Add Mobile Charger Connect (#40)

README.md

@@ -7,7 +7,7 @@ EVCC is an extensible EV Charge Controller with PV integration implemented in [G
 ### Features
 
 - simple and clean user interface
-- multiple [chargers](#charger): Wallbe (tested with Wallbe Eco S), Phoenix controllers (similar to Wallbe), go-eCharger, openWB slave, any other charger using scripting
+- multiple [chargers](#charger): Wallbe (tested with Wallbe Eco S), Phoenix controllers (similar to Wallbe), go-eCharger, openWB slave, Mobile Charger Connect (currently used by Porsche), any other charger using scripting
 - more chargers experimentally supported: NRGKick, SimpleEVSE, EVSEWifi
 - different [vehicles](#vehicle) to show battery status: Audi (eTron), BMW (i3), Tesla, Nissan (Leaf), any other vehicle using scripting
 - integration with home automation - supports shell scripts and MQTT
@@ -115,6 +115,7 @@ Available charger implementations are:
 - `evsewifi`: chargers with SimpleEVSE controllers using [SimpleEVSE-Wifi](https://github.com/CurtRod/SimpleEVSE-WiFi)
 - `nrgkick`: NRGKick chargers with Connect module
 - `go-e`: go-eCharger chargers
+- `mcc`: Mobile Charger Connect devices (Audi, Bentley, Porsche)
 - `default`: default charger implementation using configurable [plugins](#plugins) for integrating any type of charger
 
 #### Wallbe Hardware Preparation

api/http.go

@@ -54,6 +54,12 @@ func (r *HTTPHelper) decodeJSON(resp *http.Response, err error, res interface{})
 	return b, err
 }
 
+// Request executes HTTP request returns the response body
+func (r *HTTPHelper) Request(req *http.Request) ([]byte, error) {
+	resp, err := r.Client.Do(req)
+	return r.readBody(resp, err)
+}
+
 // Get executes HTTP GET request returns the response body
 func (r *HTTPHelper) Get(url string) ([]byte, error) {
 	resp, err := r.Client.Get(url)

charger/config.go

@@ -27,6 +27,8 @@ func NewFromConfig(log *api.Logger, typ string, other map[string]interface{}) ap
 		c = NewEVSEWifiFromConfig(log, other)
 	case "simpleevse", "evse":
 		c = NewSimpleEVSEFromConfig(log, other)
+	case "porsche", "audi", "bentley", "mcc":
+		c = NewMobileConnectFromConfig(log, other)
 	default:
 		log.FATAL.Fatalf("invalid charger type '%s'", typ)
 	}

