From c101249d3e610805bde12d236db61affcd6ab829 Mon Sep 17 00:00:00 2001
From: Arsen Musayelyan <moussaelianarsen@gmail.com>
Date: Fri, 15 Oct 2021 00:23:54 -0700
Subject: [PATCH] Add call notification support

---
 infinitime.go | 74 ++++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 70 insertions(+), 4 deletions(-)

diff --git a/infinitime.go b/infinitime.go
index b6c5f56..a59afad 100644
--- a/infinitime.go
+++ b/infinitime.go
@@ -4,7 +4,6 @@ import (
 	"bytes"
 	"encoding/binary"
 	"errors"
-	"fmt"
 	"time"
 
 	bt "github.com/muka/go-bluetooth/api"
@@ -17,6 +16,7 @@ const BTName = "InfiniTime"
 
 const (
 	NewAlertChar    = "00002a46-0000-1000-8000-00805f9b34fb"
+	NotifEventChar  = "00020001-78fc-48fe-8e23-433b3a1942d0"
 	FirmwareVerChar = "00002a26-0000-1000-8000-00805f9b34fb"
 	CurrentTimeChar = "00002a2b-0000-1000-8000-00805f9b34fb"
 	BatteryLvlChar  = "00002a19-0000-1000-8000-00805f9b34fb"
@@ -27,6 +27,7 @@ type Device struct {
 	opts            *Options
 	device          *device.Device1
 	newAlertChar    *gatt.GattCharacteristic1
+	notifEventChar  *gatt.GattCharacteristic1
 	fwVersionChar   *gatt.GattCharacteristic1
 	currentTimeChar *gatt.GattCharacteristic1
 	battLevelChar   *gatt.GattCharacteristic1
@@ -41,10 +42,13 @@ var ErrNotFound = errors.New("could not find any advertising InfiniTime devices"
 
 type Options struct {
 	AttemptReconnect bool
+	WhitelistEnabled bool
+	Whitelist        []string
 }
 
 var DefaultOptions = &Options{
 	AttemptReconnect: true,
+	WhitelistEnabled: false,
 }
 
 // Connect will attempt to connect to a
@@ -58,7 +62,7 @@ func Connect(opts *Options) (*Device, error) {
 		opts = DefaultOptions
 	}
 	// Attempt to connect to paired device by name
-	dev, err := connectByName()
+	dev, err := connectByName(opts)
 	// If such device does not exist
 	if errors.Is(err, ErrNoDevices) {
 		// Attempt to pair device
@@ -128,7 +132,7 @@ func (i *Device) OnReconnect(f func()) {
 }
 
 // Connect connects to a paired InfiniTime device
-func connectByName() (*Device, error) {
+func connectByName(opts *Options) (*Device, error) {
 	// Create new device
 	out := &Device{}
 	// Get devices from default adapter
@@ -140,6 +144,9 @@ func connectByName() (*Device, error) {
 	for _, dev := range devs {
 		// If device name is InfiniTime
 		if dev.Properties.Name == BTName {
+			if opts.WhitelistEnabled && !contains(opts.Whitelist, dev.Properties.Address) {
+				continue
+			}
 			// Set outout device to discovered device
 			out.device = dev
 			break
@@ -161,6 +168,15 @@ func connectByName() (*Device, error) {
 	return out, nil
 }
 
+func contains(ss []string, s string) bool {
+	for _, str := range ss {
+		if str == s {
+			return true
+		}
+	}
+	return false
+}
+
 // Pair attempts to discover and pair an InfiniTime device
 func pair() (*Device, error) {
 	// Create new device
@@ -259,6 +275,8 @@ func (i *Device) resolveChars() error {
 		switch char.Properties.UUID {
 		case NewAlertChar:
 			i.newAlertChar = char
+		case NotifEventChar:
+			i.notifEventChar = char
 		case FirmwareVerChar:
 			i.fwVersionChar = char
 		case CurrentTimeChar:
@@ -414,7 +432,55 @@ func (i *Device) Notify(title, body string) error {
 		return nil
 	}
 	return i.newAlertChar.WriteValue(
-		[]byte(fmt.Sprintf("00\x00%s\x00%s", title, body)),
+		append([]byte{0x00, 0x01, 0x00}, []byte(title+"\x00"+body)...),
 		nil,
 	)
 }
+
+// These constants represent the possible call statuses selected by the user
+const (
+	CallStatusDeclined uint8 = iota
+	CallStatusAccepted
+	CallStatusMuted
+)
+
+// NotifyCall sends a call notification to the PineTime and returns a channel.
+// This channel will contain the user's response to the call notification. It
+// can only contain one value.
+func (i *Device) NotifyCall(from string) (<-chan uint8, error) {
+	if !i.device.Properties.Connected {
+		return make(<-chan uint8), nil
+	}
+	// Write call notification to new alert characteristic
+	err := i.newAlertChar.WriteValue(
+		append([]byte{0x03, 0x01, 0x00}, []byte(from)...),
+		nil,
+	)
+	if err != nil {
+		return nil, err
+	}
+	// Start notifications on notification event characteristic
+	err = i.notifEventChar.StartNotify()
+	if err != nil {
+		return nil, err
+	}
+	// Watch properties of notification event characteristic
+	ch, err := i.notifEventChar.WatchProperties()
+	if err != nil {
+		return nil, err
+	}
+	// Create new output channel for status
+	out := make(chan uint8, 1)
+	go func() {
+		// For every event
+		for event := range ch {
+			// If value changed
+			if event.Name == "Value" {
+				// Send status to channel
+				out <- uint8(event.Value.([]byte)[0])
+				return
+			}
+		}
+	}()
+	return out, nil
+}