[feature] Support setting private notes on accounts (#1982)

* Support setting private notes on accounts

* Reformat comment whitespace

* Add missing license headers

* Use apiutil.ParseID

* Rename Note model and cache to AccountNote

* Update golden cache config in test/envparsing.sh

* Rename gtsmodel/note.go to gtsmodel/accountnote.go

* Update AccountNote uniqueness constraint name

Now has same prefix as other indexes on this table.

---------

Co-authored-by: tobi <31960611+tsmethurst@users.noreply.github.com>

6 files changed, 229 insertions, 0 deletions

diff --git a/internal/db/bundb/bundb_test.go b/internal/db/bundb/bundb_test.go
index 84e11447a..d54578795 100644
--- a/internal/db/bundb/bundb_test.go
+++ b/internal/db/bundb/bundb_test.go
@@ -49,6 +49,7 @@ type BunDBStandardTestSuite struct {
 	testFaves        map[string]*gtsmodel.StatusFave
 	testLists        map[string]*gtsmodel.List
 	testListEntries  map[string]*gtsmodel.ListEntry
+	testAccountNotes map[string]*gtsmodel.AccountNote
 }
 
 func (suite *BunDBStandardTestSuite) SetupSuite() {
@@ -68,6 +69,7 @@ func (suite *BunDBStandardTestSuite) SetupSuite() {
 	suite.testFaves = testrig.NewTestFaves()
 	suite.testLists = testrig.NewTestLists()
 	suite.testListEntries = testrig.NewTestListEntries()
+	suite.testAccountNotes = testrig.NewTestAccountNotes()
 }
 
 func (suite *BunDBStandardTestSuite) SetupTest() {
diff --git a/internal/db/bundb/migrations/20230711214815_account_notes.go b/internal/db/bundb/migrations/20230711214815_account_notes.go
new file mode 100644
index 000000000..49d60745b
--- /dev/null
+++ b/internal/db/bundb/migrations/20230711214815_account_notes.go
@@ -0,0 +1,62 @@
+// GoToSocial
+// Copyright (C) GoToSocial Authors admin@gotosocial.org
+// SPDX-License-Identifier: AGPL-3.0-or-later
+//
+// 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 migrations
+
+import (
+	"context"
+
+	gtsmodel "github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
+	"github.com/uptrace/bun"
+)
+
+func init() {
+	up := func(ctx context.Context, db *bun.DB) error {
+		return db.RunInTx(ctx, nil, func(ctx context.Context, tx bun.Tx) error {
+			// Account note table.
+			if _, err := tx.
+				NewCreateTable().
+				Model(&gtsmodel.AccountNote{}).
+				IfNotExists().
+				Exec(ctx); err != nil {
+				return err
+			}
+
+			// Add IDs index to the account note table.
+			if _, err := tx.
+				NewCreateIndex().
+				Model(&gtsmodel.AccountNote{}).
+				Index("account_notes_account_id_target_account_id_idx").
+				Column("account_id", "target_account_id").
+				Exec(ctx); err != nil {
+				return err
+			}
+
+			return nil
+		})
+	}
+
+	down := func(ctx context.Context, db *bun.DB) error {
+		return db.RunInTx(ctx, nil, func(ctx context.Context, tx bun.Tx) error {
+			return nil
+		})
+	}
+
+	if err := Migrations.Register(up, down); err != nil {
+		panic(err)
+	}
+}
diff --git a/internal/db/bundb/relationship.go b/internal/db/bundb/relationship.go
index c865f8aad..eddd73b49 100644
--- a/internal/db/bundb/relationship.go
+++ b/internal/db/bundb/relationship.go
@@ -85,6 +85,19 @@ func (r *relationshipDB) GetRelationship(ctx context.Context, requestingAccount
 		return nil, fmt.Errorf("GetRelationship: error checking blockedBy: %w", err)
 	}
 
+	// retrieve a note by the requesting account on the target account, if there is one
+	note, err := r.GetNote(
+		gtscontext.SetBarebones(ctx),
+		requestingAccount,
+		targetAccount,
+	)
+	if err != nil && !errors.Is(err, db.ErrNoEntries) {
+		return nil, fmt.Errorf("GetRelationship: error fetching note: %w", err)
+	}
+	if note != nil {
+		rel.Note = note.Comment
+	}
+
 	return &rel, nil
 }
 
