feat: scaffold go backend foundation

internal/config/config.go

@@ -0,0 +1,37 @@
+package config
+
+import "os"
+
+const (
+	defaultHTTPAddr        = ":8080"
+	defaultEnvironment     = "development"
+	defaultModelKey        = "deepseek-v4-flash"
+	defaultThirdOneBin     = "thirdone"
+	defaultWorkflowRuntime = ""
+)
+
+type Config struct {
+	HTTPAddr        string
+	Environment     string
+	WorkflowRuntime string
+	ModelKey        string
+	ThirdOneBin     string
+}
+
+func LoadFromEnv() Config {
+	return Config{
+		HTTPAddr:        envOrDefault("TUTOR_HTTP_ADDR", defaultHTTPAddr),
+		Environment:     envOrDefault("TUTOR_ENV", defaultEnvironment),
+		WorkflowRuntime: envOrDefault("TUTOR_WORKFLOW_RUNTIME", defaultWorkflowRuntime),
+		ModelKey:        envOrDefault("TUTOR_MODEL_KEY", defaultModelKey),
+		ThirdOneBin:     envOrDefault("THIRDONE_BIN", defaultThirdOneBin),
+	}
+}
+
+func envOrDefault(key string, fallback string) string {
+	value := os.Getenv(key)
+	if value == "" {
+		return fallback
+	}
+	return value
+}

internal/config/config_test.go

@@ -0,0 +1,52 @@
+package config
+
+import "testing"
+
+func TestLoadFromEnvDefaults(t *testing.T) {
+	t.Setenv("TUTOR_HTTP_ADDR", "")
+	t.Setenv("TUTOR_ENV", "")
+	t.Setenv("TUTOR_WORKFLOW_RUNTIME", "")
+	t.Setenv("TUTOR_MODEL_KEY", "")
+	t.Setenv("THIRDONE_BIN", "")
+
+	cfg := LoadFromEnv()
+
+	if cfg.HTTPAddr != defaultHTTPAddr {
+		t.Fatalf("HTTPAddr = %q, want %q", cfg.HTTPAddr, defaultHTTPAddr)
+	}
+	if cfg.Environment != defaultEnvironment {
+		t.Fatalf("Environment = %q, want %q", cfg.Environment, defaultEnvironment)
+	}
+	if cfg.ModelKey != defaultModelKey {
+		t.Fatalf("ModelKey = %q, want %q", cfg.ModelKey, defaultModelKey)
+	}
+	if cfg.ThirdOneBin != defaultThirdOneBin {
+		t.Fatalf("ThirdOneBin = %q, want %q", cfg.ThirdOneBin, defaultThirdOneBin)
+	}
+}
+
+func TestLoadFromEnvOverrides(t *testing.T) {
+	t.Setenv("TUTOR_HTTP_ADDR", ":9090")
+	t.Setenv("TUTOR_ENV", "test")
+	t.Setenv("TUTOR_WORKFLOW_RUNTIME", "runtime.yaml")
+	t.Setenv("TUTOR_MODEL_KEY", "other-model")
+	t.Setenv("THIRDONE_BIN", "C:/bin/thirdone.exe")
+
+	cfg := LoadFromEnv()
+
+	if cfg.HTTPAddr != ":9090" {
+		t.Fatalf("HTTPAddr = %q", cfg.HTTPAddr)
+	}
+	if cfg.Environment != "test" {
+		t.Fatalf("Environment = %q", cfg.Environment)
+	}
+	if cfg.WorkflowRuntime != "runtime.yaml" {
+		t.Fatalf("WorkflowRuntime = %q", cfg.WorkflowRuntime)
+	}
+	if cfg.ModelKey != "other-model" {
+		t.Fatalf("ModelKey = %q", cfg.ModelKey)
+	}
+	if cfg.ThirdOneBin != "C:/bin/thirdone.exe" {
+		t.Fatalf("ThirdOneBin = %q", cfg.ThirdOneBin)
+	}
+}