implemented the E-mail sending functionality

config/config.go

@@ -59,12 +59,14 @@ type AmConfig struct {
 		Dsn    string `yaml:"dsn"`
 	} `yaml:"database"`
 	Email struct {
-		Host     string `yaml:"host"`
-		Port     int    `yaml:"port"`
-		Tls      string `yaml:"tls"`
-		AuthType string `yaml:"authType"`
-		User     string `yaml:"user"`
-		Password string `yaml:"password"`
+		Host       string `yaml:"host"`
+		Port       int    `yaml:"port"`
+		Tls        string `yaml:"tls"`
+		AuthType   string `yaml:"authType"`
+		User       string `yaml:"user"`
+		Password   string `yaml:"password"`
+		Signature  string `yaml:"signature"`
+		Disclaimer string `yaml:"disclaimer"`
 	} `yaml:"email"`
 	Rendering struct {
 		TemplateDir string `yaml:"templatedir"`
@@ -128,6 +130,8 @@ func overlayConfig(dest *AmConfig, loaded *AmConfig, defaults *AmConfig) {
 	dest.Email.AuthType = overlayString(loaded.Email.AuthType, defaults.Email.AuthType)
 	dest.Email.User = overlayString(loaded.Email.User, defaults.Email.User)
 	dest.Email.Password = overlayString(loaded.Email.Password, defaults.Email.Password)
+	dest.Email.Signature = overlayString(loaded.Email.Signature, defaults.Email.Signature)
+	dest.Email.Disclaimer = overlayString(loaded.Email.Disclaimer, defaults.Email.Disclaimer)
 	dest.Rendering.TemplateDir = overlayString(loaded.Rendering.TemplateDir, defaults.Rendering.TemplateDir)
 	dest.Rendering.CookieKey = overlayString(loaded.Rendering.CookieKey, defaults.Rendering.CookieKey)
 }

config/default.yaml

@@ -23,6 +23,12 @@ email:
   authType: plain
   user: jrn
   password: foobiebletch
+  signature: |-
+    Amsterdam - community services, conferencing and more.  <http://git.erbosoft.com/amy/amsterdam>
+  disclaimer: |-
+    Message sent via Amsterdam Web Communities System - <http://git.erbosoft.com/amy/amsterdam>
+    The Amsterdam Project is not responsible for the contents of this message
+    Report abuses to: <abuse@example.com>
 rendering:
   templatedir: custom_templates
   cookiekey: ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz

email/message.go

@@ -10,7 +10,12 @@
 // Package email contains support for E-mail messages sent by Amsterdam.
 package email
 
-import "fmt"
+import (
+	"fmt"
+
+	"git.erbosoft.com/amy/amsterdam/util"
+	"github.com/CloudyKit/jet/v6"
+)
 
 // Message is the interface for an E-mail message to be sent.
 type Message interface {
@@ -21,18 +26,32 @@ type Message interface {
 	SetSubject(string)
 	SetText(string)
 	AddHeader(string, string)
+	SetTemplate(string)
+	AddVariable(string, any)
+	Send()
 }
 
+// amMessage is the internal structure of the Message.
 type amMessage struct {
-	from    string
-	to      []string
-	cc      []string
-	bcc     []string
-	subject string
-	text    string
-	headers map[string]string
+	from     string
+	fromAddr string
+	to       []string
+	toAddrs  []string
+	cc       []string
+	bcc      []string
+	subject  string
+	text     string
+	headers  map[string]string
+	template string
+	vars     jet.VarMap
+	uid      int32
+	ip       string
 }
 
+// freeMessages is a free list for amMessage structures.
+var freeMessages util.FreeList[amMessage]
+
+// formatAddress outputs an E-mail address with optional name associated with it.
 func formatAddress(addr string, name string) string {
 	if name == "" {
 		return addr
@@ -41,35 +60,91 @@ func formatAddress(addr string, name string) string {
 	}
 }
 
+// SetFrom sets the From: address of the message.
 func (m *amMessage) SetFrom(addr string, name string) {
 	m.from = formatAddress(addr, name)
+	m.fromAddr = addr
 }
 
