Add solar usage reporting

.gitignore

@@ -102,3 +102,4 @@ Temporary Items
 whatsapp.db
 auto-response-time-map.json
 out/
+.env

Makefile

@@ -1,5 +1,5 @@
 start: install-deps
-	go run cmd/main.go
+	source .env && go run cmd/main.go
 
 install-deps:
 	go mod tidy

cmd/main.go

@@ -6,6 +6,7 @@ import (
 	"os/signal"
 	"syscall"
 
+	"github.com/robfig/cron"
 	"go.mau.fi/whatsmeow"
 	"go.mau.fi/whatsmeow/store/sqlstore"
 	"go.mau.fi/whatsmeow/types"
@@ -41,10 +42,24 @@ func main() {
 	client.Register()
 	client.Connect()
 
+	deyeUser := os.Getenv("DEYE_USER")
+	deyePassword := os.Getenv("DEYE_PASSWORD")
+
+	if deyeUser == "" || deyePassword == "" {
+		panic("Deye user/password must be provided")
+	}
+
+	solar := internal.NewSolar(client, deyeUser, deyePassword)
+
+	myCron := cron.New()
+	myCron.AddFunc("0 0 19 * * *", solar.SendDailyReport)
+	myCron.Start()
+
 	// Listen to Ctrl+C (you can also do something else that prevents the program from exiting)
 	c := make(chan os.Signal, 1)
 	signal.Notify(c, os.Interrupt, syscall.SIGTERM)
 	<-c
 
+	myCron.Stop()
 	client.Disconnect()
 }

go.mod

@@ -2,7 +2,10 @@ module git.sangeeth.dev/wa-autoresponder
 
 go 1.24.1
 
-require go.mau.fi/whatsmeow v0.0.0-20250326122532-6680c9a6e9a7
+require (
+	github.com/robfig/cron v1.2.0
+	go.mau.fi/whatsmeow v0.0.0-20250326122532-6680c9a6e9a7
+)
 
 require rsc.io/qr v0.2.0 // indirect
 

go.sum

@@ -24,6 +24,8 @@ github.com/mdp/qrterminal v1.0.1/go.mod h1:Z33WhxQe9B6CdW37HaVqcRKzP+kByF3q/qLxO
 github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/robfig/cron v1.2.0 h1:ZjScXvvxeQ63Dbyxy76Fj3AT3Ut0aKsyd2/tl3DTMuQ=
+github.com/robfig/cron v1.2.0/go.mod h1:JGuDeoQd7Z6yL4zQhZ3OPEVHB7fL6Ka6skscFHfmt2k=
 github.com/rs/xid v1.5.0/go.mod h1:trrq9SKmegXys3aeAKXMUTdJsYXVwGY3RLcfgqegfbg=
 github.com/rs/zerolog v1.33.0 h1:1cU2KZkvPxNyfgEmhHAz/1A9Bz+llsdYzklWFzgp0r8=
 github.com/rs/zerolog v1.33.0/go.mod h1:/7mN4D5sKwJLZQ2b/znpjC3/GQWY/xaDXUM0kKWRHss=

internal/client.go

@@ -178,7 +178,7 @@ func (client *Client) eventHandler(evt interface{}) {
 
 		time.Sleep(2 * time.Duration(rand.IntN(3)) * time.Second)
 
-		msg := proto.String(client.message + "\n\nIgnore this random number: `" + strconv.FormatInt(time.Now().UnixMilli(), 10) + "`")
+		msg := proto.String(client.message + "\n\nIgnore this random number: `" + strconv.FormatInt(time.Now().Unix(), 10) + "`")
 
 		imageResp, err := client.WAClient.Upload(context.Background(), waautoresponder.Bernie, whatsmeow.MediaImage)
 
@@ -216,3 +216,26 @@ func (client *Client) eventHandler(evt interface{}) {
 		client.updateAutoResponseTime(chatUserId)
 	}
 }
+
+func (client *Client) SendTextMessage(chatId string, message string) {
+	chatJID, err := types.ParseJID(chatId)
+
+	if err != nil {
+		fmt.Println("Error parsing JID:", err)
+		return
+	}
+
+	time.Sleep(2 * time.Duration(rand.IntN(3)) * time.Second)
+	client.WAClient.SendChatPresence(chatJID, types.ChatPresenceComposing, types.ChatPresenceMediaText)
+	time.Sleep(2 * time.Duration(rand.IntN(3)) * time.Second)
+
+	client.WAClient.SendMessage(
+		context.Background(),
+		chatJID,
+		&waE2E.Message{
+			Conversation: proto.String(message),
+		},
+	)
+
+	client.WAClient.SendChatPresence(chatJID, types.ChatPresencePaused, types.ChatPresenceMediaText)
+}

