package platform

import (
	"context"
	"net/url"
	"sort"
	"strings"
)

type Store interface {
	DashboardSummary(context.Context) (DashboardSummary, error)
	Vehicles(context.Context, url.Values) (Page[VehicleRow], error)
	VehicleCoverage(context.Context, url.Values) (Page[VehicleCoverageRow], error)
	VehicleRealtime(context.Context, url.Values) (Page[VehicleRealtimeRow], error)
	RealtimeLocations(context.Context, url.Values) (Page[RealtimeLocationRow], error)
	HistoryLocations(context.Context, url.Values) (Page[HistoryLocationRow], error)
	HistoryLocationsFromTDengine(context.Context, url.Values) (Page[HistoryLocationRow], error)
	RawFrames(context.Context, RawFrameQuery) (Page[RawFrameRow], error)
	DailyMileage(context.Context, url.Values) (Page[DailyMileageRow], error)
	QualityIssues(context.Context, url.Values) (Page[QualityIssueRow], error)
	OpsHealth(context.Context) (OpsHealth, error)
}

type RawFrameQuery struct {
	Protocol      string   `json:"protocol"`
	VIN           string   `json:"vin"`
	DateFrom      string   `json:"dateFrom"`
	DateTo        string   `json:"dateTo"`
	Fields        []string `json:"fields"`
	IncludeFields bool     `json:"includeFields"`
	Limit         int      `json:"limit"`
	Offset        int      `json:"offset"`
}

type Service struct {
	store Store
}

func NewService(store Store) *Service {
	return &Service{store: store}
}

func (s *Service) DashboardSummary(ctx context.Context) (DashboardSummary, error) {
	return s.store.DashboardSummary(ctx)
}

func (s *Service) Vehicles(ctx context.Context, query url.Values) (Page[VehicleRow], error) {
	return s.store.Vehicles(ctx, query)
}

func (s *Service) VehicleCoverage(ctx context.Context, query url.Values) (Page[VehicleCoverageRow], error) {
	return s.store.VehicleCoverage(ctx, query)
}

func (s *Service) VehicleRealtime(ctx context.Context, query url.Values) (Page[VehicleRealtimeRow], error) {
	return s.store.VehicleRealtime(ctx, query)
}

func (s *Service) VehicleDetail(ctx context.Context, vin string, protocol string) (VehicleDetail, error) {
	keyword := strings.TrimSpace(vin)
	protocol = strings.TrimSpace(protocol)
	vehicleQuery := url.Values{"keyword": {keyword}, "limit": {"10"}}
	vehicles, err := s.store.Vehicles(ctx, vehicleQuery)
	if err != nil {
		return VehicleDetail{}, err
	}
	identity := resolveVehicleIdentity(keyword, vehicles.Items)
	resolvedVIN := keyword
	if identity != nil && strings.TrimSpace(identity.VIN) != "" {
		resolvedVIN = identity.VIN
	}

	realtimeQuery := url.Values{"vin": {resolvedVIN}, "limit": {"20"}}
	historyQuery := url.Values{"vin": {resolvedVIN}, "limit": {"20"}}
	rawQuery := RawFrameQuery{VIN: resolvedVIN, IncludeFields: true, Limit: 10}
	mileageQuery := url.Values{"vin": {resolvedVIN}, "limit": {"20"}}
	qualityQuery := url.Values{"vin": {resolvedVIN}, "limit": {"20"}}
	if protocol != "" {
		realtimeQuery.Set("protocol", protocol)
		historyQuery.Set("protocol", protocol)
		rawQuery.Protocol = protocol
		qualityQuery.Set("protocol", protocol)
	}
	realtime, err := s.store.RealtimeLocations(ctx, realtimeQuery)
	if err != nil {
		return VehicleDetail{}, err
	}
	history, err := s.store.HistoryLocationsFromTDengine(ctx, historyQuery)
	if err != nil {
		return VehicleDetail{}, err
	}
	raw, err := s.RawFrames(ctx, rawQuery)
	if err != nil {
		return VehicleDetail{}, err
	}
	mileage, err := s.store.DailyMileage(ctx, mileageQuery)
	if err != nil {
		return VehicleDetail{}, err
	}
	quality, err := s.store.QualityIssues(ctx, qualityQuery)
	if err != nil {
		return VehicleDetail{}, err
	}
	sourceStatus := vehicleSourceStatus(vehicles.Items, realtime.Items, history.Items, raw.Items, mileage.Items)
	sourceStatus = s.enrichVehicleSourceStatus(ctx, resolvedVIN, sourceStatus)
	return VehicleDetail{
		VIN:          resolvedVIN,
		Identity:     identity,
		Sources:      sourceNames(sourceStatus),
		SourceStatus: sourceStatus,
		Realtime:     realtime.Items,
		History:      history,
		Raw:          raw,
		Mileage:      mileage,
		Quality:      quality,
	}, nil
}

