're getting statuses of admin
+	targetAccount := suite.testAccounts["admin_account"]
+	recorder := httptest.NewRecorder()
+	ctx := suite.newContext(recorder, http.MethodGet, nil, fmt.Sprintf("/api/v1/accounts/%s/statuses?limit=20&only_media=false&only_public=true", targetAccount.ID), "")
+	ctx.Params = gin.Params{
+		gin.Param{
+			Key:   account.IDKey,
+			Value: targetAccount.ID,
+		},
+	}
+
+	// call the handler
+	suite.accountModule.AccountStatusesGETHandler(ctx)
+
+	// 1. we should have OK because our request was valid
+	suite.Equal(http.StatusOK, recorder.Code)
+
+	// 2. we should have no error message in the result body
+	result := recorder.Result()
+	defer result.Body.Close()
+
+	// check the response
+	b, err := ioutil.ReadAll(result.Body)
+	assert.NoError(suite.T(), err)
+
+	// unmarshal the returned statuses
+	apimodelStatuses := []*apimodel.Status{}
+	err = json.Unmarshal(b, &apimodelStatuses)
+	suite.NoError(err)
+	suite.NotEmpty(apimodelStatuses)
+
+	for _, s := range apimodelStatuses {
+		suite.Equal(apimodel.VisibilityPublic, s.Visibility)
+	}
+
+	suite.Equal(`<http://localhost:8080/api/v1/accounts/01F8MH17FWEB39HZJ76B6VXSKF/statuses?limit=20&max_id=01F8MH75CBF9JFX4ZAD54N0W0R&exclude_replies=false&exclude_reblogs=false&pinned_only=false&only_media=false&only_public=true>; rel="next", <http://localhost:8080/api/v1/accounts/01F8MH17FWEB39HZJ76B6VXSKF/statuses?limit=20&min_id=01G36SF3V6Y6V5BF9P4R7PQG7G&exclude_replies=false&exclude_reblogs=false&pinned_only=false&only_media=false&only_public=true>; rel="prev"`, result.Header.Get("link"))
+}
+
+func (suite *AccountStatusesTestSuite) TestGetStatusesPublicOnlyMediaOnly() {
 	// set up the request
 	// we're getting statuses of admin
 	targetAccount := suite.testAccounts["admin_account"]
@@ -74,6 +114,8 @@ func (suite *AccountStatusesTestSuite) TestGetStatusesMediaOnly() {
 		suite.NotEmpty(s.MediaAttachments)
 		suite.Equal(apimodel.VisibilityPublic, s.Visibility)
 	}
+
+	suite.Equal(`<http://localhost:8080/api/v1/accounts/01F8MH17FWEB39HZJ76B6VXSKF/statuses?limit=20&max_id=01F8MH75CBF9JFX4ZAD54N0W0R&exclude_replies=false&exclude_reblogs=false&pinned_only=false&only_media=true&only_public=true>; rel="next", <http://localhost:8080/api/v1/accounts/01F8MH17FWEB39HZJ76B6VXSKF/statuses?limit=20&min_id=01F8MH75CBF9JFX4ZAD54N0W0R&exclude_replies=false&exclude_reblogs=false&pinned_only=false&only_media=true&only_public=true>; rel="prev"`, result.Header.Get("link"))
 }
 
 func TestAccountStatusesTestSuite(t *testing.T) {

internal/api/client/favourites/favouritesget.go

@@ -61,5 +61,5 @@ func (m *Module) FavouritesGETHandler(c *gin.Context) {
 	if resp.LinkHeader != "" {
 		c.Header("Link", resp.LinkHeader)
 	}
-	c.JSON(http.StatusOK, resp.Statuses)
+	c.JSON(http.StatusOK, resp.Items)
 }

internal/api/client/notification/notificationsget.go

@@ -74,12 +74,15 @@ func (m *Module) NotificationsGETHandler(c *gin.Context) {
 		sinceID = sinceIDString
 	}
 
-	notifs, errWithCode := m.processor.NotificationsGet(c.Request.Context(), authed, limit, maxID, sinceID)
+	resp, errWithCode := m.processor.NotificationsGet(c.Request.Context(), authed, limit, maxID, sinceID)
 	if errWithCode != nil {
 		l.Debugf("error processing notifications get: %s", errWithCode.Error())
 		c.JSON(errWithCode.Code(), gin.H{"error": errWithCode.Safe()})
 		return
 	}
 
