v0.0.340

bfcodegen/enum-generate.go

@@ -37,7 +37,7 @@ var rexEnumPackage = rext.W(regexp.MustCompile(`^package\s+(?P<name>[A-Za-z0-9_]
 
 var rexEnumDef = rext.W(regexp.MustCompile(`^\s*type\s+(?P<name>[A-Za-z0-9_]+)\s+(?P<type>[A-Za-z0-9_]+)\s*//\s*(@enum:type).*$`))
 
-var rexEnumValueDef = rext.W(regexp.MustCompile(`^\s*(?P<name>[A-Za-z0-9_]+)\s+(?P<type>[A-Za-z0-9_]+)\s*=\s*(?P<value>("[A-Za-z0-9_:\s\-]+"|[0-9]+))\s*(//(?P<descr>.*))?.*$`))
+var rexEnumValueDef = rext.W(regexp.MustCompile(`^\s*(?P<name>[A-Za-z0-9_]+)\s+(?P<type>[A-Za-z0-9_]+)\s*=\s*(?P<value>("[A-Za-z0-9_:\s\-.]+"|[0-9]+))\s*(//(?P<descr>.*))?.*$`))
 
 var rexEnumChecksumConst = rext.W(regexp.MustCompile(`const ChecksumEnumGenerator = "(?P<cs>[A-Za-z0-9_]*)"`))
 

bfcodegen/enum-generate.template

@@ -75,6 +75,12 @@ func (e {{.EnumTypeName}}) Meta() enums.EnumMetaValue {
     {{if $hasDescr}} return enums.EnumMetaValue{VarName: e.VarName(), Value: e, Description: langext.Ptr(e.Description())} {{else}} return enums.EnumMetaValue{VarName: e.VarName(), Value: e, Description: nil} {{end}}
 }
 
+{{if $hasDescr}}
+func (e {{.EnumTypeName}}) DescriptionMeta() enums.EnumDescriptionMetaValue {
+    return enums.EnumDescriptionMetaValue{VarName: e.VarName(), Value: e, Description: e.Description()}
+}
+{{end}}
+
 func Parse{{.EnumTypeName}}(vv string) ({{.EnumTypeName}}, bool) {
 	for _, ev := range __{{.EnumTypeName}}Values {
 		if string(ev) == vv {
@@ -94,4 +100,12 @@ func {{.EnumTypeName}}ValuesMeta() []enums.EnumMetaValue {
 	}
 }
 
+{{if $hasDescr}}
+func {{.EnumTypeName}}ValuesDescriptionMeta() []enums.EnumDescriptionMetaValue {
+	return []enums.EnumDescriptionMetaValue{ {{range .Values}}
+            {{.VarName}}.DescriptionMeta(), {{end}}
+	}
+}
+{{end}}
+
 {{end}}

enums/enum.go

@@ -15,10 +15,17 @@ type StringEnum interface {
 type DescriptionEnum interface {
 	Enum
 	Description() string
+	DescriptionMeta() EnumDescriptionMetaValue
 }
 
 type EnumMetaValue struct {
 	VarName     string  `json:"varName"`
-	Value       any     `json:"value"`
+	Value       Enum    `json:"value"`
 	Description *string `json:"description"`
 }
+
+type EnumDescriptionMetaValue struct {
+	VarName     string `json:"varName"`
+	Value       Enum   `json:"value"`
+	Description string `json:"description"`
+}

exerr/data.go

@@ -59,6 +59,9 @@ var (
 	TypeMarshalEntityID = NewType("MARSHAL_ENTITY_ID", langext.Ptr(400))
 	TypeInvalidCSID     = NewType("INVALID_CSID", langext.Ptr(400))
 
+	TypeGoogleStatuscode = NewType("GOOGLE_STATUSCODE", langext.Ptr(400))
+	TypeGoogleResponse   = NewType("GOOGLE_RESPONSE", langext.Ptr(400))
+
 	TypeUnauthorized = NewType("UNAUTHORIZED", langext.Ptr(401))
 	TypeAuthFailed   = NewType("AUTH_FAILED", langext.Ptr(401))
 

ginext/engine.go

@@ -6,8 +6,10 @@ import (
 	"github.com/rs/zerolog/log"
 	"gogs.mikescher.com/BlackForestBytes/goext/langext"
 	"gogs.mikescher.com/BlackForestBytes/goext/mathext"
+	"gogs.mikescher.com/BlackForestBytes/goext/rext"
 	"net"
 	"net/http"
+	"regexp"
 	"strings"
 	"time"
 )
@@ -126,8 +128,8 @@ func (w *GinWrapper) DebugPrintRoutes() {
 		line := [4]string{
 			spec.Method,
 			spec.URL,
-			strings.Join(spec.Middlewares, " -> "),
+			strings.Join(langext.ArrMap(spec.Middlewares, w.cleanMiddlewareName), " -> "),
-			spec.Handler,
+			w.cleanMiddlewareName(spec.Handler),
 		}
 
 		lines = append(lines, line)
@@ -138,12 +140,38 @@ func (w *GinWrapper) DebugPrintRoutes() {
 		pad[3] = mathext.Max(pad[3], len(line[3]))
 	}
 
