9 files changed, 164 insertions, 0 deletions
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..585f016
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+/ff2mpv-go
diff --git a/COPYING b/COPYING
new file mode 100644
index 0000000..fd08ffe
--- /dev/null
+++ b/COPYING
@@ -0,0 +1,3 @@
+This software is released into the public domain.
+It is provided "as is", without warranties or conditions of any kind.
+Anyone is free to use, modify, redistribute and do anything with this software.
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..821bf90
--- /dev/null
+++ b/README.md
@@ -0,0 +1,36 @@
+ff2mpv-go
+=========
+
+Native messaging host for [ff2mpv](https://github.com/woodruffw/ff2mpv/) written in Go.
+
+Since it is a native binary, it starts faster than the official Python or Ruby
+implementations.
+
+
+Requirements
+------------
+
+- [Firefox](https://www.mozilla.org/en-US/firefox/) 50 or later
+- [ff2mpv](https://github.com/woodruffw/ff2mpv/) 3.0 or later
+- [Go](https://golang.org/) 11 or later (probably works on older versions too)
+- [mpv](https://mpv.io/) 0.21.0 or later
+
+
+Installation
+------------
+
+- `go get git.clsr.net/util/ff2mpv-go`
+- `ff2mpv-go --manifest > ~/.mozilla/native-messaging-hosts/ff2mpv.json`
+
+If `$GOBIN` is not in `$PATH`, specify the full path to the installed
+executable (e.g. `$GOBIN/ff2mpv-go`) when running it.
+
+If a custom mpv command is required, manually clone the repository and edit the
+`mpvCmd` variable in `ff2mpv.go`, then `go install` the package instead of the
+`go get` step.
+
+
+Usage
+-----
+
+Use ff2mpv as normally.
diff --git a/ff2mpv.go b/ff2mpv.go
new file mode 100644
index 0000000..7f0c939
--- /dev/null
+++ b/ff2mpv.go
@@ -0,0 +1,103 @@
+package main
+
+import (
+	"encoding/binary"
+	"encoding/json"
+	"fmt"
+	"io"
+	"os"
+	"os/exec"
+)
+
+var mpvCmd = []string{"mpv", "--player-operation-mode=pseudo-gui", "--"}
+
+type ffRequest struct {
+	URL string `json:"url"`
+}
+
+type ffManifest struct {
+	Name              string   `json:"name"`
+	Description       string   `json:"description"`
+	Path              string   `json:"path"`
+	Type              string   `json:"type"`
+	AllowedExtensions []string `json:"allowed_extensions"`
+}
+
+func ff2mpv() {
+	// extract message length from the first 4 bytes
+	var l uint32
+	// Go does not have an easy way to do sutff with native endianness without
+	// using usafe. Blame stupid WebExtension spec that uses *native* endianness in
+	// a *protocol*. Seriously, who designed that‽
+	if err := binary.Read(os.Stdin, endianness, &l); err != nil {
+		panic(err)
+	}
+	if l > 1024*1024 {
+		panic(fmt.Sprintf("native messaging message length too large: %d", l))
+	}
+
+	// read raw message
+	buf := make([]byte, l)
+	if n, err := os.Stdin.Read(buf); err != nil {
+		panic(err)
+	} else if n != len(buf) {
+		panic(fmt.Sprintf("read message length %d does not match expected length %d", n, l))
+	}
+
+	// decode JSON
+	var data ffRequest
+	if err := json.Unmarshal(buf, &data); err != nil {
+		panic(err)
+	}
+
+	// run mpv
+	args := append(mpvCmd, data.URL)
+	cmd := exec.Command(args[0], args[1:]...)
+	if err := cmd.Start(); err != nil {
+		panic(err)
+	}
+
+	// respond
+	outmsg := []byte("{}")
+	outlen := uint32(len(outmsg))
+	binary.Write(os.Stdout, endianness, outlen)
+	os.Stdout.Write(outmsg)
+}
+
+func manifest() {
+	exe, err := os.Executable()
+	if err != nil {
+		panic(err)
+	}
+	data, err := json.MarshalIndent(ffManifest{
+		Name:              "ff2mpv",
+		Description:       "ff2mpv's extenal manifest (ff2mpv-go)",
+		Path:              exe,
+		Type:              "stdio",
+		AllowedExtensions: []string{"ff2mpv@yossarian.net"},
+	}, "", "\t")
+	if err != nil {
+		panic(err)
+	}
+	os.Stdout.Write(data)
+}
+
+func usage(w io.Writer) {
+	fmt.Fprintf(os.Stderr, "args: %#v\n", os.Args)
+	fmt.Fprintf(w, "usage: %s [--manifest]\n", os.Args[0])
+}
+
+func main() {
+	arg := ""
+	if len(os.Args) == 2 {
+		arg = os.Args[1]
+	}
+	switch arg {
+	case "--manifest":
+		manifest()
+	case "--help":
+		usage(os.Stdout)
+	default:
+		ff2mpv()
+	}
+}
diff --git a/ff2mpv_386.go b/ff2mpv_386.go
new file mode 100644
index 0000000..4e77e9a
--- /dev/null
+++ b/ff2mpv_386.go
@@ -0,0 +1,5 @@
+package main
+
+import "encoding/binary"
+
+var endianness = binary.LittleEndian
diff --git a/ff2mpv_amd64.go b/ff2mpv_amd64.go
new file mode 100644
index 0000000..4e77e9a
--- /dev/null
+++ b/ff2mpv_amd64.go
@@ -0,0 +1,5 @@
+package main
+
+import "encoding/binary"
+
+var endianness = binary.LittleEndian
diff --git a/ff2mpv_arm.go b/ff2mpv_arm.go
new file mode 100644
index 0000000..4e77e9a
--- /dev/null
+++ b/ff2mpv_arm.go
@@ -0,0 +1,5 @@
+package main
+
+import "encoding/binary"
+
+var endianness = binary.LittleEndian
diff --git a/ff2mpv_arm64.go b/ff2mpv_arm64.go
new file mode 100644
index 0000000..4e77e9a
--- /dev/null
+++ b/ff2mpv_arm64.go
@@ -0,0 +1,5 @@
+package main
+
+import "encoding/binary"
+
+var endianness = binary.LittleEndian
diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..2cca1b6
--- /dev/null
+++ b/go.mod
@@ -0,0 +1 @@
+module git.clsr.net/util/ff2mpv-go