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

1 files changed, 74 insertions, 0 deletions

diff --git a/internal/processing/synchronous/status/boostedby.go b/internal/processing/synchronous/status/boostedby.go
new file mode 100644
index 000000000..8ebfcebc0
--- /dev/null
+++ b/internal/processing/synchronous/status/boostedby.go
@@ -0,0 +1,74 @@
+package status
+
+import (
+	"errors"
+	"fmt"
+
+	apimodel "github.com/superseriousbusiness/gotosocial/internal/api/model"
+	"github.com/superseriousbusiness/gotosocial/internal/gtserror"
+	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
+)
+
+func (p *processor) BoostedBy(account *gtsmodel.Account, targetStatusID string) ([]*apimodel.Account, gtserror.WithCode) {
+	l := p.log.WithField("func", "StatusBoostedBy")
+
+	l.Tracef("going to search for target status %s", targetStatusID)
+	targetStatus := &gtsmodel.Status{}
+	if err := p.db.GetByID(targetStatusID, targetStatus); err != nil {
+		return nil, gtserror.NewErrorNotFound(fmt.Errorf("StatusBoostedBy: error fetching status %s: %s", targetStatusID, err))
+	}
+
+	l.Tracef("going to search for target account %s", targetStatus.AccountID)
+	targetAccount := &gtsmodel.Account{}
+	if err := p.db.GetByID(targetStatus.AccountID, targetAccount); err != nil {
+		return nil, gtserror.NewErrorNotFound(fmt.Errorf("StatusBoostedBy: error fetching target account %s: %s", targetStatus.AccountID, err))
+	}
+
+	l.Trace("going to get relevant accounts")
+	relevantAccounts, err := p.db.PullRelevantAccountsFromStatus(targetStatus)
+	if err != nil {
+		return nil, gtserror.NewErrorNotFound(fmt.Errorf("StatusBoostedBy: error fetching related accounts for status %s: %s", targetStatusID, err))
+	}
+
+	l.Trace("going to see if status is visible")
+	visible, err := p.db.StatusVisible(targetStatus, account, relevantAccounts)
+	if err != nil {
+		return nil, gtserror.NewErrorNotFound(fmt.Errorf("StatusBoostedBy: error seeing if status %s is visible: %s", targetStatus.ID, err))
+	}
+
+	if !visible {
+		return nil, gtserror.NewErrorNotFound(errors.New("StatusBoostedBy: status is not visible"))
+	}
+
+	// get ALL accounts that faved a status -- doesn't take account of blocks and mutes and stuff
+	favingAccounts, err := p.db.WhoBoostedStatus(targetStatus)
+	if err != nil {
+		return nil, gtserror.NewErrorNotFound(fmt.Errorf("StatusBoostedBy: error seeing who boosted status: %s", err))
+	}
+
+	// filter the list so the user doesn't see accounts they blocked or which blocked them
+	filteredAccounts := []*gtsmodel.Account{}
+	for _, acc := range favingAccounts {
+		blocked, err := p.db.Blocked(account.ID, acc.ID)
+		if err != nil {
+			return nil, gtserror.NewErrorNotFound(fmt.Errorf("StatusBoostedBy: error checking blocks: %s", err))
+		}
+		if !blocked {
+			filteredAccounts = append(filteredAccounts, acc)
+		}
+	}
+
+	// TODO: filter other things here? suspended? muted? silenced?
+
+	// now we can return the masto representation of those accounts
+	mastoAccounts := []*apimodel.Account{}
+	for _, acc := range filteredAccounts {
+		mastoAccount, err := p.tc.AccountToMastoPublic(acc)
+		if err != nil {
+			return nil, gtserror.NewErrorNotFound(fmt.Errorf("StatusFavedBy: error converting account to api model: %s", err))
+		}
+		mastoAccounts = append(mastoAccounts, mastoAccount)
+	}
+
+	return mastoAccounts, nil
+}