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.

internal/domain/types.go

@@ -0,0 +1,163 @@
+package domain
+
+import "os/exec"
+
+// MediaType represents the type of media the user wants to download.
+type MediaType int
+
+const (
+	MediaTypeAudio MediaType = iota + 1
+	MediaTypeVideo
+	MediaTypeVideoAudio
+)
+
+func (m MediaType) String() string {
+	switch m {
+	case MediaTypeAudio:
+		return "audio"
+	case MediaTypeVideo:
+		return "video"
+	case MediaTypeVideoAudio:
+		return "video_audio"
+	default:
+		return "unknown"
+	}
+}
+
+// Format represents a downloadable format from yt-dlp.
+type Format struct {
+	ID          string
+	Extension   string
+	Width       int
+	Height      int
+	Resolution  string
+	Filesize    int64
+	Codec       string
+	Bitrate     string
+	Language    string
+	IsAudioOnly bool
+	IsVideoOnly bool
+	HasAudio    bool
+	HasVideo    bool
+}
+
+// MediaInfo holds the full information about a downloadable media item.
+type MediaInfo struct {
+	URL             string
+	Title           string
+	Duration        float64
+	Formats         []Format
+	Languages       []string
+	IsPlaylist      bool
+	PlaylistCount   int
+	PlaylistEntries []PlaylistEntry
+	EstimatedSize   int64
+}
+
+// PlaylistEntry represents a single entry in a playlist.
+type PlaylistEntry struct {
+	ID       string
+	Title    string
+	URL      string
+	Duration float64
+}
+
+// DownloadStatus represents the current state of a download job.
+type DownloadStatus int
+
+const (
+	StatusPending DownloadStatus = iota
+	StatusFetching
+	StatusDownloading
+	StatusProcessing
+	StatusCompleted
+	StatusFailed
+	StatusCancelled
+)
+
+func (s DownloadStatus) String() string {
+	switch s {
+	case StatusPending:
+		return "Pending"
+	case StatusFetching:
+		return "Fetching info"
+	case StatusDownloading:
+		return "Downloading"
+	case StatusProcessing:
+		return "Processing"
+	case StatusCompleted:
+		return "Completed"
+	case StatusFailed:
+		return "Failed"
+	case StatusCancelled:
+		return "Cancelled"
+	default:
+		return "Unknown"
+	}
+}
+
+// DownloadJob represents an active download process for a user.
+type DownloadJob struct {
+	ID             string
+	UserID         int64
+	ChatID         int64
+	MessageID      int
+	URL            string
+	MediaType      MediaType
+	SelectedFormat *Format
+	Container      string
+	Language       string
+	Status         DownloadStatus
+	Progress       float64
+	Speed          string
+	ETA            string
+	FileSize       int64
+	FilePath       string
+	Title          string
+	QuotaApplied   bool
+	CancelCh       chan struct{}
+	Cmd            *exec.Cmd
+}
+
+// UserPreferences holds per-user default preferences.
+type UserPreferences struct {
+	DefaultMediaType MediaType
+	DefaultQuality   string
+	DefaultContainer string
+	DefaultLanguage  string
+}
+
+// UserQuotas holds the quota usage and limits for a user.
+type UserQuotas struct {
+	DailyLimitMB   int64
+	DailyUsedMB    int64
+	DailyDate      string
+	WeeklyLimitMB  int64
+	WeeklyUsedMB   int64
+	WeekStart      string
+	MonthlyLimitMB int64
+	MonthlyUsedMB  int64
+	MonthStart     string
+}
+
+// DownloadRecord is a completed download entry stored in history.
+type DownloadRecord struct {
+	ID        int64
+	UserID    int64
+	URL       string
+	Title     string
+	MediaType string
+	FormatID  string
+	Container string
+	FileSize  int64
+	Status    string
+	CreatedAt string
+}
+
+// PlaylistState tracks the user's current playlist selection flow.
+type PlaylistState struct {
+	Entries  []PlaylistEntry
+	Page     int
+	PerPage  int
+	Selected map[string]bool
+}