package service

import (
	"reflect"
	"strings"
	"testing"
)

func TestBuildUSBTicketLayoutPrintsTopToBottom(t *testing.T) {
	data := usbTicketData{
		lotName:     "KTI AIRPORT",
		channelCode: "IN11",
		plateNo:     "2BC1875",
		entryTime:   "30-07-2026 11:14:59",
		slipNo:      "54600",
		ticketNo:    "0123456789abcdef0123456789abcdef",
	}

	ops := buildUSBTicketLayout(data)
	texts := usbTextOperations(ops)
	want := []string{
		"Parking Ticket\n",
		"KTI AIRPORT\n",
		strings.Repeat("-", 42) + "\n",
		"\n",
		"PARK AT YOUR OWN RISK\n",
		"KTI AIRPORT A-General Car\n",
		"In-Time::30-07-2026 11:14:59\n",
		"InGate::IN11\n",
		"Slip No::54600\n",
		"Veh No::2BC1875\n",
		"SCAN AND PAY WITH NEW\n",
		"THE CANADIA BANK APP\n",
	}
	if !reflect.DeepEqual(texts, want) {
		t.Fatalf("USB text order = %#v, want %#v", texts, want)
	}

	if countText(ops, strings.Repeat("-", 42)+"\n") != 1 {
		t.Fatalf("expected one 42-character divider, got %d", countText(ops, strings.Repeat("-", 42)+"\n"))
	}

	qr, ok := findUSBQRCode(ops)
	if !ok {
		t.Fatal("expected a QR-code operation")
	}
	if qr.qrData != data.ticketNo || qr.qrWidth != 12 {
		t.Fatalf("QR operation = (%q, %d), want (%q, 12)", qr.qrData, qr.qrWidth, data.ticketNo)
	}
	qrIndex := findUSBQRCodeIndex(ops)
	paymentIndex := findTextIndex(ops, "SCAN AND PAY WITH NEW\n")
	plateIndex := findTextIndex(ops, "Veh No::2BC1875\n")
	cutIndex := findUSBOpKindIndex(ops, usbOpCut)
	if qrIndex < 0 || paymentIndex < 0 || plateIndex < 0 || cutIndex < 0 || !(plateIndex < qrIndex && qrIndex < paymentIndex && paymentIndex < cutIndex) {
		t.Fatalf("expected plate before QR before payment before cut, got plate=%d QR=%d payment=%d cut=%d", plateIndex, qrIndex, paymentIndex, cutIndex)
	}
}

func TestBuildUSBTicketLayoutOmitsOptionalLines(t *testing.T) {
	ops := buildUSBTicketLayout(usbTicketData{
		lotName:   "KTI AIRPORT",
		entryTime: "30-07-2026 11:14:59",
		slipNo:    "54600",
		ticketNo:  "ticket-no",
	})

	texts := usbTextOperations(ops)
	for _, text := range texts {
		if strings.HasPrefix(text, "InGate::") || strings.HasPrefix(text, "Veh No::") {
			t.Fatalf("optional line should be omitted, got %q", text)
		}
	}
}

func TestBuildUSBTicketLayoutUsesDoubleWidthAroundTitleAndPlate(t *testing.T) {
	ops := buildUSBTicketLayout(usbTicketData{
		lotName:   "KTI AIRPORT",
		plateNo:   "2BC1875",
		entryTime: "30-07-2026 11:14:59",
		slipNo:    "54600",
		ticketNo:  "ticket-no",
	})

	titleIndex := findTextIndex(ops, "Parking Ticket\n")
	plateIndex := findTextIndex(ops, "Veh No::2BC1875\n")
	if titleIndex < 2 || plateIndex < 2 {
		t.Fatalf("title or plate operation is missing")
	}
	if !bytesEqual(ops[titleIndex-2].data, []byte{GS, '!', 0x10}) || !bytesEqual(ops[titleIndex+1].data, []byte{GS, '!', 0x00}) {
		t.Fatalf("title is not bracketed by GS ! double-width/reset operations")
	}
	if !bytesEqual(ops[titleIndex-1].data, BoldOnCmd) || !bytesEqual(ops[titleIndex+2].data, BoldOffCmd) {
		t.Fatalf("title is not bracketed by bold on/off operations")
	}
	if !bytesEqual(ops[plateIndex-2].data, []byte{GS, '!', 0x10}) || !bytesEqual(ops[plateIndex+1].data, []byte{GS, '!', 0x00}) {
		t.Fatalf("plate is not bracketed by GS ! double-width/reset operations")
	}
	if !bytesEqual(ops[plateIndex-1].data, BoldOnCmd) || !bytesEqual(ops[plateIndex+2].data, BoldOffCmd) {
		t.Fatalf("plate is not bracketed by bold on/off operations")
	}
}

func TestBuildUSBTicketLayoutUsesNormalTextDirection(t *testing.T) {
	ops := buildUSBTicketLayout(usbTicketData{
		lotName:   "Lot#1",
		plateNo:   "2BC1875",
		entryTime: "03-08-2026 10:00:00",
		slipNo:    "1",
		ticketNo:  "ticket-no",
	})