-	c.JSON(http.StatusOK, notifs)
+	if resp.LinkHeader != "" {
+		c.Header("Link", resp.LinkHeader)
+	}
+	c.JSON(http.StatusOK, resp.Items)
 }

internal/api/client/timeline/home.go

@@ -171,5 +171,5 @@ func (m *Module) HomeTimelineGETHandler(c *gin.Context) {
 	if resp.LinkHeader != "" {
 		c.Header("Link", resp.LinkHeader)
 	}
-	c.JSON(http.StatusOK, resp.Statuses)
+	c.JSON(http.StatusOK, resp.Items)
 }

internal/api/client/timeline/public.go

@@ -171,5 +171,5 @@ func (m *Module) PublicTimelineGETHandler(c *gin.Context) {
 	if resp.LinkHeader != "" {
 		c.Header("Link", resp.LinkHeader)
 	}
-	c.JSON(http.StatusOK, resp.Statuses)
+	c.JSON(http.StatusOK, resp.Items)
 }

internal/api/model/notification.go

@@ -43,3 +43,24 @@ type Notification struct {
 	// Status that was the object of the notification, e.g. in mentions, reblogs, favourites, or polls.
 	Status *Status `json:"status,omitempty"`
 }
+
+/*
+	The below functions are added onto the apimodel notification so that it satisfies
+	the Timelineable interface in internal/timeline.
+*/
+
+func (n *Notification) GetID() string {
+	return n.ID
+}
+
+func (n *Notification) GetAccountID() string {
+	return ""
+}
+
+func (n *Notification) GetBoostOfID() string {
+	return ""
+}
+
+func (n *Notification) GetBoostOfAccountID() string {
+	return ""
+}

internal/api/model/timeline.go

@@ -18,9 +18,11 @@
 
 package model
 
-// StatusTimelineResponse wraps a slice of statuses, ready to be serialized, along with the Link
+import "github.com/superseriousbusiness/gotosocial/internal/timeline"
+
+// TimelineResponse wraps a slice of timelineables, ready to be serialized, along with the Link
 // header for the previous and next queries, to be returned to the client.
-type StatusTimelineResponse struct {
+type TimelineResponse struct {
-	Statuses   []*Status
+	Items      []timeline.Timelineable
 	LinkHeader string
 }

internal/processing/account.go

@@ -46,7 +46,7 @@ func (p *processor) AccountUpdate(ctx context.Context, authed *oauth.Auth, form
 	return p.accountProcessor.Update(ctx, authed.Account, form)
 }
 
-func (p *processor) AccountStatusesGet(ctx context.Context, authed *oauth.Auth, targetAccountID string, limit int, excludeReplies bool, excludeReblogs bool, maxID string, minID string, pinnedOnly bool, mediaOnly bool, publicOnly bool) ([]apimodel.Status, gtserror.WithCode) {
+func (p *processor) AccountStatusesGet(ctx context.Context, authed *oauth.Auth, targetAccountID string, limit int, excludeReplies bool, excludeReblogs bool, maxID string, minID string, pinnedOnly bool, mediaOnly bool, publicOnly bool) (*apimodel.TimelineResponse, gtserror.WithCode) {
 	return p.accountProcessor.StatusesGet(ctx, authed.Account, targetAccountID, limit, excludeReplies, excludeReblogs, maxID, minID, pinnedOnly, mediaOnly, publicOnly)
 }
 

internal/processing/account/account.go

@@ -55,7 +55,7 @@ type Processor interface {
 	Update(ctx context.Context, account *gtsmodel.Account, form *apimodel.UpdateCredentialsRequest) (*apimodel.Account, error)
 	// StatusesGet fetches a number of statuses (in time descending order) from the given account, filtered by visibility for
 	// the account given in authed.
-	StatusesGet(ctx context.Context, requestingAccount *gtsmodel.Account, targetAccountID string, limit int, excludeReplies bool, excludeReblogs bool, maxID string, minID string, pinned bool, mediaOnly bool, publicOnly bool) ([]apimodel.Status, gtserror.WithCode)
+	StatusesGet(ctx context.Context, requestingAccount *gtsmodel.Account, targetAccountID string, limit int, excludeReplies bool, excludeReblogs bool, maxID string, minID string, pinned bool, mediaOnly bool, publicOnly bool) (*apimodel.TimelineResponse, gtserror.WithCode)
 	// FollowersGet fetches a list of the target account's followers.
 	FollowersGet(ctx context.Context, requestingAccount *gtsmodel.Account, targetAccountID string) ([]apimodel.Account, gtserror.WithCode)
 	// FollowingGet fetches a list of the accounts that target account is following.