+	fmt.Printf("Gin-Routes:")
 	for _, line := range lines {
 
-		fmt.Printf("Gin-Route: %s  %s  -->  %s  -->  %s\n",
+		fmt.Printf(" %s  %s  -->  %s  -->  %s\n",
 			langext.StrPadRight("["+line[0]+"]", " ", pad[0]+2),
 			langext.StrPadRight(line[1], " ", pad[1]),
 			langext.StrPadRight(line[2], " ", pad[2]),
 			langext.StrPadRight(line[3], " ", pad[3]))
 	}
 }
+
+func (w *GinWrapper) cleanMiddlewareName(fname string) string {
+
+	funcSuffix := rext.W(regexp.MustCompile(`\.func[0-9]+(?:\.[0-9]+)*$`))
+	if match, ok := funcSuffix.MatchFirst(fname); ok {
+		fname = fname[:len(fname)-match.FullMatch().Length()]
+	}
+
+	if strings.HasSuffix(fname, ".(*GinRoutesWrapper).WithJSONFilter") {
+		fname = "[JSONFilter]"
+	}
+
+	if fname == "ginext.BodyBuffer" {
+		fname = "[BodyBuffer]"
+	}
+
+	skipPrefixes := []string{"api.(*Handler).", "api.", "ginext.", "handler.", "admin-app.", "employee-app.", "employer-app."}
+	for _, pfx := range skipPrefixes {
+		if strings.HasPrefix(fname, pfx) {
+			fname = fname[len(pfx):]
+		}
+	}
+
+	return fname
+}

ginext/routes.go

@@ -3,11 +3,9 @@ package ginext
 import (
 	"github.com/gin-gonic/gin"
 	"gogs.mikescher.com/BlackForestBytes/goext/langext"
-	"gogs.mikescher.com/BlackForestBytes/goext/rext"
 	"net/http"
 	"path"
 	"reflect"
-	"regexp"
 	"runtime"
 	"strings"
 )
@@ -196,12 +194,6 @@ func nameOfFunction(f any) string {
 		fname = fname[:len(fname)-len("-fm")]
 	}
 
-	suffix := rext.W(regexp.MustCompile(`\.func[0-9]+(?:\.[0-9]+)*$`))
-
-	if match, ok := suffix.MatchFirst(fname); ok {
-		fname = fname[:len(fname)-match.FullMatch().Length()]
-	}
-
 	return fname
 }
 

go.mod

@@ -7,7 +7,7 @@ require (
 	github.com/jmoiron/sqlx v1.3.5
 	github.com/rs/xid v1.5.0
 	github.com/rs/zerolog v1.31.0
-	go.mongodb.org/mongo-driver v1.13.0
+	go.mongodb.org/mongo-driver v1.13.1
 	golang.org/x/crypto v0.16.0
 	golang.org/x/sys v0.15.0
 	golang.org/x/term v0.15.0

go.sum

@@ -126,6 +126,8 @@ go.mongodb.org/mongo-driver v1.12.1 h1:nLkghSU8fQNaK7oUmDhQFsnrtcoNy7Z6LVFKsEecq
 go.mongodb.org/mongo-driver v1.12.1/go.mod h1:/rGBTebI3XYboVmgz+Wv3Bcbl3aD0QF9zl6kDDw18rQ=
 go.mongodb.org/mongo-driver v1.13.0 h1:67DgFFjYOCMWdtTEmKFpV3ffWlFnh+CYZ8ZS/tXWUfY=
 go.mongodb.org/mongo-driver v1.13.0/go.mod h1:/rGBTebI3XYboVmgz+Wv3Bcbl3aD0QF9zl6kDDw18rQ=
+go.mongodb.org/mongo-driver v1.13.1 h1:YIc7HTYsKndGK4RFzJ3covLz1byri52x0IoMB0Pt/vk=
+go.mongodb.org/mongo-driver v1.13.1/go.mod h1:wcDf1JBCXy2mOW0bWHwO/IOYqdca1MPCwDtFu/Z9+eo=
 golang.org/x/arch v0.0.0-20210923205945-b76863e36670/go.mod h1:5om86z9Hs0C8fWVUuoMHwpExlXzs5Tkyp9hOrfG7pp8=
 golang.org/x/arch v0.5.0 h1:jpGode6huXQxcskEIpOCvrU+tzo81b6+oFLUYXWtH/Y=
 golang.org/x/arch v0.5.0/go.mod h1:5om86z9Hs0C8fWVUuoMHwpExlXzs5Tkyp9hOrfG7pp8=

