// matchPatterns iterates through the array of registered regular expressions
// (patterns) in the order of insertion and checks if they match any part of
// the given message's text. If they do then they are invoked with an empty
// fields array.
//
// This does not acquire a lock on the handlerMutex but one should be acquired
// for reading before calling this method.
func (d *dispatch) matchPatterns(m chat.Message) bool {
for _, pair := range d.patterns {
if pair.Exp().MatchString(m.Text()) {
pair.Handler().Handle(&state{
robot: d.robot,
message: m,
})
return true
}
}
return false
}
// ProcessMessage finds a match for a message and runs its Handler.
// If the message is considered a potential command (either sent @ the bot's
// name or in a direct message) then the next word after the bot's name is
// compared to all registered handlers. If one matches then that handler
// function is called with the remaining text seperated by whitespace
// (restpecting quotes). If none match then the default handler is called
// (with an empty fields array).
//
// If the message is not a potential command then it is checked against all
// registered patterns (with an empty fields array upon a match).
//
// This opens a read lock on the handlerMutex so new commands cannot be added
// while a message is being processed (they will block until processing is
// completed)
func (d *dispatch) ProcessMessage(m chat.Message) {
d.handlerMutex.RLock()
defer d.handlerMutex.RUnlock()
defer func() {
if e := recover(); e != nil {
log.Println("Unexpected Panic Processing Message:", m.Text(), " -- Error:", e)
return
}
}()
messageText := m.Text()
nameMatch := d.botNameRegex.FindString(messageText)
if len(nameMatch) > 0 || m.IsDirectMessage() {
// slices are cheap (reference original) so if no match then it's ok
messageText = messageText[len(nameMatch):]
if !d.matchCommands(m, messageText) {
d.callDefault(m, messageText)
}
} else if len(nameMatch) == 0 {
d.matchPatterns(m)
}
}