X-Git-Url: https://code.octet-stream.net/broadcaster/blobdiff_plain/7423c6c97eb5d6dc063e7185c50137bbb5e25a23..7b615b3c71825b5b229b78509a16db37e1d3f38d:/radio/files_machine.go

diff --git a/radio/files_machine.go b/radio/files_machine.go
new file mode 100644
index 0000000..143397a
--- /dev/null
+++ b/radio/files_machine.go
@@ -0,0 +1,117 @@
+package main
+
+import (
+	"code.octet-stream.net/broadcaster/internal/protocol"
+	"crypto/sha256"
+	"encoding/hex"
+	"io"
+	"log"
+	"net/http"
+	"os"
+	"path/filepath"
+)
+
+type FilesMachine struct {
+	specs     []protocol.FileSpec
+	cachePath string
+	missing   []string
+}
+
+func NewFilesMachine(cachePath string) FilesMachine {
+	if err := os.MkdirAll(cachePath, 0750); err != nil {
+		log.Fatal(err)
+	}
+	return FilesMachine{
+		cachePath: cachePath,
+	}
+}
+
+func (m *FilesMachine) UpdateSpecs(specs []protocol.FileSpec) {
+	m.specs = specs
+	m.RefreshMissing()
+}
+
+func (m *FilesMachine) RefreshMissing() {
+	// Delete any files in the cache dir who are not in the spec
+	entries, err := os.ReadDir(m.cachePath)
+	if err != nil {
+		log.Fatal(err)
+	}
+	okay := make([]string, 0)
+	for _, file := range entries {
+		hash := ""
+		for _, spec := range m.specs {
+			if file.Name() == spec.Name {
+				hash = spec.Hash
+				break
+			}
+		}
+		// if we have an extraneous file, delete it
+		if hash == "" {
+			log.Println("Deleting extraneous cached audio file:", file.Name())
+			os.Remove(filepath.Join(m.cachePath, file.Name()))
+			continue
+		}
+		// if the hash isn't right, delete it
+		f, err := os.Open(filepath.Join(m.cachePath, file.Name()))
+		if err != nil {
+			log.Fatal(err)
+		}
+		hasher := sha256.New()
+		io.Copy(hasher, f)
+		if hex.EncodeToString(hasher.Sum(nil)) != hash {
+			log.Println("Deleting cached audio file with incorrect hash:", file.Name())
+			os.Remove(filepath.Join(m.cachePath, file.Name()))
+		} else {
+			okay = append(okay, file.Name())
+		}
+	}
+	m.missing = nil
+	for _, spec := range m.specs {
+		missing := true
+		for _, file := range okay {
+			if spec.Name == file {
+				missing = false
+			}
+		}
+		if missing {
+			m.missing = append(m.missing, spec.Name)
+		}
+	}
+	if len(m.missing) > 1 {
+		log.Println(len(m.missing), "missing files")
+	} else if len(m.missing) == 1 {
+		log.Println("1 missing file")
+	} else {
+		log.Println("All files are in sync with server")
+	}
+	statusCollector.FilesInSync <- len(m.missing) == 0
+}
+
+func (m *FilesMachine) IsCacheComplete() bool {
+	return len(m.missing) == 0
+}
+
+func (m *FilesMachine) NextFile() string {
+	next, remainder := m.missing[0], m.missing[1:]
+	m.missing = remainder
+	return next
+}
+
+func (m *FilesMachine) DownloadSingle(filename string, downloadResult chan<- error) {
+	log.Println("Downloading", filename)
+	out, err := os.Create(filepath.Join(m.cachePath, filename))
+	if err != nil {
+		downloadResult <- err
+		return
+	}
+	defer out.Close()
+	resp, err := http.Get(config.ServerURL + "/file-downloads/" + filename)
+	if err != nil {
+		downloadResult <- err
+		return
+	}
+	defer resp.Body.Close()
+	_, err = io.Copy(out, resp.Body)
+	downloadResult <- err
+}