[core] Add support for stream schedule to twitch lib

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

pkg/twitch/schedule.go

@@ -0,0 +1,61 @@
+package twitch
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"strings"
+	"time"
+
+	"github.com/pkg/errors"
+)
+
+type (
+	// ChannelStreamSchedule represents the schedule of a channels with
+	// its segments represening single planned streams
+	ChannelStreamSchedule struct {
+		Segments []struct {
+			ID            string     `json:"id"`
+			StartTime     time.Time  `json:"start_time"`
+			EndTime       time.Time  `json:"end_time"`
+			Title         string     `json:"title"`
+			CanceledUntil *time.Time `json:"canceled_until"`
+			Category      struct {
+				ID   string `json:"id"`
+				Name string `json:"name"`
+			} `json:"category"`
+			IsRecurring bool `json:"is_recurring"`
+		} `json:"segments"`
+		BroadcasterID    string `json:"broadcaster_id"`
+		BroadcasterName  string `json:"broadcaster_name"`
+		BroadcasterLogin string `json:"broadcaster_login"`
+		Vacation         struct {
+			StartTime time.Time `json:"start_time"`
+			EndTime   time.Time `json:"end_time"`
+		} `json:"vacation"`
+	}
+)
+
+// GetChannelStreamSchedule gets the broadcaster’s streaming schedule
+func (c *Client) GetChannelStreamSchedule(ctx context.Context, channel string) (*ChannelStreamSchedule, error) {
+	channelID, err := c.GetIDForUsername(strings.TrimLeft(channel, "#@"))
+	if err != nil {
+		return nil, errors.Wrap(err, "getting channel user-id")
+	}
+
+	var payload struct {
+		Data *ChannelStreamSchedule `json:"data"`
+	}
+
+	return payload.Data, errors.Wrap(
+		c.Request(ClientRequestOpts{
+			AuthType: AuthTypeAppAccessToken,
+			Context:  ctx,
+			Method:   http.MethodGet,
+			OKStatus: http.StatusOK,
+			Out:      &payload,
+			URL:      fmt.Sprintf("https://api.twitch.tv/helix/schedule?broadcaster_id=%s", channelID),
+		}),
+		"executing request",
+	)
+}