finished the duckyscript parser

modules/hid/build_logitech.go

@@ -0,0 +1,56 @@
+package hid
+
+const (
+	frameDelay = 12
+)
+
+var (
+	helloData     = []byte{0x00, 0x4F, 0x00, 0x04, 0xB0, 0x10, 0x00, 0x00, 0x00, 0xED}
+	keepAliveData = []byte{0x00, 0x40, 0x04, 0xB0, 0x0C}
+)
+
+type LogitechBuilder struct {
+}
+
+func (b LogitechBuilder) frameFor(cmd *Command) []byte {
+	data := []byte{0, 0xC1, cmd.Mode, cmd.HID, 0, 0, 0, 0, 0, 0}
+	sz := len(data)
+	last := sz - 1
+	sum := byte(0xff)
+
+	for i := 0; i < last; i++ {
+		sum = (sum - data[i]) & 0xff
+	}
+	sum = (sum + 1) & 0xff
+	data[last] = sum
+
+	return data
+}
+
+func (b LogitechBuilder) BuildFrames(commands []*Command) error {
+	numCommands := len(commands)
+	for i, cmd := range commands {
+		if i == 0 {
+			cmd.AddFrame(helloData, frameDelay)
+		}
+
+		next := (*Command)(nil)
+		if i < numCommands-1 {
+			next = commands[i+1]
+		}
+
+		if cmd.IsHID() {
+			cmd.AddFrame(b.frameFor(cmd), frameDelay)
+			cmd.AddFrame(keepAliveData, 0)
+			if next == nil || cmd.HID == next.HID || next.IsSleep() {
+				cmd.AddFrame(b.frameFor(&Command{}), 0)
+			}
+		} else if cmd.IsSleep() {
+			for i, num := 0, cmd.Sleep/10; i < num; i++ {
+				cmd.AddFrame(keepAliveData, 10)
+			}
+		}
+	}
+
+	return nil
+}