package vpn

import (
	"os"
	"path/filepath"
	"testing"
)

func TestVXLANManagerBasics(t *testing.T) {
	tmpDir := t.TempDir()
	storePath := filepath.Join(tmpDir, "vxlan.json")

	mgr := NewVXLANManager(storePath)
	if mgr == nil {
		t.Fatal("expected non-nil VXLANManager")
	}

	// 1. Validation checks
	err := mgr.Save(&VXLANInstance{
		VNI: 0,
	})
	if err == nil {
		t.Fatal("expected error for VNI <= 0")
	}

	err = mgr.Save(&VXLANInstance{
		VNI: 16777216,
	})
	if err == nil {
		t.Fatal("expected error for VNI > 16777215")
	}

	// 2. Save a disabled VXLAN instance (does not invoke kernel netlink)
	inst1 := &VXLANInstance{
		ID:       "vxlan-test-1",
		Name:     "vxlan-test1",
		VNI:      100,
		Disabled: true,
		Comment:  "Test VXLAN 1",
	}
	if err := mgr.Save(inst1); err != nil {
		t.Fatalf("failed to save inst1: %v", err)
	}

	// Validate auto-defaults
	if inst1.Port != 4789 {
		t.Errorf("expected default port 4789, got %d", inst1.Port)
	}
	if inst1.MTU != 1500 {
		t.Errorf("expected default MTU 1500, got %d", inst1.MTU)
	}
	if inst1.MACAddress == "" {
		t.Error("expected auto-generated MAC address")
	}

	// 3. Get and List
	got, found := mgr.Get("vxlan-test-1")
	if !found || got == nil {
		t.Fatal("expected to find vxlan-test-1 by ID")
	}
	if got.Name != "vxlan-test1" {
		t.Errorf("expected name vxlan-test1, got %s", got.Name)
	}

	gotByName, found := mgr.Get("vxlan-test1")
	if !found || gotByName == nil {
		t.Fatal("expected to find vxlan-test1 by Name")
	}

	list := mgr.List()
	if len(list) != 1 {
		t.Fatalf("expected 1 tunnel, got %d", len(list))
	}

	// 4. Duplicate checks
	dupVNI := &VXLANInstance{
		ID:       "vxlan-test-dup",
		Name:     "vxlan-test-other",
		VNI:      100,
		Port:     4789,
		Disabled: true,
	}
	if err := mgr.Save(dupVNI); err == nil {
		t.Fatal("expected error on duplicate VNI+Port")
	}

	dupName := &VXLANInstance{
		ID:       "vxlan-test-dup-name",
		Name:     "vxlan-test1",
		VNI:      200,
		Disabled: true,
	}
	if err := mgr.Save(dupName); err == nil {
		t.Fatal("expected error on duplicate Name")
	}

	// 5. VTEP management
	vtep1 := &VXLANVtep{
		RemoteIP: "192.168.1.10",
		Comment:  "Remote Office VTEP",
	}
	if err := mgr.AddVtep("vxlan-test-1", vtep1); err != nil {
		t.Fatalf("failed to add VTEP: %v", err)
	}

	// Duplicate VTEP remote IP check
	if err := mgr.AddVtep("vxlan-test-1", &VXLANVtep{RemoteIP: "192.168.1.10"}); err == nil {
		t.Fatal("expected error for duplicate remote IP VTEP")
	}

	// Invalid remote IP
	if err := mgr.AddVtep("vxlan-test-1", &VXLANVtep{RemoteIP: "invalid-ip"}); err == nil {
		t.Fatal("expected error for invalid remote IP")
	}

	vteps := mgr.ListVteps("vxlan-test1")
	if len(vteps) != 1 {
		t.Fatalf("expected 1 VTEP, got %d", len(vteps))
	}
	if vteps[0].RemoteIP != "192.168.1.10" {
		t.Errorf("expected 192.168.1.10, got %s", vteps[0].RemoteIP)
	}

	// Delete VTEP
	if err := mgr.DeleteVtep("vxlan-test1", "192.168.1.10"); err != nil {
		t.Fatalf("failed to delete VTEP: %v", err)
	}
	if len(mgr.ListVteps("vxlan-test1")) != 0 {
		t.Fatal("expected 0 VTEPs after deletion")
	}

	// 6. Delete tunnel
	if err := mgr.Delete("vxlan-test-1"); err != nil {
		t.Fatalf("failed to delete tunnel: %v", err)
	}
	if len(mgr.List()) != 0 {
		t.Fatal("expected 0 tunnels after deletion")
	}

	// Verify persistence file exists and is valid
	if _, err := os.Stat(storePath); err != nil {
		t.Fatalf("expected store file to exist: %v", err)
	}
}