package calendar

import (
	"context"
	"strings"
	"time"

	"github.com/ultisuite/ulti-backend/internal/api/paginate"
	"github.com/ultisuite/ulti-backend/internal/api/query"
	"github.com/ultisuite/ulti-backend/internal/nextcloud"
)

type Service struct {
	nc *nextcloud.Client
}

func NewService(nc *nextcloud.Client) *Service {
	return &Service{nc: nc}
}

func calendarPath(userID, calID string) string {
	return "/remote.php/dav/calendars/" + userID + "/" + calID + "/"
}

func (s *Service) ListCalendars(ctx context.Context, userID string) ([]nextcloud.Calendar, error) {
	return s.nc.ListCalendars(ctx, userID)
}

type EventsList struct {
	Events     []nextcloud.Event    `json:"events"`
	Pagination query.PaginationMeta `json:"pagination,omitempty"`
}

func (s *Service) ListEvents(ctx context.Context, userID, calID string, params query.ListParams) (EventsList, error) {
	from := time.Now().AddDate(0, -1, 0)
	to := time.Now().AddDate(0, 1, 0)
	if params.From != nil {
		from = *params.From
	}
	if params.To != nil {
		to = *params.To
	}

	events, err := s.nc.ListEvents(ctx, userID, calendarPath(userID, calID), from, to)
	if err != nil {
		return EventsList{}, err
	}
	filtered := filterEvents(events, params.Q)
	page, total := paginate.Slice(filtered, params.Offset(), params.Limit())
	return EventsList{
		Events:     page,
		Pagination: params.Meta(&total),
	}, nil
}

func (s *Service) CreateEvent(ctx context.Context, userID, calID string, event *nextcloud.Event) error {
	return s.nc.CreateEvent(ctx, userID, calendarPath(userID, calID), event)
}

func (s *Service) DeleteEvent(ctx context.Context, userID, eventPath string) error {
	return s.nc.DeleteEvent(ctx, userID, eventPath)
}

func filterEvents(events []nextcloud.Event, q string) []nextcloud.Event {
	q = strings.ToLower(strings.TrimSpace(q))
	if q == "" {
		return events
	}
	out := make([]nextcloud.Event, 0, len(events))
	for _, e := range events {
		if strings.Contains(strings.ToLower(e.Summary), q) ||
			strings.Contains(strings.ToLower(e.Description), q) ||
			strings.Contains(strings.ToLower(e.Location), q) {
			out = append(out, e)
		}
	}
	return out
}