Add solar usage reporting

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
+}