[core] add streamUptime / formatDuration template functions

Signed-off-by: Knut Ahlers <knut@ahlers.me>

functions.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"fmt"
 	"strings"
 	"sync"
 	"text/template"
@@ -58,10 +59,33 @@ func init() {
 		tplFuncs.Register(n, plugins.GenericTemplateFunctionGetter(f))
 	}
 
+	tplFuncs.Register("concat", plugins.GenericTemplateFunctionGetter(func(delim string, parts ...string) string { return strings.Join(parts, delim) }))
+
+	tplFuncs.Register("formatDuration", plugins.GenericTemplateFunctionGetter(func(dur time.Duration, units ...string) string {
+		dLeft := dur
+
+		if len(units) == 0 {
+			return ""
+		}
+
+		var parts []string
+		for idx, div := range []time.Duration{time.Hour, time.Minute, time.Second} {
+			part := dLeft / div
+			dLeft -= part * div
+
+			if len(units) <= idx || units[idx] == "" {
+				continue
+			}
+
+			parts = append(parts, fmt.Sprintf("%d %s", part, units[idx]))
+		}
+
+		return strings.Join(parts, ", ")
+	}))
+
 	tplFuncs.Register("toLower", plugins.GenericTemplateFunctionGetter(strings.ToLower))
 	tplFuncs.Register("toUpper", plugins.GenericTemplateFunctionGetter(strings.ToUpper))
-	tplFuncs.Register("followDate", plugins.GenericTemplateFunctionGetter(func(from, to string) (time.Time, error) { return twitchClient.GetFollowDate(from, to) }))
-	tplFuncs.Register("concat", plugins.GenericTemplateFunctionGetter(func(delim string, parts ...string) string { return strings.Join(parts, delim) }))
+
 	tplFuncs.Register("variable", plugins.GenericTemplateFunctionGetter(func(name string, defVal ...string) string {
 		value := store.GetVariable(name)
 		if value == "" && len(defVal) > 0 {

functions_twitch.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"strings"
+	"time"
 
 	"github.com/Luzifer/twitch-bot/plugins"
 )
@@ -16,6 +17,8 @@ func init() {
 		return displayName, err
 	}))
 
+	tplFuncs.Register("followDate", plugins.GenericTemplateFunctionGetter(func(from, to string) (time.Time, error) { return twitchClient.GetFollowDate(from, to) }))
+
 	tplFuncs.Register("recentGame", plugins.GenericTemplateFunctionGetter(func(username string, v ...string) (string, error) {
 		game, _, err := twitchClient.GetRecentStreamInfo(strings.TrimLeft(username, "#"))
 		if len(v) > 0 && (err != nil || game == "") {
@@ -24,4 +27,12 @@ func init() {
 
 		return game, err
 	}))
+
+	tplFuncs.Register("streamUptime", plugins.GenericTemplateFunctionGetter(func(username string) (time.Duration, error) {
+		si, err := twitchClient.GetCurrentStreamInfo(strings.TrimLeft(username, "#"))
+		if err != nil {
+			return 0, err
+		}
+		return time.Since(si.StartedAt), nil
+	}))
 }

twitch/twitch.go

@@ -39,6 +39,23 @@ type (
 		apiCache *APICache
 	}
 
+	StreamInfo struct {
+		ID           string    `json:"id"`
+		UserID       string    `json:"user_id"`
+		UserLogin    string    `json:"user_login"`
+		UserName     string    `json:"user_name"`
+		GameID       string    `json:"game_id"`
+		GameName     string    `json:"game_name"`
+		Type         string    `json:"type"`
+		Title        string    `json:"title"`
+		ViewerCount  int64     `json:"viewer_count"`
+		StartedAt    time.Time `json:"started_at"`
+		Language     string    `json:"language"`
+		ThumbnailURL string    `json:"thumbnail_url"`
+		TagIds       []string  `json:"tag_ids"`
+		IsMature     bool      `json:"is_mature"`
+	}
+
 	User struct {
 		DisplayName     string `json:"display_name"`
 		ID              string `json:"id"`
@@ -253,6 +270,41 @@ func (c Client) HasLiveStream(username string) (bool, error) {
 	return len(payload.Data) == 1 && payload.Data[0].Type == "live", nil
 }
 
+func (c Client) GetCurrentStreamInfo(username string) (*StreamInfo, error) {
+	cacheKey := []string{"currentStreamInfo", username}
+	if si := c.apiCache.Get(cacheKey); si != nil {
+		return si.(*StreamInfo), nil
+	}
+
+	id, err := c.GetIDForUsername(username)
+	if err != nil {
+		return nil, errors.Wrap(err, "getting ID for username")
+	}
+
+	var payload struct {
+		Data []*StreamInfo `json:"data"`
+	}
+
+	if err := c.request(
+		context.Background(),
+		http.MethodGet,
+		fmt.Sprintf("https://api.twitch.tv/helix/streams?user_id=%s", id),
+		nil,
+		&payload,
+	); err != nil {
+		return nil, errors.Wrap(err, "request channel info")
+	}
+
+	if l := len(payload.Data); l != 1 {
+		return nil, errors.Errorf("unexpected number of users returned: %d", l)
+	}
+
+	// Stream-info can be changed at any moment, cache for a short period of time
+	c.apiCache.Set(cacheKey, twitchMinCacheTime, payload.Data[0])
+
+	return payload.Data[0], nil
+}
+
 func (c Client) GetIDForUsername(username string) (string, error) {
 	cacheKey := []string{"idForUsername", username}
 	if d := c.apiCache.Get(cacheKey); d != nil {

wiki/Home.md

@@ -137,9 +137,11 @@ Additionally there are some functions available in the templates:
 - `counterValue <counter name>` - Returns the current value of the counter which identifier was supplied
 - `displayName <username> [fallback]` - Returns the display name the specified user set for themselves
 - `fixUsername <username>` - Ensures the username no longer contains the `@` or `#` prefix
+- `formatDuration <duration> <hours> <minutes> <seconds>` - Returns a formated duration. Pass empty strings to leave out the part: `{{ formatDuration .dur "hours" "minutes" "" }}` yields `N hours, M minutes`
 - `followDate <from> <to>` - Looks up when `from` followed `to`
 - `group <idx> [fallback]` - Gets matching group specified by index from `match_message` regular expression, when `fallback` is defined, it is used when group has an empty match
 - `recentGame <username> [fallback]` - Returns the last played game name of the specified user (see shoutout example) or the `fallback` if the game could not be fetched. If no fallback was supplied the message will fail and not be sent.
+- `streamUptime <username>` - Returns the duration the stream is online (causes an error if no current stream is found)
 - `tag <tagname>` - Takes the message sent to the channel, returns the value of the tag specified
 - `toLower <string>` - Converts the given string to lower-case
 - `toUpper <string>` - Converts the given string to upper-case