feat: 支持后台设置是否启用整流开关

backend/internal/service/gateway_request.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"math"
+	"strings"
 	"unsafe"
 
 	"github.com/Wei-Shaw/sub2api/internal/domain"
@@ -675,3 +676,90 @@ func filterThinkingBlocksInternal(body []byte, _ bool) []byte {
 	}
 	return newBody
 }
+
+// =========================
+// Thinking Budget Rectifier
+// =========================
+
+const (
+	// BudgetRectifyBudgetTokens is the budget_tokens value to set when rectifying.
+	BudgetRectifyBudgetTokens = 32000
+	// BudgetRectifyMaxTokens is the max_tokens value to set when rectifying.
+	BudgetRectifyMaxTokens = 64000
+	// BudgetRectifyMinMaxTokens is the minimum max_tokens that must exceed budget_tokens.
+	BudgetRectifyMinMaxTokens = 32001
+)
+
+// isThinkingBudgetConstraintError detects whether an upstream error message indicates
+// a budget_tokens constraint violation (e.g. "budget_tokens >= 1024").
+// Matches three conditions (all must be true):
+//  1. Contains "budget_tokens" or "budget tokens"
+//  2. Contains "thinking"
+//  3. Contains ">= 1024" or "greater than or equal to 1024" or ("1024" + "input should be")
+func isThinkingBudgetConstraintError(errMsg string) bool {
+	m := strings.ToLower(errMsg)
+
+	// Condition 1: budget_tokens or budget tokens
+	hasBudget := strings.Contains(m, "budget_tokens") || strings.Contains(m, "budget tokens")
+	if !hasBudget {
+		return false
+	}
+
+	// Condition 2: thinking
+	if !strings.Contains(m, "thinking") {
+		return false
+	}
+
+	// Condition 3: constraint indicator
+	if strings.Contains(m, ">= 1024") || strings.Contains(m, "greater than or equal to 1024") {
+		return true
+	}
+	if strings.Contains(m, "1024") && strings.Contains(m, "input should be") {
+		return true
+	}
+
+	return false
+}
+
+// RectifyThinkingBudget modifies the request body to fix budget_tokens constraint errors.
+// It sets thinking.budget_tokens = 32000, thinking.type = "enabled" (unless adaptive),
+// and ensures max_tokens >= 32001.
+// Returns (modified body, true) if changes were applied, or (original body, false) if not.
+func RectifyThinkingBudget(body []byte) ([]byte, bool) {
+	// If thinking type is "adaptive", skip rectification entirely
+	thinkingType := gjson.GetBytes(body, "thinking.type").String()
+	if thinkingType == "adaptive" {
+		return body, false
+	}
+
+	modified := body
+	changed := false
+
+	// Set thinking.type = "enabled"
+	if thinkingType != "enabled" {
+		if result, err := sjson.SetBytes(modified, "thinking.type", "enabled"); err == nil {
+			modified = result
+			changed = true
+		}
+	}
+
+	// Set thinking.budget_tokens = 32000
+	currentBudget := gjson.GetBytes(modified, "thinking.budget_tokens").Int()
+	if currentBudget != BudgetRectifyBudgetTokens {
+		if result, err := sjson.SetBytes(modified, "thinking.budget_tokens", BudgetRectifyBudgetTokens); err == nil {
+			modified = result
+			changed = true
+		}
+	}
+
+	// Ensure max_tokens >= BudgetRectifyMinMaxTokens
+	maxTokens := gjson.GetBytes(modified, "max_tokens").Int()
+	if maxTokens < int64(BudgetRectifyMinMaxTokens) {
+		if result, err := sjson.SetBytes(modified, "max_tokens", BudgetRectifyMaxTokens); err == nil {
+			modified = result
+			changed = true
+		}
+	}
+
+	return modified, changed
+}