start implementing db interface

3 files changed, 284 insertions, 0 deletions

diff --git a/internal/db/const.go b/internal/db/const.go
new file mode 100644
index 000000000..ab0a5c03f
--- /dev/null
+++ b/internal/db/const.go
@@ -0,0 +1,36 @@
+/*
+   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 db
+
+import "regexp"
+
+const (
+	// general db defaults
+
+	// default database to use in whatever db implementation we have
+	defaultDatabase string = "gotosocial"
+
+	// implementation-specific defaults
+
+	// widely-recognised default postgres port
+	postgresDefaultPort int = 5432
+)
+
+var ipv4Regex = regexp.MustCompile(`^(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$`)
+var hostnameRegex = regexp.MustCompile(`^(?:[a-z0-9]+(?:-[a-z0-9]+)*\.)+[a-z]{2,}$`)
diff --git a/internal/db/postgres.go b/internal/db/postgres.go
new file mode 100644
index 000000000..67d0bb4e9
--- /dev/null
+++ b/internal/db/postgres.go
@@ -0,0 +1,181 @@
+/*
+   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 db
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"net/url"
+
+	"github.com/go-fed/activity/streams/vocab"
+	"github.com/go-pg/pg"
+)
+
+type postgresService struct {
+	config *Config
+	conn   *pg.DB
+	ready  bool
+}
+
+// newPostgresService returns a postgresService derived from the provided config, which implements the go-fed DB interface.
+// Under the hood, it uses https://github.com/go-pg/pg to create and maintain a database connection.
+func newPostgresService(config *Config) (*postgresService, error) {
+	opts, err := derivePGOptions(config)
+	if err != nil {
+		return nil, fmt.Errorf("could not create postgres service: %s", err)
+	}
+	conn := pg.Connect(opts)
+	return &postgresService{
+		config,
+		conn,
+		false,
+	}, nil
+
+}
+
+/*
+	HANDY STUFF
+*/
+
+// derivePGOptions takes an application config and returns either a ready-to-use *pg.Options
+// with sensible defaults, or an error if it's not satisfied by the provided config.
+func derivePGOptions(config *Config) (*pg.Options, error) {
+	if config.Type != dbTypePostgres {
+		return nil, fmt.Errorf("expected db type of %s but got %s", dbTypePostgres, config.Type)
+	}
+
+	// use sensible default port
+	var port int = config.Port
+	if port == 0 {
+		port = postgresDefaultPort
+	}
+
+	// validate address
+	address := config.Address
+	if address == "" {
+		return nil, errors.New("address not provided")
+	}
+	if !hostnameRegex.MatchString(address) && !ipv4Regex.MatchString(address) {
+		return nil, fmt.Errorf("address %s was neither an ipv4 address nor a valid hostname", address)
+	}
+
+	options := &pg.Options{
+		Addr:     fmt.Sprintf("%s:%d", config.Address, config.Port),
+		User:     config.User,
+		Password: config.Password,
+		Database: config.Database,
+		OnConnect: func(c *pg.Conn) error {
+			return nil
+		},
+	}
+
+	return options, nil
+}
+
+/*
+   GO-FED DB INTERFACE-IMPLEMENTING FUNCTIONS
+*/
+func (ps *postgresService) Lock(c context.Context, id *url.URL) error {
+	return nil
+}
+
+func (ps *postgresService) Unlock(c context.Context, id *url.URL) error {
+	return nil
+}
+
+func (ps *postgresService) InboxContains(c context.Context, inbox *url.URL, id *url.URL) (bool, error) {
+	return false, nil
+}
+
+func (ps *postgresService) GetInbox(c context.Context, inboxIRI *url.URL) (inbox vocab.ActivityStreamsOrderedCollectionPage, err error) {
+	return nil, nil
+}
+
+func (ps *postgresService) SetInbox(c context.Context, inbox vocab.ActivityStreamsOrderedCollectionPage) error {
+	return nil
+}
+