diff --git a/internal/db/bundb/relationship_note.go b/internal/db/bundb/relationship_note.go
new file mode 100644
index 000000000..97e740bcd
--- /dev/null
+++ b/internal/db/bundb/relationship_note.go
@@ -0,0 +1,99 @@
+// GoToSocial
+// Copyright (C) GoToSocial Authors admin@gotosocial.org
+// SPDX-License-Identifier: AGPL-3.0-or-later
+//
+// 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 bundb
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"github.com/superseriousbusiness/gotosocial/internal/gtscontext"
+	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
+	"github.com/uptrace/bun"
+)
+
+func (r *relationshipDB) GetNote(ctx context.Context, sourceAccountID string, targetAccountID string) (*gtsmodel.AccountNote, error) {
+	return r.getNote(
+		ctx,
+		"AccountID.TargetAccountID",
+		func(note *gtsmodel.AccountNote) error {
+			return r.conn.NewSelect().Model(note).
+				Where("? = ?", bun.Ident("account_id"), sourceAccountID).
+				Where("? = ?", bun.Ident("target_account_id"), targetAccountID).
+				Scan(ctx)
+		},
+		sourceAccountID,
+		targetAccountID,
+	)
+}
+
+func (r *relationshipDB) getNote(ctx context.Context, lookup string, dbQuery func(*gtsmodel.AccountNote) error, keyParts ...any) (*gtsmodel.AccountNote, error) {
+	// Fetch note from cache with loader callback
+	note, err := r.state.Caches.GTS.AccountNote().Load(lookup, func() (*gtsmodel.AccountNote, error) {
+		var note gtsmodel.AccountNote
+
+		// Not cached! Perform database query
+		if err := dbQuery(&note); err != nil {
+			return nil, r.conn.ProcessError(err)
+		}
+
+		return &note, nil
+	}, keyParts...)
+	if err != nil {
+		// already processed
+		return nil, err
+	}
+
+	if gtscontext.Barebones(ctx) {
+		// Only a barebones model was requested.
+		return note, nil
+	}
+
+	// Set the note source account
+	note.Account, err = r.state.DB.GetAccountByID(
+		gtscontext.SetBarebones(ctx),
+		note.AccountID,
+	)
+	if err != nil {
+		return nil, fmt.Errorf("error getting note source account: %w", err)
+	}
+
+	// Set the note target account
+	note.TargetAccount, err = r.state.DB.GetAccountByID(
+		gtscontext.SetBarebones(ctx),
+		note.TargetAccountID,
+	)
+	if err != nil {
+		return nil, fmt.Errorf("error getting note target account: %w", err)
+	}
+
+	return note, nil
+}
+
+func (r *relationshipDB) PutNote(ctx context.Context, note *gtsmodel.AccountNote) error {
+	note.UpdatedAt = time.Now()
+	return r.state.Caches.GTS.AccountNote().Store(note, func() error {
+		_, err := r.conn.
+			NewInsert().
+			Model(note).
+			On("CONFLICT (?, ?) DO UPDATE", bun.Ident("account_id"), bun.Ident("target_account_id")).
+			Set("? = ?, ? = ?", bun.Ident("updated_at"), note.UpdatedAt, bun.Ident("comment"), note.Comment).
+			Exec(ctx)
+		return r.conn.ProcessError(err)
+	})
+}
diff --git a/internal/db/bundb/relationship_test.go b/internal/db/bundb/relationship_test.go
index d3f4a31d1..cf2df5144 100644
--- a/internal/db/bundb/relationship_test.go
+++ b/internal/db/bundb/relationship_test.go
@@ -912,6 +912,53 @@ func (suite *RelationshipTestSuite) TestUpdateFollow() {
 	suite.True(relationship.Notifying)
 }
 
+func (suite *RelationshipTestSuite) TestGetNote() {
+	ctx := context.Background()
+
+	// Retrieve a fixture note
+	account1 := suite.testAccounts["local_account_1"].ID
+	account2 := suite.testAccounts["local_account_2"].ID
+	expectedNote := suite.testAccountNotes["local_account_2_note_on_1"]
+	note, err := suite.db.GetNote(ctx, account2, account1)
+	suite.NoError(err)
+	suite.NotNil(note)
+	suite.Equal(expectedNote.ID, note.ID)
+	suite.Equal(expectedNote.Comment, note.Comment)
+}
+
+func (suite *RelationshipTestSuite) TestPutNote() {
+	ctx := context.Background()
+
+	// put a note in
+	account1 := suite.testAccounts["local_account_1"].ID
+	account2 := suite.testAccounts["local_account_2"].ID
+	err := suite.db.PutNote(ctx, &gtsmodel.AccountNote{
+		ID:              "01H539R2NA0M83JX15Y5RWKE97",
+		AccountID:       account1,
+		TargetAccountID: account2,
+		Comment:         "foo",
+	})
+	suite.NoError(err)
+
+	// make sure the note is in the db
+	note, err := suite.db.GetNote(ctx, account1, account2)
+	suite.NoError(err)
+	suite.NotNil(note)
+	suite.Equal("01H539R2NA0M83JX15Y5RWKE97", note.ID)
+	suite.Equal("foo", note.Comment)
+
+	// update the note
+	note.Comment = "bar"
+	err = suite.db.PutNote(ctx, note)
+	suite.NoError(err)
+
+	// make sure the comment changes
+	note, err = suite.db.GetNote(ctx, account1, account2)
+	suite.NoError(err)
+	suite.NotNil(note)
+	suite.Equal("bar", note.Comment)
+}
+
 func TestRelationshipTestSuite(t *testing.T) {
 	suite.Run(t, new(RelationshipTestSuite))
 }
diff --git a/internal/db/relationship.go b/internal/db/relationship.go
index f8866a545..e19aee646 100644
--- a/internal/db/relationship.go
+++ b/internal/db/relationship.go
@@ -165,4 +165,10 @@ type Relationship interface {
 
 	// CountAccountFollowerRequests returns number of follow requests originating from the given account.
 	CountAccountFollowRequesting(ctx context.Context, accountID string) (int, error)
+
+	// GetNote gets a private note from a source account on a target account, if it exists.
+	GetNote(ctx context.Context, sourceAccountID string, targetAccountID string) (*gtsmodel.AccountNote, error)
+
+	// PutNote creates or updates a private note.
+	PutNote(ctx context.Context, note *gtsmodel.AccountNote) error
 }