package bookings

import (
	"context"
	"errors"
	"fmt"
	"net/url"
	"testing"
	"time"

	"bookra/apps/backend/internal/db"
	"bookra/apps/backend/internal/domain"
)

func TestCreateAppointmentRejectsConflict(t *testing.T) {
	repo := db.NewMemoryRepository()
	service := NewService(repo, nil, "http://localhost:3000")

	availability, err := service.Availability(context.Background(), "studio-atelier", AvailabilityFilter{})
	if err != nil {
		t.Fatalf("availability: %v", err)
	}

	var appointment domain.TimeSlot
	for _, slot := range availability.Slots {
		if slot.Mode == "appointment" {
			appointment = slot
			break
		}
	}
	if appointment.StartsAt == "" {
		t.Fatal("expected appointment slot")
	}

	first, err := service.Create(context.Background(), domain.CreateBookingRequest{
		TenantSlug:    "studio-atelier",
		BookingMode:   "appointment",
		ServiceID:     appointment.ServiceID,
		StaffID:       appointment.StaffID,
		LocationID:    appointment.LocationID,
		CustomerName:  "First",
		CustomerEmail: "first@example.com",
		StartsAt:      appointment.StartsAt,
		EndsAt:        appointment.EndsAt,
	})
	if err != nil {
		t.Fatalf("first create: %v", err)
	}
	if first.Status != "confirmed" {
		t.Fatalf("expected confirmed, got %s", first.Status)
	}

	_, err = service.Create(context.Background(), domain.CreateBookingRequest{
		TenantSlug:    "studio-atelier",
		BookingMode:   "appointment",
		ServiceID:     appointment.ServiceID,
		StaffID:       appointment.StaffID,
		LocationID:    appointment.LocationID,
		CustomerName:  "Second",
		CustomerEmail: "second@example.com",
		StartsAt:      appointment.StartsAt,
		EndsAt:        appointment.EndsAt,
	})
	if err == nil {
		t.Fatal("expected conflict error")
	}
	if err != ErrBookingConflict {
		t.Fatalf("expected ErrBookingConflict, got %v", err)
	}
}

func TestCreateClassFallsBackToWaitlistWhenCapacityReached(t *testing.T) {
	repo := db.NewMemoryRepository()
	service := NewService(repo, nil, "http://localhost:3000")

	availability, err := service.Availability(context.Background(), "studio-atelier", AvailabilityFilter{})
	if err != nil {
		t.Fatalf("availability: %v", err)
	}

	var classSlot domain.TimeSlot
	for _, slot := range availability.Slots {
		if slot.Mode == "class" {
			classSlot = slot
			break
		}
	}
	if classSlot.ClassSessionID == nil {
		t.Fatal("expected class slot")
	}

	for i := 0; i < 4; i++ {
		response, err := service.Create(context.Background(), domain.CreateBookingRequest{
			TenantSlug:     "studio-atelier",
			BookingMode:    "class",
			ClassSessionID: classSlot.ClassSessionID,
			LocationID:     classSlot.LocationID,
			CustomerName:   "Capacity",
			CustomerEmail:  "capacity@example.com",
			StartsAt:       classSlot.StartsAt,
			EndsAt:         classSlot.EndsAt,
		})
		if err != nil {
			t.Fatalf("create within capacity: %v", err)
		}
		if response.Status != "confirmed" {
			t.Fatalf("expected confirmed within capacity, got %s", response.Status)
		}
	}

	response, err := service.Create(context.Background(), domain.CreateBookingRequest{
		TenantSlug:     "studio-atelier",
		BookingMode:    "class",
		ClassSessionID: classSlot.ClassSessionID,
		LocationID:     classSlot.LocationID,
		CustomerName:   "Waitlist",
		CustomerEmail:  "waitlist@example.com",
		StartsAt:       classSlot.StartsAt,
		EndsAt:         classSlot.EndsAt,
	})
	if err != nil {
		t.Fatalf("create waitlist: %v", err)
	}
	if response.Status != "waitlisted" {
		t.Fatalf("expected waitlisted, got %s", response.Status)
	}
}

func TestCreateAppointmentRequiresTenantService(t *testing.T) {
	repo := db.NewMemoryRepository()
	service := NewService(repo, nil, "http://localhost:3000")