+// AddTo ads a To: address to the message.
 func (m *amMessage) AddTo(addr string, name string) {
 	m.to = append(m.to, formatAddress(addr, name))
+	m.toAddrs = append(m.toAddrs, addr)
 }
 
+// AddCC ads a Cc: address to the message.
 func (m *amMessage) AddCC(addr string, name string) {
 	m.cc = append(m.cc, formatAddress(addr, name))
+	m.toAddrs = append(m.toAddrs, addr)
 }
 
+// AddBCC ads a Bcc: address to the message.
 func (m *amMessage) AddBCC(addr string, name string) {
 	m.bcc = append(m.bcc, formatAddress(addr, name))
+	m.toAddrs = append(m.toAddrs, addr)
 }
 
+// SetSubject sets the message's subject.
 func (m *amMessage) SetSubject(s string) {
 	m.subject = s
 }
 
+// SetText sets the text of the message.
 func (m *amMessage) SetText(txt string) {
 	m.text = txt
 }
 
+// AddHaader adds a new header to the message.
 func (m *amMessage) AddHeader(name string, value string) {
 	m.headers[name] = value
 }
 
-func AmNewEmailMessage() Message {
-	rc := amMessage{to: make([]string, 0), cc: make([]string, 0), bcc: make([]string, 0), headers: make(map[string]string)}
-	return &rc
+func (m *amMessage) SetTemplate(templ string) {
+	m.template = templ
+}
+
+func (m *amMessage) AddVariable(name string, value any) {
+	m.vars.Set(name, value)
+}
+
+func (m *amMessage) Send() {
+	sendChan <- m
+}
+
+/* AmNewEmailMessage creates a new message and returns it.
+ * Parameters:
+ *     sender = User ID of the person sending the message.
+ *     ip = IP address of the person sending the message.
+ * Returns:
+ *     The new Message.
+ */
+func AmNewEmailMessage(sender int32, ip string) Message {
+	rc := freeMessages.Get()
+	if rc == nil {
+		rc = &amMessage{to: make([]string, 0), cc: make([]string, 0), bcc: make([]string, 0),
+			headers: make(map[string]string)}
+	}
+	rc.uid = sender
+	rc.ip = ip
+	return rc
+}
+
+// recycleMessage cleans out a message and puts it back on the free list.
+func recycleMessage(m *amMessage) {
+	m.from = ""
+	m.fromAddr = ""
+	m.to = make([]string, 0)
+	m.toAddrs = make([]string, 0)
+	m.cc = make([]string, 0)
+	m.bcc = make([]string, 0)
+	m.subject = ""
+	m.text = ""
+	for k := range m.headers {
+		delete(m.headers, k)
+	}
+	m.template = ""
+	for k := range m.vars {
+		delete(m.vars, k)
+	}
+	freeMessages.Put(m)
 }

