refactor(watcher): extract auth synthesis logic into separate synthesizer package

internal/watcher/synthesizer/helpers.go

@@ -0,0 +1,110 @@
+package synthesizer
+
+import (
+	"crypto/sha256"
+	"encoding/hex"
+	"fmt"
+	"sort"
+	"strings"
+
+	"github.com/router-for-me/CLIProxyAPI/v6/internal/config"
+	"github.com/router-for-me/CLIProxyAPI/v6/internal/watcher/diff"
+	coreauth "github.com/router-for-me/CLIProxyAPI/v6/sdk/cliproxy/auth"
+)
+
+// StableIDGenerator generates stable, deterministic IDs for auth entries.
+// It uses SHA256 hashing with collision handling via counters.
+// It is not safe for concurrent use.
+type StableIDGenerator struct {
+	counters map[string]int
+}
+
+// NewStableIDGenerator creates a new StableIDGenerator instance.
+func NewStableIDGenerator() *StableIDGenerator {
+	return &StableIDGenerator{counters: make(map[string]int)}
+}
+
+// Next generates a stable ID based on the kind and parts.
+// Returns the full ID (kind:hash) and the short hash portion.
+func (g *StableIDGenerator) Next(kind string, parts ...string) (string, string) {
+	if g == nil {
+		return kind + ":000000000000", "000000000000"
+	}
+	hasher := sha256.New()
+	hasher.Write([]byte(kind))
+	for _, part := range parts {
+		trimmed := strings.TrimSpace(part)
+		hasher.Write([]byte{0})
+		hasher.Write([]byte(trimmed))
+	}
+	digest := hex.EncodeToString(hasher.Sum(nil))
+	if len(digest) < 12 {
+		digest = fmt.Sprintf("%012s", digest)
+	}
+	short := digest[:12]
+	key := kind + ":" + short
+	index := g.counters[key]
+	g.counters[key] = index + 1
+	if index > 0 {
+		short = fmt.Sprintf("%s-%d", short, index)
+	}
+	return fmt.Sprintf("%s:%s", kind, short), short
+}
+
+// ApplyAuthExcludedModelsMeta applies excluded models metadata to an auth entry.
+// It computes a hash of excluded models and sets the auth_kind attribute.
+func ApplyAuthExcludedModelsMeta(auth *coreauth.Auth, cfg *config.Config, perKey []string, authKind string) {
+	if auth == nil || cfg == nil {
+		return
+	}
+	authKindKey := strings.ToLower(strings.TrimSpace(authKind))
+	seen := make(map[string]struct{})
+	add := func(list []string) {
+		for _, entry := range list {
+			if trimmed := strings.TrimSpace(entry); trimmed != "" {
+				key := strings.ToLower(trimmed)
+				if _, exists := seen[key]; exists {
+					continue
+				}
+				seen[key] = struct{}{}
+			}
+		}
+	}
+	if authKindKey == "apikey" {
+		add(perKey)
+	} else if cfg.OAuthExcludedModels != nil {
+		providerKey := strings.ToLower(strings.TrimSpace(auth.Provider))
+		add(cfg.OAuthExcludedModels[providerKey])
+	}
+	combined := make([]string, 0, len(seen))
+	for k := range seen {
+		combined = append(combined, k)
+	}
+	sort.Strings(combined)
+	hash := diff.ComputeExcludedModelsHash(combined)
+	if auth.Attributes == nil {
+		auth.Attributes = make(map[string]string)
+	}
+	if hash != "" {
+		auth.Attributes["excluded_models_hash"] = hash
+	}
+	if authKind != "" {
+		auth.Attributes["auth_kind"] = authKind
+	}
+}
+
+// addConfigHeadersToAttrs adds header configuration to auth attributes.
+// Headers are prefixed with "header:" in the attributes map.
+func addConfigHeadersToAttrs(headers map[string]string, attrs map[string]string) {
+	if len(headers) == 0 || attrs == nil {
+		return
+	}
+	for hk, hv := range headers {
+		key := strings.TrimSpace(hk)
+		val := strings.TrimSpace(hv)
+		if key == "" || val == "" {
+			continue
+		}
+		attrs["header:"+key] = val
+	}
+}