package plugins import ( "context" "encoding/json" "fmt" "net/http" "net/url" "path" "regexp" "strings" "time" "github.com/go-irc/irc" "github.com/mitchellh/hashstructure/v2" "github.com/pkg/errors" log "github.com/sirupsen/logrus" "gopkg.in/yaml.v3" "github.com/Luzifer/go_helpers/v2/str" "github.com/Luzifer/twitch-bot/v3/pkg/twitch" ) const ( contentTypeJSON = "json" contentTypeYAML = "yaml" remoteRuleFetchTimeout = 5 * time.Second ) // ErrStopRuleExecution is a way for actions to terminate execution // of the current rule gracefully. No actions after this has been // returned will be executed and no error state will be set var ErrStopRuleExecution = errors.New("stop rule execution now") type ( Rule struct { UUID string `hash:"-" json:"uuid,omitempty" yaml:"uuid,omitempty"` Description string `json:"description,omitempty" yaml:"description,omitempty"` SubscribeFrom *string `json:"subscribe_from,omitempty" yaml:"subscribe_from,omitempty"` Actions []*RuleAction `json:"actions,omitempty" yaml:"actions,omitempty"` Cooldown *time.Duration `json:"cooldown,omitempty" yaml:"cooldown,omitempty"` ChannelCooldown *time.Duration `json:"channel_cooldown,omitempty" yaml:"channel_cooldown,omitempty"` UserCooldown *time.Duration `json:"user_cooldown,omitempty" yaml:"user_cooldown,omitempty"` SkipCooldownFor []string `json:"skip_cooldown_for,omitempty" yaml:"skip_cooldown_for,omitempty"` MatchChannels []string `json:"match_channels,omitempty" yaml:"match_channels,omitempty"` MatchEvent *string `json:"match_event,omitempty" yaml:"match_event,omitempty"` MatchMessage *string `json:"match_message,omitempty" yaml:"match_message,omitempty"` MatchUsers []string `json:"match_users,omitempty" yaml:"match_users,omitempty" ` DisableOnMatchMessages []string `json:"disable_on_match_messages,omitempty" yaml:"disable_on_match_messages,omitempty"` Disable *bool `json:"disable,omitempty" yaml:"disable,omitempty"` DisableOnOffline *bool `json:"disable_on_offline,omitempty" yaml:"disable_on_offline,omitempty"` DisableOnPermit *bool `json:"disable_on_permit,omitempty" yaml:"disable_on_permit,omitempty"` DisableOnTemplate *string `json:"disable_on_template,omitempty" yaml:"disable_on_template,omitempty"` DisableOn []string `json:"disable_on,omitempty" yaml:"disable_on,omitempty"` EnableOn []string `json:"enable_on,omitempty" yaml:"enable_on,omitempty"` matchMessage *regexp.Regexp disableOnMatchMessages []*regexp.Regexp msgFormatter MsgFormatter timerStore TimerStore twitchClient *twitch.Client } RuleAction struct { Type string `json:"type" yaml:"type,omitempty"` Attributes *FieldCollection `json:"attributes" yaml:"attributes,omitempty"` } ) func (r Rule) MatcherID() string { if r.UUID != "" { return r.UUID } return r.hash() } func (r *Rule) Matches(m *irc.Message, event *string, timerStore TimerStore, msgFormatter MsgFormatter, twitchClient *twitch.Client, eventData *FieldCollection) bool { r.msgFormatter = msgFormatter r.timerStore = timerStore r.twitchClient = twitchClient var ( badges = twitch.ParseBadgeLevels(m) logger = log.WithFields(log.Fields{ "msg": m, "rule": r, }) ) for _, matcher := range []func(*log.Entry, *irc.Message, *string, twitch.BadgeCollection, *FieldCollection) bool{ r.allowExecuteDisable, r.allowExecuteChannelWhitelist, r.allowExecuteUserWhitelist, r.allowExecuteEventMatch, r.allowExecuteMessageMatcherWhitelist, r.allowExecuteMessageMatcherBlacklist, r.allowExecuteBadgeBlacklist, r.allowExecuteBadgeWhitelist, r.allowExecuteDisableOnPermit, r.allowExecuteRuleCooldown, r.allowExecuteChannelCooldown, r.allowExecuteUserCooldown, r.allowExecuteDisableOnTemplate, r.allowExecuteDisableOnOffline, } { if !matcher(logger, m, event, badges, eventData) { return false } } // Nothing objected: