10 playlist download (#71)

* leveraging message queue for playlist entries DL

* playlist support implemented

It's a little bit slow but solid enough :D

server/internal/common.go

@@ -0,0 +1,73 @@
+package internal
+
+import "time"
+
+// Progress for the Running call
+type DownloadProgress struct {
+	Status     int     `json:"process_status"`
+	Percentage string  `json:"percentage"`
+	Speed      float32 `json:"speed"`
+	ETA        int     `json:"eta"`
+}
+
+// Used to deser the yt-dlp -J output
+type DownloadInfo struct {
+	URL         string    `json:"url"`
+	Title       string    `json:"title"`
+	Thumbnail   string    `json:"thumbnail"`
+	Resolution  string    `json:"resolution"`
+	Size        int32     `json:"filesize_approx"`
+	VCodec      string    `json:"vcodec"`
+	ACodec      string    `json:"acodec"`
+	Extension   string    `json:"ext"`
+	OriginalURL string    `json:"original_url"`
+	CreatedAt   time.Time `json:"created_at"`
+}
+
+// Used to deser the formats in the -J output
+type DownloadFormats struct {
+	Formats   []Format `json:"formats"`
+	Best      Format   `json:"best"`
+	Thumbnail string   `json:"thumbnail"`
+	Title     string   `json:"title"`
+	URL       string   `json:"url"`
+}
+
+// A skimmed yt-dlp format node
+type Format struct {
+	Format_id   string  `json:"format_id"`
+	Format_note string  `json:"format_note"`
+	FPS         float32 `json:"fps"`
+	Resolution  string  `json:"resolution"`
+	VCodec      string  `json:"vcodec"`
+	ACodec      string  `json:"acodec"`
+	Size        float32 `json:"filesize_approx"`
+}
+
+// struct representing the response sent to the client
+// as JSON-RPC result field
+type ProcessResponse struct {
+	Id       string           `json:"id"`
+	Progress DownloadProgress `json:"progress"`
+	Info     DownloadInfo     `json:"info"`
+}
+
+// struct representing the current status of the memoryDB
+// used for serializaton/persistence reasons
+type Session struct {
+	Processes []ProcessResponse `json:"processes"`
+}
+
+// struct representing the intent to stop a specific process
+type AbortRequest struct {
+	Id string `json:"id"`
+}
+
+// struct representing the intent to start a download
+type DownloadRequest struct {
+	Id     string
+	URL    string
+	Path   string
+	Rename string
+	Params []string
+}