	_, err := service.Create(context.Background(), domain.CreateBookingRequest{
		TenantSlug:    "studio-atelier",
		BookingMode:   "appointment",
		CustomerName:  "Missing Service",
		CustomerEmail: "missing@example.com",
		StartsAt:      time.Now().UTC().Add(24 * time.Hour).Format(time.RFC3339),
		EndsAt:        time.Now().UTC().Add(25 * time.Hour).Format(time.RFC3339),
	})
	if !errors.Is(err, ErrInvalidBooking) {
		t.Fatalf("expected ErrInvalidBooking, got %v", err)
	}
}

func TestCreateClassRequiresExistingSession(t *testing.T) {
	repo := db.NewMemoryRepository()
	service := NewService(repo, nil, "http://localhost:3000")
	missingSessionID := "11111111-1111-1111-1111-111111111111"

	_, err := service.Create(context.Background(), domain.CreateBookingRequest{
		TenantSlug:     "studio-atelier",
		BookingMode:    "class",
		ClassSessionID: &missingSessionID,
		CustomerName:   "Missing Session",
		CustomerEmail:  "missing@example.com",
		StartsAt:       time.Now().UTC().Add(48 * time.Hour).Format(time.RFC3339),
		EndsAt:         time.Now().UTC().Add(49 * time.Hour).Format(time.RFC3339),
	})
	if !errors.Is(err, ErrInvalidBooking) {
		t.Fatalf("expected ErrInvalidBooking, got %v", err)
	}
}

func TestAvailabilityGeneratesUpcomingSlots(t *testing.T) {
	repo := db.NewMemoryRepository()
	service := NewService(repo, nil, "http://localhost:3000")

	availability, err := service.Availability(context.Background(), "studio-atelier", AvailabilityFilter{})
	if err != nil {
		t.Fatalf("availability: %v", err)
	}
	if len(availability.Slots) == 0 {
		t.Fatal("expected slots")
	}

	for _, slot := range availability.Slots {
		startsAt, err := time.Parse(time.RFC3339, slot.StartsAt)
		if err != nil {
			t.Fatalf("parse startsAt: %v", err)
		}
		if startsAt.Before(time.Now().UTC().Add(90 * time.Minute)) {
			t.Fatalf("expected upcoming slot, got %s", slot.StartsAt)
		}
	}
}

func TestCreateSchedulesReminderJobForUpcomingAppointment(t *testing.T) {
	repo := db.NewMemoryRepository()
	service := NewService(repo, nil, "http://localhost:3000")

	availability, err := service.Availability(context.Background(), "studio-atelier", AvailabilityFilter{Date: nextRuleDay(t, 2)})
	if err != nil {
		t.Fatalf("availability: %v", err)
	}

	var appointment domain.TimeSlot
	for _, slot := range availability.Slots {
		if slot.Mode == "appointment" {
			appointment = slot
			break
		}
	}
	if appointment.StartsAt == "" {
		t.Fatal("expected appointment slot")
	}

	_, err = service.Create(context.Background(), domain.CreateBookingRequest{
		TenantSlug:    "studio-atelier",
		BookingMode:   "appointment",
		ServiceID:     appointment.ServiceID,
		StaffID:       appointment.StaffID,
		LocationID:    appointment.LocationID,
		CustomerName:  "Reminder",
		CustomerEmail: "reminder@example.com",
		StartsAt:      appointment.StartsAt,
		EndsAt:        appointment.EndsAt,
	})
	if err != nil {
		t.Fatalf("create: %v", err)
	}

	reminders, err := repo.ListDueReminderJobs(context.Background(), time.Now().UTC().Add(365*24*time.Hour), 10)
	if err != nil {
		t.Fatalf("list reminder jobs: %v", err)
	}
	if len(reminders) == 0 {
		t.Fatal("expected reminder job to be scheduled")
	}
}

