1 files changed, 229 insertions, 0 deletions
diff --git a/internal/visibility/relevantaccounts.go b/internal/visibility/relevantaccounts.go
new file mode 100644
index 000000000..5957d3111
--- /dev/null
+++ b/internal/visibility/relevantaccounts.go
@@ -0,0 +1,229 @@
+/*
+   GoToSocial
+   Copyright (C) 2021 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 visibility
+
+import (
+	"errors"
+	"fmt"
+
+	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
+)
+
+// relevantAccounts denotes accounts that are replied to, boosted by, or mentioned in a status.
+type relevantAccounts struct {
+	// Who wrote the status
+	Account *gtsmodel.Account
+	// Who is the status replying to
+	InReplyToAccount *gtsmodel.Account
+	// Which accounts are mentioned (tagged) in the status
+	MentionedAccounts []*gtsmodel.Account
+	// Who authed the boosted status
+	BoostedAccount *gtsmodel.Account
+	// If the boosted status replies to another account, who does it reply to?
+	BoostedInReplyToAccount *gtsmodel.Account
+	// Who is mentioned (tagged) in the boosted status
+	BoostedMentionedAccounts []*gtsmodel.Account
+}
+
+func (f *filter) relevantAccounts(status *gtsmodel.Status, getBoosted bool) (*relevantAccounts, error) {
+	relAccts := &relevantAccounts{
+		MentionedAccounts:        []*gtsmodel.Account{},
+		BoostedMentionedAccounts: []*gtsmodel.Account{},
+	}
+
+	/*
+		Here's what we need to try and extract from the status:
+
+			// 1. Who wrote the status
+		    Account *gtsmodel.Account
+
+		    // 2. Who is the status replying to
+		    InReplyToAccount *gtsmodel.Account
+
+		    // 3. Which accounts are mentioned (tagged) in the status
+		    MentionedAccounts []*gtsmodel.Account
+
+			if getBoosted:
+				// 4. Who wrote the boosted status
+				BoostedAccount *gtsmodel.Account
+
+				// 5. If the boosted status replies to another account, who does it reply to?
+				BoostedInReplyToAccount *gtsmodel.Account
+
+				// 6. Who is mentioned (tagged) in the boosted status
+				BoostedMentionedAccounts []*gtsmodel.Account
+	*/
+
+	// 1. Account.
+	// Account might be set on the status already
+	if status.Account != nil {
+		// it was set
+		relAccts.Account = status.Account
+	} else {
+		// it wasn't set, so get it from the db
+		account, err := f.db.GetAccountByID(status.AccountID)
+		if err != nil {
+			return nil, fmt.Errorf("relevantAccounts: error getting account with id %s: %s", status.AccountID, err)
+		}
+		// set it on the status in case we need it further along
+		status.Account = account
+		// set it on relevant accounts
+		relAccts.Account = account
+	}
+
+	// 2. InReplyToAccount
+	// only get this if InReplyToAccountID is set
+	if status.InReplyToAccountID != "" {
+		// InReplyToAccount might be set on the status already
+		if status.InReplyToAccount != nil {
+			// it was set
+			relAccts.InReplyToAccount = status.InReplyToAccount
+		} else {
+			// it wasn't set, so get it from the db
+			inReplyToAccount, err := f.db.GetAccountByID(status.InReplyToAccountID)
+			if err != nil {
+				return nil, fmt.Errorf("relevantAccounts: error getting inReplyToAccount with id %s: %s", status.InReplyToAccountID, err)
+			}
+			// set it on the status in case we need it further along
+			status.InReplyToAccount = inReplyToAccount
+			// set it on relevant accounts
+			relAccts.InReplyToAccount = inReplyToAccount
+		}
+	}
+
+	// 3. MentionedAccounts