internal/processing/account/getstatuses.go

@@ -26,9 +26,11 @@
 	"github.com/superseriousbusiness/gotosocial/internal/db"
 	"github.com/superseriousbusiness/gotosocial/internal/gtserror"
 	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
+	"github.com/superseriousbusiness/gotosocial/internal/timeline"
+	"github.com/superseriousbusiness/gotosocial/internal/util"
 )
 
-func (p *processor) StatusesGet(ctx context.Context, requestingAccount *gtsmodel.Account, targetAccountID string, limit int, excludeReplies bool, excludeReblogs bool, maxID string, minID string, pinnedOnly bool, mediaOnly bool, publicOnly bool) ([]apimodel.Status, gtserror.WithCode) {
+func (p *processor) StatusesGet(ctx context.Context, requestingAccount *gtsmodel.Account, targetAccountID string, limit int, excludeReplies bool, excludeReblogs bool, maxID string, minID string, pinnedOnly bool, mediaOnly bool, publicOnly bool) (*apimodel.TimelineResponse, gtserror.WithCode) {
 	if requestingAccount != nil {
 		if blocked, err := p.db.IsBlocked(ctx, requestingAccount.ID, targetAccountID, true); err != nil {
 			return nil, gtserror.NewErrorInternalError(err)
@@ -37,29 +39,48 @@ func (p *processor) StatusesGet(ctx context.Context, requestingAccount *gtsmodel
 		}
 	}
 
-	apiStatuses := []apimodel.Status{}
-
 	statuses, err := p.db.GetAccountStatuses(ctx, targetAccountID, limit, excludeReplies, excludeReblogs, maxID, minID, pinnedOnly, mediaOnly, publicOnly)
 	if err != nil {
 		if err == db.ErrNoEntries {
-			return apiStatuses, nil
+			return util.EmptyTimelineResponse(), nil
 		}
 		return nil, gtserror.NewErrorInternalError(err)
 	}
 
+	var filtered []*gtsmodel.Status
 	for _, s := range statuses {
 		visible, err := p.filter.StatusVisible(ctx, s, requestingAccount)
-		if err != nil || !visible {
+		if err == nil && visible {
-			continue
+			filtered = append(filtered, s)
+		}
 	}
 
-		apiStatus, err := p.tc.StatusToAPIStatus(ctx, s, requestingAccount)
+	if len(filtered) == 0 {
+		return util.EmptyTimelineResponse(), nil
+	}
+
+	timelineables := []timeline.Timelineable{}
+	for _, i := range filtered {
+		apiStatus, err := p.tc.StatusToAPIStatus(ctx, i, requestingAccount)
 		if err != nil {
 			return nil, gtserror.NewErrorInternalError(fmt.Errorf("error converting status to api: %s", err))
 		}
 
-		apiStatuses = append(apiStatuses, *apiStatus)
+		timelineables = append(timelineables, apiStatus)
 	}
 
-	return apiStatuses, nil
+	return util.PackageTimelineableResponse(util.TimelineableResponseParams{
+		Items:          timelineables,
+		Path:           fmt.Sprintf("/api/v1/accounts/%s/statuses", targetAccountID),
+		NextMaxIDValue: timelineables[len(timelineables)-1].GetID(),
+		PrevMinIDValue: timelineables[0].GetID(),
+		Limit:          limit,
+		ExtraQueryParams: []string{
+			fmt.Sprintf("exclude_replies=%t", excludeReplies),
+			fmt.Sprintf("exclude_reblogs=%t", excludeReblogs),
+			fmt.Sprintf("pinned_only=%t", pinnedOnly),
+			fmt.Sprintf("only_media=%t", mediaOnly),
+			fmt.Sprintf("only_public=%t", publicOnly),
+		},
+	})
 }

internal/processing/notification.go

@@ -26,9 +26,11 @@
 	apimodel "github.com/superseriousbusiness/gotosocial/internal/api/model"
 	"github.com/superseriousbusiness/gotosocial/internal/gtserror"
 	"github.com/superseriousbusiness/gotosocial/internal/oauth"
+	"github.com/superseriousbusiness/gotosocial/internal/timeline"
+	"github.com/superseriousbusiness/gotosocial/internal/util"
 )
 
