feat: gamemaster

2026-05-03 07:59:03 +02:00
parent a7cee15115
commit 3e2622757e
229 changed files with 41521 additions and 1098 deletions
@@ -0,0 +1,343 @@
+// Package lobbyclient provides the trusted-internal Lobby REST client
+// Game Master uses to fetch membership lists for the in-process
+// authorization cache and to resolve the human-readable `game_name`
+// consumed by notification intents.
+//
+// Two endpoints are mounted today:
+//
+//   - `GET /api/v1/internal/games/{game_id}/memberships` — pagination is
+//     handled internally so callers always receive every membership of
+//     the game;
+//   - `GET /api/v1/internal/games/{game_id}` — single read used by the
+//     turn-generation orchestrator to resolve `game_name` per
+//     notification.
+package lobbyclient
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"strconv"
+	"strings"
+	"time"
+
+	"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
+
+	"galaxy/gamemaster/internal/ports"
+)
+
+const (
+	membershipsPathTemplate = "/api/v1/internal/games/%s/memberships"
+
+	gameRecordPathTemplate = "/api/v1/internal/games/%s"
+
+	// pageSize is the per-call page size; matches the Lobby spec
+	// maximum (200) so we walk fewer pages on large rosters.
+	pageSize = 200
+
+	// maxPages caps the page walk to defend against an upstream that
+	// keeps returning a `next_page_token` indefinitely. 64 pages of
+	// 200 items each cover 12_800 memberships per game — orders of
+	// magnitude beyond any realistic Galaxy roster.
+	maxPages = 64
+)
+
+// Config configures one HTTP-backed Lobby internal client.
+type Config struct {
+	// BaseURL stores the absolute base URL of the Lobby internal HTTP
+	// listener (e.g. `http://lobby:8095`).
+	BaseURL string
+
+	// RequestTimeout bounds one outbound page request. The total
+	// wall-clock for `GetMemberships` is at most
+	// `RequestTimeout * <pages>`, capped indirectly by the per-page
+	// limit and `maxPages`.
+	RequestTimeout time.Duration
+}
+
+// Client resolves Lobby memberships through the trusted internal HTTP
+// API.
+type Client struct {
+	baseURL              string
+	requestTimeout       time.Duration
+	httpClient           *http.Client
+	closeIdleConnections func()
+}
+
+type membershipListEnvelope struct {
+	Items         []membershipRecordEnvelope `json:"items"`
+	NextPageToken string                     `json:"next_page_token"`
+}
+
+type membershipRecordEnvelope struct {
+	MembershipID string `json:"membership_id"`
+	GameID       string `json:"game_id"`
+	UserID       string `json:"user_id"`
+	RaceName     string `json:"race_name"`
+	Status       string `json:"status"`
+	JoinedAt     int64  `json:"joined_at"`
+	RemovedAt    *int64 `json:"removed_at,omitempty"`
+}
+
+// gameRecordEnvelope captures the fields GM consumes from Lobby's
+// `GameRecord` schema. Lobby may carry additional fields; the JSON
+// decoder ignores them.
+type gameRecordEnvelope struct {
+	GameID   string `json:"game_id"`
+	GameName string `json:"game_name"`
+	Status   string `json:"status"`
+}
+
+type errorEnvelope struct {
+	Error *errorBody `json:"error"`
+}
+
+type errorBody struct {
+	Code    string `json:"code"`
+	Message string `json:"message"`
+}
+
+// NewClient constructs a Lobby internal client with otelhttp-wrapped
+// transport cloned from `http.DefaultTransport`. Call `Close` to
+// release idle connections at shutdown.
+func NewClient(cfg Config) (*Client, error) {
+	transport, ok := http.DefaultTransport.(*http.Transport)
+	if !ok {
+		return nil, errors.New("new lobby client: default transport is not *http.Transport")
+	}
+	cloned := transport.Clone()
+	return newClient(cfg, &http.Client{Transport: otelhttp.NewTransport(cloned)}, cloned.CloseIdleConnections)
+}
+
+func newClient(cfg Config, httpClient *http.Client, closeIdleConnections func()) (*Client, error) {
+	switch {
+	case strings.TrimSpace(cfg.BaseURL) == "":
+		return nil, errors.New("new lobby client: base url must not be empty")
+	case cfg.RequestTimeout <= 0:
+		return nil, errors.New("new lobby client: request timeout must be positive")
+	case httpClient == nil:
+		return nil, errors.New("new lobby client: http client must not be nil")
+	}
+	parsed, err := url.Parse(strings.TrimRight(strings.TrimSpace(cfg.BaseURL), "/"))
+	if err != nil {
+		return nil, fmt.Errorf("new lobby client: parse base url: %w", err)
+	}
+	if parsed.Scheme == "" || parsed.Host == "" {
+		return nil, errors.New("new lobby client: base url must be absolute")
+	}
+	return &Client{
+		baseURL:              parsed.String(),
+		requestTimeout:       cfg.RequestTimeout,
+		httpClient:           httpClient,
+		closeIdleConnections: closeIdleConnections,
+	}, nil
+}
+
+// Close releases idle HTTP connections owned by the underlying
+// transport. Safe to call multiple times.
