Initial commit

internal/feed/twitch.go

@@ -0,0 +1,248 @@
+package feed
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"log/slog"
+	"net/http"
+	"slices"
+	"sort"
+	"strings"
+	"time"
+)
+
+type TwitchCategory struct {
+	Slug         string `json:"slug"`
+	Name         string `json:"name"`
+	AvatarUrl    string `json:"avatarURL"`
+	ViewersCount int    `json:"viewersCount"`
+	Tags         []struct {
+		Name string `json:"tagName"`
+	} `json:"tags"`
+	GameReleaseDate string `json:"originalReleaseDate"`
+	IsNew           bool   `json:"-"`
+}
+
+type TwitchChannel struct {
+	Login        string
+	Exists       bool
+	Name         string
+	AvatarUrl    string
+	IsLive       bool
+	LiveSince    time.Time
+	Category     string
+	CategorySlug string
+	ViewersCount int
+}
+
+type TwitchChannels []TwitchChannel
+
+func (channels TwitchChannels) SortByViewers() {
+	sort.Slice(channels, func(i, j int) bool {
+		return channels[i].ViewersCount > channels[j].ViewersCount
+	})
+}
+
+type twitchOperationResponse struct {
+	Data       json.RawMessage
+	Extensions struct {
+		OperationName string `json:"operationName"`
+	}
+}
+
+type twitchChannelShellOperationResponse struct {
+	UserOrError struct {
+		Type            string `json:"__typename"`
+		DisplayName     string `json:"displayName"`
+		ProfileImageUrl string `json:"profileImageURL"`
+		Stream          *struct {
+			ViewersCount int `json:"viewersCount"`
+		}
+	} `json:"userOrError"`
+}
+
+type twitchStreamMetadataOperationResponse struct {
+	UserOrNull *struct {
+		Stream *struct {
+			StartedAt string `json:"createdAt"`
+			Game      *struct {
+				Slug string `json:"slug"`
+				Name string `json:"name"`
+			} `json:"game"`
+		} `json:"stream"`
+	} `json:"user"`
+}
+
+type twitchDirectoriesOperationResponse struct {
+	Data struct {
+		DirectoriesWithTags struct {
+			Edges []struct {
+				Node TwitchCategory `json:"node"`
+			} `json:"edges"`
+		} `json:"directoriesWithTags"`
+	} `json:"data"`
+}
+
+const twitchGqlEndpoint = "https://gql.twitch.tv/gql"
+const twitchGqlClientId = "kimne78kx3ncx6brgo4mv6wki5h1ko"
+
+const twitchDirectoriesOperationRequestBody = `[{"operationName": "BrowsePage_AllDirectories","variables": {"limit": %d,"options": {"sort": "VIEWER_COUNT","tags": []}},"extensions": {"persistedQuery": {"version": 1,"sha256Hash": "2f67f71ba89f3c0ed26a141ec00da1defecb2303595f5cda4298169549783d9e"}}}]`
+
+func FetchTopGamesFromTwitch(exclude []string, limit int) ([]TwitchCategory, error) {
+	reader := strings.NewReader(fmt.Sprintf(twitchDirectoriesOperationRequestBody, len(exclude)+limit))
+	request, _ := http.NewRequest("POST", twitchGqlEndpoint, reader)
+	request.Header.Add("Client-ID", twitchGqlClientId)
+	response, err := decodeJsonFromRequest[[]twitchDirectoriesOperationResponse](defaultClient, request)
+
+	if err != nil {
+		return nil, err
+	}
+
+	if len(response) == 0 {
+		return nil, errors.New("no categories could be retrieved")
+	}
+
+	edges := (response)[0].Data.DirectoriesWithTags.Edges
+	categories := make([]TwitchCategory, 0, len(edges))
+
+	for i := range edges {
+		if slices.Contains(exclude, edges[i].Node.Slug) {
+			continue
+		}
+
+		category := &edges[i].Node
+		category.AvatarUrl = strings.Replace(category.AvatarUrl, "285x380", "144x192", 1)
+
+		if len(category.Tags) > 2 {
+			category.Tags = category.Tags[:2]
+		}
+
+		gameReleasedDate, err := time.Parse("2006-01-02T15:04:05Z", category.GameReleaseDate)
+
+		if err == nil {
+			if time.Since(gameReleasedDate) < 14*24*time.Hour {
+				category.IsNew = true
+			}
+		}
+
+		categories = append(categories, *category)
+	}
+
+	if len(categories) > limit {
+		categories = categories[:limit]
+	}
+
+	return categories, nil
+}
+
+const twitchChannelStatusOperationRequestBody = `[{"operationName":"ChannelShell","variables":{"login":"%s"},"extensions":{"persistedQuery":{"version":1,"sha256Hash":"580ab410bcd0c1ad194224957ae2241e5d252b2c5173d8e0cce9d32d5bb14efe"}}},{"operationName":"StreamMetadata","variables":{"channelLogin":"%s"},"extensions":{"persistedQuery":{"version":1,"sha256Hash":"676ee2f834ede42eb4514cdb432b3134fefc12590080c9a2c9bb44a2a4a63266"}}}]`
+
+// TODO: rework
+// The operations for multiple channels can all be sent in a single request
+// rather than sending a separate request for each channel. Need to figure out
+// what the limit is for max operations per request and batch operations in
+// multiple requests if number of channels exceeds allowed limit.
