src to pkg, impl lobby.Closed

pkg/state/lobby/'

@@ -0,0 +1,58 @@
+package lobby
+
+import (
+	"context"
+	"gitea/price-is-wrong/pkg/lib/db"
+	lobby "gitea/price-is-wrong/pkg/state/lobby/internal"
+	"slices"
+)
+
+func (l *Lobby) Join(ctx context.Context, id int) error {
+	return l.upsertEvent(ctx, &lobby.PlayerJoin{ID: id})
+}
+
+func (l *Lobby) Leave(ctx context.Context, id int) error {
+	return l.upsertEvent(ctx, &lobby.PlayerLeave{ID: id})
+}
+
+func (l *Lobby) Close(ctx context.Context) error {
+	return l.upsertEvent(ctx, &lobby.Close{})
+}
+
+func (l *Lobby) upsertEvent(ctx context.Context, e lobby.Event) error {
+	if err := upsertEvent(ctx, l.id, e); err != nil {
+		return err
+	}
+
+	l2, err := openID(ctx, l.id)
+	if err != nil {
+		return err
+	}
+
+	*l = *l2
+	return nil
+}
+
+func upsertEvent(ctx context.Context, lobbyID int, e lobby.Event) error {
+	b, err := lobby.MarshalEvent(e)
+	if err != nil {
+		return err
+	}
+
+	_, err = db.From(ctx).ExecContext(ctx, `
+      INSERT INTO lobby_events (lobby_id, payload) VALUES (?, ?)
+   `, lobbyID, b)
+	return err
+}
+
+func (l *Lobby) apply(e lobby.Event) error {
+	switch e := e.(type) {
+	case *lobby.PlayerJoin:
+		if !slices.Contains(l.Players, e.ID) {
+			l.Players = append(l.Players, e.ID)
+		}
+	case *lobby.PlayerLeave:
+		l.Players = slices.DeleteFunc(l.Players, func(id int) bool { return id == e.ID })
+	}
+	return nil
+}

pkg/state/lobby/events.go

@@ -0,0 +1,60 @@
+package lobby
+
+import (
+	"context"
+	"gitea/price-is-wrong/pkg/lib/db"
+	lobby "gitea/price-is-wrong/pkg/state/lobby/internal"
+	"slices"
+)
+
+func (l *Lobby) Join(ctx context.Context, id int) error {
+	return l.upsertEvent(ctx, &lobby.PlayerJoin{ID: id})
+}
+
+func (l *Lobby) Leave(ctx context.Context, id int) error {
+	return l.upsertEvent(ctx, &lobby.PlayerLeave{ID: id})
+}
+
+func (l *Lobby) Close(ctx context.Context) error {
+	return l.upsertEvent(ctx, &lobby.Close{})
+}
+
+func (l *Lobby) upsertEvent(ctx context.Context, e lobby.Event) error {
+	if err := upsertEvent(ctx, l.id, e); err != nil {
+		return err
+	}
+
+	l2, err := openID(ctx, l.id)
+	if err != nil {
+		return err
+	}
+
+	*l = *l2
+	return nil
+}
+
+func upsertEvent(ctx context.Context, lobbyID int, e lobby.Event) error {
+	b, err := lobby.MarshalEvent(e)
+	if err != nil {
+		return err
+	}
+
+	_, err = db.From(ctx).ExecContext(ctx, `
+      INSERT INTO lobby_events (lobby_id, payload) VALUES (?, ?)
+   `, lobbyID, b)
+	return err
+}
+
+func (l *Lobby) apply(e lobby.Event) error {
+	switch e := e.(type) {
+	case *lobby.PlayerJoin:
+		if !slices.Contains(l.Players, e.ID) {
+			l.Players = append(l.Players, e.ID)
+		}
+	case *lobby.PlayerLeave:
+		l.Players = slices.DeleteFunc(l.Players, func(id int) bool { return id == e.ID })
+	case *lobby.Close:
+		l.Closed = true
+	}
+	return nil
+}

pkg/state/lobby/internal/event.go

@@ -0,0 +1,33 @@
+package lobby
+
+import (
+	"fmt"
+	"gitea/price-is-wrong/pkg/lib/event"
+)
+
+type Event interface{}
+
+type PlayerJoin struct {
+	ID int
+}
+
+type PlayerLeave struct {
+	ID int
+}
+
+type Close struct {
+}
+
+func ParseEvent(b []byte) (Event, error) {
+	typesToPointers := map[string]any{
+		"*lobby.PlayerJoin":  &PlayerJoin{},
+		"*lobby.PlayerLeave": &PlayerLeave{},
+		"*lobby.Close":       &Close{},
+	}
+	t, err := event.Parse(b, typesToPointers)
+	return typesToPointers[t], err
+}
+
+func MarshalEvent(e Event) ([]byte, error) {
+	return event.Serialize(fmt.Sprintf("%T", e), e)
+}

pkg/state/lobby/internal/event_test.go

@@ -0,0 +1,37 @@
+package lobby_test
+
+import (
+	"fmt"
+	lobby "gitea/price-is-wrong/pkg/state/lobby/internal"
+	"testing"
+)
+
+func TestMarshalUnmarshal(t *testing.T) {
+	cases := map[string]struct {
+		e lobby.Event
+	}{
+		"PlayerJoin":  {e: &lobby.PlayerJoin{ID: 1}},
+		"PlayerLeave": {e: &lobby.PlayerLeave{ID: 1}},
+	}
+
+	for name, d := range cases {
+		c := d
+		t.Run(name, func(t *testing.T) {
+			b, err := lobby.MarshalEvent(c.e)
+			if err != nil {
+				t.Fatal(err)
+			}
+			t.Logf("marshalled: %s", b)
+
+			e, err := lobby.ParseEvent(b)
+			if err != nil {
+				t.Fatal(err)
+			}
+			t.Logf("unmarshalled: %+v", e)
+
+			if fmt.Sprintf("%+v", c.e) != fmt.Sprintf("%+v", e) {
+				t.Errorf("expected %+v but got %+v", c.e, e)
+			}
+		})
+	}
+}