	directionOff := findUSBWriteDataIndices(ops, []byte{ESC, '{', 0})
	directionOn := findUSBWriteDataIndex(ops, []byte{ESC, '{', 1})
	qrIndex := findUSBQRCodeIndex(ops)
	paymentIndex := findTextIndex(ops, "SCAN AND PAY WITH NEW\n")
	cutIndex := findUSBOpKindIndex(ops, usbOpCut)
	if len(directionOff) < 2 || directionOn >= 0 || qrIndex < 0 || paymentIndex < 0 || cutIndex < 0 {
		t.Fatalf("missing normal direction/print operations: off=%d on=%d qr=%d payment=%d cut=%d", len(directionOff), directionOn, qrIndex, paymentIndex, cutIndex)
	}
	if !(directionOff[0] < qrIndex && qrIndex < directionOff[1] && directionOff[1] < paymentIndex && paymentIndex < cutIndex) {
		t.Fatalf("normal direction must precede text and be reapplied after QR: off=%v qr=%d payment=%d cut=%d", directionOff, qrIndex, paymentIndex, cutIndex)
	}
}

func TestBuildUSBTicketLayoutFeedsPastCutterBeforeCut(t *testing.T) {
	ops := buildUSBTicketLayout(usbTicketData{ticketNo: "ticket-no"})
	if len(ops) < 2 || ops[len(ops)-2].kind != usbOpFeed || ops[len(ops)-2].count != 8 || ops[len(ops)-1].kind != usbOpCut {
		t.Fatalf("ticket must end with an 8-line feed and cut, got %#v", ops[len(ops)-2:])
	}
}

func TestExecuteUSBLayoutStopsOnShortWrite(t *testing.T) {
	device := &recordingUSBDevice{shortWriteAt: 1}
	ops := []usbPrintOp{
		{kind: usbOpWrite, data: []byte("first\n")},
		{kind: usbOpWrite, data: []byte("second\n")},
		{kind: usbOpQRCode, qrData: "ticket-no", qrWidth: 8},
	}

	if err := executeUSBLayout(device, ops); err == nil {
		t.Fatal("expected short-write error")
	}
	if len(device.writes) != 1 {
		t.Fatalf("operations after short write executed: %d writes", len(device.writes))
	}
}

func TestExecuteUSBLayoutReturnsQRCodeError(t *testing.T) {
	device := &recordingUSBDevice{qrOK: false}
	ops := []usbPrintOp{{kind: usbOpQRCode, qrData: "ticket-no", qrWidth: 8}}

	if err := executeUSBLayout(device, ops); err == nil {
		t.Fatal("expected QR-code error")
	}
}

type recordingUSBDevice struct {
	writes       [][]byte
	shortWriteAt int
	qrOK         bool
}

func (d *recordingUSBDevice) Write(data []byte) int {
	d.writes = append(d.writes, append([]byte(nil), data...))
	if len(d.writes) == d.shortWriteAt {
		return len(data) - 1
	}
	return len(data)
}

func (d *recordingUSBDevice) FeedLines(int)           {}
func (d *recordingUSBDevice) QRCode(string, int) bool { return d.qrOK }
func (d *recordingUSBDevice) FullCut()                {}

func usbTextOperations(ops []usbPrintOp) []string {
	var texts []string
	for _, op := range ops {
		if op.kind == usbOpWrite && len(op.data) > 0 && op.data[len(op.data)-1] == '\n' {
			texts = append(texts, string(op.data))
		}
	}
	return texts
}

func countText(ops []usbPrintOp, want string) int {
	count := 0
	for _, text := range usbTextOperations(ops) {
		if text == want {
			count++
		}
	}
	return count
}

func findTextIndex(ops []usbPrintOp, want string) int {
	for i, op := range ops {
		if op.kind == usbOpWrite && string(op.data) == want {
			return i
		}
	}
	return -1
}

func findUSBWriteDataIndex(ops []usbPrintOp, want []byte) int {
	for i, op := range ops {
		if op.kind == usbOpWrite && bytesEqual(op.data, want) {
			return i
		}
	}
	return -1
}

func findUSBWriteDataIndices(ops []usbPrintOp, want []byte) []int {
	var indices []int
	for i, op := range ops {
		if op.kind == usbOpWrite && bytesEqual(op.data, want) {
			indices = append(indices, i)
		}
	}
	return indices
}

func findUSBQRCode(ops []usbPrintOp) (usbPrintOp, bool) {
	for _, op := range ops {
		if op.kind == usbOpQRCode {
			return op, true
		}
	}
	return usbPrintOp{}, false
}

func findUSBQRCodeIndex(ops []usbPrintOp) int {
	return findUSBOpKindIndex(ops, usbOpQRCode)
}

func findUSBOpKindIndex(ops []usbPrintOp, kind usbPrintOpKind) int {
	for i, op := range ops {
		if op.kind == kind {
			return i
		}
	}
	return -1
}

func bytesEqual(a, b []byte) bool { return reflect.DeepEqual(a, b) }