Some more work and format changes.

1 files changed, 41 insertions, 5 deletions

diff --git a/src/transfer.rs b/src/transfer.rs
index 617eb62..31594dd 100644
--- a/src/transfer.rs
+++ b/src/transfer.rs
@@ -1,16 +1,52 @@
-const initial_transmission : u8 = 'b' as u8;
-
+#[derive(Copy, Clone)]
 pub enum TransferState {
     FirstContact,
     WaitAck,
+    SendHeader,
     Finished
 }
 
 use serial;
-use serial::SystemPort;
 
 pub fn first_contact(port : &mut serial::SystemPort) -> TransferState {
+    const INITIAL_TRANSMISSION: u8 = 'b' as u8;
+    use std::io::Write;
+
+    match (*port).write(&vec![INITIAL_TRANSMISSION]) {
+        Err(_) => TransferState::FirstContact,
+        Ok(b) => {
+            if b == 1 {
+                TransferState::WaitAck
+            }
+            else
+            {
+                TransferState::FirstContact
+            }
+        }
+    }
+}
+
+pub fn wait_ack(port : &mut serial::SystemPort, prev_state: TransferState) -> TransferState {
+
+    // For some reason, this trait has to be imported,
+    // but shouldn't serial::SerialPort be already doing this?
+    use std::io::Read;
+
+    let mut buffer : [u8; 1] = [0];
 
-    *port.write(&initial_transmission);
-    TransferState::WaitAck
+    match (*port).read(&mut buffer) {
+        Err(_) => TransferState::WaitAck,
+        Ok(b) => {
+            if b == 1 {
+                match prev_state {
+                    TransferState::FirstContact => TransferState::SendHeader,
+                    _ => TransferState::Finished
+                }
+            }
+            else
+            {
+                TransferState::WaitAck
+            }
+        }
+    }
 }