goextVersion.go

@@ -1,5 +1,5 @@
 package goext
 
-const GoextVersion = "0.0.327"
+const GoextVersion = "0.0.340"
 
-const GoextVersionTimestamp = "2023-12-02T13:15:19+0100"
+const GoextVersionTimestamp = "2023-12-07T14:42:25+0100"

googleapi/README.md

@@ -0,0 +1,54 @@
+
+Google OAuth Setup (to send mails)
+==================================
+
+
+ - Login @ https://console.cloud.google.com
+
+ - GMail API akivieren: https://console.cloud.google.com/apis/library/gmail.googleapis.com?
+
+ - Create new Project (aka 'BackendMailAPI') @ https://console.cloud.google.com/projectcreate
+   User Type: Intern
+   Anwendungsname: 'BackendMailAPI'
+   Support-Email: ...
+   Authorisierte Domains: 'heydyno.de' (or project domain)
+   Kontakt-Email: ...
+   
+
+ - Unter "Anmeldedaten" neuer OAuth Client erstellen @ https://console.cloud.google.com/apis/credentials
+   Anwendungstyp: Web
+   Name: 'BackendMailOAuth'
+   Redirect-Uri: 'http://localhost/oauth'
+   Client-ID und Client-Key merken
+
+ - Open in Browser:
+   https://accounts.google.com/o/oauth2/v2/auth?redirect_uri=http://localhost/oauth&prompt=consent&response_type=code&client_id={...}&scope=https://www.googleapis.com/auth/gmail.send&access_type=offline
+   Code aus redirected URI merken
+
+ - Code via request einlösen (und refresh_roken merken):
+
+```
+curl --request POST \
+  --url https://oauth2.googleapis.com/token \
+  --data code={...} \
+  --data redirect_uri=http://localhost/oauth \
+  --data client_id={...} \
+  --data client_secret={...} \
+  --data grant_type=authorization_code \
+  --data scope=https://www.googleapis.com/auth/gmail.send
+```
+
+ - Fertig, mit `client_id`, `client_secret` und `refresh_token` kann das package benutzt werden
+
+
+
+
+
+
+
+
+
+
+
+
+

googleapi/attachment.go

@@ -0,0 +1,46 @@
+package googleapi
+
+import (
+	"encoding/base64"
+	"fmt"
+)
+
+type MailAttachment struct {
+	IsInline    bool
+	ContentType string
+	Filename    string
+	Data        []byte
+}
+
+func (a MailAttachment) dump() []string {
+	res := make([]string, 0, 4)
+
+	if a.ContentType != "" {
+		res = append(res, "Content-Type: "+a.ContentType+"; charset=UTF-8")
+	}
+
+	res = append(res, "Content-Transfer-Encoding: base64")
+
+	if a.IsInline {
+		if a.Filename != "" {
+			res = append(res, fmt.Sprintf("Content-Disposition: inline;filename=\"%s\"", a.Filename))
+		} else {
+			res = append(res, "Content-Disposition: inline")
+		}
+	} else {
+		if a.Filename != "" {
+			res = append(res, fmt.Sprintf("Content-Disposition: attachment;filename=\"%s\"", a.Filename))
+		} else {
+			res = append(res, "Content-Disposition: attachment")
+		}
+	}
+
+	b64 := base64.StdEncoding.EncodeToString(a.Data)
+	for i := 0; i < len(b64); i += 80 {
+		res = append(res, b64[i:min(i+80, len(b64))])
+	}
+
+	res = append(res)
+
+	return res
+}

googleapi/body.go

@@ -0,0 +1,6 @@
+package googleapi
+
+type MailBody struct {
+	Plain string
+	HTML  string
+}

