package cmd

import (
	"cmp"
	"context"
	"errors"
	"fmt"
	"os"
	"regexp"
	"slices"
	"strconv"
	"strings"
	"sync"
	"time"

	paho "github.com/eclipse/paho.mqtt.golang"
	"github.com/evcc-io/evcc/api"
	"github.com/evcc-io/evcc/api/globalconfig"
	"github.com/evcc-io/evcc/charger"
	"github.com/evcc-io/evcc/charger/ocpp"
	"github.com/evcc-io/evcc/cmd/shutdown"
	"github.com/evcc-io/evcc/core"
	"github.com/evcc-io/evcc/core/circuit"
	"github.com/evcc-io/evcc/core/keys"
	"github.com/evcc-io/evcc/core/loadpoint"
	coresettings "github.com/evcc-io/evcc/core/settings"
	"github.com/evcc-io/evcc/hems"
	hemsapi "github.com/evcc-io/evcc/hems/hems"
	"github.com/evcc-io/evcc/hems/shm"
	"github.com/evcc-io/evcc/messenger"
	"github.com/evcc-io/evcc/meter"
	"github.com/evcc-io/evcc/plugin/golang"
	"github.com/evcc-io/evcc/plugin/javascript"
	"github.com/evcc-io/evcc/plugin/mqtt"
	"github.com/evcc-io/evcc/server"
	"github.com/evcc-io/evcc/server/db"
	"github.com/evcc-io/evcc/server/db/settings"
	"github.com/evcc-io/evcc/server/eebus"
	"github.com/evcc-io/evcc/server/modbus"
	"github.com/evcc-io/evcc/server/providerauth"
	"github.com/evcc-io/evcc/tariff"
	"github.com/evcc-io/evcc/util"
	"github.com/evcc-io/evcc/util/config"
	"github.com/evcc-io/evcc/util/locale"
	"github.com/evcc-io/evcc/util/machine"
	"github.com/evcc-io/evcc/util/request"
	_ "github.com/evcc-io/evcc/util/service"
	"github.com/evcc-io/evcc/util/sponsor"
	"github.com/evcc-io/evcc/util/templates"
	"github.com/evcc-io/evcc/vehicle"
	"github.com/gorilla/handlers"
	"github.com/gorilla/mux"
	"github.com/libp2p/zeroconf/v2"
	"github.com/samber/lo"
	"github.com/spf13/cast"
	"github.com/spf13/cobra"
	vpr "github.com/spf13/viper"
	"golang.org/x/sync/errgroup"
	"golang.org/x/text/currency"
)

var conf = globalconfig.All{
	Interval: 30 * time.Second,
	Log:      "info",
	Network: globalconfig.Network{
		Host: "",
		Port: 7070,
	},
	Ocpp: ocpp.Config{
		Port: 8887,
	},
	Mqtt: globalconfig.Mqtt{
		Topic: "evcc",
	},
	EEBus: eebus.Config{
		Port: 4712,
	},
	Database: globalconfig.DB{
		Type: "sqlite",
		Dsn:  "",
	},
}

var yamlSource struct {
	sponsor   globalconfig.YamlSource
	hems      globalconfig.YamlSource
	eebus     globalconfig.YamlSource
	tariffs   globalconfig.YamlSource
	messaging globalconfig.YamlSource
}

var nameRE = regexp.MustCompile(`^[a-zA-Z0-9_.:-]+$`)

func nameValid(name string) error {
	if !nameRE.MatchString(name) {
		return fmt.Errorf("name must not contain special characters or spaces: %s", name)
	}
	return nil
}

func loadConfigFile(conf *globalconfig.All, checkDB bool) error {
	if err := viper.ReadInConfig(); err != nil {
		if _, ok := errors.AsType[vpr.ConfigFileNotFoundError](err); !ok {
			return fmt.Errorf("failed reading config file: %w", err)
		}
	}

	if cfgFile := viper.ConfigFileUsed(); cfgFile != "" {
		log.INFO.Println("using config file:", cfgFile)
	} else {
		log.INFO.Println("config file not found, database-only mode")
	}

	if err := viper.UnmarshalExact(conf); err != nil {
		return fmt.Errorf("failed parsing config file: %w", err)
	}

	// user did not specify a database path
	if conf.Database.Dsn == "" && checkDB {
		// check if service database exists
		if _, err := os.Stat(serviceDB); err == nil {
			// service database found, ask user what to do
			sudo := ""
			if !isWritable(serviceDB) {
				sudo = "sudo "
			}
			log.FATAL.Fatal(`
Found systemd service database at "` + serviceDB + `", evcc has been invoked with no explicit database path.
Running the same config with multiple databases can lead to expiring vehicle tokens.