email/sender.go

@@ -0,0 +1,220 @@
+/*
+ * Amsterdam Web Communities System
+ * Copyright (c) 2025 Erbosoft Metaverse Design Solutions, All Rights Reserved
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
+// Package email contains support for E-mail messages sent by Amsterdam.
+package email
+
+import (
+	"bytes"
+	"embed"
+	"fmt"
+	"io"
+	"maps"
+	"net/smtp"
+	"os"
+	"slices"
+	"strings"
+
+	"git.erbosoft.com/amy/amsterdam/config"
+	"git.erbosoft.com/amy/amsterdam/database"
+	"github.com/CloudyKit/jet/v6"
+	"github.com/CloudyKit/jet/v6/loaders/embedfs"
+	log "github.com/sirupsen/logrus"
+)
+
+//go:embed templates/*
+var emailTemplates embed.FS
+
+// email_renderer is a separate Jet instance for making E-mail messages.
+var emailRenderer *jet.Set
+
+// disclaimerLines is the disclaimer from the configuration broken into lines.
+var disclaimerLines []string
+
+// signatureLines is the signature from the configuration broken into lines.
+var signatureLines []string
+
+// The mail host and port.
+var mailHost string
+
+// The SMTP authentication to use.
+var auth smtp.Auth
+
+// formatMessage takes a message and turns it into serialized bytes for sending.
+func formatMessage(m *amMessage) ([]byte, error) {
+	if m.template != "" {
+		// Render the template for the message, which may reset Subject.
+		templ, err := emailRenderer.GetTemplate(m.template)
+		if err == nil {
+			var buf bytes.Buffer
+			err = templ.Execute(&buf, m.vars, Message(m))
+			if err == nil {
+				m.text = buf.String()
+			}
+		}
+		if err != nil {
+			return make([]byte, 0), err
+		}
+	}
+	user, err := database.AmGetUser(m.uid)
+	if err == nil {
+		// Build the final headers.
+		hdrs := make(map[string]string)
+		maps.Copy(hdrs, m.headers)
+		hdrs["From"] = m.from
+		hdrs["To"] = strings.Join(m.to, ", ")
+		hdrs["Cc"] = strings.Join(m.cc, ", ")
+		hdrs["Bcc"] = strings.Join(m.bcc, ", ")
+		hdrs["Subject"] = m.subject
+		hdrs["Content-Type"] = "text/plain; charset=UTF-8"
+		me, _ := os.Hostname()
+		hdrs["X-Amsterdam-Server-Info"] = fmt.Sprintf("%s (Amsterdam/%s)", me, config.AMSTERDAM_VERSION)
+		hdrs["X-Amsterdam-Sender-Info"] = fmt.Sprintf("uid %d, name %s, ip [%s]", m.uid, user.Username, m.ip)
+		for i, v := range disclaimerLines {
+			hdrs[fmt.Sprintf("X-Disclaimer-%d", i)] = v
+		}
+
+		// Sort the header keys tro make for a better presentation.
+		keys := make([]string, 0, len(hdrs))
+		for k := range hdrs {
+			keys = append(keys, k)
+		}
+		slices.Sort(keys)
+
+		// Build the actual message.
+		var out bytes.Buffer
+		for _, k := range keys {
+			fmt.Fprintf(&out, "%s: %s\r\n", k, hdrs[k])
+		}
+		out.WriteString("\r\n")
+		for _, l := range strings.Split(m.text, "\n") {
+			fmt.Fprintf(&out, "%s\r\n", l)
+		}
+		out.WriteString("--\r\n")
+		for _, l := range signatureLines {
+			fmt.Fprintf(&out, "%s\r\n", l)
+		}
+		return out.Bytes(), nil
+	}
+	return make([]byte, 0), err
+}
+
+// transmitMessage handles the sending of the message.
+func transmitMessage(m *amMessage, body []byte) {
+	cl, err := smtp.Dial(mailHost)
+	if err == nil {
+		defer cl.Close()
+		me, _ := os.Hostname()
+		if err = cl.Hello(me); err == nil {
+			if config.GlobalConfig.Email.Tls == "starttls" {
+				if ok, _ := cl.Extension("STARTTLS"); ok {
+					err = cl.StartTLS(nil)
+				} else {
+					log.Infof("server %s does not support STARTTLS", mailHost)
+				}
+			}
+			if err == nil {
+				if err = cl.Auth(auth); err == nil {
+					if err = cl.Mail(m.fromAddr); err == nil {
+						for _, addr := range m.toAddrs {
+							if err = cl.Rcpt(addr); err != nil {
+								log.Errorf("failed to set recipient address: %v", err)
+								break
+							}
+						}
+						if err == nil {
+							var w io.WriteCloser
+							w, err = cl.Data()
+							if err == nil {
+								_, err = w.Write(body)
+								if err != nil {
+									log.Errorf("failed to write message data: %v", err)
+								}
+								err = w.Close()
+								if err != nil {
+									log.Errorf("failed to close and send: %v", err)
+								}
+								err = cl.Quit()
+								if err != nil {
+									log.Errorf("failed to quit session: %v", err)
+								}
+							} else {
+								log.Errorf("failed to start writing data: %v", err)
+							}
+						}
+					} else {
+						log.Errorf("failed to set sender: %v", err)
+					}
+				} else {
+					log.Errorf("failed to authenticate to server: %v", err)
+				}
+			} else {
+				log.Errorf("failed to start TLS handshake: %v", err)
+			}
+		} else {
+			log.Errorf("error sending HELO to server: %v", err)
+		}
+	} else {
+		log.Errorf("unable to contact host %s via SMTP: %v", mailHost, err)
+	}
+}
+
+// senderLoop collects E-mail messages from the channel and pushes them out.
+func senderLoop(sent chan *amMessage, done chan bool) {
+	for m := range sent {
+		body, err := formatMessage(m)
+		if err == nil {
+			transmitMessage(m, body)
+		} else {
+			log.Errorf("unable to format message: %v", err)
+		}
+		go recycleMessage(m)
+	}
+	done <- true // signal done for synchronization
+}
+
+// sendChan is the channel we put E-mail messages on to be sent.
+var sendChan chan *amMessage
+
+// doneChan is the channel that gets signaled when the senderLoop breaks.
+var doneChan chan bool
+
+// SetupMailSender starts the mail-sending goroutine.
+func SetupMailSender() {
+	// Initialize mail host and authentication.
+	mailHost = fmt.Sprintf("%s:%d", config.GlobalConfig.Email.Host, config.GlobalConfig.Email.Port)
+	switch config.GlobalConfig.Email.AuthType {
+	case "plain":
+		auth = smtp.PlainAuth("", config.GlobalConfig.Email.User, config.GlobalConfig.Email.Password,
+			config.GlobalConfig.Email.Host)
+	default:
+		panic("Unknown auth type: " + config.GlobalConfig.Email.AuthType)
+	}
+
+	// Split the configured disclaimer and signature.
+	disclaimerLines = strings.Split(config.GlobalConfig.Email.Disclaimer, "\n")
+	signatureLines = strings.Split(config.GlobalConfig.Email.Signature, "\n")
+
+	// Initialize the template engine.
+	emailRenderer = jet.NewSet(
+		embedfs.NewLoader("templates/", emailTemplates),
+		jet.DevelopmentMode(true),
+	)
+
+	// Start the sender loop.
+	sendChan = make(chan *amMessage, 16)
+	doneChan = make(chan bool)
+	go senderLoop(sendChan, doneChan)
+}
+
+// EndMailServer shuts down the mail-sending goroutine.
+func EndMailServer() {
+	close(sendChan) // will break the loop in senderLoop
+	<-doneChan      // wait for routine to complete
+}

