Initial import.

conn/twilio/config.go

@@ -0,0 +1,83 @@
+package twilio
+
+import (
+	"errors"
+	"fmt"
+	"log"
+	"net/http"
+	"net/url"
+)
+
+type Config struct {
+	Contacts   []string `yaml:"contacts"`
+	contacts   map[string]bool
+	AccountSID string `yaml:"account_sid"`
+	AuthToken  string `yaml:"auth_token"`
+	Number     string `yaml:"telno"` // kas' telno
+}
+
+func (cfg *Config) postURL() string {
+	return fmt.Sprintf("https://api.twilio.com/2010-04-01/Accounts/%s/Messages.json",
+		cfg.AccountSID)
+}
+
+func (cfg *Config) buildContacts() {
+	cfg.contacts = map[string]bool{}
+	for _, telno := range cfg.Contacts {
+		cfg.contacts[telno] = true
+	}
+}
+
+func (cfg *Config) NumberAuthorized(s string) bool {
+	if cfg.contacts == nil || len(cfg.contacts) != len(cfg.Contacts) {
+		cfg.buildContacts()
+	}
+
+	return cfg.contacts[s]
+}
+
+func validate(cfg *Config) error {
+	if len(cfg.Contacts) == 0 {
+		return errors.New("twilio: no authorized numbers (you won't be able to receive any messages)")
+	}
+
+	if cfg.AccountSID == "" {
+		return errors.New("twilio: missing account SID")
+	}
+
+	if cfg.AuthToken == "" {
+		return errors.New("twilio: missing auth token")
+	}
+
+	if cfg.Number == "" {
+		return errors.New("twilio: no number configured")
+	}
+
+	return nil
+}
+
+var config *Config
+
+func SetConfig(cfg *Config) error {
+	if err := validate(cfg); err != nil {
+		return err
+	}
+	config = cfg
+	return nil
+}
+
+func Send(to string, message string) error {
+	form := url.Values{
+		"Body": {message},
+		"From": {config.Number},
+		"To":   {to},
+	}
+
+	resp, err := http.PostForm(config.postURL(), form)
+	if err != nil {
+		log.Printf("twilio send: %s", err)
+	}
+
+	resp.Body.Close()
+	return nil
+}

conn/twilio/message.go

@@ -0,0 +1,116 @@
+package twilio
+
+import (
+	"net/url"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// ErrInvalidMessage is returned when a bad message is sent to the Twilio
+// receive hook; it tries to clarify why the message is invalid.
+type ErrInvalidMessage struct {
+	missing []string
+	cause   string
+}
+
+// Error satisfies the error interface.
+func (err *ErrInvalidMessage) Error() string {
+	errParts := []string{}
+	if len(err.missing) > 0 {
+		errParts = append(errParts, "missing="+strings.Join(err.missing, ","))
+	}
+
+	if err.cause != "" {
+		errParts = append(errParts, "cause="+err.cause)
+	}
+
+	return strings.Join(errParts, ", ")
+}
+
+// isInvalidMessage returns an error given a list of missing fields and an
+// underlying cause, returning nil if the message is valid.
+func isInvalidMessage(missing []string, cause string) error {
+	if len(missing) == 0 && cause == "" {
+		return nil
+	}
+
+	return &ErrInvalidMessage{
+		missing: missing,
+		cause:   cause,
+	}
+}
+
+// Message represents an incoming Twilio message.
+type Message struct {
+	Source   string
+	To       string
+	Body     string
+	When     time.Time
+	MediaURL string
+	ASID     string
+	MSID     string
+	Price    float64
+	Mime     string
+}
+
+// MessageFromValues returns a Message from a set of form values.
+func MessageFromValues(v url.Values) (*Message, error) {
+	missing := []string{}
+	cause := ""
+
+	m := &Message{
+		Source:   v.Get("From"),
+		To:       v.Get("To"),
+		Body:     v.Get("Body"),
+		MediaURL: v.Get("MediaUrl0"),
+		ASID:     v.Get("AccountSid"),
+		MSID:     v.Get("MessageSid"),
+		When:     time.Now().UTC(),
+		Price:    0.0075,
+	}
+
+	if m.Source == "" {
+		missing = append(missing, "From")
+	}
+
+	if m.To == "" {
+		missing = append(missing, "To")
+	}
+
+	numMediaValue := v.Get("NumMedia")
+	if numMediaValue == "" {
+		numMediaValue = "0"
+	}
+
+	nMedia, err := strconv.Atoi(numMediaValue)
+	if err != nil {
+		return nil, err
+	}
+
+	if nMedia == 0 && m.Body == "" {
+		cause = "message has no body or media attachment"
+	} else if nMedia != 0 {
+		if m.MediaURL == "" {
+			missing = append(missing, "MediaUrl0")
+		}
+		m.Price = 0.01
+		if m.Mime = v.Get("MediaContentType0"); m.Mime == "" {
+			missing = append(missing, "MediaContentType0")
+		}
+	}
+
+	if sent := v.Get("DateSent"); sent != "" {
+		t, err := time.Parse(time.RFC1123Z, sent)
+		if err != nil {
+			return nil, err
+		}
+
+		m.When = t.UTC()
+	}
+
+	if err := isInvalidMessage(missing, cause); err != nil {
+		return nil, err
+	}
+	return m, nil
+}

conn/twilio/twilio.go

@@ -0,0 +1,49 @@
+package twilio
+
+import (
+	"context"
+	"kas/cps"
+	"log"
+	"net/http"
+)
+
+func handler(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodPost {
+		log.Printf("twilio receive hook: received %s request; only %s requests are supported",
+			r.Method, http.MethodPost)
+		http.Error(w, "invalid request", http.StatusBadRequest)
+		return
+	}
+
+	err := r.ParseForm()
+	if err != nil {
+		log.Printf("twilio receive hook: couldn't parse form contents: %s", err)
+		http.Error(w, "invalid request", http.StatusBadRequest)
+		return
+	}
+
+	message, err := MessageFromValues(r.Form)
+	if err != nil {
+		log.Printf("twilio receive hook: received an invalid message: %s", err)
+		http.Error(w, "invalid request", http.StatusBadRequest)
+		return
+	}
+
+	if !config.NumberAuthorized(message.Source) {
+		log.Printf("twilio receive hook: received message from unknown sender %v", message)
+		http.Error(w, "not authorized", http.StatusUnauthorized)
+		return
+	}
+
+	w.Write([]byte("accepted"))
+
+	response, err := cps.Handle(context.Background(), message.Body)
+	if err != nil {
+		log.Printf("twilio receive hook: %s", err)
+	}
+
+	err = Send(message.Source, response.String())
+	if err != nil {
+		log.Printf("twilio receive hook: %s", err)
+	}
+}