If you want to use the existing service database run the following command:

` + sudo + `evcc --database ` + serviceDB + `

If you want to create a new user-space database run the following command:

evcc --database ~/.evcc/evcc.db

If you know what you're doing, you can skip the database check with the --ignore-db flag.
			`)
		}
	}

	// parse log levels after reading config
	parseLogLevels()

	return nil
}

func isWritable(filePath string) bool {
	file, err := os.OpenFile(filePath, os.O_WRONLY, 0o666)
	if err != nil {
		return false
	}
	file.Close()
	return true
}

func configureCircuits(conf *[]config.Named) error {
	// migrate settings
	if settings.Exists(keys.Circuits) {
		*conf = []config.Named{}
		if err := settings.Yaml(keys.Circuits, new([]map[string]any), &conf); err != nil {
			return err
		}
	}

	children := slices.Clone(*conf)

	// TODO check for circular references
NEXT:
	for i, cc := range children {
		if cc.Name == "" {
			return fmt.Errorf("cannot create circuit: missing name")
		}

		if err := nameValid(cc.Name); err != nil {
			return fmt.Errorf("cannot create circuit: duplicate name: %s", cc.Name)
		}

		if parent := cast.ToString(cc.Property("parent")); parent != "" {
			if _, err := config.Circuits().ByName(parent); err != nil {
				continue
			}
		}

		log := util.NewLogger("circuit-" + cc.Name)

		props, err := customDevice(cc.Other)
		if err != nil {
			return fmt.Errorf("cannot decode custom circuit '%s': %w", cc.Name, err)
		}

		instance, err := circuit.NewFromConfig(context.TODO(), log, props)
		if err != nil {
			return fmt.Errorf("cannot create circuit '%s': %w", cc.Name, err)
		}

		// ensure config has title
		if instance.GetTitle() == "" {
			//lint:ignore SA1019 as Title is safe on ascii
			instance.SetTitle(strings.Title(cc.Name))
		}

		if err := config.Circuits().Add(config.NewStaticDevice(cc, instance)); err != nil {
			return err
		}

		children = slices.Delete(children, i, i+1)
		goto NEXT
	}

	if len(children) > 0 {
		return fmt.Errorf("circuit is missing parent: %s", children[0].Name)
	}

	var rootFound bool
	for _, dev := range config.Circuits().Devices() {
		c := dev.Instance()

		if c.GetParent() == nil {
			if rootFound {
				return errors.New("cannot have multiple root circuits")
			}
			rootFound = true
		}
	}

	if !rootFound && len(config.Circuits().Devices()) > 0 {
		return errors.New("root circuit required")
	}

	return nil
}

type newFromConfFunc[T any] func(context.Context, string, map[string]any) (T, error)

func staticInstance[T any](typ string, cc config.Named, newFromConf newFromConfFunc[T], h config.Handler[T]) error {
	ctx := util.WithLogger(context.TODO(), util.NewLogger(cc.Name))

	instance, err := newFromConf(ctx, cc.Type, cc.Other)
	if err != nil {
		return &DeviceError{cc.Name, fmt.Errorf("cannot create %s '%s': %w", typ, cc.Name, err)}
	}

	if err := h.Add(config.NewStaticDevice(cc, instance)); err != nil {
		return &DeviceError{cc.Name, err}
	}

	return nil
}

func configurableInstance[T any](typ string, conf *config.Config, newFromConf newFromConfFunc[T], h config.Handler[T]) error {
	cc := conf.Named()
	ctx := util.WithLogger(context.TODO(), util.NewLogger(cc.Name))

	props, err := customDevice(cc.Other)
	if err != nil {
		err = &DeviceError{cc.Name, fmt.Errorf("cannot decode custom %s '%s': %w", typ, cc.Name, err)}
	}

	var instance T
	if err == nil {
		instance, err = newFromConf(ctx, cc.Type, props)
		if err != nil {
			err = &DeviceError{cc.Name, fmt.Errorf("cannot create %s '%s': %w", typ, cc.Name, err)}
		}
	}

	if e := h.Add(config.NewConfigurableDevice(conf, instance)); e != nil && err == nil {
		err = &DeviceError{cc.Name, e}
	}

	return err
}

func configureMeters(static []config.Named, names ...string) error {
	var eg errgroup.Group

	for i, cc := range static {
		if cc.Name == "" {
			return fmt.Errorf("cannot create meter %d: missing name", i+1)
		}

		// configure all, if no name refs are given
		if len(names) > 0 && !slices.Contains(names, cc.Name) {
			continue
		}

		if err := nameValid(cc.Name); err != nil {
			log.WARN.Printf("create meter %d: %v", i+1, err)
		}

		eg.Go(func() error {
			return staticInstance("meter", cc, meter.NewFromConfig, config.Meters())
		})
	}