googleapi/mimeMessage.go

@@ -0,0 +1,224 @@
+package googleapi
+
+import (
+	"gogs.mikescher.com/BlackForestBytes/goext/langext"
+	"mime"
+	"strings"
+	"time"
+)
+
+// https://datatracker.ietf.org/doc/html/rfc2822
+func encodeMimeMail(from string, recipients []string, cc []string, bcc []string, subject string, body MailBody, attachments []MailAttachment) string {
+
+	data := make([]string, 0, 32)
+
+	data = append(data, "Date: "+time.Now().Format(time.RFC1123Z))
+	data = append(data, "MIME-Version: 1.0")
+	data = append(data, "From: "+mime.QEncoding.Encode("UTF-8", from))
+	data = append(data, "To: "+strings.Join(langext.ArrMap(recipients, func(v string) string { return mime.QEncoding.Encode("UTF-8", v) }), ", "))
+	if len(cc) > 0 {
+		data = append(data, "To: "+strings.Join(langext.ArrMap(cc, func(v string) string { return mime.QEncoding.Encode("UTF-8", v) }), ", "))
+	}
+	if len(bcc) > 0 {
+		data = append(data, "Bcc: "+strings.Join(langext.ArrMap(bcc, func(v string) string { return mime.QEncoding.Encode("UTF-8", v) }), ", "))
+	}
+	data = append(data, "Subject: "+mime.QEncoding.Encode("UTF-8", subject))
+
+	hasInlineAttachments := langext.ArrAny(attachments, func(v MailAttachment) bool { return v.IsInline })
+	hasNormalAttachments := langext.ArrAny(attachments, func(v MailAttachment) bool { return !v.IsInline })
+	hasPlain := body.Plain != ""
+	hasHTML := body.HTML != ""
+
+	mixedBoundary := langext.MustRawHexUUID()
+	relatedBoundary := langext.MustRawHexUUID()
+	altBoundary := langext.MustRawHexUUID()
+
+	inlineAttachments := langext.ArrFilter(attachments, func(v MailAttachment) bool { return v.IsInline })
+	normalAttachments := langext.ArrFilter(attachments, func(v MailAttachment) bool { return !v.IsInline })
+
+	if hasInlineAttachments && hasNormalAttachments {
+		// "mixed+related"
+
+		data = append(data, "Content-Type: multipart/mixed; boundary="+mixedBoundary)
+		data = append(data, "")
+		data = append(data, "--"+mixedBoundary)
+
+		data = append(data, "Content-Type: multipart/related; boundary="+relatedBoundary)
+		data = append(data, "")
+
+		data = append(data, dumpMailBody(body, hasInlineAttachments, hasNormalAttachments, relatedBoundary, altBoundary)...)
+		data = append(data, "")
+
+		for i, attachment := range inlineAttachments {
+			data = append(data, "--"+relatedBoundary)
+			data = append(data, attachment.dump()...)
+
+			if i < len(inlineAttachments)-1 {
+				data = append(data, "")
+			}
+		}
+
+		data = append(data, "--"+relatedBoundary+"--")
+
+		for i, attachment := range normalAttachments {
+			data = append(data, "--"+mixedBoundary)
+			data = append(data, attachment.dump()...)
+
+			if i < len(normalAttachments)-1 {
+				data = append(data, "")
+			}
+		}
+
+		data = append(data, "--"+mixedBoundary+"--")
+
+	} else if hasNormalAttachments {
+		// "mixed"
+
+		data = append(data, "Content-Type: multipart/mixed; boundary="+mixedBoundary)
+		data = append(data, "")
+
+		data = append(data, dumpMailBody(body, hasInlineAttachments, hasNormalAttachments, mixedBoundary, altBoundary)...)
+		if hasPlain && hasHTML {
+			data = append(data, "")
+		}
+
+		for i, attachment := range normalAttachments {
+			data = append(data, "--"+mixedBoundary)
+			data = append(data, attachment.dump()...)
+
+			if i < len(normalAttachments)-1 {
+				data = append(data, "")
+			}
+		}
+
+		data = append(data, "--"+mixedBoundary+"--")
+
+	} else if hasInlineAttachments {
+		// "related"
+
+		data = append(data, "Content-Type: multipart/related; boundary="+relatedBoundary)
+		data = append(data, "")
+
+		data = append(data, dumpMailBody(body, hasInlineAttachments, hasNormalAttachments, relatedBoundary, altBoundary)...)
+		data = append(data, "")
+
+		for i, attachment := range inlineAttachments {
