package api

import (
	"bytes"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"path/filepath"
	"testing"

	"debtik/internal/auth"
	"debtik/internal/vpn"
)

func setupTestVXLANServer(t *testing.T) (*Server, *vpn.Manager) {
	tmpDir := t.TempDir()
	authPath := filepath.Join(tmpDir, "users.json")
	authMgr := auth.NewManager(authPath)

	vpnMgr := &vpn.Manager{
		VXLAN: vpn.NewVXLANManager(filepath.Join(tmpDir, "vxlan.json")),
	}

	srv := &Server{
		vpnMgr:    vpnMgr,
		authMgr:   authMgr,
		mux:       http.NewServeMux(),
		fsHandler: http.NotFoundHandler(),
	}
	srv.registerRoutes()
	return srv, vpnMgr
}

func TestVXLANAPIEndpoints(t *testing.T) {
	srv, _ := setupTestVXLANServer(t)

	// 1. GET /api/vpn/vxlan (empty initially)
	req := httptest.NewRequest(http.MethodGet, "/api/vpn/vxlan", nil)
	rec := httptest.NewRecorder()
	srv.mux.ServeHTTP(rec, req)
	if rec.Code != http.StatusOK {
		t.Fatalf("GET /api/vpn/vxlan code = %d; want 200", rec.Code)
	}

	var list []*vpn.VXLANInstance
	if err := json.NewDecoder(rec.Body).Decode(&list); err != nil {
		t.Fatalf("decode failed: %v", err)
	}
	if len(list) != 0 {
		t.Fatalf("expected 0 vxlan tunnels, got %d", len(list))
	}

	// 2. POST /api/vpn/vxlan (create disabled instance)
	payload := vpn.VXLANInstance{
		ID:       "vxlan-unit-1",
		Name:     "vxlan-test",
		VNI:      1050,
		Port:     4789,
		Disabled: true,
		Comment:  "API test vxlan",
	}
	b, _ := json.Marshal(payload)
	req = httptest.NewRequest(http.MethodPost, "/api/vpn/vxlan", bytes.NewReader(b))
	rec = httptest.NewRecorder()
	srv.mux.ServeHTTP(rec, req)
	if rec.Code != http.StatusOK {
		t.Fatalf("POST /api/vpn/vxlan code = %d, body = %s; want 200", rec.Code, rec.Body.String())
	}

	// 3. GET /api/interface/vxlan alias
	req = httptest.NewRequest(http.MethodGet, "/api/interface/vxlan", nil)
	rec = httptest.NewRecorder()
	srv.mux.ServeHTTP(rec, req)
	if rec.Code != http.StatusOK {
		t.Fatalf("GET /api/interface/vxlan code = %d; want 200", rec.Code)
	}
	list = nil
	_ = json.NewDecoder(rec.Body).Decode(&list)
	if len(list) != 1 || list[0].Name != "vxlan-test" {
		t.Fatalf("expected 1 vxlan named vxlan-test, got %+v", list)
	}

	// 4. POST /api/vpn/vxlan/vteps
	vtepPayload := vpn.VXLANVtep{
		Interface: "vxlan-test",
		RemoteIP:  "192.168.100.2",
		Comment:   "Remote VTEP 1",
	}
	vb, _ := json.Marshal(vtepPayload)
	req = httptest.NewRequest(http.MethodPost, "/api/vpn/vxlan/vteps", bytes.NewReader(vb))
	rec = httptest.NewRecorder()
	srv.mux.ServeHTTP(rec, req)
	if rec.Code != http.StatusOK {
		t.Fatalf("POST /api/vpn/vxlan/vteps code = %d, body = %s; want 200", rec.Code, rec.Body.String())
	}

	// 5. GET /api/vpn/vxlan/vteps
	req = httptest.NewRequest(http.MethodGet, "/api/vpn/vxlan/vteps?interface=vxlan-test", nil)
	rec = httptest.NewRecorder()
	srv.mux.ServeHTTP(rec, req)
	if rec.Code != http.StatusOK {
		t.Fatalf("GET /api/vpn/vxlan/vteps code = %d; want 200", rec.Code)
	}
	var vteps []*vpn.VXLANVtep
	_ = json.NewDecoder(rec.Body).Decode(&vteps)
	if len(vteps) != 1 || vteps[0].RemoteIP != "192.168.100.2" {
		t.Fatalf("expected 1 vtep with remote-ip 192.168.100.2, got %+v", vteps)
	}

	// 6. DELETE /api/vpn/vxlan/{id}/vteps/{vtepid}
	req = httptest.NewRequest(http.MethodDelete, "/api/vpn/vxlan/vxlan-unit-1/vteps/192.168.100.2", nil)
	rec = httptest.NewRecorder()
	srv.mux.ServeHTTP(rec, req)
	if rec.Code != http.StatusOK {
		t.Fatalf("DELETE vtep code = %d, body = %s; want 200", rec.Code, rec.Body.String())
	}

	// 7. DELETE /api/vpn/vxlan/{id}
	req = httptest.NewRequest(http.MethodDelete, "/api/vpn/vxlan/vxlan-unit-1", nil)
	rec = httptest.NewRecorder()
	srv.mux.ServeHTTP(rec, req)
	if rec.Code != http.StatusOK {
		t.Fatalf("DELETE vxlan code = %d; want 200", rec.Code)
	}

	req = httptest.NewRequest(http.MethodGet, "/api/vpn/vxlan", nil)
	rec = httptest.NewRecorder()
	srv.mux.ServeHTTP(rec, req)
	list = nil
	_ = json.NewDecoder(rec.Body).Decode(&list)
	if len(list) != 0 {
		t.Fatalf("expected 0 vxlan tunnels after delete, got %d", len(list))
	}
}