// nextRuleDay returns the first day at least minOffset days out whose weekday
// has a seeded availability rule (Mon–Fri), formatted YYYY-MM-DD.
func nextRuleDay(t *testing.T, minOffset int) string {
	t.Helper()
	for offset := minOffset; offset < minOffset+7; offset++ {
		day := time.Now().AddDate(0, 0, offset)
		if day.Weekday() >= time.Monday && day.Weekday() <= time.Friday {
			return day.Format("2006-01-02")
		}
	}
	t.Fatal("no rule day found")
	return ""
}

func TestAvailabilityDateFilterReturnsFullDaySlots(t *testing.T) {
	repo := db.NewMemoryRepository()
	service := NewService(repo, nil, "http://localhost:3000")

	day := nextRuleDay(t, 2)
	availability, err := service.Availability(context.Background(), "studio-atelier", AvailabilityFilter{Date: day})
	if err != nil {
		t.Fatalf("availability: %v", err)
	}
	if len(availability.Slots) == 0 {
		t.Fatal("expected day slots")
	}
	tenantLocation, err := time.LoadLocation(availability.Timezone)
	if err != nil {
		t.Fatalf("load timezone: %v", err)
	}
	for _, slot := range availability.Slots {
		if slot.Mode != "appointment" {
			t.Fatalf("expected only appointment slots, got %s", slot.Mode)
		}
		startsAt, err := time.Parse(time.RFC3339, slot.StartsAt)
		if err != nil {
			t.Fatalf("parse startsAt: %v", err)
		}
		if startsAt.In(tenantLocation).Format("2006-01-02") != day {
			t.Fatalf("slot %s outside requested day %s", slot.StartsAt, day)
		}
		if slot.StaffName == nil || *slot.StaffName == "" {
			t.Fatal("expected staffName on slot")
		}
	}
}

func TestAvailabilityHonorsTenantWideBlockedDay(t *testing.T) {
	repo := db.NewMemoryRepository()
	service := NewService(repo, nil, "http://localhost:3000")

	day := nextRuleDay(t, 2)
	dayStart, err := time.Parse("2006-01-02", day)
	if err != nil {
		t.Fatalf("parse day: %v", err)
	}
	if _, err := repo.CreateBlockedDay(context.Background(), db.CreateBlockedDayParams{
		TenantID:  "5d6b3551-0a3e-4b86-bdf0-e9df20a47148",
		StartsAt:  dayStart.UTC(),
		EndsAt:    dayStart.Add(26 * time.Hour).UTC(),
		Kind:      "blocked",
		Reason:    "holiday",
	}); err != nil {
		t.Fatalf("create blocked day: %v", err)
	}

	availability, err := service.Availability(context.Background(), "studio-atelier", AvailabilityFilter{Date: day})
	if err != nil {
		t.Fatalf("availability: %v", err)
	}
	if len(availability.Slots) != 0 {
		t.Fatalf("expected no slots on blocked day, got %d", len(availability.Slots))
	}
}

func TestAvailabilityStaffFilterValidatesTenantStaff(t *testing.T) {
	repo := db.NewMemoryRepository()
	service := NewService(repo, nil, "http://localhost:3000")
	foreignStaff := "22222222-2222-2222-2222-222222222222"

