maubot/matrix/commands.go
2018-06-20 22:25:33 +03:00

138 lines
3.6 KiB
Go

// maubot - A plugin-based Matrix bot system written in Go.
// Copyright (C) 2018 Tulir Asokan
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <https://www.gnu.org/licenses/>.
package matrix
import (
"fmt"
"regexp"
"strings"
log "maunium.net/go/maulogger"
"maubot.xyz"
)
type ParsedCommand struct {
Name string
StartsWith string
Matches *regexp.Regexp
MatchAgainst string
MatchesEvent *maubot.Event
}
func (pc *ParsedCommand) parseCommandSyntax(command maubot.Command) error {
regexBuilder := &strings.Builder{}
swBuilder := &strings.Builder{}
argumentEncountered := false
regexBuilder.WriteRune('^')
words := strings.Split(command.Syntax, " ")
for i, word := range words {
argument, ok := command.Arguments[word]
if ok {
argumentEncountered = true
regex := argument.Matches
if argument.Required {
regex = fmt.Sprintf("(?:%s)?", regex)
}
regexBuilder.WriteString(regex)
} else {
if !argumentEncountered {
swBuilder.WriteString(word)
}
regexBuilder.WriteString(regexp.QuoteMeta(word))
}
if i < len(words) - 1 {
if !argumentEncountered {
swBuilder.WriteRune(' ')
}
regexBuilder.WriteRune(' ')
}
}
regexBuilder.WriteRune('$')
var err error
pc.StartsWith = swBuilder.String()
// Trim the extra space at the end added in the parse loop
pc.StartsWith = pc.StartsWith[:len(pc.StartsWith)-1]
pc.Matches, err = regexp.Compile(regexBuilder.String())
pc.MatchAgainst = "body"
return err
}
func (pc *ParsedCommand) parsePassiveCommandSyntax(command maubot.PassiveCommand) error {
pc.MatchAgainst = command.MatchAgainst
var err error
pc.Matches, err = regexp.Compile(command.Matches)
pc.MatchesEvent = command.MatchEvent
return err
}
func ParseSpec(spec *maubot.CommandSpec) (commands []*ParsedCommand) {
for _, command := range spec.Commands {
parsing := &ParsedCommand{
Name: command.Syntax,
}
err := parsing.parseCommandSyntax(command)
if err != nil {
log.Warnf("Failed to parse regex of command %s: %v\n", command.Syntax, err)
continue
}
commands = append(commands, parsing)
}
for _, command := range spec.PassiveCommands {
parsing := &ParsedCommand{
Name: command.Name,
}
err := parsing.parsePassiveCommandSyntax(command)
if err != nil {
log.Warnf("Failed to parse regex of passive command %s: %v\n", command.Name, err)
continue
}
commands = append(commands, parsing)
}
return commands
}
func deepGet(from map[string]interface{}, path string) interface{} {
for {
dotIndex := strings.IndexRune(path, '.')
if dotIndex == -1 {
return from[path]
}
var key string
key, path = path[:dotIndex], path[dotIndex+1:]
var ok bool
from, ok = from[key].(map[string]interface{})
if !ok {
return nil
}
}
}
func (pc *ParsedCommand) Match(evt *maubot.Event) bool {
matchAgainst, ok := deepGet(evt.Content.Raw, pc.MatchAgainst).(string)
if !ok {
matchAgainst = evt.Content.Body
}
return strings.HasPrefix(matchAgainst, pc.StartsWith) &&
pc.Matches.MatchString(matchAgainst) &&
(pc.MatchesEvent == nil || pc.MatchesEvent.Equals(evt))
}