WeKnora deployment source with the reviewed wiki identity, summary and recovery fixes

internal/models/chat/usage.go

@@ -0,0 +1,46 @@
+package chat
+
+import (
+	"context"
+	"strings"
+
+	"github.com/Tencent/WeKnora/internal/logger"
+	"github.com/Tencent/WeKnora/internal/types"
+)
+
+// logUsage emits the standard "[LLM Usage]" line shared by every Chat
+// implementation. It is a no-op when usage is nil so callers can pass through
+// optional usage blocks without guarding at each call site.
+func logUsage(ctx context.Context, model string, u *types.TokenUsage) {
+	if u == nil {
+		return
+	}
+	purpose, prefixFingerprint := types.LLMCallMetadataFromContext(ctx)
+	logger.Infof(ctx,
+		"[LLM Usage] model=%s, purpose=%s, prompt_prefix=%s, prompt_tokens=%d, completion_tokens=%d, "+
+			"total_tokens=%d, cached_tokens=%d, cache_read_tokens=%d, cache_write_tokens=%d, "+
+			"cache_miss_tokens=%d, cache_hit_rate=%.1f%%, cache_reported=%t, cache_status=%s%s",
+		model, purpose, prefixFingerprint, u.PromptTokens, u.CompletionTokens, u.TotalTokens,
+		u.CachedTokens, u.CacheReadTokens, u.CacheWriteTokens, u.CacheMissTokens,
+		u.PromptCacheHitRate(), u.CacheReported, u.CacheStatus, usageAttribution(ctx))
+}
+
+// usageAttribution renders the ", session_id=…, principal=…" suffix that
+// attributes a usage line to the session and terminal principal that
+// triggered the call. Calls that run outside a session or without a resolved
+// principal (document parsing, title generation, background jobs) render an
+// empty suffix, keeping their lines byte-identical to before.
+func usageAttribution(ctx context.Context) string {
+	var b strings.Builder
+	if sessionID, ok := types.SessionIDFromContext(ctx); ok && sessionID != "" {
+		b.WriteString(", session_id=")
+		b.WriteString(sessionID)
+	}
+	if principal, ok := types.PrincipalFromContext(ctx); ok {
+		b.WriteString(", principal=")
+		b.WriteString(principal.Type)
+		b.WriteString(":")
+		b.WriteString(principal.ID)
+	}
+	return b.String()
+}