	_, err := service.Availability(context.Background(), "studio-atelier", AvailabilityFilter{StaffID: foreignStaff})
	if !errors.Is(err, ErrInvalidBooking) {
		t.Fatalf("expected ErrInvalidBooking, got %v", err)
	}
}

func TestCatalogReturnsServicesAndActiveStaff(t *testing.T) {
	repo := db.NewMemoryRepository()
	service := NewService(repo, nil, "http://localhost:3000")

	catalog, err := service.Catalog(context.Background(), "studio-atelier")
	if err != nil {
		t.Fatalf("catalog: %v", err)
	}
	if len(catalog.Services) == 0 {
		t.Fatal("expected services")
	}
	if len(catalog.Staff) == 0 {
		t.Fatal("expected staff")
	}
	for _, staff := range catalog.Staff {
		if staff.DisplayName == "" {
			t.Fatal("expected display name")
		}
	}
}

func TestCreateAppointmentRejectsTimeOutsideAvailabilityWindow(t *testing.T) {
	repo := db.NewMemoryRepository()
	service := NewService(repo, nil, "http://localhost:3000")

	catalog, err := service.Catalog(context.Background(), "studio-atelier")
	if err != nil {
		t.Fatalf("catalog: %v", err)
	}
	serviceID := catalog.Services[0].ID
	staffID := catalog.Staff[0].ID

	// 03:00 on a rule day is outside the seeded 09:00–17:00 window.
	day := nextRuleDay(t, 2)
	startsAt, err := time.Parse(time.RFC3339, day+"T03:00:00Z")
	if err != nil {
		t.Fatalf("parse startsAt: %v", err)
	}
	_, err = service.Create(context.Background(), domain.CreateBookingRequest{
		TenantSlug:    "studio-atelier",
		BookingMode:   "appointment",
		ServiceID:     &serviceID,
		StaffID:       &staffID,
		CustomerName:  "Night Owl",
		CustomerEmail: "night@example.com",
		StartsAt:      startsAt.Format(time.RFC3339),
		EndsAt:        startsAt.Add(time.Hour).Format(time.RFC3339),
	})
	if !errors.Is(err, ErrInvalidBooking) {
		t.Fatalf("expected ErrInvalidBooking, got %v", err)
	}
}

func TestCreateAppointmentRejectsForeignStaff(t *testing.T) {
	repo := db.NewMemoryRepository()
	service := NewService(repo, nil, "http://localhost:3000")

	availability, err := service.Availability(context.Background(), "studio-atelier", AvailabilityFilter{})
	if err != nil {
		t.Fatalf("availability: %v", err)
	}
	var appointment domain.TimeSlot
	for _, slot := range availability.Slots {
		if slot.Mode == "appointment" {
			appointment = slot
			break
		}
	}
	if appointment.StartsAt == "" {
		t.Fatal("expected appointment slot")
	}
	foreignStaff := "22222222-2222-2222-2222-222222222222"
	_, err = service.Create(context.Background(), domain.CreateBookingRequest{
		TenantSlug:    "studio-atelier",
		BookingMode:   "appointment",
		ServiceID:     appointment.ServiceID,
		StaffID:       &foreignStaff,
		CustomerName:  "Impersonator",
		CustomerEmail: "fake@example.com",
		StartsAt:      appointment.StartsAt,
		EndsAt:        appointment.EndsAt,
	})
	if !errors.Is(err, ErrInvalidBooking) {
		t.Fatalf("expected ErrInvalidBooking, got %v", err)
	}
}

func TestCustomerCancelPromotesWaitlist(t *testing.T) {
	repo := db.NewMemoryRepository()
	service := NewService(repo, nil, "http://localhost:3000")
	customerService := NewCustomerService(repo, nil, "http://localhost:3000")
	ctx := context.Background()

	session, err := repo.GetClassSessionByID(ctx, "4bf74c12-44dd-45ca-86bb-b104f16f2435")
	if err != nil {
		t.Fatalf("get session: %v", err)
	}
	sessionID := session.ID
	book := func(email string) domain.CreateBookingResponse {
		resp, err := service.Create(ctx, domain.CreateBookingRequest{
			TenantSlug:     "studio-atelier",
			BookingMode:    "class",
			ClassSessionID: &sessionID,
			CustomerName:   "Test User",
			CustomerEmail:  email,
			StartsAt:       session.StartsAt.UTC().Format(time.RFC3339),
			EndsAt:         session.EndsAt.UTC().Format(time.RFC3339),
		})
		if err != nil {
			t.Fatalf("book %s: %v", email, err)
		}
		return resp
	}