+func (client *Client) Close() error {
+	if client == nil || client.closeIdleConnections == nil {
+		return nil
+	}
+	client.closeIdleConnections()
+	return nil
+}
+
+// GetMemberships returns every membership of gameID, walking the
+// pagination chain transparently. Transport faults, non-2xx responses,
+// malformed payloads, and pagination overflow all surface as
+// `ports.ErrLobbyUnavailable` so callers can branch with `errors.Is`.
+func (client *Client) GetMemberships(ctx context.Context, gameID string) ([]ports.Membership, error) {
+	if client == nil || client.httpClient == nil {
+		return nil, errors.New("lobby get memberships: nil client")
+	}
+	if ctx == nil {
+		return nil, errors.New("lobby get memberships: nil context")
+	}
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
+	if strings.TrimSpace(gameID) == "" {
+		return nil, errors.New("lobby get memberships: game id must not be empty")
+	}
+
+	var memberships []ports.Membership
+	pathPrefix := fmt.Sprintf(membershipsPathTemplate, url.PathEscape(gameID))
+	pageToken := ""
+	for range maxPages {
+		payload, statusCode, err := client.doRequest(ctx, http.MethodGet, buildPagedQuery(pathPrefix, pageToken))
+		if err != nil {
+			return nil, fmt.Errorf("%w: %w", ports.ErrLobbyUnavailable, err)
+		}
+		if statusCode != http.StatusOK {
+			errorCode := decodeErrorCode(payload)
+			if errorCode != "" {
+				return nil, fmt.Errorf("%w: unexpected status %d (error_code=%s)", ports.ErrLobbyUnavailable, statusCode, errorCode)
+			}
+			return nil, fmt.Errorf("%w: unexpected status %d", ports.ErrLobbyUnavailable, statusCode)
+		}
+		var envelope membershipListEnvelope
+		if err := decodeJSONPayload(payload, &envelope); err != nil {
+			return nil, fmt.Errorf("%w: decode response: %w", ports.ErrLobbyUnavailable, err)
+		}
+		for index, item := range envelope.Items {
+			converted, err := toMembership(item)
+			if err != nil {
+				return nil, fmt.Errorf("%w: items[%d]: %w", ports.ErrLobbyUnavailable, index, err)
+			}
+			memberships = append(memberships, converted)
+		}
+		if strings.TrimSpace(envelope.NextPageToken) == "" {
+			return memberships, nil
+		}
+		pageToken = envelope.NextPageToken
+	}
+	return nil, fmt.Errorf("%w: pagination overflow after %d pages", ports.ErrLobbyUnavailable, maxPages)
+}
+
+// GetGameSummary returns the narrow projection of Lobby's GameRecord
+// (game id, game name, lifecycle status) for gameID. Transport faults,
+// non-2xx responses, malformed payloads, and missing required fields
+// surface as `ports.ErrLobbyUnavailable` so callers can branch with
+// `errors.Is`.