	// append devices from database
	configurable, err := config.ConfigurationsByClass(templates.Meter)
	if err != nil {
		return err
	}

	for _, conf := range configurable {
		eg.Go(func() error {
			cc := conf.Named()

			// always skip unreferenced db devices
			if !slices.Contains(names, cc.Name) {
				return nil
			}

			return configurableInstance("meter", &conf, meter.NewFromConfig, config.Meters())
		})
	}

	return eg.Wait()
}

func configureChargers(static []config.Named, names ...string) error {
	var eg errgroup.Group

	for i, cc := range static {
		if cc.Name == "" {
			return fmt.Errorf("cannot create charger %d: missing name", i+1)
		}

		// configure all, if no name refs are given
		if len(names) > 0 && !slices.Contains(names, cc.Name) {
			continue
		}

		if err := nameValid(cc.Name); err != nil {
			log.WARN.Printf("create charger %d: %v", i+1, err)
		}

		eg.Go(func() error {
			return staticInstance("charger", cc, charger.NewFromConfig, config.Chargers())
		})
	}

	// append devices from database
	configurable, err := config.ConfigurationsByClass(templates.Charger)
	if err != nil {
		return err
	}

	for _, conf := range configurable {
		eg.Go(func() error {
			cc := conf.Named()

			// always skip unreferenced db devices
			if !slices.Contains(names, cc.Name) {
				return nil
			}

			return configurableInstance("charger", &conf, charger.NewFromConfig, config.Chargers())
		})
	}

	return eg.Wait()
}

func vehicleInstance(cc config.Named) (api.Vehicle, error) {
	ctx := util.WithLogger(context.TODO(), util.NewLogger(cc.Name))

	props, err := customDevice(cc.Other)

	var instance api.Vehicle
	if err == nil {
		instance, err = vehicle.NewFromConfig(ctx, cc.Type, props)
	}

	if err != nil {
		if _, ok := errors.AsType[*util.ConfigError](err); ok {
			return nil, err
		}

		// wrap non-config vehicle errors to prevent fatals
		log.ERROR.Printf("creating vehicle %s failed: %v", cc.Name, err)
		instance = vehicle.NewWrapper(cc.Name, cc.Type, cc.Other, err)
	}

	// ensure vehicle config has title
	if instance.GetTitle() == "" {
		//lint:ignore SA1019 as Title is safe on ascii
		instance.SetTitle(strings.Title(cc.Name))
	}

	return instance, nil
}

func configureVehicles(static []config.Named, names ...string) error {
	var mu sync.Mutex
	var eg errgroup.Group

	// stable-sort vehicles by name
	devs1 := make([]config.Device[api.Vehicle], 0, len(static))

	for i, cc := range static {
		if cc.Name == "" {
			return fmt.Errorf("cannot create vehicle %d: missing name", i+1)
		}

		if len(names) > 0 && !slices.Contains(names, cc.Name) {
			continue
		}

		if err := nameValid(cc.Name); err != nil {
			return fmt.Errorf("cannot create vehicle %d: %w", i+1, err)
		}

		eg.Go(func() error {
			instance, err := vehicleInstance(cc)
			if err != nil {
				return fmt.Errorf("cannot create vehicle '%s': %w", cc.Name, err)
			}

			mu.Lock()
			defer mu.Unlock()
			devs1 = append(devs1, config.NewStaticDevice(cc, instance))

			return nil
		})
	}

	// append devices from database
	configurable, err := config.ConfigurationsByClass(templates.Vehicle)
	if err != nil {
		return err
	}

	// stable-sort vehicles by id
	devs2 := make([]config.ConfigurableDevice[api.Vehicle], 0, len(configurable))

	for _, conf := range configurable {
		eg.Go(func() error {
			cc := conf.Named()

			if len(names) > 0 && !slices.Contains(names, cc.Name) {
				return nil
			}

			instance, err := vehicleInstance(cc)
			if err != nil {
				return fmt.Errorf("cannot create vehicle '%s': %w", cc.Name, err)
			}

			mu.Lock()
			defer mu.Unlock()
			devs2 = append(devs2, config.NewConfigurableDevice(&conf, instance))

			return nil
		})
	}

	if err := eg.Wait(); err != nil {
		return err
	}

	slices.SortFunc(devs1, func(i, j config.Device[api.Vehicle]) int {
		return cmp.Compare(strings.ToLower(i.Config().Name), strings.ToLower(j.Config().Name))
	})

	for _, dev := range devs1 {
		if err := config.Vehicles().Add(dev); err != nil {
			return err
		}
	}

	slices.SortFunc(devs2, func(i, j config.ConfigurableDevice[api.Vehicle]) int {
		return cmp.Compare(i.ID(), j.ID())
	})

	for _, dev := range devs2 {
		if err := config.Vehicles().Add(dev); err != nil {
			return err
		}
	}

	return nil
}

func configureSponsorship(token string) (err error) {
	if settings.Exists(keys.SponsorToken) {
		if token, err = settings.String(keys.SponsorToken); err != nil {
			return err
		}
	} else if token != "" {
		yamlSource.sponsor = globalconfig.YamlSourceFile
	}

	return sponsor.ConfigureSponsorship(token)
}

func configureEnvironment(cmd *cobra.Command, conf *globalconfig.All) error {
	// full http request log
	if cmd.Flag(flagHeaders).Changed {
		request.LogHeaders = true
	}

