package server

import (
	"errors"
	"fmt"
	"os"

	"git.ctrlz.es/mgdelacroix/birthdaybot/model"
	"git.ctrlz.es/mgdelacroix/birthdaybot/notification"
	"git.ctrlz.es/mgdelacroix/birthdaybot/parser"
	"github.com/charmbracelet/log"
)

var ErrNoNotificationServices = errors.New("there are no notification services configured")

type Server struct {
	Logger               *log.Logger
	config               *model.Config
	workers              []*Worker
	birthdays            []*model.Birthday
	notificationServices []notification.NotificationService
}

func createNotificationServices(logger *log.Logger, config *model.Config) ([]notification.NotificationService, error) {
	notificationServices := []notification.NotificationService{}

	if config.TelegramNotifications != nil {
		telegramNotificationService, err := notification.NewTelegramNotificationService(logger, config.TelegramNotifications)
		if err != nil {
			return nil, fmt.Errorf("cannot create telegram notification service: %w", err)
		}
		notificationServices = append(notificationServices, telegramNotificationService)
	}

	if len(notificationServices) == 0 {
		return nil, ErrNoNotificationServices
	}

	return notificationServices, nil
}

func New(config *model.Config) (*Server, error) {
	logger := log.New(os.Stderr)

	logger.Debug("parsing CSV file", "birthdayFile", config.BirthdayFile)

	birthdays, err := parser.ParseCSV(config.BirthdayFile)
	if err != nil {
		logger.Error("cannot parse CSV file", "birthdayFile", config.BirthdayFile, "error", err)
		return nil, fmt.Errorf("cannot parse CSV file %s: %w", config.BirthdayFile, err)
	}

	logger.Debug("creating notification services from config")

	notificationServices, err := createNotificationServices(logger, config)
	if err != nil {
		logger.Error("error creating notification services", "error", err)
		return nil, err
	}

	logger.Info("creating server")

	server := &Server{
		Logger:               logger,
		config:               config,
		birthdays:            birthdays,
		notificationServices: notificationServices,
	}
	server.workers = []*Worker{NewWorker(server)}

	return server, nil
}

func (s *Server) Start() {
	s.Logger.Info("starting server")
	for _, worker := range s.workers {
		worker.Start()
	}
	s.Logger.Info("server started", "workers", len(s.workers))
}

func (s *Server) Stop() {
	s.Logger.Info("stopping server")
	for _, worker := range s.workers {
		worker.Stop()
	}
	s.Logger.Info("server stopped", "workers", len(s.workers))
}

func (s *Server) Notify(birthday *model.Birthday) error {
	errs := []error{}
	for _, service := range s.notificationServices {
		err := service.Notify(birthday)
		if err != nil {
			errs = append(errs, err)
		}
	}

	if len(errs) == 0 {
		return nil
	}
	return errors.Join(errs...)
}

func (s *Server) Birthdays() []*model.Birthday {
	return s.birthdays
}