Matches! return true } func (r *Rule) GetMatchMessage() *regexp.Regexp { var err error if r.matchMessage == nil { if r.matchMessage, err = regexp.Compile(*r.MatchMessage); err != nil { log.WithError(err).Error("Unable to compile expression") return nil } } return r.matchMessage } func (r *Rule) SetCooldown(timerStore TimerStore, m *irc.Message, evtData *FieldCollection) { if r.Cooldown != nil { timerStore.AddCooldown(TimerTypeCooldown, "", r.MatcherID(), time.Now().Add(*r.Cooldown)) } if r.ChannelCooldown != nil && DeriveChannel(m, evtData) != "" { timerStore.AddCooldown(TimerTypeCooldown, DeriveChannel(m, evtData), r.MatcherID(), time.Now().Add(*r.ChannelCooldown)) } if r.UserCooldown != nil && DeriveUser(m, evtData) != "" { timerStore.AddCooldown(TimerTypeCooldown, DeriveUser(m, evtData), r.MatcherID(), time.Now().Add(*r.UserCooldown)) } } func (r *Rule) UpdateFromSubscription() (bool, error) { if r.SubscribeFrom == nil || len(*r.SubscribeFrom) == 0 { return false, nil } prevHash := r.hash() remoteURL, err := url.Parse(*r.SubscribeFrom) if err != nil { return false, errors.Wrap(err, "parsing remote subscription url") } ctx, cancel := context.WithTimeout(context.Background(), remoteRuleFetchTimeout) defer cancel() req, err := http.NewRequestWithContext(ctx, http.MethodGet, remoteURL.String(), nil) if err != nil { return false, errors.Wrap(err, "assembling request") } resp, err := http.DefaultClient.Do(req) if err != nil { return false, errors.Wrap(err, "executing request") } defer resp.Body.Close() if resp.StatusCode != http.StatusOK { return false, errors.Errorf("unxpected HTTP status %d", resp.StatusCode) } inputType, err := r.fileTypeFromRequest(remoteURL, resp) if err != nil { return false, errors.Wrap(err, "detecting content type") } var newRule Rule switch inputType { case contentTypeJSON: err = json.NewDecoder(resp.Body).Decode(&newRule) case contentTypeYAML: err = yaml.NewDecoder(resp.Body).Decode(&newRule) default: return false, errors.New("unexpected format") } if err != nil { return false, errors.Wrap(err, "decoding remote rule") } if newRule.hash() == prevHash { // No update, exit now return false, nil } *r = newRule return true, nil } func (r Rule) Validate(tplValidate TemplateValidatorFunc) error { if r.MatchMessage != nil { if _, err := regexp.Compile(*r.MatchMessage); err != nil { return errors.Wrap(err, "compiling match_message field regex") } } if r.DisableOnTemplate != nil { if err := tplValidate(*r.DisableOnTemplate); err != nil { return errors.Wrap(err, "parsing disable_on_template template") } } return nil } func (r *Rule) allowExecuteBadgeBlacklist(logger *log.Entry, _ *irc.Message, _ *string, badges twitch.BadgeCollection, _ *FieldCollection) bool { for _, b := range r.DisableOn { if badges.Has(b) { logger.Tracef("Non-Match: Disable-Badge %s", b) return false } } return true } func (r *Rule) allowExecuteBadgeWhitelist(_ *log.Entry, _ *irc.Message, _ *string, badges twitch.BadgeCollection, _ *FieldCollection) bool { if len(r.EnableOn) == 0 { // No match criteria set, does not speak against matching return true } for _, b := range r.EnableOn { if badges.Has(b) { return true } } return false } func (r *Rule) allowExecuteChannelCooldown(logger *log.Entry, m *irc.Message, _ *string, badges twitch.BadgeCollection, evtData *FieldCollection) bool { if r.ChannelCooldown == nil || DeriveChannel(m, evtData) == "" { // No match criteria set, does not speak against matching return true } inCooldown, err := r.timerStore.InCooldown(TimerTypeCooldown, DeriveChannel(m, evtData), r.MatcherID()) if err != nil { logger.WithError(err).Error("checking channel cooldown") return false } if !inCooldown { return true } for _, b := range r.SkipCooldownFor { if badges.Has(b) { return