	// setup persistence
	err := wrapErrorWithClass(ClassDatabase, configureDatabase(conf.Database))

	// setup additional templates
	if err == nil {
		if cmd.Flags().Changed(flagTemplate) {
			class, err := templates.ClassString(cmd.Flags().Lookup(flagTemplateType).Value.String())
			if err != nil {
				return err
			}

			if err := templates.Register(class, cmd.Flag(flagTemplate).Value.String()); err != nil {
				return err
			}
		}
	}

	// setup translations
	if err == nil {
		// TODO decide wrapping
		err = locale.Init()
	}

	// setup machine id
	if err == nil && conf.Plant != "" {
		// TODO decide wrapping
		err = machine.CustomID(conf.Plant)
	}

	// setup sponsorship (allow env override)
	if err == nil {
		err = wrapErrorWithClass(ClassSponsorship, configureSponsorship(conf.SponsorToken))
	}

	// setup mqtt client listener
	if err == nil {
		err = wrapErrorWithClass(ClassMqtt, configureMqtt(&conf.Mqtt))
	}

	// setup OCPP server
	if err == nil {
		configureOCPP(&conf.Ocpp, conf.Network.ExternalUrl)
	}

	// setup EEBus server
	if err == nil {
		err = wrapErrorWithClass(ClassEEBus, configureEEBus(&conf.EEBus))
	}

	// setup javascript VMs
	if err == nil {
		err = wrapErrorWithClass(ClassJavascript, configureJavascript(conf.Javascript))
	}

	// setup go VMs
	if err == nil {
		err = wrapErrorWithClass(ClassGo, configureGo(conf.Go))
	}

	return err
}

// configureDatabase configures session database
func configureDatabase(conf globalconfig.DB) error {
	if conf.Dsn == "" {
		conf.Dsn = userDB
	}

	if err := db.NewInstance(conf.Type, conf.Dsn); err != nil {
		return err
	}

	persistSettings := func() {
		if err := settings.Persist(); err != nil {
			log.ERROR.Println("cannot save settings:", err)
		}
	}

	// persist unsaved settings on shutdown
	shutdown.Register(persistSettings)

	// persist unsaved settings every 30 minutes
	go func() {
		for range time.Tick(time.Minute) {
			persistSettings()
		}
	}()

	return nil
}

// configureInflux configures influx database
func configureInflux(conf *globalconfig.Influx) (*server.Influx, error) {
	// read settings
	if settings.Exists(keys.Influx) {
		if err := settings.Json(keys.Influx, &conf); err != nil {
			return nil, err
		}
	}

	if conf.URL == "" {
		return nil, nil
	}

	influx := server.NewInfluxClient(
		conf.URL,
		conf.Token,
		conf.Org,
		conf.User,
		conf.Password,
		conf.Database,
		conf.Insecure,
	)

	return influx, nil
}

// setup mqtt
func configureMqtt(conf *globalconfig.Mqtt) error {
	// migrate settings
	if settings.Exists(keys.Mqtt) {
		if err := settings.Json(keys.Mqtt, &conf); err != nil {
			return err
		}
	}

	if conf.Broker == "" {
		return nil
	}

	log := util.NewLogger("mqtt")

	instance, err := mqtt.RegisteredClient(log, conf.Broker, conf.User, conf.Password, conf.ClientID, 1, conf.Insecure, conf.CaCert, conf.ClientCert, conf.ClientKey, func(options *paho.ClientOptions) {
		if !runAsService || conf.Topic == "" {
			return
		}

		topic := fmt.Sprintf("%s/status", strings.Trim(conf.Topic, "/"))
		options.SetWill(topic, "offline", 1, true)

		oc := options.OnConnect
		options.SetOnConnectHandler(func(client paho.Client) {
			oc(client)                                   // original handler
			_ = client.Publish(topic, 1, true, "online") // alive - not logged
		})
	})
	if err != nil {
		return fmt.Errorf("failed configuring mqtt: %w", err)
	}

	mqtt.Instance = instance
	return nil
}

// setup SHM
func configureSHM(conf *shm.Config, externalUrl string, site *core.Site, httpd *server.HTTPd) error {
	if settings.Exists(keys.Shm) {
		if err := settings.Json(keys.Shm, &conf); err != nil {
			return err
		}
	}

	if err := shm.NewFromConfig(*conf, externalUrl, site, httpd.Addr, httpd.Router()); err != nil {
		return fmt.Errorf("failed configuring shm: %w", err)
	}

	return nil
}

// setup javascript
func configureJavascript(conf []globalconfig.Javascript) error {
	for _, cc := range conf {
		if _, err := javascript.RegisteredVM(cc.VM, cc.Script); err != nil {
			return fmt.Errorf("failed configuring javascript: %w", err)
		}
	}
	return nil
}

