package service

import (
	"context"
	"fmt"
	"time"

	"git.espin.casa/albert/cml04-falcon-system/internal/types"
	"github.com/nats-io/nats.go"
	"gorm.io/driver/postgres"
	"gorm.io/gorm"
)

const TimeOut time.Duration = time.Second * 2

type DBConfig struct {
	Username string
	Password string
	Host     string
	Port     int
	Name     string
}

type NATSconfig struct {
	Host string
	Port int
}

func Nats(conf *NATSconfig) (*nats.Conn, error) {
	// NATS connect
	nc, err := nats.Connect(fmt.Sprintf("nats://%s:%d", conf.Host, conf.Port))
	if err != nil {
		return nil, err
	}
	return nc, nil
}

func DataBase(conf *DBConfig) (*gorm.DB, error) {
	// create dsn string
	dsn := fmt.Sprintf("host=%s user=%s password=%s dbname=%s port=%d sslmode=disable TimeZone=Europe/Madrid",
		conf.Host,
		conf.Username,
		conf.Password,
		conf.Name,
		conf.Port,
	)
	// create open database connection
	db, err := gorm.Open(postgres.Open(dsn), &gorm.Config{})
	if err != nil {
		return nil, err
	}
	return db, nil
}

type Service interface {
	Close(ctx context.Context) error
	StoreLabelData(ctx context.Context, data *types.Label) error
	PublishNewLabelData(ctx context.Context, id string) error
}

type service struct {
	db *gorm.DB
	nc *nats.Conn
}

// Close implements Service.
func (s *service) Close(ctx context.Context) error {
	if err := s.nc.Flush(); err != nil {
		return err
	}
	s.nc.Close()
	return nil
}

// PublishNewLabelData implements Service.
func (s *service) PublishNewLabelData(ctx context.Context, id string) error {
	_, err := s.nc.Request("new.label.data", []byte(id), TimeOut)
	if err != nil {
		return err
	}
	return nil
}

// StoreLabelData implements Service.
func (s *service) StoreLabelData(ctx context.Context, data *types.Label) error {
	return s.db.WithContext(ctx).Save(data).Error
}

func AutoMigrate(db *gorm.DB) error {
	return db.AutoMigrate(&types.Label{})
}

func New(dbConf *DBConfig, natsConf *NATSconfig) (Service, error) {
	// create data base
	db, err := DataBase(dbConf)
	if err != nil {
		return nil, err
	}
	// auto migrate
	if err := AutoMigrate(db); err != nil {
		return nil, err
	}
	// create nc connection
	nc, err := Nats(natsConf)
	if err != nil {
		return nil, err
	}
	return &service{
		db: db,
		nc: nc,
	}, nil
}