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, 92 insertions, 0 deletions

diff --git a/internal/processing/synchronous/status/unfave.go b/internal/processing/synchronous/status/unfave.go
new file mode 100644
index 000000000..54cbbf509
--- /dev/null
+++ b/internal/processing/synchronous/status/unfave.go
@@ -0,0 +1,92 @@
+package status
+
+import (
+	"errors"
+	"fmt"
+
+	apimodel "github.com/superseriousbusiness/gotosocial/internal/api/model"
+	"github.com/superseriousbusiness/gotosocial/internal/db"
+	"github.com/superseriousbusiness/gotosocial/internal/gtserror"
+	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
+)
+
+func (p *processor) Unfave(account *gtsmodel.Account, targetStatusID string) (*apimodel.Status, gtserror.WithCode) {
+	l := p.log.WithField("func", "StatusUnfave")
+	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("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("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("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) // requestingAccount might well be nil here, but StatusVisible knows how to take care of that
+	if err != nil {
+		return nil, gtserror.NewErrorNotFound(fmt.Errorf("error seeing if status %s is visible: %s", targetStatus.ID, err))
+	}
+
+	if !visible {
+		return nil, gtserror.NewErrorNotFound(errors.New("status is not visible"))
+	}
+
+	// check if we actually have a fave for this status
+	var toUnfave bool
+
+	gtsFave := &gtsmodel.StatusFave{}
+	err = p.db.GetWhere([]db.Where{{Key: "status_id", Value: targetStatus.ID}, {Key: "account_id", Value: account.ID}}, gtsFave)
+	if err == nil {
+		// we have a fave
+		toUnfave = true
+	}
+	if err != nil {
+		// something went wrong in the db finding the fave
+		if _, ok := err.(db.ErrNoEntries); !ok {
+			return nil, gtserror.NewErrorInternalError(fmt.Errorf("error fetching existing fave from database: %s", err))
+		}
+		// we just don't have a fave
+		toUnfave = false
+	}
+
+	if toUnfave {
+		// we had a fave, so take some action to get rid of it
+		if err := p.db.DeleteWhere([]db.Where{{Key: "status_id", Value: targetStatus.ID}, {Key: "account_id", Value: account.ID}}, gtsFave); err != nil {
+			return nil, gtserror.NewErrorInternalError(fmt.Errorf("error unfaveing status: %s", err))
+		}
+
+		// send it back to the processor for async processing
+		p.fromClientAPI <- gtsmodel.FromClientAPI{
+			APObjectType:   gtsmodel.ActivityStreamsLike,
+			APActivityType: gtsmodel.ActivityStreamsUndo,
+			GTSModel:       gtsFave,
+			OriginAccount:  account,
+			TargetAccount:  targetAccount,
+		}
+	}
+
+	// return the status (whatever its state) back to the caller
+	var boostOfStatus *gtsmodel.Status
+	if targetStatus.BoostOfID != "" {
+		boostOfStatus = &gtsmodel.Status{}
+		if err := p.db.GetByID(targetStatus.BoostOfID, boostOfStatus); err != nil {
+			return nil, gtserror.NewErrorInternalError(fmt.Errorf("error fetching boosted status %s: %s", targetStatus.BoostOfID, err))
+		}
+	}
+
+	mastoStatus, err := p.tc.StatusToMasto(targetStatus, targetAccount, account, relevantAccounts.BoostedAccount, relevantAccounts.ReplyToAccount, boostOfStatus)
+	if err != nil {
+		return nil, gtserror.NewErrorInternalError(fmt.Errorf("error converting status %s to frontend representation: %s", targetStatus.ID, err))
+	}
+
+	return mastoStatus, nil
+}