query-orchestration/internal/serviceconfig/ratelimit/config_test.go

package ratelimit

import (
	"os"
	"testing"
	"time"

	"golang.org/x/time/rate"
)

func TestDefaultConfig(t *testing.T) {
	cfg := DefaultConfig()

	// Test global defaults
	if cfg.GlobalRate != 500 {
		t.Errorf("Expected GlobalRate=500, got %v", cfg.GlobalRate)
	}
	if cfg.GlobalBurst != 1000 {
		t.Errorf("Expected GlobalBurst=1000, got %d", cfg.GlobalBurst)
	}

	// Test per-IP defaults
	if cfg.DefaultRate != 5 {
		t.Errorf("Expected DefaultRate=5, got %v", cfg.DefaultRate)
	}
	if cfg.DefaultBurst != 10 {
		t.Errorf("Expected DefaultBurst=10, got %d", cfg.DefaultBurst)
	}
	if cfg.ExpiresIn != 3*time.Minute {
		t.Errorf("Expected ExpiresIn=3m, got %v", cfg.ExpiresIn)
	}
	if cfg.EndpointOverrides == nil {
		t.Error("Expected EndpointOverrides to be initialized")
	}
}

func TestLoadConfigDefaults(t *testing.T) {
	// Clear all env vars
	os.Unsetenv("RATE_LIMIT_GLOBAL_RATE")
	os.Unsetenv("RATE_LIMIT_GLOBAL_BURST")
	os.Unsetenv("RATE_LIMIT_DEFAULT_RATE")
	os.Unsetenv("RATE_LIMIT_DEFAULT_BURST")
	os.Unsetenv("RATE_LIMIT_EXPIRES_IN")
	os.Unsetenv("RATE_LIMIT_ENDPOINT_OVERRIDES")

	cfg, err := LoadConfig()
	if err != nil {
		t.Fatalf("LoadConfig failed: %v", err)
	}

	// Should use defaults
	if cfg.GlobalRate != 500 {
		t.Errorf("Expected GlobalRate=500, got %v", cfg.GlobalRate)
	}
	if cfg.DefaultRate != 5 {
		t.Errorf("Expected DefaultRate=5, got %v", cfg.DefaultRate)
	}
}

func TestLoadConfigFromEnvironment(t *testing.T) {
	// Set env vars
	t.Setenv("RATE_LIMIT_GLOBAL_RATE", "500")
	t.Setenv("RATE_LIMIT_GLOBAL_BURST", "1000")
	t.Setenv("RATE_LIMIT_DEFAULT_RATE", "5")
	t.Setenv("RATE_LIMIT_DEFAULT_BURST", "10")
	t.Setenv("RATE_LIMIT_EXPIRES_IN", "300")

	cfg, err := LoadConfig()
	if err != nil {
		t.Fatalf("LoadConfig failed: %v", err)
	}

	// Test global limits
	if cfg.GlobalRate != rate.Limit(500) {
		t.Errorf("Expected GlobalRate=500, got %v", cfg.GlobalRate)
	}
	if cfg.GlobalBurst != 1000 {
		t.Errorf("Expected GlobalBurst=1000, got %d", cfg.GlobalBurst)
	}

	// Test per-IP limits
	if cfg.DefaultRate != rate.Limit(5) {
		t.Errorf("Expected DefaultRate=5, got %v", cfg.DefaultRate)
	}
	if cfg.DefaultBurst != 10 {
		t.Errorf("Expected DefaultBurst=10, got %d", cfg.DefaultBurst)
	}
	if cfg.ExpiresIn != 5*time.Minute {
		t.Errorf("Expected ExpiresIn=5m, got %v", cfg.ExpiresIn)
	}
}

func TestLoadConfigWithEndpointOverrides(t *testing.T) {
	// Set endpoint overrides
	overridesJSON := `{
		"POST /documents": {
			"global_rate": 100,
			"global_burst": 200,
			"rate": 5,
			"burst": 10
		},
		"GET /health": {
			"global_rate": 500,
			"global_burst": 1000,
			"rate": 100,
			"burst": 200
		}
	}`
	t.Setenv("RATE_LIMIT_ENDPOINT_OVERRIDES", overridesJSON)

	cfg, err := LoadConfig()
	if err != nil {
		t.Fatalf("LoadConfig failed: %v", err)
	}

	// Test POST /documents override
	override, exists := cfg.EndpointOverrides["POST /documents"]
	if !exists {
		t.Fatal("Expected 'POST /documents' override to exist")
	}
	if override.GlobalRate != rate.Limit(100) {
		t.Errorf("Expected GlobalRate=100, got %v", override.GlobalRate)
	}
	if override.GlobalBurst != 200 {
		t.Errorf("Expected GlobalBurst=200, got %d", override.GlobalBurst)
	}
	if override.Rate != rate.Limit(5) {
		t.Errorf("Expected Rate=5, got %v", override.Rate)
	}
	if override.Burst != 10 {
		t.Errorf("Expected Burst=10, got %d", override.Burst)
	}

	// Test GET /health override
	override, exists = cfg.EndpointOverrides["GET /health"]
	if !exists {
		t.Fatal("Expected 'GET /health' override to exist")
	}
	if override.GlobalRate != rate.Limit(500) {
		t.Errorf("Expected GlobalRate=500, got %v", override.GlobalRate)
	}
	if override.Rate != rate.Limit(100) {
		t.Errorf("Expected Rate=100, got %v", override.Rate)
	}
}

func TestLoadConfigWithEmptyOverrides(t *testing.T) {
	t.Setenv("RATE_LIMIT_ENDPOINT_OVERRIDES", "{}")

	cfg, err := LoadConfig()
	if err != nil {
		t.Fatalf("LoadConfig failed: %v", err)
	}

	if len(cfg.EndpointOverrides) != 0 {
		t.Errorf("Expected no overrides, got %d", len(cfg.EndpointOverrides))
	}
}

func TestLoadConfigWithInvalidJSON(t *testing.T) {
	t.Setenv("RATE_LIMIT_ENDPOINT_OVERRIDES", "invalid json")

	cfg, err := LoadConfig()
	if err != nil {
		t.Fatalf("LoadConfig failed: %v", err)
	}

	// Should ignore invalid JSON and use defaults
	if len(cfg.EndpointOverrides) != 0 {
		t.Errorf("Expected no overrides for invalid JSON, got %d", len(cfg.EndpointOverrides))
	}
}

func TestLoadConfigWithInvalidNumbers(t *testing.T) {
	t.Setenv("RATE_LIMIT_GLOBAL_RATE", "invalid")
	t.Setenv("RATE_LIMIT_DEFAULT_BURST", "not_a_number")

	cfg, err := LoadConfig()
	if err != nil {
		t.Fatalf("LoadConfig failed: %v", err)
	}

	// Should use defaults for invalid values
	if cfg.GlobalRate != 500 {
		t.Errorf("Expected GlobalRate=500 (default), got %v", cfg.GlobalRate)
	}
	if cfg.DefaultBurst != 10 {
		t.Errorf("Expected DefaultBurst=10 (default), got %d", cfg.DefaultBurst)
	}
}