Allow downloads to be created, prompt the user for a profile.

download/download.go

@@ -0,0 +1,172 @@
+package download
+
+import (
+	"fmt"
+	"io"
+	"os/exec"
+	"regexp"
+	"strconv"
+	"strings"
+	"sync"
+
+	"github.com/tardisx/gropple/config"
+)
+
+type Download struct {
+	Id              int                    `json:"id"`
+	Url             string                 `json:"url"`
+	Pid             int                    `json:"pid"`
+	ExitCode        int                    `json:"exit_code"`
+	State           string                 `json:"state"`
+	DownloadProfile config.DownloadProfile `json:"download_profile"`
+	Finished        bool                   `json:"finished"`
+	Files           []string               `json:"files"`
+	Eta             string                 `json:"eta"`
+	Percent         float32                `json:"percent"`
+	Log             []string               `json:"log"`
+	Config          *config.Config
+}
+
+// Begin starts a download, by starting the command specified in the DownloadProfile.
+// It blocks until the download is complete.
+func (dl *Download) Begin() {
+	cmdSlice := []string{}
+	cmdSlice = append(cmdSlice, dl.DownloadProfile.Args...)
+	cmdSlice = append(cmdSlice, dl.Url)
+
+	cmd := exec.Command(dl.DownloadProfile.Command, cmdSlice...)
+	cmd.Dir = dl.Config.Server.DownloadPath
+
+	stdout, err := cmd.StdoutPipe()
+	if err != nil {
+		dl.State = "failed"
+		dl.Finished = true
+		dl.Log = append(dl.Log, fmt.Sprintf("error setting up stdout pipe: %v", err))
+		return
+	}
+
+	stderr, err := cmd.StderrPipe()
+	if err != nil {
+		dl.State = "failed"
+		dl.Finished = true
+		dl.Log = append(dl.Log, fmt.Sprintf("error setting up stderr pipe: %v", err))
+		return
+	}
+
+	err = cmd.Start()
+	if err != nil {
+		dl.State = "failed"
+		dl.Finished = true
+		dl.Log = append(dl.Log, fmt.Sprintf("error starting youtube-dl: %v", err))
+		return
+	}
+	dl.Pid = cmd.Process.Pid
+
+	var wg sync.WaitGroup
+
+	wg.Add(2)
+	go func() {
+		defer wg.Done()
+		dl.updateDownload(stdout)
+	}()
+
+	go func() {
+		defer wg.Done()
+		dl.updateDownload(stderr)
+	}()
+
+	wg.Wait()
+	cmd.Wait()
+
+	dl.State = "complete"
+	dl.Finished = true
+	dl.ExitCode = cmd.ProcessState.ExitCode()
+
+	if dl.ExitCode != 0 {
+		dl.State = "failed"
+	}
+
+}
+
+func (dl *Download) updateDownload(r io.Reader) {
+	// XXX not sure if we might get a partial line?
+	buf := make([]byte, 1024)
+	for {
+		n, err := r.Read(buf)
+		if n > 0 {
+			s := string(buf[:n])
+			lines := strings.Split(s, "\n")
+
+			for _, l := range lines {
+
+				if l == "" {
+					continue
+				}
+
+				// append the raw log
+				dl.Log = append(dl.Log, l)
+
+				// look for the percent and eta and other metadata
+				dl.updateMetadata(l)
+			}
+		}
+		if err != nil {
+			break
+		}
+	}
+}
+
+func (dl *Download) updateMetadata(s string) {
+
+	// [download]  49.7% of ~15.72MiB at  5.83MiB/s ETA 00:07
+	etaRE := regexp.MustCompile(`download.+ETA +(\d\d:\d\d)`)
+	matches := etaRE.FindStringSubmatch(s)
+	if len(matches) == 2 {
+		dl.Eta = matches[1]
+		dl.State = "downloading"
+
+	}
+
+	percentRE := regexp.MustCompile(`download.+?([\d\.]+)%`)
+	matches = percentRE.FindStringSubmatch(s)
+	if len(matches) == 2 {
+		p, err := strconv.ParseFloat(matches[1], 32)
+		if err == nil {
+			dl.Percent = float32(p)
+		} else {
+			panic(err)
+		}
+	}
+
+	// This appears once per destination file
+	// [download] Destination: Filename with spaces and other punctuation here be careful!.mp4
+	filename := regexp.MustCompile(`download.+?Destination: (.+)$`)
+	matches = filename.FindStringSubmatch(s)
+	if len(matches) == 2 {
+		dl.Files = append(dl.Files, matches[1])
+	}
+
+	// This means a file has been "created" by merging others
+	// [ffmpeg] Merging formats into "Toto - Africa (Official HD Video)-FTQbiNvZqaY.mp4"
+	mergedFilename := regexp.MustCompile(`Merging formats into "(.+)"$`)
+	matches = mergedFilename.FindStringSubmatch(s)
+	if len(matches) == 2 {
+		dl.Files = append(dl.Files, matches[1])
+	}
+
+	// This means a file has been deleted
+	// Gross - this time it's unquoted and has trailing guff
+	// Deleting original file Toto - Africa (Official HD Video)-FTQbiNvZqaY.f137.mp4 (pass -k to keep)
+	// This is very fragile
+	deletedFile := regexp.MustCompile(`Deleting original file (.+) \(pass -k to keep\)$`)
+	matches = deletedFile.FindStringSubmatch(s)
+	if len(matches) == 2 {
+		// find the index
+		for i, f := range dl.Files {
+			if f == matches[1] {
+				dl.Files = append(dl.Files[:i], dl.Files[i+1:]...)
+				break
+			}
+		}
+	}
+}