	var confirmed []domain.CreateBookingResponse
	for i := 0; i < 4; i++ {
		confirmed = append(confirmed, book(fmt.Sprintf("seat%d@example.com", i)))
	}
	waiter := book("waiter@example.com")
	if waiter.Status != "waitlisted" {
		t.Fatalf("expected waitlisted, got %s", waiter.Status)
	}

	// Customer cancels a confirmed seat via the management token.
	manageURL, _ := url.Parse(confirmed[0].ManageURL)
	token := manageURL.Query().Get("token")
	if err := customerService.CancelBooking(ctx, confirmed[0].Reference, token); err != nil {
		t.Fatalf("customer cancel: %v", err)
	}

	booking, _ := repo.GetBookingByID(ctx, waiter.BookingID)
	if booking.Status != "confirmed" {
		t.Fatalf("expected waiter promoted to confirmed, got %q", booking.Status)
	}
}

func TestDashboardSummaryComputesKPIsWithTrends(t *testing.T) {
	repo := db.NewMemoryRepository()
	service := NewService(repo, nil, "http://localhost:3000")
	ctx := context.Background()

	membership, err := repo.GetTenantMembershipBySubject(ctx, "demo-owner")
	if err != nil {
		t.Fatalf("membership: %v", err)
	}
	tenantID := membership.Tenant.ID

	now := time.Now().UTC()
	seed := func(offsetDays int, hours int, status string) {
		t.Helper()
		starts := now.AddDate(0, 0, offsetDays).Add(time.Duration(hours) * time.Hour)
		_, err := repo.CreateBooking(ctx, db.CreateBookingParams{
			TenantID:    tenantID,
			BookingMode: "appointment",
			StartsAt:    starts,
			EndsAt:      starts.Add(time.Hour),
			Status:      status,
			Reference:   "BK-T",
		})
		if err != nil {
			t.Fatalf("seed booking: %v", err)
		}
	}

	// Next 7 days: 3 bookings, one cancelled.
	seed(1, 0, "confirmed")
	seed(2, 0, "confirmed")
	seed(3, 0, "cancelled")
	// Last 7 days: 1 confirmed booking that already ended.
	seed(-2, 0, "confirmed")
	// 7-14 days ago: 2 completed bookings.
	seed(-8, 0, "confirmed")
	seed(-9, 0, "confirmed")

	summary, err := service.DashboardSummary(ctx, domain.Principal{Subject: "demo-owner", Role: "owner"})
	if err != nil {
		t.Fatalf("dashboard summary: %v", err)
	}
	if len(summary.KPIs) != 4 {
		t.Fatalf("expected 4 kpis, got %d", len(summary.KPIs))
	}
	byCode := map[string]domain.DashboardKPI{}
	for _, kpi := range summary.KPIs {
		byCode[kpi.Code] = kpi
	}

	bookings := byCode["bookings_this_week"]
	if bookings.Value != "3" || bookings.Change != "+2" || bookings.Trend != "up" {
		t.Fatalf("bookings kpi = %+v", bookings)
	}
	completed := byCode["completed"]
	if completed.Value != "1" || completed.Change != "-1" || completed.Trend != "down" {
		t.Fatalf("completed kpi = %+v", completed)
	}
	cancellations := byCode["cancellations"]
	if cancellations.Value != "1" || cancellations.Change != "+1" || cancellations.Trend != "up" {
		t.Fatalf("cancellations kpi = %+v", cancellations)
	}
	utilization := byCode["utilization"]
	if utilization.Value != "66%" || utilization.Trend != "down" {
		t.Fatalf("utilization kpi = %+v", utilization)
	}
}