-func (p *processor) NotificationsGet(ctx context.Context, authed *oauth.Auth, limit int, maxID string, sinceID string) ([]*apimodel.Notification, gtserror.WithCode) {
+func (p *processor) NotificationsGet(ctx context.Context, authed *oauth.Auth, limit int, maxID string, sinceID string) (*apimodel.TimelineResponse, gtserror.WithCode) {
 	l := logrus.WithField("func", "NotificationsGet")
 
 	notifs, err := p.db.GetNotifications(ctx, authed.Account.ID, limit, maxID, sinceID)
@@ -36,15 +38,26 @@ func (p *processor) NotificationsGet(ctx context.Context, authed *oauth.Auth, li
 		return nil, gtserror.NewErrorInternalError(err)
 	}
 
-	apiNotifs := []*apimodel.Notification{}
+	if len(notifs) == 0 {
+		return util.EmptyTimelineResponse(), nil
+	}
+
+	timelineables := []timeline.Timelineable{}
 	for _, n := range notifs {
 		apiNotif, err := p.tc.NotificationToAPINotification(ctx, n)
 		if err != nil {
 			l.Debugf("got an error converting a notification to api, will skip it: %s", err)
 			continue
 		}
-		apiNotifs = append(apiNotifs, apiNotif)
+		timelineables = append(timelineables, apiNotif)
 	}
 
-	return apiNotifs, nil
+	return util.PackageTimelineableResponse(util.TimelineableResponseParams{
+		Items:          timelineables,
+		Path:           "api/v1/notifications",
+		NextMaxIDValue: timelineables[len(timelineables)-1].GetID(),
+		PrevMinIDKey:   "since_id",
+		PrevMinIDValue: timelineables[0].GetID(),
+		Limit:          limit,
+	})
 }

internal/processing/notification_test.go

@@ -23,6 +23,7 @@
 	"testing"
 
 	"github.com/stretchr/testify/suite"
+	apimodel "github.com/superseriousbusiness/gotosocial/internal/api/model"
 )
 
 type NotificationTestSuite struct {
@@ -32,14 +33,19 @@ type NotificationTestSuite struct {
 // get a notification where someone has liked our status
 func (suite *NotificationTestSuite) TestGetNotifications() {
 	receivingAccount := suite.testAccounts["local_account_1"]
-	notifs, err := suite.processor.NotificationsGet(context.Background(), suite.testAutheds["local_account_1"], 10, "", "")
+	notifsResponse, err := suite.processor.NotificationsGet(context.Background(), suite.testAutheds["local_account_1"], 10, "", "")
 	suite.NoError(err)
-	suite.Len(notifs, 1)
+	suite.Len(notifsResponse.Items, 1)
-	notif := notifs[0]
+	notif, ok := notifsResponse.Items[0].(*apimodel.Notification)
+	if !ok {
+		panic("notif in response wasn't *apimodel.Notification")
+	}
+
 	suite.NotNil(notif.Status)
 	suite.NotNil(notif.Status)
 	suite.NotNil(notif.Status.Account)
 	suite.Equal(receivingAccount.ID, notif.Status.Account.ID)
+	suite.Equal(`<http://localhost:8080/api/v1/notifications?limit=10&max_id=01F8Q0ANPTWW10DAKTX7BRPBJP>; rel="next", <http://localhost:8080/api/v1/notifications?limit=10&since_id=01F8Q0ANPTWW10DAKTX7BRPBJP>; rel="prev"`, notifsResponse.LinkHeader)
 }
 
 func TestNotificationTestSuite(t *testing.T) {

internal/processing/processor.go

@@ -83,7 +83,7 @@ type Processor interface {
 	AccountUpdate(ctx context.Context, authed *oauth.Auth, form *apimodel.UpdateCredentialsRequest) (*apimodel.Account, error)
 	// AccountStatusesGet fetches a number of statuses (in time descending order) from the given account, filtered by visibility for
 	// the account given in authed.
-	AccountStatusesGet(ctx context.Context, authed *oauth.Auth, targetAccountID string, limit int, excludeReplies bool, excludeReblogs bool, maxID string, minID string, pinned bool, mediaOnly bool, publicOnly bool) ([]apimodel.Status, gtserror.WithCode)
+	AccountStatusesGet(ctx context.Context, authed *oauth.Auth, targetAccountID string, limit int, excludeReplies bool, excludeReblogs bool, maxID string, minID string, pinned bool, mediaOnly bool, publicOnly bool) (*apimodel.TimelineResponse, gtserror.WithCode)
 	// AccountFollowersGet fetches a list of the target account's followers.
 	AccountFollowersGet(ctx context.Context, authed *oauth.Auth, targetAccountID string) ([]apimodel.Account, gtserror.WithCode)
 	// AccountFollowingGet fetches a list of the accounts that target account is following.
@@ -150,7 +150,7 @@ type Processor interface {
 	MediaUpdate(ctx context.Context, authed *oauth.Auth, attachmentID string, form *apimodel.AttachmentUpdateRequest) (*apimodel.Attachment, gtserror.WithCode)
 