+func (client *Client) GetGameSummary(ctx context.Context, gameID string) (ports.GameSummary, error) {
+	if client == nil || client.httpClient == nil {
+		return ports.GameSummary{}, errors.New("lobby get game summary: nil client")
+	}
+	if ctx == nil {
+		return ports.GameSummary{}, errors.New("lobby get game summary: nil context")
+	}
+	if err := ctx.Err(); err != nil {
+		return ports.GameSummary{}, err
+	}
+	if strings.TrimSpace(gameID) == "" {
+		return ports.GameSummary{}, errors.New("lobby get game summary: game id must not be empty")
+	}
+
+	requestPath := fmt.Sprintf(gameRecordPathTemplate, url.PathEscape(gameID))
+	payload, statusCode, err := client.doRequest(ctx, http.MethodGet, requestPath)
+	if err != nil {
+		return ports.GameSummary{}, fmt.Errorf("%w: %w", ports.ErrLobbyUnavailable, err)
+	}
+	if statusCode != http.StatusOK {
+		errorCode := decodeErrorCode(payload)
+		if errorCode != "" {
+			return ports.GameSummary{}, fmt.Errorf(
+				"%w: unexpected status %d (error_code=%s)",
+				ports.ErrLobbyUnavailable, statusCode, errorCode,
+			)
+		}
+		return ports.GameSummary{}, fmt.Errorf(
+			"%w: unexpected status %d", ports.ErrLobbyUnavailable, statusCode,
+		)
+	}
+	var envelope gameRecordEnvelope
+	if err := decodeJSONPayload(payload, &envelope); err != nil {
+		return ports.GameSummary{}, fmt.Errorf("%w: decode response: %w", ports.ErrLobbyUnavailable, err)
+	}
+	if strings.TrimSpace(envelope.GameID) == "" {
+		return ports.GameSummary{}, fmt.Errorf("%w: missing game_id", ports.ErrLobbyUnavailable)
+	}
+	if strings.TrimSpace(envelope.GameName) == "" {
+		return ports.GameSummary{}, fmt.Errorf("%w: missing game_name", ports.ErrLobbyUnavailable)
+	}
+	if strings.TrimSpace(envelope.Status) == "" {
+		return ports.GameSummary{}, fmt.Errorf("%w: missing status", ports.ErrLobbyUnavailable)
+	}
+	return ports.GameSummary{
+		GameID:   envelope.GameID,
+		GameName: envelope.GameName,
+		Status:   envelope.Status,
+	}, nil
+}
+
+func buildPagedQuery(path, pageToken string) string {
+	params := url.Values{}
+	params.Set("page_size", strconv.Itoa(pageSize))
+	if pageToken != "" {
+		params.Set("page_token", pageToken)
+	}
+	return path + "?" + params.Encode()
+}
+
+func toMembership(record membershipRecordEnvelope) (ports.Membership, error) {
+	if strings.TrimSpace(record.UserID) == "" {
+		return ports.Membership{}, errors.New("missing user_id")
+	}
+	if strings.TrimSpace(record.RaceName) == "" {
+		return ports.Membership{}, errors.New("missing race_name")
+	}
+	if strings.TrimSpace(record.Status) == "" {
+		return ports.Membership{}, errors.New("missing status")
+	}
+	membership := ports.Membership{
+		UserID:   record.UserID,
+		RaceName: record.RaceName,
+		Status:   record.Status,
+		JoinedAt: time.UnixMilli(record.JoinedAt).UTC(),
+	}
+	if record.RemovedAt != nil {
+		removedAt := time.UnixMilli(*record.RemovedAt).UTC()
+		membership.RemovedAt = &removedAt
+	}
+	return membership, nil
+}
+
+func (client *Client) doRequest(ctx context.Context, method, requestPath string) ([]byte, int, error) {
+	attemptCtx, cancel := context.WithTimeout(ctx, client.requestTimeout)
+	defer cancel()
+
+	req, err := http.NewRequestWithContext(attemptCtx, method, client.baseURL+requestPath, nil)
+	if err != nil {
+		return nil, 0, fmt.Errorf("build request: %w", err)
+	}
+	req.Header.Set("Accept", "application/json")
+
+	resp, err := client.httpClient.Do(req)
+	if err != nil {
+		return nil, 0, err
+	}
+	defer resp.Body.Close()
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, 0, fmt.Errorf("read response body: %w", err)
+	}
+	return body, resp.StatusCode, nil
+}
+
+func decodeJSONPayload(payload []byte, target any) error {
+	decoder := json.NewDecoder(bytes.NewReader(payload))
+	if err := decoder.Decode(target); err != nil {
+		return err
+	}
+	if err := decoder.Decode(&struct{}{}); err != io.EOF {
+		if err == nil {
+			return errors.New("unexpected trailing JSON input")
+		}
+		return err
+	}
+	return nil
+}
+
+func decodeErrorCode(payload []byte) string {
+	if len(payload) == 0 {
+		return ""
+	}
+	var envelope errorEnvelope
+	if err := json.Unmarshal(payload, &envelope); err != nil {
+		return ""
+	}
+	if envelope.Error == nil {
+		return ""
+	}
+	return envelope.Error.Code
+}
+
+// Compile-time assertion: Client implements ports.LobbyClient.
+var _ ports.LobbyClient = (*Client)(nil)