[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/processing/admin/rule.go

@@ -0,0 +1,127 @@
+// 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 admin
+
+import (
+	"context"
+	"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"
+	"github.com/superseriousbusiness/gotosocial/internal/id"
+	"github.com/superseriousbusiness/gotosocial/internal/util"
+)
+
+// RulesGet returns all rules stored on this instance.
+func (p *Processor) RulesGet(
+	ctx context.Context,
+) ([]*apimodel.AdminInstanceRule, gtserror.WithCode) {
+	rules, err := p.state.DB.GetActiveRules(ctx)
+
+	if err != nil {
+		return nil, gtserror.NewErrorInternalError(err)
+	}
+
+	apiRules := make([]*apimodel.AdminInstanceRule, len(rules))
+
+	for i := range rules {
+		apiRules[i] = p.tc.InstanceRuleToAdminAPIRule(&rules[i])
+	}
+
+	return apiRules, nil
+}
+
+// RuleGet returns one rule, with the given ID.
+func (p *Processor) RuleGet(ctx context.Context, id string) (*apimodel.AdminInstanceRule, gtserror.WithCode) {
+	rule, err := p.state.DB.GetRuleByID(ctx, id)
+	if err != nil {
+		if err == db.ErrNoEntries {
+			return nil, gtserror.NewErrorNotFound(err)
+		}
+		return nil, gtserror.NewErrorInternalError(err)
+	}
+
+	return p.tc.InstanceRuleToAdminAPIRule(rule), nil
+}
+
+// RuleCreate adds a new rule to the instance.
+func (p *Processor) RuleCreate(ctx context.Context, form *apimodel.InstanceRuleCreateRequest) (*apimodel.AdminInstanceRule, gtserror.WithCode) {
+	ruleID, err := id.NewRandomULID()
+	if err != nil {
+		return nil, gtserror.NewErrorInternalError(fmt.Errorf("error creating id for new instance rule: %s", err), "error creating rule ID")
+	}
+
+	rule := &gtsmodel.Rule{
+		ID:   ruleID,
+		Text: form.Text,
+	}
+
+	if err = p.state.DB.PutRule(ctx, rule); err != nil {
+		return nil, gtserror.NewErrorInternalError(err)
+	}
+
+	return p.tc.InstanceRuleToAdminAPIRule(rule), nil
+}
+
+// RuleUpdate updates text for an existing rule.
+func (p *Processor) RuleUpdate(ctx context.Context, id string, form *apimodel.InstanceRuleCreateRequest) (*apimodel.AdminInstanceRule, gtserror.WithCode) {
+	rule, err := p.state.DB.GetRuleByID(ctx, id)
+	if err != nil {
+		if errors.Is(err, db.ErrNoEntries) {
+			err = fmt.Errorf("RuleUpdate: no rule with id %s found in the db", id)
+			return nil, gtserror.NewErrorNotFound(err)
+		}
+		err := fmt.Errorf("RuleUpdate: db error: %s", err)
+		return nil, gtserror.NewErrorInternalError(err)
+	}
+
+	rule.Text = form.Text
+
+	updatedRule, err := p.state.DB.UpdateRule(ctx, rule)
+
+	if err != nil {
+		return nil, gtserror.NewErrorInternalError(err)
+	}
+
+	return p.tc.InstanceRuleToAdminAPIRule(updatedRule), nil
+}
+
+// RuleDelete deletes an existing rule.
+func (p *Processor) RuleDelete(ctx context.Context, id string) (*apimodel.AdminInstanceRule, gtserror.WithCode) {
+	rule, err := p.state.DB.GetRuleByID(ctx, id)
+	if err != nil {
+		if errors.Is(err, db.ErrNoEntries) {
+			err = fmt.Errorf("RuleUpdate: no rule with id %s found in the db", id)
+			return nil, gtserror.NewErrorNotFound(err)
+		}
+		err := fmt.Errorf("RuleUpdate: db error: %s", err)
+		return nil, gtserror.NewErrorInternalError(err)
+	}
+
+	rule.Deleted = util.Ptr(true)
+	deletedRule, err := p.state.DB.UpdateRule(ctx, rule)
+
+	if err != nil {
+		return nil, gtserror.NewErrorInternalError(err)
+	}
+
+	return p.tc.InstanceRuleToAdminAPIRule(deletedRule), nil
+}