pkg/state/lobby/lobby_test.go

@@ -0,0 +1,53 @@
+package lobby_test
+
+import (
+	"gitea/price-is-wrong/pkg/lib"
+	"gitea/price-is-wrong/pkg/state/lobby"
+	"testing"
+)
+
+func TestOpen(t *testing.T) {
+	ctx := lib.NewTestCtx(t)
+
+	l, err := lobby.Open(ctx, "id")
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Logf("%+v", l)
+
+	if len(l.Players) != 0 {
+		t.Errorf("new lobby has players: %+v", l.Players)
+	}
+
+	if err := l.Join(ctx, 1); err != nil {
+		t.Fatal("failed to join:", err)
+	} else if len(l.Players) != 1 {
+		t.Errorf("wrong number of players after first join: %+v", l.Players)
+	}
+
+	if err := l.Leave(ctx, 1); err != nil {
+		t.Fatal("failed to join:", err)
+	} else if len(l.Players) != 0 {
+		t.Errorf("wrong number of players after only leaves: %+v", l.Players)
+	}
+
+	if err := l.Join(ctx, 1); err != nil {
+		t.Fatal("failed to join:", err)
+	} else if err := l.Join(ctx, 1); err != nil {
+		t.Fatal("failed to join redundant:", err)
+	} else if len(l.Players) != 1 {
+		t.Errorf("redundant join yielded wrong players: %+v", l.Players)
+	}
+
+	if err := l.Join(ctx, 2); err != nil {
+		t.Fatal("failed to second join:", err)
+	} else if len(l.Players) != 2 {
+		t.Errorf("second join yielded wrong players: %+v", l.Players)
+	}
+
+	if err := l.Close(ctx); err != nil {
+		t.Fatal(err)
+	} else if !l.Closed {
+		t.Error(l.Closed)
+	}
+}

pkg/state/lobby/open.go

@@ -0,0 +1,111 @@
+package lobby
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+	"gitea/price-is-wrong/pkg/lib/db"
+	lobby "gitea/price-is-wrong/pkg/state/lobby/internal"
+)
+
+type Lobby struct {
+	id      int
+	Players []int
+	Closed  bool
+}
+
+func Open(ctx context.Context, name string) (*Lobby, error) {
+	if err := initialize(ctx); err != nil {
+		return nil, fmt.Errorf("failed to initialize lobbies: %w", err)
+	}
+
+	if result, err := open(ctx, name); err != nil {
+		return nil, err
+	} else if result == nil {
+		if err := create(ctx, name); err != nil {
+			return nil, err
+		}
+	}
+
+	return mustOpen(ctx, name)
+}
+
+func mustOpen(ctx context.Context, name string) (*Lobby, error) {
+	result, err := open(ctx, name)
+	if err != nil {
+		return nil, err
+	}
+	if result == nil {
+		return nil, fmt.Errorf("no lobby found with name %s", name)
+	}
+	return result, nil
+}
+
+func open(ctx context.Context, name string) (*Lobby, error) {
+	row := db.From(ctx).QueryRow(`SELECT id FROM lobbies WHERE name=?`, name)
+	if err := row.Err(); err != nil {
+		return nil, fmt.Errorf("no lobby found with name %s", name)
+	}
+
+	var id sql.NullInt32
+	if err := row.Scan(&id); err == sql.ErrNoRows || !id.Valid {
+		return nil, nil
+	} else if err != nil {
+		return nil, fmt.Errorf("failed to scan id from lobby: %w", err)
+	}
+
+	return openID(ctx, int(id.Int32))
+}
+
+func openID(ctx context.Context, id int) (*Lobby, error) {
+	rows, err := db.From(ctx).QueryContext(ctx, `
+      SELECT payload
+      FROM lobby_events
+      WHERE lobby_events.lobby_id=?
+      ORDER BY id
+   `, id)
+	if err != nil {
+		return nil, fmt.Errorf("failed to query event payloads for id %d: %w", id, err)
+	}
+	defer rows.Close()
+
+	result := Lobby{id: id}
+	for rows.Next() {
+		var b []byte
+		if err := rows.Scan(&b); err != nil {
+			return nil, fmt.Errorf("failed to scan event: %w", err)
+		}
+		event, err := lobby.ParseEvent(b)
+		if err != nil {
+			return nil, fmt.Errorf("failed to parse event: %w", err)
+		}
+		if err := result.apply(event); err != nil {
+			return nil, fmt.Errorf("failed to apply event %s: %w", b, err)
+		}
+	}
+
+	return &result, rows.Err()
+}
+
+func create(ctx context.Context, name string) error {
+	_, err := db.From(ctx).ExecContext(ctx, `
+      INSERT INTO lobbies (name) VALUES (?)
+   `, name)
+	return err
+}
+
+func initialize(ctx context.Context) error {
+	_, err := db.From(ctx).ExecContext(ctx, `
+      CREATE TABLE IF NOT EXISTS lobbies (
+         id INTEGER PRIMARY KEY,
+         name TEXT
+      );
+      CREATE TABLE IF NOT EXISTS lobby_events (
+         id INTEGER PRIMARY KEY,
+         lobby_id NUMBER,
+         payload TEXT,
+         FOREIGN KEY (lobby_id) REFERENCES lobbies (id)
+      );
+   `)
+	return err
+}