 	// NotificationsGet
-	NotificationsGet(ctx context.Context, authed *oauth.Auth, limit int, maxID string, sinceID string) ([]*apimodel.Notification, gtserror.WithCode)
+	NotificationsGet(ctx context.Context, authed *oauth.Auth, limit int, maxID string, sinceID string) (*apimodel.TimelineResponse, gtserror.WithCode)
 
 	// SearchGet performs a search with the given params, resolving/dereferencing remotely as desired
 	SearchGet(ctx context.Context, authed *oauth.Auth, searchQuery *apimodel.SearchQuery) (*apimodel.SearchResult, gtserror.WithCode)
@@ -177,11 +177,11 @@ type Processor interface {
 	StatusGetContext(ctx context.Context, authed *oauth.Auth, targetStatusID string) (*apimodel.Context, gtserror.WithCode)
 
 	// HomeTimelineGet returns statuses from the home timeline, with the given filters/parameters.
-	HomeTimelineGet(ctx context.Context, authed *oauth.Auth, maxID string, sinceID string, minID string, limit int, local bool) (*apimodel.StatusTimelineResponse, gtserror.WithCode)
+	HomeTimelineGet(ctx context.Context, authed *oauth.Auth, maxID string, sinceID string, minID string, limit int, local bool) (*apimodel.TimelineResponse, gtserror.WithCode)
 	// PublicTimelineGet returns statuses from the public/local timeline, with the given filters/parameters.
-	PublicTimelineGet(ctx context.Context, authed *oauth.Auth, maxID string, sinceID string, minID string, limit int, local bool) (*apimodel.StatusTimelineResponse, gtserror.WithCode)
+	PublicTimelineGet(ctx context.Context, authed *oauth.Auth, maxID string, sinceID string, minID string, limit int, local bool) (*apimodel.TimelineResponse, gtserror.WithCode)
 	// FavedTimelineGet returns faved statuses, with the given filters/parameters.
-	FavedTimelineGet(ctx context.Context, authed *oauth.Auth, maxID string, minID string, limit int) (*apimodel.StatusTimelineResponse, gtserror.WithCode)
+	FavedTimelineGet(ctx context.Context, authed *oauth.Auth, maxID string, minID string, limit int) (*apimodel.TimelineResponse, gtserror.WithCode)
 
 	// AuthorizeStreamingRequest returns a gotosocial account in exchange for an access token, or an error if the given token is not valid.
 	AuthorizeStreamingRequest(ctx context.Context, accessToken string) (*gtsmodel.Account, error)

internal/processing/statustimeline.go

@@ -22,18 +22,17 @@
 	"context"
 	"errors"
 	"fmt"
-	"net/url"
 
 	"github.com/sirupsen/logrus"
 
 	apimodel "github.com/superseriousbusiness/gotosocial/internal/api/model"
-	"github.com/superseriousbusiness/gotosocial/internal/config"
 	"github.com/superseriousbusiness/gotosocial/internal/db"
 	"github.com/superseriousbusiness/gotosocial/internal/gtserror"
 	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
 	"github.com/superseriousbusiness/gotosocial/internal/oauth"
 	"github.com/superseriousbusiness/gotosocial/internal/timeline"
 	"github.com/superseriousbusiness/gotosocial/internal/typeutils"
+	"github.com/superseriousbusiness/gotosocial/internal/util"
 	"github.com/superseriousbusiness/gotosocial/internal/visibility"
 )
 
@@ -139,114 +138,100 @@ func StatusSkipInsertFunction() timeline.SkipInsertFunction {
 	}
 }
 