email/templates/email_confirm.jet

@@ -0,0 +1,13 @@
+{{ .SetSubject("Amsterdam Email Confirmation") }}
+Welcome to the Amsterdam conferencing system!  In order to fully activate your
+account after you register or change your E-mail address, you must provide a
+confirmation number to the system.  Please enter this number into the "Confirm
+E-mail Address" dialog on the system when indicated.
+
+Your confirmation number for your account "{{ username }}" is {{ confnum }}.
+
+Access the E-mail verification dialog at <http://example.com/verifyemail>.
+
+Thank you, and enjoy the Amsterdam conferencing system!
+
+- The Management

email/templates/pass_change.jet

@@ -0,0 +1,12 @@
+{{ .SetSubject("Amsterdam Password Changed") }}
+The password for your account "{{ username }}" has been changed.  The new
+password is "{{ password }}".
+
+You should log into Amsterdam immediately and change the password to something
+else.  You can change the password for your account, once you are logged in,
+by clicking on the "Profile" link in the top bar.
+
+If you did NOT request a password change on your account, please notify the
+system administrator IMMEDIATELY.
+
+- The Management

email/templates/pass_remind.jet

@@ -0,0 +1,20 @@
+{{ .SetSubject("Amsterdam Password Reminder Message") }}
+Here is the password reminder for your account "{{ username }}" as you requested:
+
+{{ reminder }}
+
+If this reminder is not sufficient for you to remember what your password is,
+then the system can change your password for you.  To do so, please visit
+the following URL:
+
+http://example.com/passrecovery/{{ change_uid }}.{{ change.auth }}
+
+Your password will be changed and a new password will be E-mailed to you
+at this address.
+
+If you did NOT request a password reminder, then this message was sent
+by someone attempting to access your account without your knowledge.  Do
+not panic!  Nothing has happened to your account or password yet, but
+please do notify the system administrator.
+
+- The Management

login.go

@@ -10,7 +10,6 @@
 package main
 
 import (
-	"errors"
 	"fmt"
 
