feat(util): implement dynamic thinking suffix normalization and refactor budget resolution logic

- Added support for parsing and normalizing dynamic thinking model suffixes.
- Centralized budget resolution across executors and payload helpers.
- Retired legacy Gemini-specific thinking handlers in favor of unified logic.
- Updated executors to use metadata-based thinking configuration.
- Added `ResolveOriginalModel` utility for resolving normalized upstream models using request metadata.
- Updated executors (Gemini, Codex, iFlow, OpenAI, Qwen) to incorporate upstream model resolution and substitute model values in payloads and request URLs.
- Ensured fallbacks handle cases with missing or malformed metadata to derive models robustly.
- Refactored upstream model resolution to dynamically incorporate metadata for selecting and normalizing models.
- Improved handling of thinking configurations and model overrides in executors.
- Removed hardcoded thinking model entries and migrated logic to metadata-based resolution.
- Updated payload mutations to always include the resolved model.

internal/util/gemini_thinking.go

@@ -1,8 +1,6 @@
 package util
 
 import (
-	"encoding/json"
-	"strconv"
 	"strings"
 
 	"github.com/tidwall/gjson"
@@ -15,80 +13,6 @@ const (
 	GeminiOriginalModelMetadataKey   = "gemini_original_model"
 )
 
-func ParseGeminiThinkingSuffix(model string) (string, *int, *bool, bool) {
-	if model == "" {
-		return model, nil, nil, false
-	}
-	lower := strings.ToLower(model)
-	if !strings.HasPrefix(lower, "gemini-") {
-		return model, nil, nil, false
-	}
-
-	if strings.HasSuffix(lower, "-nothinking") {
-		base := model[:len(model)-len("-nothinking")]
-		budgetValue := 0
-		if strings.HasPrefix(lower, "gemini-2.5-pro") {
-			budgetValue = 128
-		}
-		include := false
-		return base, &budgetValue, &include, true
-	}
-
-	// Handle "-reasoning" suffix: enables thinking with dynamic budget (-1)
-	// Maps: gemini-2.5-flash-reasoning -> gemini-2.5-flash with thinkingBudget=-1
-	if strings.HasSuffix(lower, "-reasoning") {
-		base := model[:len(model)-len("-reasoning")]
-		budgetValue := -1 // Dynamic budget
-		include := true
-		return base, &budgetValue, &include, true
-	}
-
-	idx := strings.LastIndex(lower, "-thinking-")
-	if idx == -1 {
-		return model, nil, nil, false
-	}
-
-	digits := model[idx+len("-thinking-"):]
-	if digits == "" {
-		return model, nil, nil, false
-	}
-	end := len(digits)
-	for i := 0; i < len(digits); i++ {
-		if digits[i] < '0' || digits[i] > '9' {
-			end = i
-			break
-		}
-	}
-	if end == 0 {
-		return model, nil, nil, false
-	}
-	valueStr := digits[:end]
-	value, err := strconv.Atoi(valueStr)
-	if err != nil {
-		return model, nil, nil, false
-	}
-	base := model[:idx]
-	budgetValue := value
-	return base, &budgetValue, nil, true
-}
-
-func NormalizeGeminiThinkingModel(modelName string) (string, map[string]any) {
-	baseModel, budget, include, matched := ParseGeminiThinkingSuffix(modelName)
-	if !matched {
-		return baseModel, nil
-	}
-	metadata := map[string]any{
-		GeminiOriginalModelMetadataKey: modelName,
-	}
-	if budget != nil {
-		metadata[GeminiThinkingBudgetMetadataKey] = *budget
-	}
-	if include != nil {
-		metadata[GeminiIncludeThoughtsMetadataKey] = *include
-	}
-	return baseModel, metadata
-}
-
 func ApplyGeminiThinkingConfig(body []byte, budget *int, includeThoughts *bool) []byte {
 	if budget == nil && includeThoughts == nil {
 		return body
@@ -133,80 +57,6 @@ func ApplyGeminiCLIThinkingConfig(body []byte, budget *int, includeThoughts *boo
 	return updated
 }
 