+
+func fetchChannelFromTwitchTask(channel string) (TwitchChannel, error) {
+	result := TwitchChannel{
+		Login: strings.ToLower(channel),
+	}
+
+	reader := strings.NewReader(fmt.Sprintf(twitchChannelStatusOperationRequestBody, channel, channel))
+	request, _ := http.NewRequest("POST", twitchGqlEndpoint, reader)
+	request.Header.Add("Client-ID", twitchGqlClientId)
+
+	response, err := decodeJsonFromRequest[[]twitchOperationResponse](defaultClient, request)
+
+	if err != nil {
+		return result, err
+	}
+
+	if len(response) != 2 {
+		return result, fmt.Errorf("expected 2 operation responses, got %d", len(response))
+	}
+
+	var channelShell twitchChannelShellOperationResponse
+	var streamMetadata twitchStreamMetadataOperationResponse
+
+	for i := range response {
+		switch response[i].Extensions.OperationName {
+		case "ChannelShell":
+			err = json.Unmarshal(response[i].Data, &channelShell)
+
+			if err != nil {
+				return result, fmt.Errorf("failed to unmarshal channel shell: %w", err)
+			}
+		case "StreamMetadata":
+			err = json.Unmarshal(response[i].Data, &streamMetadata)
+
+			if err != nil {
+				return result, fmt.Errorf("failed to unmarshal stream metadata: %w", err)
+			}
+		default:
+			return result, fmt.Errorf("unknown operation name: %s", response[i].Extensions.OperationName)
+		}
+	}
+
+	if channelShell.UserOrError.Type != "User" {
+		result.Name = result.Login
+		return result, nil
+	}
+
+	result.Exists = true
+	result.Name = channelShell.UserOrError.DisplayName
+	result.AvatarUrl = channelShell.UserOrError.ProfileImageUrl
+
+	if channelShell.UserOrError.Stream != nil {
+		result.IsLive = true
+		result.ViewersCount = channelShell.UserOrError.Stream.ViewersCount
+
+		if streamMetadata.UserOrNull != nil && streamMetadata.UserOrNull.Stream != nil && streamMetadata.UserOrNull.Stream.Game != nil {
+			result.Category = streamMetadata.UserOrNull.Stream.Game.Name
+			result.CategorySlug = streamMetadata.UserOrNull.Stream.Game.Slug
+			startedAt, err := time.Parse("2006-01-02T15:04:05Z", streamMetadata.UserOrNull.Stream.StartedAt)
+
+			if err == nil {
+				result.LiveSince = startedAt
+			} else {
+				slog.Warn("failed to parse twitch stream started at", "error", err, "started_at", streamMetadata.UserOrNull.Stream.StartedAt)
+			}
+		}
+	}
+
+	return result, nil
+}
+
+func FetchChannelsFromTwitch(channelLogins []string) (TwitchChannels, error) {
+	result := make(TwitchChannels, 0, len(channelLogins))
+
+	job := newJob(fetchChannelFromTwitchTask, channelLogins).withWorkers(10)
+	channels, errs, err := workerPoolDo(job)
+
+	if err != nil {
+		return result, err
+	}
+
+	var failed int
+
+	for i := range channels {
+		if errs[i] != nil {
+			failed++
+			slog.Warn("failed to fetch twitch channel", "channel", channelLogins[i], "error", errs[i])
+			continue
+		}
+
+		result = append(result, channels[i])
+	}
+
+	if failed == len(channelLogins) {
+		return result, ErrNoContent
+	}
+
+	if failed > 0 {
+		return result, fmt.Errorf("%w: failed to fetch %d channels", ErrPartialContent, failed)
+	}
+
+	return result, nil
+}