// setup go
func configureGo(conf []globalconfig.Go) error {
	for _, cc := range conf {
		if _, err := golang.RegisteredVM(cc.VM, cc.Script); err != nil {
			return fmt.Errorf("failed configuring go: %w", err)
		}
	}
	return nil
}

// setup HEMS
func configureHEMS(conf *globalconfig.Hems, site *core.Site) (hemsapi.API, error) {
	// use yaml if configured
	if conf.Type == "" {
		if settings.Exists(keys.Hems) {
			*conf = globalconfig.Hems{}
			if err := settings.Yaml(keys.Hems, new(map[string]any), &conf); err != nil {
				return nil, err
			}
			yamlSource.hems = globalconfig.YamlSourceDb
		}
	} else {
		yamlSource.hems = globalconfig.YamlSourceFile
	}

	if conf.Type == "" {
		return nil, nil
	}

	props, err := customDevice(conf.Other)
	if err != nil {
		return nil, fmt.Errorf("cannot decode custom hems '%s': %w", conf.Type, err)
	}

	hems, err := hems.NewFromConfig(context.TODO(), conf.Type, props, site)
	if err != nil {
		return nil, fmt.Errorf("failed configuring hems: %w", err)
	}

	go hems.Run()

	return hems, nil
}

// networkSettings reads/migrates network settings
func networkSettings(conf *globalconfig.Network) error {
	if settings.Exists(keys.Network) {
		return settings.Json(keys.Network, &conf)
	}

	return nil
}

// setup MDNS
func configureMDNS(conf globalconfig.Network) error {
	host := strings.TrimSuffix(conf.Host, ".local")
	if host == "" {
		host = "evcc"
	}

	internalURL := conf.InternalURL()
	text := []string{"path=/", "internal_url=" + internalURL}

	if externalURL := conf.ExternalURL(); externalURL != internalURL {
		text = append(text, "external_url="+externalURL)
	}

	zc, err := zeroconf.RegisterProxy("evcc", "_http._tcp", "local.", conf.Port, host, nil, text, nil)
	if err != nil {
		return err
	}

	shutdown.Register(zc.Shutdown)

	return nil
}

// setup OCPP
func configureOCPP(cfg *ocpp.Config, externalUrl string) {
	ocpp.Init(*cfg, externalUrl)
}

// setup EEBus
func configureEEBus(conf *eebus.Config) error {
	// migrate settings
	if settings.Exists(keys.EEBus) {
		if err := migrateYamlToJson(keys.EEBus, conf); err != nil {
			return err
		}
	} else if conf.IsConfigured() {
		yamlSource.eebus = globalconfig.YamlSourceFile
	}

	if !conf.IsConfigured() {
		cc, err := eebus.DefaultConfig(conf)
		if err != nil {
			return err
		}

		*conf = *cc
		if err := settings.SetJson(keys.EEBus, conf); err != nil {
			return err
		}
	}

	var err error
	if eebus.Instance, err = eebus.NewServer(*conf); err != nil {
		return fmt.Errorf("failed configuring eebus: %w", err)
	}

	eebus.Instance.Run()
	shutdown.Register(eebus.Instance.Shutdown)

	return nil
}

func configureMessengers(confMessaging *globalconfig.Messaging, confEvents *globalconfig.MessagingEvents, vehicles messenger.Vehicles, valueChan chan<- util.Param, cache *util.ParamCache) (chan messenger.Event, error) {
	// yaml config from file
	if len(confMessaging.Events) != 0 || len(confMessaging.Services) != 0 {
		yamlSource.messaging = globalconfig.YamlSourceFile
	}