-func GeminiThinkingFromMetadata(metadata map[string]any) (*int, *bool, bool) {
-	if len(metadata) == 0 {
-		return nil, nil, false
-	}
-	var (
-		budgetPtr  *int
-		includePtr *bool
-		matched    bool
-	)
-	if rawBudget, ok := metadata[GeminiThinkingBudgetMetadataKey]; ok {
-		switch v := rawBudget.(type) {
-		case int:
-			budget := v
-			budgetPtr = &budget
-			matched = true
-		case int32:
-			budget := int(v)
-			budgetPtr = &budget
-			matched = true
-		case int64:
-			budget := int(v)
-			budgetPtr = &budget
-			matched = true
-		case float64:
-			budget := int(v)
-			budgetPtr = &budget
-			matched = true
-		case json.Number:
-			if val, err := v.Int64(); err == nil {
-				budget := int(val)
-				budgetPtr = &budget
-				matched = true
-			}
-		}
-	}
-	if rawInclude, ok := metadata[GeminiIncludeThoughtsMetadataKey]; ok {
-		switch v := rawInclude.(type) {
-		case bool:
-			include := v
-			includePtr = &include
-			matched = true
-		case string:
-			if parsed, err := strconv.ParseBool(v); err == nil {
-				include := parsed
-				includePtr = &include
-				matched = true
-			}
-		case json.Number:
-			if val, err := v.Int64(); err == nil {
-				include := val != 0
-				includePtr = &include
-				matched = true
-			}
-		case int:
-			include := v != 0
-			includePtr = &include
-			matched = true
-		case int32:
-			include := v != 0
-			includePtr = &include
-			matched = true
-		case int64:
-			include := v != 0
-			includePtr = &include
-			matched = true
-		case float64:
-			include := v != 0
-			includePtr = &include
-			matched = true
-		}
-	}
-	return budgetPtr, includePtr, matched
-}
-
 // modelsWithDefaultThinking lists models that should have thinking enabled by default
 // when no explicit thinkingConfig is provided.
 var modelsWithDefaultThinking = map[string]bool{

