Add debug flag which prints out responses to stderr.

Author: tedpearson

internal/app/api.go

@@ -8,6 +8,7 @@ import (
 	"io"
 	"net/http"
 	"net/url"
+	"os"
 	"strings"
 	"time"
 )
@@ -35,9 +36,23 @@ func Auth(config SmartHubConfig) (string, error) {
 	if err != nil {
 		return "", err
 	}
-	decoder := json.NewDecoder(resp.Body)
+	defer func(Body io.ReadCloser) {
+		err := Body.Close()
+		if err != nil {
+			fmt.Println("Error: failed to close response body")
+		}
+	}(resp.Body)
+	reader := resp.Body.(io.Reader)
+	if debug {
+		_, _ = fmt.Fprintln(os.Stderr, "\nDEBUG: Response from auth endpoint:")
+		reader = io.TeeReader(reader, os.Stderr)
+	}
+	decoder := json.NewDecoder(reader)
 	oauth := &OAuth{}
 	err = decoder.Decode(oauth)
+	if debug {
+		_, _ = fmt.Fprintf(os.Stderr, "\n\n")
+	}
 	if err != nil {
 		return "", err
 	}

internal/app/main.go

@@ -37,13 +37,17 @@ type Config struct {
 	InfluxDB    InfluxConfig   `yaml:"influxdb"`
 }
 
+var debug bool
+
 // Main runs the program.
 func Main() error {
 	configFlag := flag.String("config", "config.yaml", "Config file")
 	startFlag := flag.String("start", "", "Start date of period to extract from electric co.")
 	endFlag := flag.String("end", "", "End date of period to extract from electric co.")
+	debugFlag := flag.Bool("debug", false, "Enable to print out verbose debugging logs.")
 	flag.Parse()
 
+	debug = *debugFlag
 	// read config
 	file, err := os.ReadFile(*configFlag)
 	if err != nil {

internal/app/parser.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"os"
 	"time"
 )
 
@@ -64,22 +65,31 @@ func (t *RetryableError) Error() string {
 
 // ParseReader parses the json response received in FetchData from the SmartHub poll api.
 // It can return a normal error, a RetryableError, or parsed ElectricUsage.
-func ParseReader(reader io.ReadCloser) ([]ElectricUsage, error) {
+func ParseReader(readCloser io.ReadCloser) ([]ElectricUsage, error) {
 	defer func() {
-		if err := reader.Close(); err != nil {
-			panic(err)
+		if err := readCloser.Close(); err != nil {
+			fmt.Println("Error: failed to close response body")
 		}
 	}()
+	reader := readCloser.(io.Reader)
+	if debug {
+		_, _ = fmt.Fprintln(os.Stderr, "\nDEBUG: Response from poll endpoint:")
+		reader = io.TeeReader(readCloser, os.Stderr)
+	}
 	resp := &Response{}
 	err := json.NewDecoder(reader).Decode(resp)
 	if err != nil {
 		return nil, err
 	}
+	if debug {
+		_, _ = fmt.Fprintln(os.Stderr, "\n\nDEBUG: Parsed data from poll endpoint:")
+		_, _ = fmt.Fprintf(os.Stderr, "%+v\n\n", resp)
+	}
 	if resp.Status != "COMPLETE" {
 		fmt.Println("Data not ready, retrying...")
 		return nil, NewRetryableError("data processing not complete")
 	}
-	fmt.Println("Data received, parsing...")
+	fmt.Println("Data received, transforming...")
 	datas, ok := resp.Data["ELECTRIC"]
 	if !ok {
 		return nil, errors.New("no ELECTRIC key")