	// yaml config from db (deprecated)
	if settings.Exists(keys.Messaging) {
		if yamlSource.messaging == globalconfig.YamlSourceFile {
			// just warn, no error to not break previous behavior
			log.WARN.Println("messaging configured via UI yaml; evcc.yaml config will be ignored")
		}
		*confMessaging = globalconfig.Messaging{}
		if err := settings.Yaml(keys.Messaging, new(map[string]any), &confMessaging); err != nil {
			return nil, err
		}
		yamlSource.messaging = globalconfig.YamlSourceDb
	}

	if settings.Exists(keys.MessagingEvents) {
		*confEvents = globalconfig.MessagingEvents{}
		if err := settings.Json(keys.MessagingEvents, &confEvents); err != nil {
			return nil, err
		}
		if yamlSource.messaging != globalconfig.YamlSourceNone && confEvents != nil {
			return nil, errors.New("yaml and device config exists for messaging; remove yaml config")
		}
	}

	messageChan := make(chan messenger.Event, 1)

	var eg errgroup.Group

	for i, cc := range confMessaging.Services {
		// add name for meter/charger parity
		cc := config.Named{
			Name:  fmt.Sprintf("push-%d", i+1),
			Type:  cc.Type,
			Other: cc.Other,
		}

		eg.Go(func() error {
			return staticInstance("messenger", cc, messenger.NewFromConfig, config.Messengers())
		})
	}

	// append devices from database
	configurable, err := config.ConfigurationsByClass(templates.Messenger)
	if err != nil {
		return messageChan, err
	}

	for _, conf := range configurable {
		eg.Go(func() error {
			return configurableInstance("messenger", &conf, messenger.NewFromConfig, config.Messengers())
		})
	}

	if err := eg.Wait(); err != nil {
		return messageChan, &ClassError{ClassMessenger, err}
	}

	var events globalconfig.MessagingEvents

	if len(*confEvents) > 0 {
		events = conf.MessagingEvents
	} else {
		events = confMessaging.Events
	}

	messageHub, err := messenger.NewHub(events, vehicles, cache)

	if err != nil {
		return messageChan, fmt.Errorf("failed configuring push services: %w", err)
	}

	for _, dev := range config.Messengers().Devices() {
		if inst := dev.Instance(); inst != nil {
			messageHub.Add(inst)
		}
	}

	go messageHub.Run(messageChan, valueChan)

	return messageChan, nil
}

func tariffInstance(name string, conf config.Typed) (api.Tariff, error) {
	ctx := util.WithLogger(context.TODO(), util.NewLogger(name))

	props, err := customDevice(conf.Other)
	if err != nil {
		return nil, fmt.Errorf("cannot decode custom tariff '%s': %w", name, err)
	}

	instance, err := tariff.NewFromConfig(ctx, conf.Type, props)
	if err != nil {
		if _, ok := errors.AsType[*util.ConfigError](err); ok {
			return nil, err
		}

		// wrap non-config tariff errors to prevent fatals
		log.ERROR.Printf("creating tariff %s failed: %v", name, err)
		instance = tariff.NewWrapper(conf.Type, conf.Other, err)
	}

	return instance, nil
}

func configureSolarTariff(conf []config.Typed, t *api.Tariff) error {
	var eg errgroup.Group
	tt := make([]api.Tariff, len(conf))

	for i, conf := range conf {
		eg.Go(func() error {
			if conf.Type == "" {
				return errors.New("missing type")
			}

			name := fmt.Sprintf("%s-%s-%d", api.TariffUsageSolar, tariff.Name(conf), i)
			res, err := tariffInstance(name, conf)
			if err != nil {
				return &DeviceError{name, err}
			}

			tt[i] = res
			return nil
		})
	}

	if err := eg.Wait(); err != nil {
		return err
	}

	*t = tariff.NewCombined(tt)
	return nil
}

func configureTariff(conf config.Typed, deviceName string, target *api.Tariff) error {
	if conf.Type != "" {
		instance, err := tariffInstance("tariff", conf)
		if err != nil {
			return err
		}
		*target = instance
		return nil
	}
	if deviceName != "" {
		dev, err := config.Tariffs().ByName(deviceName)
		if err != nil {
			return fmt.Errorf("tariff device not found: %w", err)
		}
		*target = dev.Instance()
	}
	return nil
}

func configureSolarTariffs(confs []config.Typed, deviceNames []string, target *api.Tariff) error {
	if len(confs) > 0 {
		if len(confs) == 1 {
			return configureTariff(confs[0], "", target)
		}
		return configureSolarTariff(confs, target)
	}
	if len(deviceNames) > 0 {
		if len(deviceNames) == 1 {
			return configureTariff(config.Typed{}, deviceNames[0], target)
		}
		tt := make([]api.Tariff, len(deviceNames))
		for i, name := range deviceNames {
			dev, err := config.Tariffs().ByName(name)
			if err != nil {
				return fmt.Errorf("tariff device %s not found: %w", name, err)
			}
			tt[i] = dev.Instance()
		}
		*target = tariff.NewCombined(tt)
	}
	return nil
}

func configureTariffs(conf *globalconfig.Tariffs, names ...string) (*tariff.Tariffs, error) {
	tariffs := tariff.Tariffs{
		Currency: currency.EUR,
	}

	// yaml config from file
	if conf.IsConfigured() {
		yamlSource.tariffs = globalconfig.YamlSourceFile
	}