+func (ps *postgresService) Owns(c context.Context, id *url.URL) (owns bool, err error) {
+	return false, nil
+}
+
+func (ps *postgresService) ActorForOutbox(c context.Context, outboxIRI *url.URL) (actorIRI *url.URL, err error) {
+	return nil, nil
+}
+
+func (ps *postgresService) ActorForInbox(c context.Context, inboxIRI *url.URL) (actorIRI *url.URL, err error) {
+	return nil, nil
+}
+
+func (ps *postgresService) OutboxForInbox(c context.Context, inboxIRI *url.URL) (outboxIRI *url.URL, err error) {
+	return nil, nil
+}
+
+func (ps *postgresService) Exists(c context.Context, id *url.URL) (exists bool, err error) {
+	return false, nil
+}
+
+func (ps *postgresService) Get(c context.Context, id *url.URL) (value vocab.Type, err error) {
+	return nil, nil
+}
+
+func (ps *postgresService) Create(c context.Context, asType vocab.Type) error {
+	return nil
+}
+
+func (ps *postgresService) Update(c context.Context, asType vocab.Type) error {
+	return nil
+}
+
+func (ps *postgresService) Delete(c context.Context, id *url.URL) error {
+	return nil
+}
+
+func (ps *postgresService) GetOutbox(c context.Context, outboxIRI *url.URL) (inbox vocab.ActivityStreamsOrderedCollectionPage, err error) {
+	return nil, nil
+}
+
+func (ps *postgresService) SetOutbox(c context.Context, outbox vocab.ActivityStreamsOrderedCollectionPage) error {
+	return nil
+}
+
+func (ps *postgresService) NewID(c context.Context, t vocab.Type) (id *url.URL, err error) {
+	return nil, nil
+}
+
+func (ps *postgresService) Followers(c context.Context, actorIRI *url.URL) (followers vocab.ActivityStreamsCollection, err error) {
+	return nil, nil
+}
+
+func (ps *postgresService) Following(c context.Context, actorIRI *url.URL) (followers vocab.ActivityStreamsCollection, err error) {
+	return nil, nil
+}
+
+func (ps *postgresService) Liked(c context.Context, actorIRI *url.URL) (followers vocab.ActivityStreamsCollection, err error) {
+	return nil, nil
+}
+
+/*
+	EXTRA FUNCTIONS
+*/
+
+func (ps *postgresService) Ready() bool {
+	return false
+}
diff --git a/internal/db/service.go b/internal/db/service.go
new file mode 100644
index 000000000..6163b3c69
--- /dev/null
+++ b/internal/db/service.go
@@ -0,0 +1,67 @@
+/*
+   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 db
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/go-fed/activity/pub"
+)
+
+const dbTypePostgres string = "POSTGRES"
+
+// Service provides methods for interacting with an underlying database (for now, just postgres).
+// The function mapping lines up with the Database interface described in go-fed.
+// See here: https://github.com/go-fed/activity/blob/master/pub/database.go
+type Service interface {
+	/*
+		GO-FED DATABASE FUNCTIONS
+	*/
+	pub.Database
+
+	/*
+		ANY ADDITIONAL DESIRED FUNCTIONS
+	*/
+
+	// Ready indicates whether the database is ready to handle queries and whatnot.
+	Ready() bool
+}
+
+// Config provides configuration options for the database connection
+type Config struct {
+	Type            string
+	Address         string
+	Port            int
+	User            string
+	Password        string
+	Database        string
+	ApplicationName string
+}
+
+// NewService returns a new database service that satisfies the Service interface and, by extension,
+// the go-fed database interface described here: https://github.com/go-fed/activity/blob/master/pub/database.go
+func NewService(config *Config) (Service, error) {
+	switch strings.ToUpper(config.Type) {
+	case dbTypePostgres:
+		return newPostgresService(config)
+	default:
+		return nil, fmt.Errorf("database type %s not supported", config.Type)
+	}
+}