package uhf

import (
	"testing"
	"time"

	"github.com/stretchr/testify/require"
)

func TestChannelEventsUseMonotonicIDs(t *testing.T) {
	channelEventMu.Lock()
	previousQueue := ChannelEventQueue
	previousNextID := channelEventNextID
	ChannelEventQueue = make([]ChannelEvent, 0, 50)
	channelEventNextID = 0
	channelEventMu.Unlock()
	t.Cleanup(func() {
		channelEventMu.Lock()
		ChannelEventQueue = previousQueue
		channelEventNextID = previousNextID
		channelEventMu.Unlock()
	})

	PushChannelEvent(ChannelEvent{RFIDTag: "A", Timestamp: 100})
	PushChannelEvent(ChannelEvent{RFIDTag: "B", Timestamp: 100})

	all := GetChannelEvents(0)
	require.Len(t, all, 2)
	require.Equal(t, uint64(1), all[0].ID)
	require.Equal(t, uint64(2), all[1].ID)

	afterFirst := GetChannelEvents(all[0].ID)
	require.Len(t, afterFirst, 1)
	require.Equal(t, "B", afterFirst[0].RFIDTag)
}

func TestDeviceHandlerAcceptReportDeduplicatesDeviceAndEPC(t *testing.T) {
	h := &DeviceHandler{lastReport: make(map[string]time.Time)}
	base := time.Unix(100, 0)
	report := &ReportData{DeviceCode: "RFID-01", Epcs: []string{"e20001"}}

	if !h.acceptReport(report, base) {
		t.Fatal("first report should be accepted")
	}
	if h.acceptReport(report, base.Add(reportDebounceWindow-time.Nanosecond)) {
		t.Fatal("duplicate report inside debounce window should be rejected")
	}
	if !h.acceptReport(report, base.Add(reportDebounceWindow)) {
		t.Fatal("report at the end of debounce window should be accepted")
	}
}

func TestDeviceHandlerAcceptReportAllowsDifferentEPCs(t *testing.T) {
	h := &DeviceHandler{lastReport: make(map[string]time.Time)}
	now := time.Unix(200, 0)

	if !h.acceptReport(&ReportData{DeviceCode: "RFID-01", Epcs: []string{"e20001"}}, now) {
		t.Fatal("first EPC should be accepted")
	}
	if !h.acceptReport(&ReportData{DeviceCode: "RFID-01", Epcs: []string{"e20002"}}, now) {
		t.Fatal("different EPC should be accepted")
	}
	if !h.acceptReport(&ReportData{DeviceCode: "RFID-02", Epcs: []string{"e20001"}}, now) {
		t.Fatal("same EPC from a different device should be accepted")
	}
}