-func (p *processor) packageStatusResponse(statuses []*apimodel.Status, path string, nextMaxID string, prevMinID string, limit int) (*apimodel.StatusTimelineResponse, gtserror.WithCode) {
+func (p *processor) HomeTimelineGet(ctx context.Context, authed *oauth.Auth, maxID string, sinceID string, minID string, limit int, local bool) (*apimodel.TimelineResponse, gtserror.WithCode) {
-	resp := &apimodel.StatusTimelineResponse{
-		Statuses: []*apimodel.Status{},
-	}
-	resp.Statuses = statuses
-
-	// prepare the next and previous links
-	if len(statuses) != 0 {
-		protocol := config.GetProtocol()
-		host := config.GetHost()
-
-		nextLink := &url.URL{
-			Scheme:   protocol,
-			Host:     host,
-			Path:     path,
-			RawQuery: fmt.Sprintf("limit=%d&max_id=%s", limit, nextMaxID),
-		}
-		next := fmt.Sprintf("<%s>; rel=\"next\"", nextLink.String())
-
-		prevLink := &url.URL{
-			Scheme:   protocol,
-			Host:     host,
-			Path:     path,
-			RawQuery: fmt.Sprintf("limit=%d&min_id=%s", limit, prevMinID),
-		}
-		prev := fmt.Sprintf("<%s>; rel=\"prev\"", prevLink.String())
-		resp.LinkHeader = fmt.Sprintf("%s, %s", next, prev)
-	}
-
-	return resp, nil
-}
-
-func (p *processor) HomeTimelineGet(ctx context.Context, authed *oauth.Auth, maxID string, sinceID string, minID string, limit int, local bool) (*apimodel.StatusTimelineResponse, gtserror.WithCode) {
 	preparedItems, err := p.statusTimelines.GetTimeline(ctx, authed.Account.ID, maxID, sinceID, minID, limit, local)
 	if err != nil {
 		return nil, gtserror.NewErrorInternalError(err)
 	}
 
 	if len(preparedItems) == 0 {
-		return &apimodel.StatusTimelineResponse{
+		return util.EmptyTimelineResponse(), nil
-			Statuses: []*apimodel.Status{},
-		}, nil
 	}
 
-	statuses := []*apimodel.Status{}
+	timelineables := []timeline.Timelineable{}
 	for _, i := range preparedItems {
 		status, ok := i.(*apimodel.Status)
 		if !ok {
 			return nil, gtserror.NewErrorInternalError(errors.New("error converting prepared timeline entry to api status"))
 		}
-		statuses = append(statuses, status)
+		timelineables = append(timelineables, status)
 	}
 
-	return p.packageStatusResponse(statuses, "api/v1/timelines/home", statuses[len(preparedItems)-1].ID, statuses[0].ID, limit)
+	return util.PackageTimelineableResponse(util.TimelineableResponseParams{
+		Items:          timelineables,
+		Path:           "api/v1/timelines/home",
+		NextMaxIDValue: timelineables[len(timelineables)-1].GetID(),
+		PrevMinIDValue: timelineables[0].GetID(),
+		Limit:          limit,
+	})
 }
 
-func (p *processor) PublicTimelineGet(ctx context.Context, authed *oauth.Auth, maxID string, sinceID string, minID string, limit int, local bool) (*apimodel.StatusTimelineResponse, gtserror.WithCode) {
+func (p *processor) PublicTimelineGet(ctx context.Context, authed *oauth.Auth, maxID string, sinceID string, minID string, limit int, local bool) (*apimodel.TimelineResponse, gtserror.WithCode) {
 	statuses, err := p.db.GetPublicTimeline(ctx, authed.Account.ID, maxID, sinceID, minID, limit, local)
 	if err != nil {
 		if err == db.ErrNoEntries {
 			// there are just no entries left
-			return &apimodel.StatusTimelineResponse{
+			return util.EmptyTimelineResponse(), nil
-				Statuses: []*apimodel.Status{},
-			}, nil
 		}
 		// there's an actual error
 		return nil, gtserror.NewErrorInternalError(err)
 	}
 
-	s, err := p.filterPublicStatuses(ctx, authed, statuses)
+	filtered, err := p.filterPublicStatuses(ctx, authed, statuses)
 	if err != nil {
 		return nil, gtserror.NewErrorInternalError(err)
 	}
 
-	if len(s) == 0 {
+	if len(filtered) == 0 {
-		return &apimodel.StatusTimelineResponse{
+		return util.EmptyTimelineResponse(), nil
-			Statuses: []*apimodel.Status{},
-		}, nil
 	}
 