 	"git.erbosoft.com/amy/amsterdam/database"
@@ -67,15 +66,21 @@ func Login(ctxt ui.AmContext) (string, any, error) {
 		}
 
 		action := dlg.WhichButton(ctxt)
-		if action == "cancel" {
+		if action == "cancel" { // Cancel button pressed
 			return "redirect", target, nil
 		}
-		if action == "remind" {
-			// TODO: send password reminder
+		if action == "remind" { // Password Reminder button pressed
+			user, uerr := database.AmGetUserByName(dlg.Field("user").Value)
+			if uerr == nil {
+				_ = user
+				// TODO: send password reminder
+
+			}
+
 			dlg.Field("pass").Value = ""
 			return dlg.RenderError(ctxt, "Password reminder has been sent to your E-mail address.")
 		}
-		if action == "login" {
+		if action == "login" { // Login button pressed
 			// authenticate the user
 			user, uerr := database.AmAuthenticateUser(dlg.Field("user").Value, dlg.Field("pass").Value, ctxt.RemoteIP())
 			if uerr != nil {
@@ -89,7 +94,8 @@ func Login(ctxt ui.AmContext) (string, any, error) {
 			// TODO: bounce to E-mail verify if we can do so
 			return "redirect", target, nil
 		}
-		err = errors.New("no known button click on POST to login function")
+		dlg.Field("pass").Value = ""
+		return dlg.RenderError(ctxt, "No known button click on POST to login function.")
 	}
 	return ui.ErrorPage(ctxt, err)
 }

main.go

@@ -20,6 +20,7 @@ import (
 
 	"git.erbosoft.com/amy/amsterdam/config"
 	"git.erbosoft.com/amy/amsterdam/database"
+	"git.erbosoft.com/amy/amsterdam/email"
 	"git.erbosoft.com/amy/amsterdam/ui"
 	"github.com/labstack/echo-contrib/session"
 	"github.com/labstack/echo/v4"
@@ -60,6 +61,8 @@ func main() {
 		panic(fmt.Sprintf("Database open failure: %v", err))
 	}
 	defer database.ClosedownDb()
+	email.SetupMailSender()
+	defer email.EndMailServer()
 	ui.SetupTemplates()
 	ui.SetupSessionManager()
 	ui.SetupLeftMenus()

util/freelist.go

@@ -0,0 +1,67 @@
+/*
+ * Amsterdam Web Communities System
+ * Copyright (c) 2025 Erbosoft Metaverse Design Solutions, All Rights Reserved
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
+// Package util contains utility definitions.
+package util
+
+import "sync"
+
+// freeListElem is an element of the free list.
+type freeListElem[T any] struct {
+	next *freeListElem[T]
+	prev *freeListElem[T]
+	data *T
+}
+
+// FreeList defines a free list.
+type FreeList[T any] struct {
+	New     func() *T
+	mutex   sync.Mutex
+	listptr *freeListElem[T]
+}
+
+// Put adds a value to the free list.
+func (l *FreeList[T]) Put(value *T) {
+	l.mutex.Lock()
+	defer l.mutex.Unlock()
+	ne := freeListElem[T]{data: value}
+	if l.listptr == nil {
+		ne.next = &ne
+		ne.prev = &ne
+		l.listptr = &ne
+	} else {
+		ne.next = l.listptr
+		ne.prev = l.listptr.prev
+		ne.next.prev = &ne
+		ne.prev.next = &ne
+	}
+}
+
+// Get removes a value from the free list. If there are no values and New is specified, is calls that.
+func (l *FreeList[T]) Get() *T {
+	l.mutex.Lock()
+	defer l.mutex.Unlock()
+	var rc *T = nil
+	if l.listptr == nil {
+		if l.New != nil {
+			rc = l.New()
+		}
+	} else {
+		elt := l.listptr
+		rc = elt.data
+		l.listptr = elt.next
+		if l.listptr == elt {
+			l.listptr = nil
+		} else {
+			elt.prev.next = elt.next
+			elt.next.prev = elt.prev
+		}
+	}
+	return rc
+}