feat: initial implementation of uptodownbot

Telegram bot for downloading media from any site using yt-dlp.
Supports audio/video/both, quality selection, language picker,
container format selection, playlist pagination, progress updates,
per-user quotas, user preferences, download history, cancel at any step,
polling and webhook modes, proxy support, and SQLite persistence.

cmd/bot/webhook.go

@@ -0,0 +1,48 @@
+package main
+
+import (
+	"context"
+	"log/slog"
+	"net/http"
+	"os"
+
+	tgbot "github.com/go-telegram/bot"
+
+	"uptodownBot/internal/handler"
+)
+
+func startWebhook(ctx context.Context, b *tgbot.Bot, h *handler.Handler, webhookURL string) {
+	if _, err := b.DeleteWebhook(ctx, &tgbot.DeleteWebhookParams{}); err != nil {
+		slog.Warn("failed to delete webhook", "error", err)
+	}
+
+	if _, err := b.SetWebhook(ctx, &tgbot.SetWebhookParams{URL: webhookURL}); err != nil {
+		slog.Error("set webhook", "error", err)
+		os.Exit(1)
+	}
+
+	listenAddr := getEnvDefault("BOT_LISTEN", ":8080")
+	tlsCert := os.Getenv("BOT_TLS_CERT")
+	tlsKey := os.Getenv("BOT_TLS_KEY")
+
+	if tlsCert != "" && tlsKey != "" {
+		slog.Info("starting HTTPS webhook", "addr", listenAddr)
+		go func() {
+			if err := http.ListenAndServeTLS(listenAddr, tlsCert, tlsKey, b.WebhookHandler()); err != nil {
+				slog.Error("HTTPS server", "error", err)
+				os.Exit(1)
+			}
+		}()
+	} else {
+		slog.Info("starting HTTP webhook (TLS by reverse proxy)", "addr", listenAddr)
+		go func() {
+			if err := http.ListenAndServe(listenAddr, b.WebhookHandler()); err != nil {
+				slog.Error("HTTP server", "error", err)
+				os.Exit(1)
+			}
+		}()
+	}
+
+	slog.Info("webhook registered", "url", webhookURL)
+	b.StartWebhook(ctx)
+}