Oauth/token (#7)

* add host and protocol options

* some fiddling

* tidying up and comments

* tick off /oauth/token

* tidying a bit

* tidying

* go mod tidy

* allow attaching middleware to server

* add middleware

* more user friendly

* add comments

* comments

* store account + app

* tidying

* lots of restructuring

* lint + tidy

internal/db/pg-fed.go

@@ -0,0 +1,137 @@
+package db
+
+import (
+	"context"
+	"errors"
+	"net/url"
+	"sync"
+
+	"github.com/go-fed/activity/pub"
+	"github.com/go-fed/activity/streams"
+	"github.com/go-fed/activity/streams/vocab"
+	"github.com/go-pg/pg/v10"
+)
+
+type postgresFederation struct {
+	locks *sync.Map
+	conn  *pg.DB
+}
+
+func newPostgresFederation(conn *pg.DB) pub.Database {
+	return &postgresFederation{
+		locks: new(sync.Map),
+		conn:  conn,
+	}
+}
+
+/*
+   GO-FED DB INTERFACE-IMPLEMENTING FUNCTIONS
+*/
+func (pf *postgresFederation) Lock(ctx context.Context, id *url.URL) error {
+	// Before any other Database methods are called, the relevant `id`
+	// entries are locked to allow for fine-grained concurrency.
+
+	// Strategy: create a new lock, if stored, continue. Otherwise, lock the
+	// existing mutex.
+	mu := &sync.Mutex{}
+	mu.Lock() // Optimistically lock if we do store it.
+	i, loaded := pf.locks.LoadOrStore(id.String(), mu)
+	if loaded {
+		mu = i.(*sync.Mutex)
+		mu.Lock()
+	}
+	return nil
+}
+
+func (pf *postgresFederation) Unlock(ctx context.Context, id *url.URL) error {
+	// Once Go-Fed is done calling Database methods, the relevant `id`
+	// entries are unlocked.
+
+	i, ok := pf.locks.Load(id.String())
+	if !ok {
+		return errors.New("missing an id in unlock")
+	}
+	mu := i.(*sync.Mutex)
+	mu.Unlock()
+	return nil
+}
+
+func (pf *postgresFederation) InboxContains(ctx context.Context, inbox *url.URL, id *url.URL) (bool, error) {
+	return false, nil
+}
+
+func (pf *postgresFederation) GetInbox(ctx context.Context, inboxIRI *url.URL) (inbox vocab.ActivityStreamsOrderedCollectionPage, err error) {
+	return nil, nil
+}
+
+func (pf *postgresFederation) SetInbox(ctx context.Context, inbox vocab.ActivityStreamsOrderedCollectionPage) error {
+	return nil
+}
+
+func (pf *postgresFederation) Owns(ctx context.Context, id *url.URL) (owns bool, err error) {
+	return false, nil
+}
+
+func (pf *postgresFederation) ActorForOutbox(ctx context.Context, outboxIRI *url.URL) (actorIRI *url.URL, err error) {
+	return nil, nil
+}
+
+func (pf *postgresFederation) ActorForInbox(ctx context.Context, inboxIRI *url.URL) (actorIRI *url.URL, err error) {
+	return nil, nil
+}
+
+func (pf *postgresFederation) OutboxForInbox(ctx context.Context, inboxIRI *url.URL) (outboxIRI *url.URL, err error) {
+	return nil, nil
+}
+
+func (pf *postgresFederation) Exists(ctx context.Context, id *url.URL) (exists bool, err error) {
+	return false, nil
+}
+
+func (pf *postgresFederation) Get(ctx context.Context, id *url.URL) (value vocab.Type, err error) {
+	return nil, nil
+}
+
+func (pf *postgresFederation) Create(ctx context.Context, asType vocab.Type) error {
+	t, err := streams.NewTypeResolver()
+	if err != nil {
+		return err
+	}
+	if err := t.Resolve(ctx, asType); err != nil {
+		return err
+	}
+	asType.GetTypeName()
+	return nil
+}
+
+func (pf *postgresFederation) Update(ctx context.Context, asType vocab.Type) error {
+	return nil
+}
+
+func (pf *postgresFederation) Delete(ctx context.Context, id *url.URL) error {
+	return nil
+}
+
+func (pf *postgresFederation) GetOutbox(ctx context.Context, outboxIRI *url.URL) (inbox vocab.ActivityStreamsOrderedCollectionPage, err error) {
+	return nil, nil
+}
+
+func (pf *postgresFederation) SetOutbox(ctx context.Context, outbox vocab.ActivityStreamsOrderedCollectionPage) error {
+	return nil
+}
+
+func (pf *postgresFederation) NewID(ctx context.Context, t vocab.Type) (id *url.URL, err error) {
+	return nil, nil
+}
+
+func (pf *postgresFederation) Followers(ctx context.Context, actorIRI *url.URL) (followers vocab.ActivityStreamsCollection, err error) {
+	return nil, nil
+}
+
+func (pf *postgresFederation) Following(ctx context.Context, actorIRI *url.URL) (followers vocab.ActivityStreamsCollection, err error) {
+	return nil, nil
+}
+
+func (pf *postgresFederation) Liked(ctx context.Context, actorIRI *url.URL) (followers vocab.ActivityStreamsCollection, err error) {
+	return nil, nil
+}