Centralize execution setting and session validation

internal/llm/openai_compatible_client.go

@@ -70,8 +70,8 @@ func NewOpenAICompatibleClient(cfg OpenAICompatibleConfig) (*OpenAICompatibleCli
 }
 
 func (c *OpenAICompatibleClient) Generate(ctx context.Context, req domain.GenerateRequest) (*domain.GenerateResponse, error) {
-	if req.Target.TimeoutSeconds < 0 {
-		return nil, fmt.Errorf("%w: timeout_seconds must be greater than or equal to 0", ErrInvalidRequest)
+	if err := domain.ValidateExecutionTargetSettings(req.Target); err != nil {
+		return nil, fmt.Errorf("%w: %v", ErrInvalidRequest, err)
 	}
 
 	endpoint := strings.TrimSpace(req.Target.Endpoint)

internal/llm/openai_compatible_client_test.go

@@ -7,6 +7,7 @@ import (
 	"math"
 	"net/http"
 	"net/http/httptest"
+	"strconv"
 	"strings"
 	"testing"
 	"time"
@@ -1128,7 +1129,7 @@ func TestOpenAICompatibleClientCancellationReturnsRequestFailure(t *testing.T) {
 	}
 }
 
-func TestOpenAICompatibleClientNegativeTimeoutRejected(t *testing.T) {
+func TestOpenAICompatibleClientRejectsInvalidExecutionSettings(t *testing.T) {
 	client, err := NewOpenAICompatibleClient(OpenAICompatibleConfig{
 		BaseURL: "http://example.com/v1",
 		Model:   "m",
@@ -1137,15 +1138,34 @@ func TestOpenAICompatibleClientNegativeTimeoutRejected(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	_, err = client.Generate(context.Background(), domain.GenerateRequest{
-		Prompt: domain.RenderedPrompt{Messages: []domain.RenderedMessage{{Role: "user", Content: "hi"}}},
-		Target: domain.ExecutionTarget{TimeoutSeconds: -1},
-	})
-	if err == nil {
-		t.Fatal("expected invalid request error")
+	type testCase struct {
+		name   string
+		target domain.ExecutionTarget
 	}
-	if !errors.Is(err, ErrInvalidRequest) {
-		t.Fatalf("expected ErrInvalidRequest, got %v", err)
+	tests := []testCase{
+		{name: "non-finite temperature", target: domain.ExecutionTarget{Temperature: math.NaN()}},
+		{name: "negative max tokens", target: domain.ExecutionTarget{MaxTokens: -1}},
+		{name: "non-finite top p", target: domain.ExecutionTarget{TopP: math.Inf(1)}},
+		{name: "negative timeout", target: domain.ExecutionTarget{TimeoutSeconds: -1}},
+	}
+	if strconv.IntSize == 64 {
+		durationLimit := int64(math.MaxInt64 / int64(time.Second))
+		tests = append(tests, testCase{name: "unrepresentable timeout", target: domain.ExecutionTarget{TimeoutSeconds: int(durationLimit) + 1}})
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			_, err := client.Generate(context.Background(), domain.GenerateRequest{
+				Prompt: domain.RenderedPrompt{Messages: []domain.RenderedMessage{{Role: "user", Content: "hi"}}},
+				Target: tt.target,
+			})
+			if err == nil {
+				t.Fatal("expected invalid request error")
+			}
+			if !errors.Is(err, ErrInvalidRequest) {
+				t.Fatalf("expected ErrInvalidRequest, got %v", err)
+			}
+		})
 	}
 }