internal/solar.go

@@ -0,0 +1,144 @@
+package internal
+
+import (
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"regexp"
+	"strconv"
+	"time"
+)
+
+const adminStatusEndpoint = "http://deye-solar-inverter/status.html"
+const expectedDailyOutput float64 = 20
+
+var yieldTodayPattern = regexp.MustCompile(`var webdata_today_e = "([^"]+)";`)
+var yieldTotalPattern = regexp.MustCompile(`var webdata_total_e = "([^"]+)";`)
+
+type Solar struct {
+	client        *Client
+	channelId     string
+	adminUser     string
+	adminPassword string
+}
+
+func NewSolar(client *Client, adminUser, adminPassword string) *Solar {
+	channelId := os.Getenv("SOLAR_REPORT_CHANNEL_ID")
+
+	if channelId == "" {
+		panic("SOLAR_REPORT_CHANNEL_ID must be set")
+	}
+
+	return &Solar{
+		client:        client,
+		adminUser:     adminUser,
+		adminPassword: adminPassword,
+		channelId:     channelId,
+	}
+}
+
+func (this *Solar) SendDailyReport() {
+	metrics, err := this.querySolarMetrics()
+
+	if err != nil {
+		fmt.Println("Error querying soalr metrics:", err)
+		return
+	}
+
+	fmt.Printf("[SOLAR] Metrics: %v\n", metrics)
+
+	deltaYieldToday := metrics.today - expectedDailyOutput
+
+	var summary string
+
+	if deltaYieldToday < 0 {
+		summary = fmt.Sprintf("☹️ Below expected daily yield of %.2f kWh", expectedDailyOutput)
+	} else {
+		summary = fmt.Sprintf("😁 Above expected daily yield by %.2f kWh", deltaYieldToday)
+	}
+
+	var todayFormatted = time.Now().Format("Monday, 2 Jan 2006")
+
+	message := fmt.Sprintf(
+		"*🔆 Solar Production Report, %s*\n\n"+
+			summary+
+			"\n\n"+
+			"Today: %.2f kWh\n"+
+			"Total: %.2f kWh\n\n"+
+			"`DO NOT CLICK: %d`",
+		todayFormatted,
+		metrics.today,
+		metrics.total,
+		time.Now().Unix(),
+	)
+
+	fmt.Printf("[SOLAR] Message to be sent:\n%s", message)
+
+	this.client.SendTextMessage(
+		this.channelId,
+		message,
+	)
+}
+
+func (this *Solar) querySolarMetrics() (*struct {
+	today float64
+	total float64
+}, error) {
+	req, err := http.NewRequest("GET", adminStatusEndpoint, nil)
+	if err != nil {
+		panic(err)
+	}
+
+	req.SetBasicAuth(this.adminUser, this.adminPassword)
+	res, err := http.DefaultClient.Do(req)
+
+	if err != nil {
+		panic(err)
+	}
+
+	if res.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("Bad status %d querying status page", res.StatusCode)
+	}
+
+	defer res.Body.Close()
+
+	rawBody, err := io.ReadAll(res.Body)
+
+	if err != nil {
+		return nil, err
+	}
+
+	html := string(rawBody)
+	matches := yieldTodayPattern.FindStringSubmatch(html)
+
+	if len(matches) != 2 {
+		return nil, fmt.Errorf("Regex failed to match today's yield")
+	}
+
+	yieldToday, err := strconv.ParseFloat(matches[1], 64)
+
+	if err != nil {
+		return nil, fmt.Errorf("Failed to convert %s to float64: %w", matches[1], err)
+	}
+
+	matches = yieldTotalPattern.FindStringSubmatch(html)
+
+	if len(matches) != 2 {
+		return nil, fmt.Errorf("Regex failed to match total yield")
+	}
+
+	yieldTotal, err := strconv.ParseFloat(matches[1], 64)
+
+	if err != nil {
+		return nil, fmt.Errorf("Failed to convert %s to float64: %w", matches[1], err)
+	}
+
+	return &struct {
+		today float64
+		total float64
+	}{
+		today: yieldToday,
+		total: yieldTotal,
+	}, nil
+}