+			data = append(data, "--"+relatedBoundary)
+			data = append(data, attachment.dump()...)
+
+			if i < len(inlineAttachments)-1 {
+				data = append(data, "")
+			}
+		}
+
+		data = append(data, "--"+relatedBoundary+"--")
+
+	} else if hasPlain && hasHTML {
+		// "alternative"
+
+		data = append(data, "Content-Type: multipart/alternative; boundary="+altBoundary)
+		data = append(data, "")
+
+		data = append(data, dumpMailBody(body, hasInlineAttachments, hasNormalAttachments, altBoundary, altBoundary)...)
+		data = append(data, "")
+
+		data = append(data, "--"+altBoundary+"--")
+
+	} else if hasPlain {
+		// "plain"
+
+		data = append(data, "Content-Type: text/plain; charset=UTF-8")
+		data = append(data, "Content-Transfer-Encoding: 7bit")
+		data = append(data, "")
+		data = append(data, body.Plain)
+
+	} else if hasHTML {
+		// "plain"
+
+		data = append(data, "Content-Type: text/html; charset=UTF-8")
+		data = append(data, "Content-Transfer-Encoding: 7bit")
+		data = append(data, "")
+		data = append(data, body.HTML)
+
+	} else {
+		// "empty??"
+
+	}
+
+	return strings.Join(data, "\r\n")
+}
+
+func dumpMailBody(body MailBody, hasInlineAttachments bool, hasNormalAttachments bool, boundary string, boundaryAlt string) []string {
+
+	if body.HTML != "" && body.Plain != "" && !hasInlineAttachments && hasNormalAttachments {
+		data := make([]string, 0, 16)
+		data = append(data, "--"+boundary)
+		data = append(data, "Content-Type: multipart/alternative; boundary="+boundaryAlt)
+		data = append(data, "")
+		data = append(data, "--"+boundaryAlt)
+		data = append(data, "Content-Type: text/plain; charset=UTF-8")
+		data = append(data, "Content-Transfer-Encoding: 7bit")
+		data = append(data, "")
+		data = append(data, body.Plain)
+		data = append(data, "")
+		data = append(data, "--"+boundaryAlt)
+		data = append(data, "Content-Type: text/html; charset=UTF-8")
+		data = append(data, "Content-Transfer-Encoding: 7bit")
+		data = append(data, "")
+		data = append(data, body.HTML)
+		data = append(data, "")
+		data = append(data, "--"+boundaryAlt+"--")
+		return data
+	}
+
+	if body.HTML != "" && body.Plain != "" && hasInlineAttachments {
+		data := make([]string, 0, 2)
+		data = append(data, "--"+boundary)
+		data = append(data, body.HTML)
+		return data
+	}
+
+	if body.HTML != "" && body.Plain != "" {
+		data := make([]string, 0, 8)
+		data = append(data, "--"+boundary)
+		data = append(data, "Content-Type: text/plain; charset=UTF-8")
+		data = append(data, "Content-Transfer-Encoding: 7bit")
+		data = append(data, "")
+		data = append(data, body.Plain)
+		data = append(data, "")
+		data = append(data, "--"+boundary)
+		data = append(data, "Content-Type: text/html; charset=UTF-8")
+		data = append(data, "Content-Transfer-Encoding: 7bit")
+		data = append(data, "")
+		data = append(data, body.HTML)
+		return data
+	}
+
+	if body.HTML != "" {
+		data := make([]string, 0, 2)
+		data = append(data, "--"+boundary)
+		data = append(data, "Content-Type: text/html; charset=UTF-8")
+		data = append(data, "Content-Transfer-Encoding: 7bit")
+		data = append(data, "")
+		data = append(data, body.HTML)
+		return data
+	}
+
+	if body.Plain != "" {
+		data := make([]string, 0, 2)
+		data = append(data, "--"+boundary)
+		data = append(data, "Content-Type: text/plain; charset=UTF-8")
+		data = append(data, "Content-Transfer-Encoding: 7bit")
+		data = append(data, "")
+		data = append(data, body.Plain)
+		return data
+	}
+
+	data := make([]string, 0, 16)
+	data = append(data, "--"+boundary)
+	data = append(data, "Content-Type: text/plain; charset=UTF-8")
+	data = append(data, "Content-Transfer-Encoding: 7bit")
+	data = append(data, "")
+	data = append(data, "") // no content ?!?
+	return data
+}

