Timeline manager (#40)

* start messing about with timeline manager

* i have no idea what i'm doing

* i continue to not know what i'm doing

* it's coming along

* bit more progress

* update timeline with new posts as they come in

* lint and fmt

* Select accounts where empty string

* restructure a bunch, get unfaves working

* moving stuff around

* federate status deletes properly

* mention regex better but not 100% there

* fix regex

* some more hacking away at the timeline code phew

* fix up some little things

* i can't even

* more timeline stuff

* move to ulid

* fiddley

* some lil fixes for kibou compatibility

* timelines working pretty alright!

* tidy + lint

internal/timeline/index.go

@@ -0,0 +1,143 @@
+package timeline
+
+import (
+	"errors"
+	"fmt"
+	"time"
+
+	"github.com/superseriousbusiness/gotosocial/internal/db"
+	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
+)
+
+func (t *timeline) IndexBefore(statusID string, include bool, amount int) error {
+	// 	filtered := []*gtsmodel.Status{}
+	// 	offsetStatus := statusID
+
+	// grabloop:
+	// 	for len(filtered) < amount {
+	// 		statuses, err := t.db.GetStatusesWhereFollowing(t.accountID, amount, offsetStatus, include, true)
+	// 		if err != nil {
+	// 			if _, ok := err.(db.ErrNoEntries); !ok {
+	// 				return fmt.Errorf("IndexBeforeAndIncluding: error getting statuses from db: %s", err)
+	// 			}
+	// 			break grabloop // we just don't have enough statuses left in the db so index what we've got and then bail
+	// 		}
+
+	// 		for _, s := range statuses {
+	// 			relevantAccounts, err := t.db.PullRelevantAccountsFromStatus(s)
+	// 			if err != nil {
+	// 				continue
+	// 			}
+	// 			visible, err := t.db.StatusVisible(s, t.account, relevantAccounts)
+	// 			if err != nil {
+	// 				continue
+	// 			}
+	// 			if visible {
+	// 				filtered = append(filtered, s)
+	// 			}
+	// 			offsetStatus = s.ID
+	// 		}
+	// 	}
+
+	// 	for _, s := range filtered {
+	// 		if err := t.IndexOne(s.CreatedAt, s.ID); err != nil {
+	// 			return fmt.Errorf("IndexBeforeAndIncluding: error indexing status with id %s: %s", s.ID, err)
+	// 		}
+	// 	}
+
+	return nil
+}
+
+func (t *timeline) IndexBehind(statusID string, amount int) error {
+	filtered := []*gtsmodel.Status{}
+	offsetStatus := statusID
+
+grabloop:
+	for len(filtered) < amount {
+		statuses, err := t.db.GetStatusesWhereFollowing(t.accountID, offsetStatus, "", "", amount, false)
+		if err != nil {
+			if _, ok := err.(db.ErrNoEntries); ok {
+				break grabloop // we just don't have enough statuses left in the db so index what we've got and then bail
+			}
+			return fmt.Errorf("IndexBehindAndIncluding: error getting statuses from db: %s", err)
+		}
+
+		for _, s := range statuses {
+			relevantAccounts, err := t.db.PullRelevantAccountsFromStatus(s)
+			if err != nil {
+				continue
+			}
+			visible, err := t.db.StatusVisible(s, t.account, relevantAccounts)
+			if err != nil {
+				continue
+			}
+			if visible {
+				filtered = append(filtered, s)
+			}
+			offsetStatus = s.ID
+		}
+	}
+
+	for _, s := range filtered {
+		if err := t.IndexOne(s.CreatedAt, s.ID); err != nil {
+			return fmt.Errorf("IndexBehindAndIncluding: error indexing status with id %s: %s", s.ID, err)
+		}
+	}
+
+	return nil
+}
+
+func (t *timeline) IndexOneByID(statusID string) error {
+	return nil
+}
+
+func (t *timeline) IndexOne(statusCreatedAt time.Time, statusID string) error {
+	t.Lock()
+	defer t.Unlock()
+
+	postIndexEntry := &postIndexEntry{
+		statusID: statusID,
+	}
+
+	return t.postIndex.insertIndexed(postIndexEntry)
+}
+
+func (t *timeline) IndexAndPrepareOne(statusCreatedAt time.Time, statusID string) error {
+	t.Lock()
+	defer t.Unlock()
+
+	postIndexEntry := &postIndexEntry{
+		statusID: statusID,
+	}
+
+	if err := t.postIndex.insertIndexed(postIndexEntry); err != nil {
+		return fmt.Errorf("IndexAndPrepareOne: error inserting indexed: %s", err)
+	}
+
+	if err := t.prepare(statusID); err != nil {
+		return fmt.Errorf("IndexAndPrepareOne: error preparing: %s", err)
+	}
+
+	return nil
+}
+
+func (t *timeline) OldestIndexedPostID() (string, error) {
+	var id string
+	if t.postIndex == nil || t.postIndex.data == nil {
+		// return an empty string if postindex hasn't been initialized yet
+		return id, nil
+	}
+
+	e := t.postIndex.data.Back()
+
+	if e == nil {
+		// return an empty string if there's no back entry (ie., the index list hasn't been initialized yet)
+		return id, nil
+	}
+
+	entry, ok := e.Value.(*postIndexEntry)
+	if !ok {
+		return id, errors.New("OldestIndexedPostID: could not parse e as a postIndexEntry")
+	}
+	return entry.statusID, nil
+}