charger/mcc.go

@@ -0,0 +1,333 @@
+package charger
+
+import (
+	"crypto/tls"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/url"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/andig/evcc/api"
+)
+
+const (
+	apiLogin                   apiFunction = "jwt/login"
+	apiRefresh                 apiFunction = "jwt/refresh"
+	apiChargeState             apiFunction = "v1/api/WebServer/properties/chargeState"
+	apiCurrentSession          apiFunction = "v1/api/WebServer/properties/swaggerCurrentSession"
+	apiEnergy                  apiFunction = "v1/api/iCAN/properties/propjIcanEnergy"
+	apiSetCurrentLimit         apiFunction = "v1/api/SCC/properties/propHMICurrentLimit?value="
+	apiCurrentCableInformation apiFunction = "v1/api/SCC/properties/json_CurrentCableInformation"
+)
+
+// MCCErrorResponse is the API response if status not OK
+type MCCErrorResponse struct {
+	Error string
+}
+
+// MCCTokenResponse is the apiLogin response
+type MCCTokenResponse struct {
+	Token string
+}
+
+// MCCCurrentSession is the apiCurrentSession response
+type MCCCurrentSession struct {
+	Duration     time.Duration
+	EnergySumKwh float64
+}
+
+// MCCEnergyPhase is the apiEnergy response for a single phase
+type MCCEnergyPhase struct {
+	Power float64
+}
+
+// MCCEnergy is the apiEnergy response
+type MCCEnergy struct {
+	L1, L2, L3 MCCEnergyPhase
+}
+
+// MCCCurrentCableInformation is the apiCurrentCableInformation response
+type MCCCurrentCableInformation struct {
+	MaxValue, MinValue, Value int64
+}
+
+// MobileConnect charger supporting devices from Audi, Bentley, Porsche
+type MobileConnect struct {
+	*api.HTTPHelper
+	uri              string
+	password         string
+	token            string
+	tokenValid       time.Time
+	tokenRefresh     time.Time
+	cableInformation MCCCurrentCableInformation
+}
+
+// NewMobileConnectFromConfig creates a MCC charger from generic config
+func NewMobileConnectFromConfig(log *api.Logger, other map[string]interface{}) api.Charger {
+	cc := struct{ URI, Password string }{}
+	api.DecodeOther(log, other, &cc)
+
+	return NewMobileConnect(cc.URI, cc.Password)
+}
+
+// NewMobileConnect creates MCC charger
+func NewMobileConnect(uri string, password string) *MobileConnect {
+	mcc := &MobileConnect{
+		HTTPHelper: api.NewHTTPHelper(api.NewLogger("mcc ")),
+		uri:        strings.TrimRight(uri, "/"),
+		password:   password,
+	}
+
+	// ignore the self signed certificate
+	customTransport := http.DefaultTransport.(*http.Transport).Clone()
+	customTransport.TLSClientConfig = &tls.Config{InsecureSkipVerify: true}
+
+	mcc.HTTPHelper.Client.Transport = customTransport
+
+	return mcc
+}
+
+// construct the URL for a given apiFunction
+func (mcc *MobileConnect) apiURL(api apiFunction) string {
+	return fmt.Sprintf("%s/%s", mcc.uri, api)
+}
+
+// process the http request to fetch the auth token for a login or refresh request
+func (mcc *MobileConnect) fetchToken(request *http.Request) error {
+	var tr MCCTokenResponse
+	b, err := mcc.RequestJSON(request, &tr)
+	if err == nil {
+		if len(tr.Token) == 0 && len(b) > 0 {
+			var error MCCErrorResponse
+
+			if err := json.Unmarshal(b, &error); err != nil {
+				return err
+			}
+
+			return fmt.Errorf("response: %s", error.Error)
+		}
+
+		mcc.token = tr.Token
+		// According to the Web Interface, the token is valid for 10 minutes
+		mcc.tokenValid = time.Now().Add(10 * time.Minute)
+
+		// the web interface updates the token every 2 minutes, so lets do the same here
+		mcc.tokenRefresh = time.Now().Add(2 * time.Minute)
+	}
+
+	return err
+}
+
+// login as the home user with the given password
+func (mcc *MobileConnect) login(password string) error {
+	uri := fmt.Sprintf("%s/%s", mcc.uri, apiLogin)
+
+	data := url.Values{
+		"user": []string{"user"},
+		"pass": []string{mcc.password},
+	}
+
+	req, err := http.NewRequest(http.MethodPost, uri, strings.NewReader(data.Encode()))
+	if err != nil {
+		return err
+	}
+
+	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+
+	return mcc.fetchToken(req)
+}
+
+// refresh the auth token with a new one
+func (mcc *MobileConnect) refresh() error {
+	uri := fmt.Sprintf("%s/%s", mcc.uri, apiRefresh)
+
+	req, err := http.NewRequest(http.MethodGet, uri, nil)
+	if err != nil {
+		return err
+	}
+
+	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", mcc.token))
+
+	return mcc.fetchToken(req)
+}
+
+// creates a http request that contains the auth token
+func (mcc *MobileConnect) request(method, uri string) (*http.Request, error) {
+	// do we need to login?
+	if mcc.token == "" || time.Since(mcc.tokenValid) > 0 {
+		if err := mcc.login(mcc.password); err != nil {
+			return nil, err
+		}
+	}
+
+	// is it time to refresh the token?
+	if time.Since(mcc.tokenRefresh) > 0 {
+		if err := mcc.refresh(); err != nil {
+			return nil, err