+	// First check if status.Mentions is populated with all mentions that correspond to status.MentionIDs
+	for _, mID := range status.MentionIDs {
+		if mID == "" {
+			continue
+		}
+		if !idIn(mID, status.Mentions) {
+			// mention with ID isn't in status.Mentions
+			mention, err := f.db.GetMention(mID)
+			if err != nil {
+				return nil, fmt.Errorf("relevantAccounts: error getting mention with id %s: %s", mID, err)
+			}
+			if mention == nil {
+				return nil, fmt.Errorf("relevantAccounts: mention with id %s was nil", mID)
+			}
+			status.Mentions = append(status.Mentions, mention)
+		}
+	}
+	// now filter mentions to make sure we only have mentions with a corresponding ID
+	nm := []*gtsmodel.Mention{}
+	for _, m := range status.Mentions {
+		if m == nil {
+			continue
+		}
+		if mentionIn(m, status.MentionIDs) {
+			nm = append(nm, m)
+		}
+	}
+	status.Mentions = nm
+
+	if len(status.Mentions) != len(status.MentionIDs) {
+		return nil, errors.New("relevantAccounts: mentions length did not correspond with mentionIDs length")
+	}
+
+	// if getBoosted is set, we should check the same properties on the boosted account as well
+	if getBoosted {
+		// 4, 5, 6. Boosted status items
+		// get the boosted status if it's not set on the status already
+		if status.BoostOfID != "" && status.BoostOf == nil {
+			boostedStatus, err := f.db.GetStatusByID(status.BoostOfID)
+			if err != nil {
+				return nil, fmt.Errorf("relevantAccounts: error getting boosted status with id %s: %s", status.BoostOfID, err)
+			}
+			status.BoostOf = boostedStatus
+		}
+
+		if status.BoostOf != nil {
+			// return relevant accounts for the boosted status
+			boostedRelAccts, err := f.relevantAccounts(status.BoostOf, false) // false because we don't want to recurse
+			if err != nil {
+				return nil, fmt.Errorf("relevantAccounts: error getting relevant accounts of boosted status %s: %s", status.BoostOf.ID, err)
+			}
+			relAccts.BoostedAccount = boostedRelAccts.Account
+			relAccts.BoostedInReplyToAccount = boostedRelAccts.InReplyToAccount
+			relAccts.BoostedMentionedAccounts = boostedRelAccts.MentionedAccounts
+		}
+	}
+
+	return relAccts, nil
+}
+
+// domainBlockedRelevant checks through all relevant accounts attached to a status
+// to make sure none of them are domain blocked by this instance.
+func (f *filter) domainBlockedRelevant(r *relevantAccounts) (bool, error) {
+	domains := []string{}
+
+	if r.Account != nil {
+		domains = append(domains, r.Account.Domain)
+	}
+
+	if r.InReplyToAccount != nil {
+		domains = append(domains, r.InReplyToAccount.Domain)
+	}
+
+	for _, a := range r.MentionedAccounts {
+		if a != nil {
+			domains = append(domains, a.Domain)
+		}
+	}
+
+	if r.BoostedAccount != nil {
+		domains = append(domains, r.BoostedAccount.Domain)
+	}
+
+	if r.BoostedInReplyToAccount != nil {
+		domains = append(domains, r.BoostedInReplyToAccount.Domain)
+	}
+
+	for _, a := range r.BoostedMentionedAccounts {
+		if a != nil {
+			domains = append(domains, a.Domain)
+		}
+	}
+
+	return f.db.AreDomainsBlocked(domains)
+}
+
+func idIn(id string, mentions []*gtsmodel.Mention) bool {
+	for _, m := range mentions {
+		if m == nil {
+			continue
+		}
+		if m.ID == id {
+			return true
+		}
+	}
+	return false
+}
+
+func mentionIn(mention *gtsmodel.Mention, ids []string) bool {
+	if mention == nil {
+		return false
+	}
+	for _, i := range ids {
+		if mention.ID == i {
+			return true
+		}
+	}
+	return false
+}