	// yaml config from db (deprecated)
	if settings.Exists(keys.Tariffs) {
		if yamlSource.tariffs == globalconfig.YamlSourceFile {
			// just warn, no error to not break previous behavior
			log.WARN.Println("tariffs configured via UI; evcc.yaml config will be ignored")
		}
		*conf = globalconfig.Tariffs{}
		if err := settings.Yaml(keys.Tariffs, new(map[string]any), &conf); err != nil {
			return &tariffs, err
		}
		yamlSource.tariffs = globalconfig.YamlSourceDb
	}

	// device config from db
	var refs globalconfig.TariffRefs
	if settings.Exists(keys.TariffRefs) {
		if err := settings.Json(keys.TariffRefs, &refs); err != nil {
			return &tariffs, err
		}
		if yamlSource.tariffs != globalconfig.YamlSourceNone && refs.IsConfigured() {
			return &tariffs, errors.New("tariffs are configured via UI; having an additional yaml config is not allowed")
		}
	}

	// load tariff devices from database
	configurable, err := config.ConfigurationsByClass(templates.Tariff)
	if err != nil {
		return &tariffs, err
	}

	var eg errgroup.Group

	for _, conf := range configurable {
		eg.Go(func() error {
			cc := conf.Named()

			if len(names) > 0 && !slices.Contains(names, cc.Name) {
				return nil
			}

			instance, err := tariffInstance(cc.Name, config.Typed{Type: cc.Type, Other: cc.Other})
			if err != nil {
				return err
			}

			if e := config.Tariffs().Add(config.NewConfigurableDevice(&conf, instance)); e != nil {
				return &DeviceError{cc.Name, e}
			}

			return nil
		})
	}

	if err := eg.Wait(); err != nil {
		return &tariffs, err
	}

	// resolve tariff roles
	eg = errgroup.Group{}
	eg.Go(func() error { return configureTariff(conf.Grid, refs.Grid, &tariffs.Grid) })
	eg.Go(func() error { return configureTariff(conf.FeedIn, refs.FeedIn, &tariffs.FeedIn) })
	eg.Go(func() error { return configureTariff(conf.Co2, refs.Co2, &tariffs.Co2) })
	eg.Go(func() error { return configureTariff(conf.Planner, refs.Planner, &tariffs.Planner) })
	eg.Go(func() error { return configureSolarTariffs(conf.Solar, refs.Solar, &tariffs.Solar) })
	if err := eg.Wait(); err != nil {
		return &tariffs, &ClassError{ClassTariff, err}
	}

	// validate currency
	if cur, _ := settings.String(keys.Currency); cur != "" {
		conf.Currency = cur
	}
	if conf.Currency != "" {
		cur, err := currency.ParseISO(conf.Currency)
		if err != nil {
			return &tariffs, err
		}
		tariffs.Currency = cur
	}

	return &tariffs, nil
}

func configureDevices(conf globalconfig.All) error {
	// collect references for filtering used devices
	if err := collectRefs(conf); err != nil {
		return err
	}

	// make sure all devices are configured
	var errs []error

	if err := configureMeters(conf.Meters, references.meter...); err != nil {
		errs = append(errs, &ClassError{ClassMeter, err})
	}

	if err := configureChargers(conf.Chargers, references.charger...); err != nil {
		errs = append(errs, &ClassError{ClassCharger, err})
	}

	if err := configureVehicles(conf.Vehicles); err != nil {
		errs = append(errs, &ClassError{ClassVehicle, err})
	}

	if err := configureCircuits(&conf.Circuits); err != nil {
		errs = append(errs, &ClassError{ClassCircuit, err})
	}

	return joinErrors(errs...)
}

func configureModbusProxy(conf *[]globalconfig.ModbusProxy) error {
	if settings.Exists(keys.ModbusProxy) {
		if err := migrateYamlToJson(keys.ModbusProxy, conf); err != nil {
			return err
		}
	}

	// prevent panic
	if conf == nil {
		return nil
	}

	for _, cfg := range *conf {
		var mode modbus.ReadOnlyMode
		mode, err := modbus.ReadOnlyModeString(cfg.ReadOnly)
		if err != nil {
			return err
		}

		if err = modbus.StartProxy(cfg.Port, cfg.Settings, mode); err != nil {
			return err
		}
	}

	return nil
}

func configureSiteAndLoadpoints(conf *globalconfig.All) (*core.Site, error) {
	// migrate settings
	if settings.Exists(keys.Interval) {
		d, err := settings.Int(keys.Interval)
		if err != nil {
			return nil, err
		}
		conf.Interval = time.Duration(d)
	}

	var errs []error

	if err := configureDevices(*conf); err != nil {
		errs = append(errs, err)
	}

	if err := configureLoadpoints(*conf); err != nil {
		errs = append(errs, &ClassError{ClassLoadpoint, err})
	}