true } } return false } func (r *Rule) allowExecuteChannelWhitelist(logger *log.Entry, m *irc.Message, _ *string, _ twitch.BadgeCollection, evtData *FieldCollection) bool { if len(r.MatchChannels) == 0 { // No match criteria set, does not speak against matching return true } if DeriveChannel(m, evtData) == "" || (!str.StringInSlice(DeriveChannel(m, evtData), r.MatchChannels) && !str.StringInSlice(strings.TrimPrefix(DeriveChannel(m, evtData), "#"), r.MatchChannels)) { logger.Trace("Non-Match: Channel") return false } return true } func (r *Rule) allowExecuteDisable(logger *log.Entry, _ *irc.Message, _ *string, _ twitch.BadgeCollection, _ *FieldCollection) bool { if r.Disable == nil { // No match criteria set, does not speak against matching return true } if *r.Disable { logger.Trace("Non-Match: Disable") return false } return true } func (r *Rule) allowExecuteDisableOnOffline(logger *log.Entry, m *irc.Message, _ *string, _ twitch.BadgeCollection, evtData *FieldCollection) bool { if r.DisableOnOffline == nil || !*r.DisableOnOffline || DeriveChannel(m, evtData) == "" { // No match criteria set, does not speak against matching return true } streamLive, err := r.twitchClient.HasLiveStream(strings.TrimLeft(DeriveChannel(m, evtData), "#")) if err != nil { logger.WithError(err).Error("Unable to determine live status") return false } if !streamLive { logger.Trace("Non-Match: Stream offline") return false } return true } func (r *Rule) allowExecuteDisableOnPermit(logger *log.Entry, m *irc.Message, _ *string, _ twitch.BadgeCollection, evtData *FieldCollection) bool { hasPermit, err := r.timerStore.HasPermit(DeriveChannel(m, evtData), DeriveUser(m, evtData)) if err != nil { logger.WithError(err).Error("checking permit") return false } if r.DisableOnPermit != nil && *r.DisableOnPermit && DeriveChannel(m, evtData) != "" && hasPermit { logger.Trace("Non-Match: Permit") return false } return true } func (r *Rule) allowExecuteDisableOnTemplate(logger *log.Entry, m *irc.Message, _ *string, _ twitch.BadgeCollection, evtData *FieldCollection) bool { if r.DisableOnTemplate == nil || *r.DisableOnTemplate == "" { // No match criteria set, does not speak against matching return true } res, err := r.msgFormatter(*r.DisableOnTemplate, m, r, evtData) if err != nil { logger.WithError(err).Error("Unable to check DisableOnTemplate field") // Caused an error, forbid execution return false } if res == "true" { logger.Trace("Non-Match: Template") return false } return true } func (r *Rule) allowExecuteEventMatch(logger *log.Entry, _ *irc.Message, event *string, _ twitch.BadgeCollection, _ *FieldCollection) bool { // The user defines either no event to match or they define an // event to match. We now need to ensure this match is valid for // the current execution: // // - If the user gave no event we MUST NOT have an event defined // - If the user gave an event we MUST have the same event defined // // To aid fighting spam we do define some excemption from these // rules: // // - Bits are sent using IRC messages and might contains spam // therefore we additionally match them through a message // matcher // - Resubs are also IRC messages and might be abused to spam // though this is quite unlikely. Even though it's unlikely // we also allow a match for message matchers to aid mods // // As all set events are always pointer to non-empty strings we // assume an empty string in case either is not set and then // compare the string contents. var mE, gE string if r.MatchEvent != nil { mE = *r.MatchEvent } if event != nil { gE = *event } if mE == gE { // Event does exactly match return true } if mE == "" && str.StringInSlice(gE, []string{"bits", "resub"}) { // Additional message matchers - see explanation