+		}
+	}
+
+	// now lets process the request with the fetched token
+	req, err := http.NewRequest(method, uri, nil)
+	if err != nil {
+		return req, err
+	}
+
+	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", mcc.token))
+
+	return req, nil
+}
+
+// use http GET to fetch a non structured value from an URI and stores it in result
+func (mcc *MobileConnect) getValue(uri string) ([]byte, error) {
+	req, err := mcc.request(http.MethodGet, uri)
+	if err != nil {
+		return nil, err
+	}
+
+	return mcc.Request(req)
+}
+
+// use http GET to fetch an escaped JSON string and unmarshal the data in result
+func (mcc *MobileConnect) getEscapedJSON(uri string, result interface{}) error {
+	req, err := mcc.request(http.MethodGet, uri)
+	if err != nil {
+		return err
+	}
+
+	b, err := mcc.Request(req)
+	if err == nil {
+		var s string
+		if s, err = strconv.Unquote(strings.Trim(string(b), "\n")); err == nil {
+			err = json.Unmarshal([]byte(s), &result)
+		}
+	}
+
+	return err
+}
+
+// Status implements the Charger.Status interface
+func (mcc *MobileConnect) Status() (api.ChargeStatus, error) {
+	b, err := mcc.getValue(mcc.apiURL(apiChargeState))
+	if err != nil {
+		return api.StatusNone, err
+	}
+
+	chargeState, err := strconv.ParseInt(strings.Trim(string(b), "\n"), 10, 8)
+	if err != nil {
+		return api.StatusNone, err
+	}
+
+	switch chargeState {
+	case 0: // Unplugged
+		return api.StatusA, nil
+	case 1, 3, 4, 6: // 1: Connecting, 3: Established, 4: Paused, 6: Finished
+		return api.StatusB, nil
+	case 2: // Error
+		return api.StatusF, nil
+	case 5: // Active
+		return api.StatusC, nil
+	default:
+		return api.StatusNone, fmt.Errorf("properties unknown result: %d", chargeState)
+	}
+}
+
+// Enabled implements the Charger.Enabled interface
+func (mcc *MobileConnect) Enabled() (bool, error) {
+	// Check if the car is connected and Paused, Active, or Finished
+	b, err := mcc.getValue(mcc.apiURL(apiChargeState))
+	if err != nil {
+		return false, err
+	}
+
+	// return value is returned in the format 0\n
+	chargeState, err := strconv.ParseInt(strings.Trim(string(b), "\n"), 10, 8)
+	if err != nil {
+		return false, err
+	}
+
+	if chargeState >= 4 && chargeState <= 6 {
+		return true, nil
+	}
+
+	return false, nil
+}
+
+// Enable implements the Charger.Enable interface
+func (mcc *MobileConnect) Enable(enable bool) error {
+	// As we don't know of the API to disable charging this for now always returns an error
+	return nil
+}
+
+// MaxCurrent implements the Charger.MaxCurrent interface
+func (mcc *MobileConnect) MaxCurrent(current int64) error {
+	// The device doesn't return an error if we set a value greater than the
+	// current allowed max or smaller than the allowed min
+	// instead it will simply set it to max or min and return "OK" anyway
+	// Since the API here works differently, we fetch the limits
+	// and then return an error if the value is outside of the limits or
+	// otherwise set the new value
+	if mcc.cableInformation.MaxValue == 0 {
+		if err := mcc.getEscapedJSON(mcc.apiURL(apiCurrentCableInformation), &mcc.cableInformation); err != nil {
+			return err
+		}
+	}
+
+	if current < mcc.cableInformation.MinValue {
+		return fmt.Errorf("value is lower than the allowed minimum value %d", mcc.cableInformation.MinValue)
+	}
+
+	if current > mcc.cableInformation.MaxValue {
+		return fmt.Errorf("value is higher than the allowed maximum value %d", mcc.cableInformation.MaxValue)
+	}
+
+	url := fmt.Sprintf("%s%d", mcc.apiURL(apiSetCurrentLimit), current)
+
+	req, err := mcc.request(http.MethodPut, url)
+	if err != nil {
+		return err
+	}
+
+	b, err := mcc.Request(req)
+	if err != nil {
+		return err
+	}
+
+	// return value is returned in the format "OK"\n
+	if strings.Trim(string(b), "\n\"") != "OK" {
+		return fmt.Errorf("maxcurrent unexpected response: %s", string(b))
+	}
+
+	return nil
+}
+
+// CurrentPower implements the Meter interface.
+func (mcc *MobileConnect) CurrentPower() (float64, error) {
+	var energy MCCEnergy
+	err := mcc.getEscapedJSON(mcc.apiURL(apiEnergy), &energy)
+
+	return energy.L1.Power + energy.L2.Power + energy.L3.Power, err
+}
+
+// ChargedEnergy implements the ChargeRater interface.
+func (mcc *MobileConnect) ChargedEnergy() (float64, error) {
+	var currentSession MCCCurrentSession
+	if err := mcc.getEscapedJSON(mcc.apiURL(apiCurrentSession), &currentSession); err != nil {
+		return 0, err
+	}
+
+	return currentSession.EnergySumKwh, nil
+}
+
+// ChargingTime yields current charge run duration
+func (mcc *MobileConnect) ChargingTime() (time.Duration, error) {
+	var currentSession MCCCurrentSession
+	if err := mcc.getEscapedJSON(mcc.apiURL(apiCurrentSession), &currentSession); err != nil {
+		return 0, err
+	}
+
+	return time.Duration(currentSession.Duration * time.Second), nil
+}