build uppon paramParser

Backend/helper/paramParser/main.go

@@ -1,8 +1,10 @@
 package paramParser
 
 import (
+	"fmt"
 	"log/slog"
 	"net/url"
+	"strconv"
 	"time"
 )
 
@@ -10,22 +12,82 @@ type ParamsParser struct {
 	urlParams url.Values
 }
 
+type NoValueError struct {
+	Key string
+}
+
+func (e *NoValueError) Error() string {
+	return fmt.Sprintf("No value found for key %s", e.Key)
+}
+
 func New(_urlParams url.Values) ParamsParser {
 	return ParamsParser{
 		urlParams: _urlParams,
 	}
 }
 
-func (p *ParamsParser) ParseTimestamp(key string, format string, fallback time.Time) time.Time {
-	paramTimestamp := p.urlParams.Get(key)
-	if paramTimestamp == "" {
+func (p *ParamsParser) ParseTimestampFallback(key string, format string, fallback time.Time) time.Time {
+	if !p.urlParams.Has(key) {
 		return fallback
 	}
+	paramTimestamp := p.urlParams.Get(key)
 	if timestamp, err := time.Parse(format, paramTimestamp); err == nil {
 		return timestamp
 	} else {
-		slog.Warn("Error parsing HTTP Params to timestamp", slog.Any("key", key), slog.Any("error", err))
+		slog.Warn("Error parsing HTTP Params to time.Time", slog.Any("key", key), slog.Any("error", err))
 		return fallback
 	}
-
+}
+
+func (p *ParamsParser) ParseTimestamp(key string, format string) (time.Time, error) {
+	if !p.urlParams.Has(key) {
+		return time.Time{}, &NoValueError{Key: key}
+	}
+	paramTimestamp := p.urlParams.Get(key)
+	if timestamp, err := time.Parse(format, paramTimestamp); err == nil {
+		return timestamp, nil
+	} else {
+		slog.Debug("Error parsing HTTP Params to time.Time", slog.Any("key", key), slog.Any("error", err))
+		return timestamp, err
+	}
+}
+
+func (p *ParamsParser) ParseStringFallback(key string, fallback string) string {
+	if !p.urlParams.Has(key) {
+		return fallback
+	}
+	return p.urlParams.Get(key)
+}
+
+func (p *ParamsParser) ParseString(key string, fallback string) (string, error) {
+	if !p.urlParams.Has(key) {
+		return "", &NoValueError{Key: key}
+	}
+	return p.urlParams.Get(key), nil
+}
+
+func (p *ParamsParser) ParseIntFallback(key string, fallback int) int {
+	if !p.urlParams.Has(key) {
+		return fallback
+	}
+	paramInt := p.urlParams.Get(key)
+	if result, err := strconv.Atoi(paramInt); err == nil {
+		return result
+	} else {
+		slog.Warn("Error parsing HTTP Params to Int", slog.Any("key", key), slog.Any("error", err))
+		return fallback
+	}
+}
+
+func (p *ParamsParser) ParseInt(key string) (int, error) {
+	if !p.urlParams.Has(key) {
+		return 0, &NoValueError{Key: key}
+	}
+	paramInt := p.urlParams.Get(key)
+	if result, err := strconv.Atoi(paramInt); err == nil {
+		return result, nil
+	} else {
+		slog.Debug("Error parsing HTTP Params to Int", slog.Any("key", key), slog.Any("error", err))
+		return 0, err
+	}
 }