	tariffs, err := configureTariffs(&conf.Tariffs, references.tariff...)
	if err != nil {
		errs = append(errs, &ClassError{ClassTariff, err})
	}

	loadpoints := lo.Map(config.Loadpoints().Devices(), func(dev config.Device[loadpoint.API], _ int) *core.Loadpoint {
		return dev.Instance().(*core.Loadpoint)
	})

	site, err := configureSite(conf.Site, loadpoints, tariffs)
	if err != nil {
		errs = append(errs, err)
	}

	if len(errs) > 0 {
		return site, joinErrors(errs...)
	}

	if len(config.Circuits().Devices()) > 0 {
		if err := validateCircuits(loadpoints); err != nil {
			return site, &ClassError{ClassCircuit, err}
		}
	}

	return site, nil
}

func validateCircuits(loadpoints []*core.Loadpoint) error {
	var hasRoot bool

CONTINUE:
	for _, dev := range config.Circuits().Devices() {
		instance := dev.Instance()

		isRoot := instance.GetParent() == nil
		if isRoot {
			if hasRoot {
				return errors.New("multiple root circuits")
			}

			hasRoot = true
		}

		if slices.ContainsFunc(loadpoints, func(lp *core.Loadpoint) bool {
			return lp.GetCircuit() == instance
		}) {
			continue CONTINUE
		}

		if !isRoot && !instance.HasMeter() {
			log.INFO.Printf("circuit %s has no meter and no loadpoint assigned", dev.Config().Name)
		}
	}

	if !hasRoot {
		return errors.New("missing root circuit")
	}

	return nil
}

func configureSite(conf map[string]any, loadpoints []*core.Loadpoint, tariffs *tariff.Tariffs) (*core.Site, error) {
	site, err := core.NewSiteFromConfig(conf)
	if err != nil {
		return site, err
	}

	if err := site.Boot(log, loadpoints, tariffs); err != nil {
		return site, fmt.Errorf("failed booting site: %w", err)
	}

	return site, nil
}

func configureLoadpoints(conf globalconfig.All) error {
	for id, cc := range conf.Loadpoints {
		cc.Name = "lp-" + strconv.Itoa(id+1)

		log := util.NewLoggerWithLoadpoint(cc.Name, id+1)
		settings := coresettings.NewDatabaseSettingsAdapter(fmt.Sprintf("lp%d.", id+1))

		instance, err := core.NewLoadpointFromConfig(log, settings, cc.Other)
		if err != nil {
			return &DeviceError{cc.Name, err}
		}

		if err := config.Loadpoints().Add(config.NewStaticDevice(cc, loadpoint.API(instance))); err != nil {
			return &DeviceError{cc.Name, err}
		}
	}

	// append devices from database
	configurable, err := config.ConfigurationsByClass(templates.Loadpoint)
	if err != nil {
		return err
	}

	for _, conf := range configurable {
		cc := conf.Named()

		id := len(config.Loadpoints().Devices())
		name := "lp-" + strconv.Itoa(id+1)
		log := util.NewLoggerWithLoadpoint(name, id+1)

		settings := coresettings.NewConfigSettingsAdapter(log, &conf)

		dynamic, static, err := loadpoint.SplitConfig(cc.Other)
		if err != nil {
			return &DeviceError{cc.Name, err}
		}

		instance, err := core.NewLoadpointFromConfig(log, settings, static)
		if err != nil {
			err = &DeviceError{cc.Name, err}
		}

		dev := config.NewConfigurableDevice[loadpoint.API](&conf, instance)
		if e := config.Loadpoints().Add(dev); e != nil && err == nil {
			err = &DeviceError{cc.Name, e}
		}

		if instance != nil {
			// ignore dynamic config in case of startup errors that will leave instance empty
			if e := dynamic.Apply(instance); e != nil && err == nil {
				err = &DeviceError{cc.Name, e}
			}
		}

		if err != nil {
			return err
		}
	}

	return nil
}

// configureAuth handles routing for devices. For now only api.AuthProvider related routes
func configureAuth(router *mux.Router, paramC chan<- util.Param) {
	auth := router.PathPrefix("/providerauth").Subrouter()
	auth.Use(handlers.CompressHandler)
	auth.Use(handlers.CORS(
		handlers.AllowedHeaders([]string{"Content-Type"}),
	))

	// backwards-compatible revert of https://github.com/evcc-io/evcc/pull/21266
	router.PathPrefix("/oauth").Handler(auth)

	// wire the handler
	providerauth.Setup(auth, paramC)
}

// isExperimental returns if experimental features are enabled
func isExperimental() bool {
	b, _ := settings.Bool(keys.Experimental)
	return b
}