internal/util/thinking_suffix.go

@@ -0,0 +1,327 @@
+package util
+
+import (
+	"encoding/json"
+	"strconv"
+	"strings"
+)
+
+const (
+	ThinkingBudgetMetadataKey          = "thinking_budget"
+	ThinkingIncludeThoughtsMetadataKey = "thinking_include_thoughts"
+	ReasoningEffortMetadataKey         = "reasoning_effort"
+	ThinkingOriginalModelMetadataKey   = "thinking_original_model"
+)
+
+// NormalizeThinkingModel parses dynamic thinking suffixes on model names and returns
+// the normalized base model with extracted metadata. Supported patterns:
+//   - "-thinking-<number>" extracts a numeric budget
+//   - "-thinking-<level>" extracts a reasoning effort level (minimal/low/medium/high/xhigh/auto/none)
+//   - "-thinking" maps to a default reasoning effort of "medium"
+//   - "-reasoning" maps to dynamic budget (-1) and include_thoughts=true
+//   - "-nothinking" maps to budget=0 and include_thoughts=false
+func NormalizeThinkingModel(modelName string) (string, map[string]any) {
+	if modelName == "" {
+		return modelName, nil
+	}
+
+	lower := strings.ToLower(modelName)
+	baseModel := modelName
+
+	var (
+		budgetOverride  *int
+		includeThoughts *bool
+		reasoningEffort *string
+		matched         bool
+	)
+
+	switch {
+	case strings.HasSuffix(lower, "-nothinking"):
+		baseModel = modelName[:len(modelName)-len("-nothinking")]
+		budget := 0
+		include := false
+		budgetOverride = &budget
+		includeThoughts = &include
+		matched = true
+	case strings.HasSuffix(lower, "-reasoning"):
+		baseModel = modelName[:len(modelName)-len("-reasoning")]
+		budget := -1
+		include := true
+		budgetOverride = &budget
+		includeThoughts = &include
+		matched = true
+	default:
+		if idx := strings.LastIndex(lower, "-thinking-"); idx != -1 {
+			value := modelName[idx+len("-thinking-"):]
+			if value != "" {
+				if parsed, ok := parseIntPrefix(value); ok {
+					baseModel = modelName[:idx]
+					budgetOverride = &parsed
+					matched = true
+				} else if effort, okEffort := normalizeReasoningEffort(value); okEffort {
+					baseModel = modelName[:idx]
+					reasoningEffort = &effort
+					matched = true
+				}
+			}
+		} else if strings.HasSuffix(lower, "-thinking") {
+			baseModel = modelName[:len(modelName)-len("-thinking")]
+			effort := "medium"
+			reasoningEffort = &effort
+			matched = true
+		}
+	}
+
+	if !matched {
+		return baseModel, nil
+	}
+
+	metadata := map[string]any{
+		ThinkingOriginalModelMetadataKey: modelName,
+	}
+	if budgetOverride != nil {
+		metadata[ThinkingBudgetMetadataKey] = *budgetOverride
+	}
+	if includeThoughts != nil {
+		metadata[ThinkingIncludeThoughtsMetadataKey] = *includeThoughts
+	}
+	if reasoningEffort != nil {
+		metadata[ReasoningEffortMetadataKey] = *reasoningEffort
+	}
+	return baseModel, metadata
+}
+
+// ThinkingFromMetadata extracts thinking overrides from metadata produced by NormalizeThinkingModel.
+// It accepts both the new generic keys and legacy Gemini-specific keys.
+func ThinkingFromMetadata(metadata map[string]any) (*int, *bool, *string, bool) {
+	if len(metadata) == 0 {
+		return nil, nil, nil, false
+	}
+
+	var (
+		budgetPtr  *int
+		includePtr *bool
+		effortPtr  *string
+		matched    bool
+	)
+
+	readBudget := func(key string) {
+		if budgetPtr != nil {
+			return
+		}
+		if raw, ok := metadata[key]; ok {
+			if v, okNumber := parseNumberToInt(raw); okNumber {
+				budget := v
+				budgetPtr = &budget
+				matched = true
+			}
+		}
+	}
+
+	readInclude := func(key string) {
+		if includePtr != nil {
+			return
+		}
+		if raw, ok := metadata[key]; ok {
+			switch v := raw.(type) {
+			case bool:
+				val := v
+				includePtr = &val
+				matched = true
+			case *bool:
+				if v != nil {
+					val := *v
+					includePtr = &val
+					matched = true
+				}
+			}
+		}
+	}
+
+	readEffort := func(key string) {
+		if effortPtr != nil {
+			return
+		}
+		if raw, ok := metadata[key]; ok {
+			if val, okStr := raw.(string); okStr && strings.TrimSpace(val) != "" {
+				normalized := strings.ToLower(strings.TrimSpace(val))
+				effortPtr = &normalized
+				matched = true
+			}
+		}
+	}
+
+	readBudget(ThinkingBudgetMetadataKey)
+	readBudget(GeminiThinkingBudgetMetadataKey)
+	readInclude(ThinkingIncludeThoughtsMetadataKey)
+	readInclude(GeminiIncludeThoughtsMetadataKey)
+	readEffort(ReasoningEffortMetadataKey)
+	readEffort("reasoning.effort")