googleapi/mimeMessage_test.go

@@ -0,0 +1,77 @@
+package googleapi
+
+import (
+	"fmt"
+	"gogs.mikescher.com/BlackForestBytes/goext/tst"
+	"os"
+	"testing"
+)
+
+func TestEncodeMimeMail(t *testing.T) {
+
+	mail := encodeMimeMail(
+		"noreply@heydyno.de",
+		[]string{"trash@mikescher.de"},
+		nil,
+		nil,
+		"Hello Test Mail",
+		MailBody{Plain: "Plain Text"},
+		nil)
+
+	fmt.Printf("%s\n\n", mail)
+}
+
+func TestEncodeMimeMail2(t *testing.T) {
+
+	mail := encodeMimeMail(
+		"noreply@heydyno.de",
+		[]string{"trash@mikescher.de"},
+		nil,
+		nil,
+		"Hello Test Mail (alternative)",
+		MailBody{
+			Plain: "Plain Text",
+			HTML:  "<html><body><u>Non</u> Pl<i>ai</i>n T<b>ex</b>t</body></html>",
+		},
+		nil)
+
+	fmt.Printf("%s\n\n", mail)
+}
+
+func TestEncodeMimeMail3(t *testing.T) {
+
+	mail := encodeMimeMail(
+		"noreply@heydyno.de",
+		[]string{"trash@mikescher.de"},
+		nil,
+		nil,
+		"Hello Test Mail (alternative)",
+		MailBody{
+			HTML: "<html><body><u>Non</u> Pl<i>ai</i>n T<b>ex</b>t</body></html>",
+		},
+		[]MailAttachment{
+			{Data: []byte("HelloWorld"), Filename: "test.txt", IsInline: false, ContentType: "text/plain"},
+		})
+
+	fmt.Printf("%s\n\n", mail)
+}
+
+func TestEncodeMimeMail4(t *testing.T) {
+
+	b := tst.Must(os.ReadFile("/home/mike/Pictures/Screenshot_20220706_190205.png"))(t)
+
+	mail := encodeMimeMail(
+		"noreply@heydyno.de",
+		[]string{"trash@mikescher.de"},
+		nil,
+		nil,
+		"Hello Test Mail (inline)",
+		MailBody{
+			HTML: "<html><body><u>Non</u> Pl<i>ai</i>n T<b>ex</b>t</body></html>",
+		},
+		[]MailAttachment{
+			{Data: b, Filename: "img.png", IsInline: true, ContentType: "image/png"},
+		})
+
+	fmt.Printf("%s\n\n", mail)
+}

googleapi/oAuth.go

@@ -0,0 +1,91 @@
+package googleapi
+
+import (
+	"encoding/json"
+	"fmt"
+	"gogs.mikescher.com/BlackForestBytes/goext/exerr"
+	"gogs.mikescher.com/BlackForestBytes/goext/langext"
+	"gogs.mikescher.com/BlackForestBytes/goext/timeext"
+	"io"
+	"net/http"
+	"sync"
+	"time"
+)
+
+type GoogleOAuth interface {
+	AccessToken() (string, error)
+}
+
+type oauth struct {
+	clientID     string
+	clientSecret string
+	refreshToken string
+
+	lock        sync.RWMutex
+	accessToken *string
+	expiryDate  *time.Time
+}
+
+func NewGoogleOAuth(clientid string, clientsecret, refreshtoken string) GoogleOAuth {
+	return &oauth{
+		clientID:     clientid,
+		clientSecret: clientsecret,
+		refreshToken: refreshtoken,
+	}
+}
+
+func (c *oauth) AccessToken() (string, error) {
+	c.lock.RLock()
+	if c.accessToken != nil && c.expiryDate != nil && (*c.expiryDate).After(time.Now()) {
+		c.lock.RUnlock()
+		return *c.accessToken, nil // still valid
+	}
+	c.lock.RUnlock()
+
+	httpclient := http.Client{}
+
+	url := fmt.Sprintf("https://oauth2.googleapis.com/token?client_id=%s&client_secret=%s&grant_type=%s&refresh_token=%s",
+		c.clientID,
+		c.clientSecret,
+		"refresh_token",
+		c.refreshToken)
+
+	req, err := http.NewRequest(http.MethodPost, url, nil)
+	if err != nil {
+		return "", err
+	}
+
+	reqStartTime := time.Now()
+
+	res, err := httpclient.Do(req)
+
+	type response struct {
+		AccessToken string `json:"access_token"`
+		ExpiresIn   int    `json:"expires_in"`
+		Scope       string `json:"scope"`
+		TokenType   string `json:"token_type"`
+	}
+
+	var r response
+
+	data, err := io.ReadAll(res.Body)
+	if err != nil {
+		return "", err
+	}
+
+	err = json.Unmarshal(data, &r)
+	if err != nil {
+		return "", err
+	}
+
+	if r.ExpiresIn == 0 || r.AccessToken == "" {
+		return "", exerr.New(exerr.TypeGoogleResponse, "google oauth returned no response").Str("body", string(data)).Build()
+	}
+
+	c.lock.Lock()
+	c.expiryDate = langext.Ptr(reqStartTime.Add(timeext.FromSeconds(r.ExpiresIn - 10)))
+	c.accessToken = langext.Ptr(r.AccessToken)
+	c.lock.Unlock()
+
+	return r.AccessToken, nil
+}

