[feature] Instance rules (#2125)

* init instance rules database model, admin api

* expose instance rules in public instance api

* public /api/v1/instance/rules route

* GET ruleById

* createRule route

* createRule auth check

* updateRule

* deleteRule

* list rules on about page

* ruleGet auth

* add about page ids for anchors

* process and store adding violated rules to reports

* admin api models for instance rules

* instance rule edit frontend

* change rule inputs to textareas

* database fixes after rebase (#2124)

* remove unused imports

* fix db migration column name

* fix tests

* fix more tests

* fix postgres error with wrongly used Ident

* add some tests, fiddle with rule model a bit, fix postgres migration

* swagger docs

---------

Co-authored-by: tsmethurst <tobi.smethurst@protonmail.com>

internal/db/bundb/rule.go

@@ -0,0 +1,149 @@
+// 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"
+	"errors"
+	"time"
+
+	"github.com/superseriousbusiness/gotosocial/internal/config"
+	"github.com/superseriousbusiness/gotosocial/internal/db"
+	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
+	"github.com/superseriousbusiness/gotosocial/internal/log"
+	"github.com/superseriousbusiness/gotosocial/internal/state"
+	"github.com/superseriousbusiness/gotosocial/internal/util"
+	"github.com/uptrace/bun"
+)
+
+type ruleDB struct {
+	db    *DB
+	state *state.State
+}
+
+func (r *ruleDB) GetRuleByID(ctx context.Context, id string) (*gtsmodel.Rule, error) {
+	var rule gtsmodel.Rule
+
+	q := r.db.
+		NewSelect().
+		Model(&rule).
+		Where("? = ?", bun.Ident("rule.id"), id)
+
+	if err := q.Scan(ctx); err != nil {
+		return nil, err
+	}
+
+	return &rule, nil
+}
+
+func (r *ruleDB) GetRulesByIDs(ctx context.Context, ids []string) ([]*gtsmodel.Rule, error) {
+	rules := make([]*gtsmodel.Rule, 0, len(ids))
+
+	for _, id := range ids {
+		// Attempt to fetch status from DB.
+		rule, err := r.GetRuleByID(ctx, id)
+		if err != nil {
+			log.Errorf(ctx, "error getting rule %q: %v", id, err)
+			continue
+		}
+
+		// Append status to return slice.
+		rules = append(rules, rule)
+	}
+
+	return rules, nil
+}
+
+func (r *ruleDB) GetActiveRules(ctx context.Context) ([]gtsmodel.Rule, error) {
+	rules := make([]gtsmodel.Rule, 0)
+
+	q := r.db.
+		NewSelect().
+		Model(&rules).
+		// Ignore deleted (ie., inactive) rules.
+		Where("? = ?", bun.Ident("rule.deleted"), false).
+		Order("rule.order ASC")
+
+	if err := q.Scan(ctx); err != nil {
+		return nil, err
+	}
+
+	return rules, nil
+}
+
+func (r *ruleDB) PutRule(ctx context.Context, rule *gtsmodel.Rule) error {
+	var lastRuleOrder uint
+
+	// Select highest existing rule order.
+	err := r.db.
+		NewSelect().
+		TableExpr("? AS ?", bun.Ident("rules"), bun.Ident("rule")).
+		Column("rule.order").
+		Order("rule.order DESC").
+		Limit(1).
+		Scan(ctx, &lastRuleOrder)
+
+	switch {
+	case errors.Is(err, db.ErrNoEntries):
+		// No rules set yet, index from 0.
+		rule.Order = util.Ptr(uint(0))
+
+	case err != nil:
+		// Real db error.
+		return err
+
+	default:
+		// No error means previous rule(s)
+		// existed. New rule order should
+		// be 1 higher than previous rule.
+		rule.Order = func() *uint {
+			o := lastRuleOrder + 1
+			return &o
+		}()
+	}
+
+	if _, err := r.db.
+		NewInsert().
+		Model(rule).
+		Exec(ctx); err != nil {
+		return err
+	}
+
+	// invalidate cached local instance response, so it gets updated with the new rules
+	r.state.Caches.GTS.Instance().Invalidate("Domain", config.GetHost())
+
+	return nil
+}
+
+func (r *ruleDB) UpdateRule(ctx context.Context, rule *gtsmodel.Rule) (*gtsmodel.Rule, error) {
+	// Update the rule's last-updated
+	rule.UpdatedAt = time.Now()
+
+	if _, err := r.db.
+		NewUpdate().
+		Model(rule).
+		WherePK().
+		Exec(ctx); err != nil {
+		return nil, err
+	}
+
+	// invalidate cached local instance response, so it gets updated with the new rules
+	r.state.Caches.GTS.Instance().Invalidate("Domain", config.GetHost())
+
+	return rule, nil
+}