+
+	return budgetPtr, includePtr, effortPtr, matched
+}
+
+// ResolveThinkingConfigFromMetadata derives thinking budget/include overrides,
+// converting reasoning effort strings into budgets when possible.
+func ResolveThinkingConfigFromMetadata(model string, metadata map[string]any) (*int, *bool, bool) {
+	budget, include, effort, matched := ThinkingFromMetadata(metadata)
+	if !matched {
+		return nil, nil, false
+	}
+
+	if budget == nil && effort != nil {
+		if derived, ok := ThinkingEffortToBudget(model, *effort); ok {
+			budget = &derived
+		}
+	}
+	return budget, include, budget != nil || include != nil || effort != nil
+}
+
+// ReasoningEffortFromMetadata resolves a reasoning effort string from metadata,
+// inferring "auto" and "none" when budgets request dynamic or disabled thinking.
+func ReasoningEffortFromMetadata(metadata map[string]any) (string, bool) {
+	budget, include, effort, matched := ThinkingFromMetadata(metadata)
+	if !matched {
+		return "", false
+	}
+	if effort != nil && *effort != "" {
+		return *effort, true
+	}
+	if budget != nil {
+		switch *budget {
+		case -1:
+			return "auto", true
+		case 0:
+			return "none", true
+		}
+	}
+	if include != nil && !*include {
+		return "none", true
+	}
+	return "", true
+}
+
+// ThinkingEffortToBudget maps reasoning effort levels to approximate budgets,
+// clamping the result to the model's supported range.
+func ThinkingEffortToBudget(model, effort string) (int, bool) {
+	if effort == "" {
+		return 0, false
+	}
+	switch strings.ToLower(effort) {
+	case "none":
+		return 0, true
+	case "auto":
+		return NormalizeThinkingBudget(model, -1), true
+	case "minimal":
+		return NormalizeThinkingBudget(model, 512), true
+	case "low":
+		return NormalizeThinkingBudget(model, 1024), true
+	case "medium":
+		return NormalizeThinkingBudget(model, 8192), true
+	case "high":
+		return NormalizeThinkingBudget(model, 24576), true
+	case "xhigh":
+		return NormalizeThinkingBudget(model, 32768), true
+	default:
+		return 0, false
+	}
+}
+
+// ResolveOriginalModel returns the original model name stored in metadata (if present),
+// otherwise falls back to the provided model.
+func ResolveOriginalModel(model string, metadata map[string]any) string {
+	normalize := func(name string) string {
+		if name == "" {
+			return ""
+		}
+		if base, _ := NormalizeThinkingModel(name); base != "" {
+			return base
+		}
+		return strings.TrimSpace(name)
+	}
+
+	if metadata != nil {
+		if v, ok := metadata[ThinkingOriginalModelMetadataKey]; ok {
+			if s, okStr := v.(string); okStr && strings.TrimSpace(s) != "" {
+				if base := normalize(s); base != "" {
+					return base
+				}
+			}
+		}
+		if v, ok := metadata[GeminiOriginalModelMetadataKey]; ok {
+			if s, okStr := v.(string); okStr && strings.TrimSpace(s) != "" {
+				if base := normalize(s); base != "" {
+					return base
+				}
+			}
+		}
+	}
+	// Fallback: try to re-normalize the model name when metadata was dropped.
+	if base := normalize(model); base != "" {
+		return base
+	}
+	return model
+}
+
+func parseIntPrefix(value string) (int, bool) {
+	if value == "" {
+		return 0, false
+	}
+	digits := strings.TrimLeft(value, "-")
+	if digits == "" {
+		return 0, false
+	}
+	end := len(digits)
+	for i := 0; i < len(digits); i++ {
+		if digits[i] < '0' || digits[i] > '9' {
+			end = i
+			break
+		}
+	}
+	if end == 0 {
+		return 0, false
+	}
+	val, err := strconv.Atoi(digits[:end])
+	if err != nil {
+		return 0, false
+	}
+	return val, true
+}
+
+func parseNumberToInt(raw any) (int, bool) {
+	switch v := raw.(type) {
+	case int:
+		return v, true
+	case int32:
+		return int(v), true
+	case int64:
+		return int(v), true
+	case float64:
+		return int(v), true
+	case json.Number:
+		if val, err := v.Int64(); err == nil {
+			return int(val), true
+		}
+	case string:
+		if strings.TrimSpace(v) == "" {
+			return 0, false
+		}
+		if parsed, err := strconv.Atoi(strings.TrimSpace(v)); err == nil {
+			return parsed, true
+		}
+	}
+	return 0, false
+}
+
+func normalizeReasoningEffort(value string) (string, bool) {
+	if value == "" {
+		return "", false
+	}
+	effort := strings.ToLower(strings.TrimSpace(value))
+	switch effort {
+	case "minimal", "low", "medium", "high", "xhigh", "auto", "none":
+		return effort, true
+	default:
+		return "", false
+	}
+}