googleapi/sendMail.go

@@ -0,0 +1,69 @@
+package googleapi
+
+import (
+	"bytes"
+	"context"
+	"encoding/base64"
+	"encoding/json"
+	"fmt"
+	"gogs.mikescher.com/BlackForestBytes/goext"
+	"gogs.mikescher.com/BlackForestBytes/goext/exerr"
+	"gogs.mikescher.com/BlackForestBytes/goext/langext"
+	"io"
+	"net/http"
+)
+
+type MailRef struct {
+	ID       string   `json:"id"`
+	ThreadID string   `json:"threadId"`
+	LabelIDs []string `json:"labelIds"`
+}
+
+func (c *client) SendMail(ctx context.Context, from string, recipients []string, cc []string, bcc []string, subject string, body MailBody, attachments []MailAttachment) (MailRef, error) {
+
+	mm := encodeMimeMail(from, recipients, cc, bcc, subject, body, attachments)
+
+	tok, err := c.oauth.AccessToken()
+	if err != nil {
+		return MailRef{}, exerr.Wrap(err, "").Build()
+	}
+
+	url := fmt.Sprintf("https://gmail.googleapis.com/gmail/v1/users/%s/messages/send?alt=json&prettyPrint=false", "me")
+
+	msgbody, err := json.Marshal(langext.H{"raw": base64.URLEncoding.EncodeToString([]byte(mm))})
+	if err != nil {
+		return MailRef{}, exerr.Wrap(err, "").Build()
+	}
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, url, bytes.NewReader(msgbody))
+	if err != nil {
+		return MailRef{}, exerr.Wrap(err, "").Build()
+	}
+
+	req.Header.Add("Authorization", "Bearer "+tok)
+	req.Header.Add("X-Goog-Api-Client", "blackforestbytes-goext/"+goext.GoextVersion)
+	req.Header.Add("User-Agent", "blackforestbytes-goext/"+goext.GoextVersion)
+	req.Header.Add("Content-Type", "application/json")
+
+	resp, err := c.http.Do(req)
+	if err != nil {
+		return MailRef{}, exerr.Wrap(err, "").Build()
+	}
+
+	respBody, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return MailRef{}, exerr.Wrap(err, "").Build()
+	}
+
+	if resp.StatusCode != 200 {
+		return MailRef{}, exerr.New(exerr.TypeGoogleStatuscode, "gmail returned non-200 statuscode").Int("sc", resp.StatusCode).Str("body", string(respBody)).Build()
+	}
+
+	var respObj MailRef
+	err = json.Unmarshal(respBody, &respObj)
+	if err != nil {
+		return MailRef{}, exerr.Wrap(err, "").Str("body", string(respBody)).Build()
+	}
+
+	return respObj, nil
+}

