fix(openai): normalize codex responses payloads

backend/internal/service/openai_codex_transform_test.go

@@ -164,6 +164,131 @@ func TestApplyCodexOAuthTransform_ImageAndWebSearchCallsDoNotGainCallID(t *testi
 	require.False(t, hasCallID)
 }
 
+func TestApplyCodexOAuthTransform_ConvertsToolRoleMessageToFunctionCallOutput(t *testing.T) {
+	reqBody := map[string]any{
+		"model": "gpt-5.4",
+		"input": []any{
+			map[string]any{
+				"type":         "message",
+				"role":         "tool",
+				"tool_call_id": "call_1",
+				"content":      "ok",
+			},
+		},
+	}
+
+	applyCodexOAuthTransform(reqBody, true, false)
+
+	input, ok := reqBody["input"].([]any)
+	require.True(t, ok)
+	require.Len(t, input, 1)
+
+	item, ok := input[0].(map[string]any)
+	require.True(t, ok)
+	require.Equal(t, "function_call_output", item["type"])
+	require.Equal(t, "fc1", item["call_id"])
+	require.Equal(t, "ok", item["output"])
+	_, hasRole := item["role"]
+	require.False(t, hasRole)
+}
+
+func TestApplyCodexOAuthTransform_StringifiesNonStringMessageContentText(t *testing.T) {
+	reqBody := map[string]any{
+		"model": "gpt-5.4",
+		"input": []any{
+			map[string]any{
+				"type": "message",
+				"role": "user",
+				"content": []any{
+					map[string]any{"type": "input_text", "text": []any{"a", "b"}},
+				},
+			},
+		},
+	}
+
+	applyCodexOAuthTransform(reqBody, true, false)
+
+	input, ok := reqBody["input"].([]any)
+	require.True(t, ok)
+	item, ok := input[0].(map[string]any)
+	require.True(t, ok)
+	content, ok := item["content"].([]any)
+	require.True(t, ok)
+	part, ok := content[0].(map[string]any)
+	require.True(t, ok)
+	require.Equal(t, `["a","b"]`, part["text"])
+}
+
+func TestApplyCodexOAuthTransform_DowngradesUnknownToolChoice(t *testing.T) {
+	reqBody := map[string]any{
+		"model": "gpt-5.4",
+		"tools": []any{
+			map[string]any{"type": "function", "name": "shell"},
+		},
+		"tool_choice": map[string]any{"type": "custom"},
+	}
+
+	applyCodexOAuthTransform(reqBody, true, false)
+
+	require.Equal(t, "auto", reqBody["tool_choice"])
+}
+
+func TestApplyCodexOAuthTransform_PreservesKnownToolChoice(t *testing.T) {
+	reqBody := map[string]any{
+		"model": "gpt-5.4",
+		"tools": []any{
+			map[string]any{"type": "custom", "name": "shell"},
+		},
+		"tool_choice": map[string]any{"type": "custom"},
+	}
+
+	applyCodexOAuthTransform(reqBody, true, false)
+
+	choice, ok := reqBody["tool_choice"].(map[string]any)
+	require.True(t, ok)
+	require.Equal(t, "custom", choice["type"])
+}
+
+func TestApplyCodexOAuthTransform_AddsFallbackNameForFunctionCallInput(t *testing.T) {
+	reqBody := map[string]any{
+		"model": "gpt-5.4",
+		"input": []any{
+			map[string]any{"type": "message", "role": "user", "content": "run tool"},
+			map[string]any{"type": "function_call", "call_id": "call_1", "arguments": "{}"},
+		},
+	}
+
+	applyCodexOAuthTransform(reqBody, true, false)
+
+	input, ok := reqBody["input"].([]any)
+	require.True(t, ok)
+	require.Len(t, input, 2)
+	item, ok := input[1].(map[string]any)
+	require.True(t, ok)
+	require.Equal(t, "function_call", item["type"])
+	require.Equal(t, "tool", item["name"])
+	require.Equal(t, "fc1", item["call_id"])
+}
+
+func TestApplyCodexOAuthTransform_PreservesFunctionCallInputName(t *testing.T) {
+	reqBody := map[string]any{
+		"model": "gpt-5.4",
+		"input": []any{
+			map[string]any{"type": "custom_tool_call", "call_id": "call_1", "name": "shell", "input": "pwd"},
+		},
+	}
+
+	applyCodexOAuthTransform(reqBody, true, false)
+
+	input, ok := reqBody["input"].([]any)
+	require.True(t, ok)
+	require.Len(t, input, 1)
+	item, ok := input[0].(map[string]any)
+	require.True(t, ok)
+	require.Equal(t, "shell", item["name"])
+	require.Equal(t, "fc1", item["call_id"])
+}
+
 func TestApplyCodexOAuthTransform_ExplicitStoreFalsePreserved(t *testing.T) {
 	// 续链场景：显式 store=false 不再强制为 true，保持 false。