func (s *Service) enrichVehicleSourceStatus(ctx context.Context, vin string, statuses []VehicleSourceStatus) []VehicleSourceStatus {
	for index := range statuses {
		protocol := statuses[index].Protocol
		if protocol == "" {
			continue
		}
		if !statuses[index].HasHistory {
			query := url.Values{"vin": {vin}, "protocol": {protocol}, "limit": {"1"}}
			if page, err := s.store.HistoryLocationsFromTDengine(ctx, query); err == nil && len(page.Items) > 0 {
				statuses[index].HasHistory = true
				statuses[index].LastSeen = latestString(statuses[index].LastSeen, firstNonEmpty(page.Items[0].ServerTime, page.Items[0].DeviceTime))
			}
		}
		if !statuses[index].HasRaw {
			page, err := s.store.RawFrames(ctx, RawFrameQuery{VIN: vin, Protocol: protocol, Limit: 1})
			if err == nil && len(page.Items) > 0 {
				statuses[index].HasRaw = true
				statuses[index].LastSeen = latestString(statuses[index].LastSeen, firstNonEmpty(page.Items[0].ServerTime, page.Items[0].DeviceTime))
			}
		}
	}
	return statuses
}

func resolveVehicleIdentity(keyword string, vehicles []VehicleRow) *VehicleRow {
	keyword = strings.TrimSpace(keyword)
	if keyword == "" {
		return nil
	}
	for index := range vehicles {
		if strings.EqualFold(vehicles[index].VIN, keyword) {
			return &vehicles[index]
		}
	}
	for index := range vehicles {
		if strings.EqualFold(vehicles[index].Plate, keyword) || strings.EqualFold(vehicles[index].Phone, keyword) {
			return &vehicles[index]
		}
	}
	if len(vehicles) > 0 {
		return &vehicles[0]
	}
	return nil
}

func (s *Service) RealtimeLocations(ctx context.Context, query url.Values) (Page[RealtimeLocationRow], error) {
	return s.store.RealtimeLocations(ctx, query)
}

func (s *Service) HistoryLocations(ctx context.Context, query url.Values) (Page[HistoryLocationRow], error) {
	return s.store.HistoryLocationsFromTDengine(ctx, query)
}

func (s *Service) RawFrames(ctx context.Context, query RawFrameQuery) (Page[RawFrameRow], error) {
	if query.Limit <= 0 || query.Limit > 500 {
		query.Limit = 100
	}
	return s.store.RawFrames(ctx, query)
}

func (s *Service) DailyMileage(ctx context.Context, query url.Values) (Page[DailyMileageRow], error) {
	return s.store.DailyMileage(ctx, query)
}

func (s *Service) QualityIssues(ctx context.Context, query url.Values) (Page[QualityIssueRow], error) {
	return s.store.QualityIssues(ctx, query)
}

func (s *Service) OpsHealth(ctx context.Context) (OpsHealth, error) {
	return s.store.OpsHealth(ctx)
}

func vehicleSourceStatus(vehicles []VehicleRow, realtime []RealtimeLocationRow, history []HistoryLocationRow, raw []RawFrameRow, mileage []DailyMileageRow) []VehicleSourceStatus {
	statusByProtocol := map[string]*VehicleSourceStatus{}
	ensure := func(protocol string) *VehicleSourceStatus {
		protocol = strings.TrimSpace(protocol)
		if protocol == "" {
			return nil
		}
		if current := statusByProtocol[protocol]; current != nil {
			return current
		}
		current := &VehicleSourceStatus{Protocol: protocol}
		statusByProtocol[protocol] = current
		return current
	}
	setLastSeen := func(current *VehicleSourceStatus, value string) {
		value = strings.TrimSpace(value)
		if value == "" {
			return
		}
		if current.LastSeen == "" || value > current.LastSeen {
			current.LastSeen = value
		}
	}
	for _, row := range vehicles {
		if current := ensure(row.Protocol); current != nil {
			current.Online = current.Online || row.Online
			setLastSeen(current, row.LastSeen)
		}
	}
	for _, row := range realtime {
		if current := ensure(row.Protocol); current != nil {
			current.HasRealtime = true
			setLastSeen(current, row.LastSeen)
		}
	}
	for _, row := range history {
		if current := ensure(row.Protocol); current != nil {
			current.HasHistory = true
			setLastSeen(current, firstNonEmpty(row.ServerTime, row.DeviceTime))
		}
	}
	for _, row := range raw {
		if current := ensure(row.Protocol); current != nil {
			current.HasRaw = true
			setLastSeen(current, firstNonEmpty(row.ServerTime, row.DeviceTime))
		}
	}
	for _, row := range mileage {
		if current := ensure(row.Source); current != nil {
			current.HasMileage = true
			setLastSeen(current, row.Date)
		}
	}
	out := make([]VehicleSourceStatus, 0, len(statusByProtocol))
	for _, current := range statusByProtocol {
		out = append(out, *current)
	}
	sort.Slice(out, func(i, j int) bool { return out[i].Protocol < out[j].Protocol })
	return out
}

func latestString(left string, right string) string {
	left = strings.TrimSpace(left)
	right = strings.TrimSpace(right)
	if left == "" {
		return right
	}
	if right == "" || left >= right {
		return left
	}
	return right
}

func sourceNames(statuses []VehicleSourceStatus) []string {
	out := make([]string, 0, len(statuses))
	for _, status := range statuses {
		out = append(out, status.Protocol)
	}
	return out
}