[chore] Make paging logic more generic (#901)

* make paging logic more generic
not just for timelines!

* linty linterson

2 files changed, 119 insertions, 117 deletions

diff --git a/internal/util/paging.go b/internal/util/paging.go
new file mode 100644
index 000000000..5984ee9f1
--- /dev/null
+++ b/internal/util/paging.go
@@ -0,0 +1,119 @@
+/*
+   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"
+)
+
+// PageableResponseParams models the parameters to pass to PackagePageableResponse.
+//
+// The given items will be provided in the paged 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 PageableResponseParams struct {
+	Items            []interface{} // Sorted slice of items (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'
+}
+
+// PackagePageableResponse is a convenience function for returning
+// a bunch of pageable items (notifications, statuses, etc), as well
+// as a Link header to inform callers of where to find next/prev items.
+func PackagePageableResponse(params PageableResponseParams) (*apimodel.PageableResponse, gtserror.WithCode) {
+	if params.NextMaxIDKey == "" {
+		params.NextMaxIDKey = "max_id"
+	}
+
+	if params.PrevMinIDKey == "" {
+		params.PrevMinIDKey = "min_id"
+	}
+
+	pageableResponse := EmptyPageableResponse()
+
+	if len(params.Items) == 0 {
+		return pageableResponse, nil
+	}
+
+	// items
+	pageableResponse.Items = params.Items
+
+	protocol := config.GetProtocol()
+	host := config.GetHost()
+
+	// next
+	nextRaw := params.NextMaxIDKey + "=" + params.NextMaxIDValue
+	if params.Limit != 0 {
+		nextRaw = fmt.Sprintf("limit=%d&", params.Limit) + nextRaw
+	}
+	for _, p := range params.ExtraQueryParams {
+		nextRaw = nextRaw + "&" + p
+	}
+	nextLink := &url.URL{
+		Scheme:   protocol,
+		Host:     host,
+		Path:     params.Path,
+		RawQuery: nextRaw,
+	}
+	nextLinkString := nextLink.String()
+	pageableResponse.NextLink = nextLinkString
+
+	// prev
+	prevRaw := params.PrevMinIDKey + "=" + params.PrevMinIDValue
+	if params.Limit != 0 {
+		prevRaw = fmt.Sprintf("limit=%d&", params.Limit) + prevRaw
+	}
+	for _, p := range params.ExtraQueryParams {
+		prevRaw = prevRaw + "&" + p
+	}
+	prevLink := &url.URL{
+		Scheme:   protocol,
+		Host:     host,
+		Path:     params.Path,
+		RawQuery: prevRaw,
+	}
+	prevLinkString := prevLink.String()
+	pageableResponse.PrevLink = prevLinkString
+
+	// link header
+	next := fmt.Sprintf("<%s>; rel=\"next\"", nextLinkString)
+	prev := fmt.Sprintf("<%s>; rel=\"prev\"", prevLinkString)
+	pageableResponse.LinkHeader = next + ", " + prev
+
+	return pageableResponse, nil
+}
+
+// EmptyPageableResponse just returns an empty
+// PageableResponse with no link header or items.
+func EmptyPageableResponse() *apimodel.PageableResponse {
+	return &apimodel.PageableResponse{
+		Items: []interface{}{},
+	}
+}
diff --git a/internal/util/timeline.go b/internal/util/timeline.go
deleted file mode 100644
index bdb0f3f03..000000000
--- a/internal/util/timeline.go
+++ /dev/null
@@ -1,117 +0,0 @@
-/*
-   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,
-	}
-
-	if len(params.Items) != 0 {
-		protocol := config.GetProtocol()
-		host := config.GetHost()
-
-		// next
-		nextRaw := params.NextMaxIDKey + "=" + params.NextMaxIDValue
-		if params.Limit != 0 {
-			nextRaw = fmt.Sprintf("limit=%d&", params.Limit) + nextRaw
-		}
-		for _, p := range params.ExtraQueryParams {
-			nextRaw = nextRaw + "&" + p
-		}
-		nextLink := &url.URL{
-			Scheme:   protocol,
-			Host:     host,
-			Path:     params.Path,
-			RawQuery: nextRaw,
-		}
-		nextLinkString := nextLink.String()
-		timelineResponse.NextLink = nextLinkString
-
-		// prev
-		prevRaw := params.PrevMinIDKey + "=" + params.PrevMinIDValue
-		if params.Limit != 0 {
-			prevRaw = fmt.Sprintf("limit=%d&", params.Limit) + prevRaw
-		}
-		for _, p := range params.ExtraQueryParams {
-			prevRaw = prevRaw + "&" + p
-		}
-		prevLink := &url.URL{
-			Scheme:   protocol,
-			Host:     host,
-			Path:     params.Path,
-			RawQuery: prevRaw,
-		}
-		prevLinkString := prevLink.String()
-		timelineResponse.PrevLink = prevLinkString
-
-		// link header
-		next := fmt.Sprintf("<%s>; rel=\"next\"", nextLinkString)
-		prev := fmt.Sprintf("<%s>; rel=\"prev\"", prevLinkString)
-		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{},
-	}
-}