model-registry: add upstream check endpoint

internal/service/model_registry.go

@@ -9,6 +9,7 @@ import (
 	"fmt"
 	"io"
 	"net/http"
+	"net/url"
 	"os"
 	"path/filepath"
 	"regexp"
@@ -30,8 +31,9 @@ type ModelRegistryConfig struct {
 	Enabled      bool
 	RefreshEvery time.Duration
 
-	ModelsDevBaseURL string
-	ModelsDevRef     string
+	ModelsDevBaseURL    string
+	ModelsDevAPIBaseURL string
+	ModelsDevRef        string
 
 	CacheDir string
 	Timeout  time.Duration
@@ -58,6 +60,9 @@ func NewModelRegistryService(db *gorm.DB, rdb *redis.Client, cfg ModelRegistryCo
 	if strings.TrimSpace(cfg.ModelsDevBaseURL) == "" {
 		cfg.ModelsDevBaseURL = "https://codeload.github.com/sst/models.dev/tar.gz"
 	}
+	if strings.TrimSpace(cfg.ModelsDevAPIBaseURL) == "" {
+		cfg.ModelsDevAPIBaseURL = "https://api.github.com"
+	}
 	if strings.TrimSpace(cfg.ModelsDevRef) == "" {
 		cfg.ModelsDevRef = "dev"
 	}
@@ -136,6 +141,41 @@ func (s *ModelRegistryService) Status(ctx context.Context) (*ModelRegistryStatus
 	return out, nil
 }
 
+type ModelRegistryCheckResult struct {
+	Enabled            bool   `json:"enabled"`
+	UpstreamRef        string `json:"upstream_ref"`
+	CurrentVersion     string `json:"current_version,omitempty"`
+	LatestVersion      string `json:"latest_version,omitempty"`
+	NeedsRefresh       bool   `json:"needs_refresh"`
+	CurrentUpstreamRef string `json:"current_upstream_ref,omitempty"`
+}
+
+func (s *ModelRegistryService) Check(ctx context.Context, ref string) (*ModelRegistryCheckResult, error) {
+	if strings.TrimSpace(ref) == "" {
+		ref = s.cfg.ModelsDevRef
+	}
+
+	latest, err := s.fetchModelsDevRefSHA(ctx, ref)
+	if err != nil {
+		return nil, err
+	}
+
+	meta, _ := s.rdb.HGetAll(ctx, "meta:models_meta").Result()
+	currentVersion := strings.TrimSpace(meta["version"])
+	currentUpstreamRef := strings.TrimSpace(meta["upstream_ref"])
+
+	needsRefresh := currentVersion == "" || !versionsEqual(currentVersion, latest)
+
+	return &ModelRegistryCheckResult{
+		Enabled:            s.cfg.Enabled,
+		UpstreamRef:        ref,
+		CurrentVersion:     currentVersion,
+		LatestVersion:      latest,
+		NeedsRefresh:       needsRefresh,
+		CurrentUpstreamRef: currentUpstreamRef,
+	}, nil
+}
+
 func (s *ModelRegistryService) Refresh(ctx context.Context, ref string) error {
 	if strings.TrimSpace(ref) == "" {
 		ref = s.cfg.ModelsDevRef
@@ -263,6 +303,58 @@ func (s *ModelRegistryService) setError(err error) {
 	s.lastRefresh = time.Now()
 }
 
+func (s *ModelRegistryService) fetchModelsDevRefSHA(ctx context.Context, ref string) (string, error) {
+	base := strings.TrimRight(strings.TrimSpace(s.cfg.ModelsDevAPIBaseURL), "/")
+	if base == "" {
+		base = "https://api.github.com"
+	}
+
+	u := base + "/repos/sst/models.dev/commits/" + url.PathEscape(strings.TrimSpace(ref))
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, u, nil)
+	if err != nil {
+		return "", err
+	}
+	req.Header.Set("Accept", "application/vnd.github+json")
+	req.Header.Set("User-Agent", "ez-api")
+
+	resp, err := s.client.Do(req)
+	if err != nil {
+		return "", err
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode/100 != 2 {
+		b, _ := io.ReadAll(io.LimitReader(resp.Body, 8<<10))
+		return "", fmt.Errorf("models.dev commit check failed: %s body=%s", resp.Status, string(b))
+	}
+
+	var payload struct {
+		SHA string `json:"sha"`
+	}
+	if err := json.NewDecoder(io.LimitReader(resp.Body, 1<<20)).Decode(&payload); err != nil {
+		return "", fmt.Errorf("decode github commit: %w", err)
+	}
+	sha := strings.TrimSpace(payload.SHA)
+	if sha == "" {
+		return "", fmt.Errorf("github commit sha missing for ref %q", ref)
+	}
+	return sha, nil
+}
+
+func versionsEqual(current, latest string) bool {
+	c := strings.TrimSpace(current)
+	l := strings.TrimSpace(latest)
+	if c == "" || l == "" {
+		return false
+	}
+	if len(c) <= len(l) && strings.HasPrefix(l, c) {
+		return true
+	}
+	if len(l) <= len(c) && strings.HasPrefix(c, l) {
+		return true
+	}
+	return false
+}
+
 type boolVal struct {
 	Known bool
 	Val   bool