-	return p.packageStatusResponse(s, "api/v1/timelines/public", s[len(s)-1].ID, s[0].ID, limit)
+	timelineables := []timeline.Timelineable{}
+	for _, i := range filtered {
+		timelineables = append(timelineables, i)
 	}
 
-func (p *processor) FavedTimelineGet(ctx context.Context, authed *oauth.Auth, maxID string, minID string, limit int) (*apimodel.StatusTimelineResponse, gtserror.WithCode) {
+	return util.PackageTimelineableResponse(util.TimelineableResponseParams{
+		Items:          timelineables,
+		Path:           "api/v1/timelines/public",
+		NextMaxIDValue: timelineables[len(timelineables)-1].GetID(),
+		PrevMinIDValue: timelineables[0].GetID(),
+		Limit:          limit,
+	})
+}
+
+func (p *processor) FavedTimelineGet(ctx context.Context, authed *oauth.Auth, maxID string, minID string, limit int) (*apimodel.TimelineResponse, gtserror.WithCode) {
 	statuses, nextMaxID, prevMinID, err := p.db.GetFavedTimeline(ctx, authed.Account.ID, maxID, minID, limit)
 	if err != nil {
 		if err == db.ErrNoEntries {
 			// there are just no entries left
-			return &apimodel.StatusTimelineResponse{
+			return util.EmptyTimelineResponse(), nil
-				Statuses: []*apimodel.Status{},
-			}, nil
 		}
 		// there's an actual error
 		return nil, gtserror.NewErrorInternalError(err)
 	}
 
-	s, err := p.filterFavedStatuses(ctx, authed, statuses)
+	filtered, err := p.filterFavedStatuses(ctx, authed, statuses)
 	if err != nil {
 		return nil, gtserror.NewErrorInternalError(err)
 	}
 
-	if len(s) == 0 {
+	if len(filtered) == 0 {
-		return &apimodel.StatusTimelineResponse{
+		return util.EmptyTimelineResponse(), nil
-			Statuses: []*apimodel.Status{},
-		}, nil
 	}
 
-	return p.packageStatusResponse(s, "api/v1/favourites", nextMaxID, prevMinID, limit)
+	timelineables := []timeline.Timelineable{}
+	for _, i := range filtered {
+		timelineables = append(timelineables, i)
+	}
+
+	return util.PackageTimelineableResponse(util.TimelineableResponseParams{
+		Items:          timelineables,
+		Path:           "api/v1/favourites",
+		NextMaxIDValue: nextMaxID,
+		PrevMinIDValue: prevMinID,
+		Limit:          limit,
+	})
 }
 
 func (p *processor) filterPublicStatuses(ctx context.Context, authed *oauth.Auth, statuses []*gtsmodel.Status) ([]*apimodel.Status, error) {