googleapi/sendMail_test.go

@@ -0,0 +1,151 @@
+package googleapi
+
+import (
+	"context"
+	"fmt"
+	"gogs.mikescher.com/BlackForestBytes/goext/exerr"
+	"gogs.mikescher.com/BlackForestBytes/goext/langext"
+	"gogs.mikescher.com/BlackForestBytes/goext/tst"
+	"os"
+	"testing"
+)
+
+func TestMain(m *testing.M) {
+	if !exerr.Initialized() {
+		exerr.Init(exerr.ErrorPackageConfigInit{ZeroLogErrTraces: langext.PFalse, ZeroLogAllTraces: langext.PFalse})
+	}
+	os.Exit(m.Run())
+}
+
+func TestSendMail1(t *testing.T) {
+	t.Skip()
+	return
+
+	auth := NewGoogleOAuth(
+		"554617284247-8di0j6s5dcmlk4lmk4hdf9kdn8scss54.apps.googleusercontent.com",
+		"TODO",
+		"TODO")
+
+	ctx := context.Background()
+
+	gclient := NewGoogleClient(auth)
+
+	mail, err := gclient.SendMail(
+		ctx,
+		"noreply@heydyno.de",
+		[]string{"trash@mikescher.de"},
+		nil,
+		nil,
+		"Hello Test Mail",
+		MailBody{Plain: "Plain Text"},
+		nil)
+
+	tst.AssertNoErr(t, err)
+
+	fmt.Printf("mail.ID        := %s\n", mail.ID)
+	fmt.Printf("mail.ThreadID  := %s\n", mail.ThreadID)
+	fmt.Printf("mail.LabelIDs  := %v\n", mail.LabelIDs)
+}
+
+func TestSendMail2(t *testing.T) {
+	t.Skip()
+	return
+
+	auth := NewGoogleOAuth(
+		"554617284247-8di0j6s5dcmlk4lmk4hdf9kdn8scss54.apps.googleusercontent.com",
+		"TODO",
+		"TODO")
+
+	ctx := context.Background()
+
+	gclient := NewGoogleClient(auth)
+
+	mail, err := gclient.SendMail(
+		ctx,
+		"noreply@heydyno.de",
+		[]string{"trash@mikescher.de"},
+		nil,
+		nil,
+		"Hello Test Mail (alternative)",
+		MailBody{
+			Plain: "Plain Text",
+			HTML:  "<html><body><u>Non</u> Pl<i>ai</i>n T<b>ex</b>t</body></html>",
+		},
+		nil)
+
+	tst.AssertNoErr(t, err)
+
+	fmt.Printf("mail.ID        := %s\n", mail.ID)
+	fmt.Printf("mail.ThreadID  := %s\n", mail.ThreadID)
+	fmt.Printf("mail.LabelIDs  := %v\n", mail.LabelIDs)
+}
+
+func TestSendMail3(t *testing.T) {
+	t.Skip()
+	return
+
+	auth := NewGoogleOAuth(
+		"554617284247-8di0j6s5dcmlk4lmk4hdf9kdn8scss54.apps.googleusercontent.com",
+		"TODO",
+		"TODO")
+
+	ctx := context.Background()
+
+	gclient := NewGoogleClient(auth)
+
+	mail, err := gclient.SendMail(
+		ctx,
+		"noreply@heydyno.de",
+		[]string{"trash@mikescher.de"},
+		nil,
+		nil,
+		"Hello Test Mail (attach)",
+		MailBody{
+			HTML: "<html><body><u>Non</u> Pl<i>ai</i>n T<b>ex</b>t</body></html>",
+		},
+		[]MailAttachment{
+			{Data: []byte("HelloWorld"), Filename: "test.txt", IsInline: false, ContentType: "text/plain"},
+		})
+
+	tst.AssertNoErr(t, err)
+
+	fmt.Printf("mail.ID        := %s\n", mail.ID)
+	fmt.Printf("mail.ThreadID  := %s\n", mail.ThreadID)
+	fmt.Printf("mail.LabelIDs  := %v\n", mail.LabelIDs)
+}
+
+func TestSendMail4(t *testing.T) {
+	t.Skip()
+	return
+
+	auth := NewGoogleOAuth(
+		"554617284247-8di0j6s5dcmlk4lmk4hdf9kdn8scss54.apps.googleusercontent.com",
+		"TODO",
+		"TODO")
+
+	ctx := context.Background()
+
+	gclient := NewGoogleClient(auth)
+
+	b := tst.Must(os.ReadFile("/home/mike/Pictures/Screenshot_20220706_190205.png"))(t)
+
+	mail, err := gclient.SendMail(
+		ctx,
+		"noreply@heydyno.de",
+		[]string{"trash@mikescher.de"},
+		nil,
+		nil,
+		"Hello Test Mail (inline)",
+		MailBody{
+			HTML: "<html><body><u>Non</u> Pl<i>ai</i>n T<b>ex</b>t</body></html>",
+		},
+		[]MailAttachment{
+			{Data: b, Filename: "img.png", IsInline: true, ContentType: "image/png"},
+		})
+
+	tst.AssertNoErr(t, err)
+
+	fmt.Printf("mail.ID        := %s\n", mail.ID)
+	fmt.Printf("mail.ThreadID  := %s\n", mail.ThreadID)
+	fmt.Printf("mail.LabelIDs  := %v\n", mail.LabelIDs)
+}

googleapi/service.go

@@ -0,0 +1,22 @@
+package googleapi
+
+import (
+	"context"
+	"net/http"
+)
+
+type GoogleClient interface {
+	SendMail(ctx context.Context, from string, recipients []string, cc []string, bcc []string, subject string, body MailBody, attachments []MailAttachment) (MailRef, error)
+}
+
+type client struct {
+	oauth GoogleOAuth
+	http  http.Client
+}
+
+func NewGoogleClient(oauth GoogleOAuth) GoogleClient {
+	return &client{
+		oauth: oauth,
+		http:  http.Client{},
+	}
+}