above return true } logger.Trace("Non-Match: Event") return false } func (r *Rule) allowExecuteMessageMatcherBlacklist(logger *log.Entry, m *irc.Message, _ *string, _ twitch.BadgeCollection, _ *FieldCollection) bool { if len(r.DisableOnMatchMessages) == 0 { // No match criteria set, does not speak against matching return true } // If the regexps were not pre-compiled, do it now if len(r.disableOnMatchMessages) != len(r.DisableOnMatchMessages) { r.disableOnMatchMessages = nil for _, dm := range r.DisableOnMatchMessages { dmr, err := regexp.Compile(dm) if err != nil { logger.WithError(err).Error("Unable to compile expression") return false } r.disableOnMatchMessages = append(r.disableOnMatchMessages, dmr) } } for _, rex := range r.disableOnMatchMessages { if m != nil && rex.MatchString(m.Trailing()) { logger.Trace("Non-Match: Disable-On-Message") return false } } return true } func (r *Rule) allowExecuteMessageMatcherWhitelist(logger *log.Entry, m *irc.Message, _ *string, _ twitch.BadgeCollection, _ *FieldCollection) bool { if r.MatchMessage == nil { // No match criteria set, does not speak against matching return true } var err error // If the regexp was not yet compiled, cache it if r.matchMessage == nil { if r.matchMessage, err = regexp.Compile(*r.MatchMessage); err != nil { logger.WithError(err).Error("Unable to compile expression") return false } } // Check whether the message matches if m == nil || !r.matchMessage.MatchString(m.Trailing()) { logger.Trace("Non-Match: Message") return false } return true } func (r *Rule) allowExecuteRuleCooldown(logger *log.Entry, _ *irc.Message, _ *string, badges twitch.BadgeCollection, _ *FieldCollection) bool { if r.Cooldown == nil { // No match criteria set, does not speak against matching return true } inCooldown, err := r.timerStore.InCooldown(TimerTypeCooldown, "", r.MatcherID()) if err != nil { logger.WithError(err).Error("checking rule cooldown") return false } if !inCooldown { return true } for _, b := range r.SkipCooldownFor { if badges.Has(b) { return true } } return false } func (r *Rule) allowExecuteUserCooldown(logger *log.Entry, m *irc.Message, _ *string, badges twitch.BadgeCollection, evtData *FieldCollection) bool { if r.UserCooldown == nil { // No match criteria set, does not speak against matching return true } inCooldown, err := r.timerStore.InCooldown(TimerTypeCooldown, DeriveUser(m, evtData), r.MatcherID()) if err != nil { logger.WithError(err).Error("checking user cooldown") return false } if DeriveUser(m, evtData) == "" || !inCooldown { return true } for _, b := range r.SkipCooldownFor { if badges.Has(b) { return true } } return false } func (r *Rule) allowExecuteUserWhitelist(logger *log.Entry, m *irc.Message, _ *string, _ twitch.BadgeCollection, evtData *FieldCollection) bool { if len(r.MatchUsers) == 0 { // No match criteria set, does not speak against matching return true } if DeriveUser(m, evtData) == "" || !str.StringInSlice(strings.ToLower(DeriveUser(m, evtData)), r.MatchUsers) { logger.Trace("Non-Match: Users") return false } return true } func (r Rule) fileTypeFromRequest(remoteURL *url.URL, resp *http.Response) (string, error) { switch path.Ext(remoteURL.Path) { case ".json": return contentTypeJSON, nil case ".yaml", ".yml": return contentTypeYAML, nil } switch strings.Split(resp.Header.Get("Content-Type"), ";")[0] { case "application/json": return contentTypeJSON, nil case "application/yaml", "application/x-yaml", "text/x-yaml": return contentTypeYAML, nil } return "", errors.New("no valid file type detected") } func (r Rule) hash() string { h, err := hashstructure.Hash(r, hashstructure.FormatV2, nil) if err != nil { panic(errors.Wrap(err, "hashing rule")) } return fmt.Sprintf("hashstructure:%x", h) }