internal/util/timeline.go

@@ -0,0 +1,104 @@
+/*
+   GoToSocial
+   Copyright (C) 2021-2022 GoToSocial Authors admin@gotosocial.org
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Affero General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Affero General Public License for more details.
+
+   You should have received a copy of the GNU Affero General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package util
+
+import (
+	"fmt"
+	"net/url"
+
+	apimodel "github.com/superseriousbusiness/gotosocial/internal/api/model"
+	"github.com/superseriousbusiness/gotosocial/internal/config"
+	"github.com/superseriousbusiness/gotosocial/internal/gtserror"
+	"github.com/superseriousbusiness/gotosocial/internal/timeline"
+)
+
+// TimelineableResponseParams models the parameters to pass to PackageTimelineableResponse.
+//
+// The given items will be provided in the timeline response.
+//
+// The other values are all used to create the Link header so that callers know
+// which endpoint to query next and previously in order to do paging.
+type TimelineableResponseParams struct {
+	Items            []timeline.Timelineable // Sorted slice of Timelineables (statuses, notifications, etc)
+	Path             string                  // path to use for next/prev queries in the link header
+	NextMaxIDKey     string                  // key to use for the next max id query param in the link header, defaults to 'max_id'
+	NextMaxIDValue   string                  // value to use for next max id
+	PrevMinIDKey     string                  // key to use for the prev min id query param in the link header, defaults to 'min_id'
+	PrevMinIDValue   string                  // value to use for prev min id
+	Limit            int                     // limit number of entries to return
+	ExtraQueryParams []string                // any extra query parameters to provide in the link header, should be in the format 'example=value'
+}
+
+// PackageTimelineableResponse is a convenience function for returning
+// a bunch of timelineable items (notifications, statuses, etc), as well
+// as a Link header to inform callers of where to find next/prev items.
+func PackageTimelineableResponse(params TimelineableResponseParams) (*apimodel.TimelineResponse, gtserror.WithCode) {
+	if params.NextMaxIDKey == "" {
+		params.NextMaxIDKey = "max_id"
+	}
+
+	if params.PrevMinIDKey == "" {
+		params.PrevMinIDKey = "min_id"
+	}
+
+	timelineResponse := &apimodel.TimelineResponse{
+		Items: params.Items,
+	}
+
+	// prepare the next and previous links
+	if len(params.Items) != 0 {
+		protocol := config.GetProtocol()
+		host := config.GetHost()
+
+		nextRaw := fmt.Sprintf("limit=%d&%s=%s", params.Limit, params.NextMaxIDKey, params.NextMaxIDValue)
+		for _, p := range params.ExtraQueryParams {
+			nextRaw = nextRaw + "&" + p
+		}
+		nextLink := &url.URL{
+			Scheme:   protocol,
+			Host:     host,
+			Path:     params.Path,
+			RawQuery: nextRaw,
+		}
+		next := fmt.Sprintf("<%s>; rel=\"next\"", nextLink.String())
+
+		prevRaw := fmt.Sprintf("limit=%d&%s=%s", params.Limit, params.PrevMinIDKey, params.PrevMinIDValue)
+		for _, p := range params.ExtraQueryParams {
+			prevRaw = prevRaw + "&" + p
+		}
+		prevLink := &url.URL{
+			Scheme:   protocol,
+			Host:     host,
+			Path:     params.Path,
+			RawQuery: prevRaw,
+		}
+		prev := fmt.Sprintf("<%s>; rel=\"prev\"", prevLink.String())
+		timelineResponse.LinkHeader = next + ", " + prev
+	}
+
+	return timelineResponse, nil
+}
+
+// EmptyTimelineResponse just returns an empty
+// TimelineResponse with no link header or items.
+func EmptyTimelineResponse() *apimodel.TimelineResponse {
+	return &apimodel.TimelineResponse{
+		Items: []timeline.Timelineable{},
+	}
+}

internal/web/profile.go

@@ -29,6 +29,7 @@
 	"github.com/sirupsen/logrus"
 	"github.com/superseriousbusiness/gotosocial/internal/ap"
 	"github.com/superseriousbusiness/gotosocial/internal/api"
+	apimodel "github.com/superseriousbusiness/gotosocial/internal/api/model"
 	"github.com/superseriousbusiness/gotosocial/internal/config"
 	"github.com/superseriousbusiness/gotosocial/internal/oauth"
 )
@@ -79,7 +80,7 @@ func (m *Module) profileTemplateHandler(c *gin.Context) {
 	// get latest 10 top-level public statuses;
 	// ie., exclude replies and boosts, public only,
 	// with or without media
-	statuses, errWithCode := m.processor.AccountStatusesGet(ctx, authed, account.ID, 10, true, true, "", "", false, false, true)
+	statusResp, errWithCode := m.processor.AccountStatusesGet(ctx, authed, account.ID, 10, true, true, "", "", false, false, true)
 	if errWithCode != nil {
 		l.Debugf("error getting statuses from processor: %s", errWithCode.Error())
 		c.JSON(errWithCode.Code(), gin.H{"error": errWithCode.Safe()})
@@ -92,7 +93,11 @@ func (m *Module) profileTemplateHandler(c *gin.Context) {
 		randomIndex := rand.Intn(len(m.defaultAvatars))
 		dummyAvatar := m.defaultAvatars[randomIndex]
 		account.Avatar = dummyAvatar
-		for _, s := range statuses {
+		for _, i := range statusResp.Items {
+			s, ok := i.(*apimodel.Status)
+			if !ok {
+				panic("timelineable was not *apimodel.Status")
+			}
 			s.Account.Avatar = dummyAvatar
 		}
 	}
@@ -100,7 +105,7 @@ func (m *Module) profileTemplateHandler(c *gin.Context) {
 	c.HTML(http.StatusOK, "profile.tmpl", gin.H{
 		"instance": instance,
 		"account":  account,
-		"statuses": statuses,
+		"statuses": statusResp.Items,
 		"stylesheets": []string{
 			"/assets/Fork-Awesome/css/fork-awesome.min.css",
 			"/assets/status.css",