Initial TopDeck: self-hosted ranked favorites

A single Go binary with SQLite that serves a public page of the owner's
ranked lists (movies, TV, albums, songs, video games, theater) and a
login-gated editor.

- Lists of 1–65,535 entries (100 recommended), several per category
- Search-to-add via TMDB, TheTVDB, IGDB, Deezer/MusicBrainz, Wikipedia;
  manual entry as a fallback
- Theater entries carry a production (Broadway, tour, …), venue and cast
- Artwork cached locally; URL override and uploads
- Drag, arrow and type-a-rank reordering; paginated for long lists
- 12 theme presets plus custom CSS
- First-run setup code or env-provided admin; bcrypt, rate-limited login,
  CSRF-guarded JSON API
- Dockerfile and docker-compose.yml

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/providers/igdb.go

@@ -0,0 +1,141 @@
+package providers
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"net/url"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+)
+
+// igdb searches the Internet Game Database, authenticating through Twitch.
+type igdb struct {
+	r      *Registry
+	id     string
+	secret string
+}
+
+type igdbTokens struct {
+	mu      sync.Mutex
+	credKey string
+	token   string
+	expires time.Time
+}
+
+func (g *igdb) Name() string  { return "igdb" }
+func (g *igdb) Label() string { return "IGDB" }
+
+func (g *igdb) token(ctx context.Context, fresh bool) (string, error) {
+	c := g.r.igdb
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	credKey := g.id + "\x00" + g.secret
+	if !fresh && c.credKey == credKey && c.token != "" && time.Now().Before(c.expires) {
+		return c.token, nil
+	}
+	q := url.Values{"client_id": {g.id}, "client_secret": {g.secret}, "grant_type": {"client_credentials"}}
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, "https://id.twitch.tv/oauth2/token?"+q.Encode(), nil)
+	if err != nil {
+		return "", err
+	}
+	var resp struct {
+		AccessToken string `json:"access_token"`
+		ExpiresIn   int64  `json:"expires_in"`
+	}
+	if err := g.r.do(req, &resp); err != nil {
+		if isStatus(err, 400) || isStatus(err, 403) {
+			return "", fmt.Errorf("Twitch rejected the IGDB client ID/secret; check them under Settings → Integrations")
+		}
+		return "", err
+	}
+	c.credKey, c.token = credKey, resp.AccessToken
+	c.expires = time.Now().Add(time.Duration(resp.ExpiresIn)*time.Second - time.Hour)
+	return c.token, nil
+}
+
+func (g *igdb) Search(ctx context.Context, query string) ([]Result, error) {
+	q := strings.NewReplacer(`\`, ``, `"`, `\"`).Replace(query)
+	body := `search "` + q + `";
+fields name,first_release_date,cover.image_id,summary,url,involved_companies.developer,involved_companies.company.name,platforms.abbreviation,platforms.name;
+limit 25;`
+	var games []struct {
+		ID               int64  `json:"id"`
+		Name             string `json:"name"`
+		FirstReleaseDate int64  `json:"first_release_date"`
+		Summary          string `json:"summary"`
+		URL              string `json:"url"`
+		Cover            struct {
+			ImageID string `json:"image_id"`
+		} `json:"cover"`
+		InvolvedCompanies []struct {
+			Developer bool `json:"developer"`
+			Company   struct {
+				Name string `json:"name"`
+			} `json:"company"`
+		} `json:"involved_companies"`
+		Platforms []struct {
+			Abbreviation string `json:"abbreviation"`
+			Name         string `json:"name"`
+		} `json:"platforms"`
+	}
+	for attempt := 0; ; attempt++ {
+		tok, err := g.token(ctx, attempt > 0)
+		if err != nil {
+			return nil, err
+		}
+		req, err := http.NewRequestWithContext(ctx, http.MethodPost, "https://api.igdb.com/v4/games", strings.NewReader(body))
+		if err != nil {
+			return nil, err
+		}
+		req.Header.Set("Client-ID", g.id)
+		req.Header.Set("Authorization", "Bearer "+tok)
+		req.Header.Set("Content-Type", "text/plain")
+		err = g.r.do(req, &games)
+		if isStatus(err, 401) && attempt == 0 {
+			continue
+		}
+		if err != nil {
+			return nil, err
+		}
+		break
+	}
+	out := make([]Result, 0, len(games))
+	for _, gm := range games {
+		var devs, plats []string
+		for _, ic := range gm.InvolvedCompanies {
+			if ic.Developer && ic.Company.Name != "" {
+				devs = append(devs, ic.Company.Name)
+			}
+		}
+		for _, p := range gm.Platforms {
+			name := p.Abbreviation
+			if name == "" {
+				name = p.Name
+			}
+			plats = append(plats, name)
+		}
+		r := Result{
+			Provider:    "igdb",
+			ProviderID:  strconv.FormatInt(gm.ID, 10),
+			Title:       gm.Name,
+			Subtitle:    strings.Join(devs, ", "),
+			ExternalURL: gm.URL,
+			Overview:    truncate(gm.Summary, 600),
+			Extra:       map[string]string{},
+		}
+		if gm.FirstReleaseDate > 0 {
+			r.Year = strconv.Itoa(time.Unix(gm.FirstReleaseDate, 0).UTC().Year())
+		}
+		if gm.Cover.ImageID != "" {
+			r.ImageURL = "https://images.igdb.com/igdb/image/upload/t_cover_big_2x/" + gm.Cover.ImageID + ".jpg"
+		}
+		if len(plats) > 0 {
+			r.Extra["platforms"] = strings.Join(plats, ", ")
+		}
+		out = append(out, r)
+	}
+	return out, nil
+}