# HG changeset patch
# User unC0Rr
# Date 1542124480 -3600
# Node ID 257b296169a89ebca390272787828edd5d3cd738
# Parent  a8fe9cd511547a8fced393e372eadb993cf2d7e1
Start working on engine messages parser

diff -r a8fe9cd51154 -r 257b296169a8 rust/hedgewars-engine-messages/Cargo.toml
--- a/rust/hedgewars-engine-messages/Cargo.toml	Tue Nov 13 07:43:36 2018 +0100
+++ b/rust/hedgewars-engine-messages/Cargo.toml	Tue Nov 13 16:54:40 2018 +0100
@@ -2,6 +2,7 @@
 name = "hedgewars-engine-messages"
 version = "0.1.0"
 authors = ["Andrey Korotaev <a.korotaev@hedgewars.org>"]
+edition = "2018"
 
 [dependencies]
 nom = "4.1.1"
diff -r a8fe9cd51154 -r 257b296169a8 rust/hedgewars-engine-messages/src/lib.rs
--- a/rust/hedgewars-engine-messages/src/lib.rs	Tue Nov 13 07:43:36 2018 +0100
+++ b/rust/hedgewars-engine-messages/src/lib.rs	Tue Nov 13 16:54:40 2018 +0100
@@ -1,10 +1,13 @@
-use crate::command::Command;
+use nom::*;
+use std::str;
 
+#[derive(Debug, PartialEq)]
 pub enum KeystrokeAction {
     Press,
     Release,
 }
 
+#[derive(Debug, PartialEq)]
 pub enum SyncedEngineMessage {
     Left(KeystrokeAction),
     Right(KeystrokeAction),
@@ -14,7 +17,6 @@
     Attack(KeystrokeAction),
     NextTurn,
     Switch,
-    Empty,
     Timer(u8),
     Slot(u8),
     SetWeapon(u8),
@@ -26,6 +28,7 @@
     TeamControlLost(String),
 }
 
+#[derive(Debug, PartialEq)]
 pub enum UnsyncedEngineMessage {
     Ping,
     Pong,
@@ -39,6 +42,7 @@
     GameSetupChecksum(String),
 }
 
+#[derive(Debug, PartialEq)]
 pub enum ConfigEngineMessage {
     ConfigRequest,
     SetAmmo(String),
@@ -70,7 +74,8 @@
     SetTurnTime(u32),
     SetMinesTime(u32),
     SetWorldEdge(u8),
-    Draw, // TODO
+    Draw,
+    // TODO
     SetVoicePack(String),
     AddHedgehog(String, u8, u32),
     AddTeam(String, u8),
@@ -109,10 +114,13 @@
     SetShoppaBorder(bool),
 }
 
+#[derive(Debug, PartialEq)]
 pub enum EngineMessage {
     Synced(SyncedEngineMessage, u32),
     Unsynced(UnsyncedEngineMessage),
     Config(ConfigEngineMessage),
+    Unknown,
+    Empty,
 }
 
 impl EngineMessage {
@@ -125,10 +133,89 @@
     }
 }
 
-#[cfg(test)]
-mod tests {
-    #[test]
-    fn it_works() {
-        assert_eq!(2 + 2, 4);
-    }
+named!(length_specifier<&[u8], u16>, alt!(
+    verify!(map!(take!(1), |a : &[u8]| a[0] as u16), |l| l < 64)
+    | map!(take!(2), |a| (a[0] as u16 - 64) * 256 + a[1] as u16 + 64)
+    )
+);
+
+named!(unrecognized_message<&[u8], EngineMessage>,
+    do_parse!(rest >> (EngineMessage::Unknown))
+);
+
+named!(string_tail<&[u8], String>, map!(map_res!(rest, str::from_utf8), String::from));
+
+named!(synced_message<&[u8], SyncedEngineMessage>, alt!(
+      do_parse!(tag!("+l") >> (SyncedEngineMessage::Left(KeystrokeAction::Press)))
+));
+
+named!(unsynced_message<&[u8], UnsyncedEngineMessage>, alt!(
+      do_parse!(tag!("?") >> (UnsyncedEngineMessage::Ping))
+    | do_parse!(tag!("!") >> (UnsyncedEngineMessage::Ping))
+    | do_parse!(tag!("esay ") >> s: string_tail  >> (UnsyncedEngineMessage::Say(s)))
+));
+
+named!(config_message<&[u8], ConfigEngineMessage>, alt!(
+    do_parse!(tag!("C") >> (ConfigEngineMessage::ConfigRequest))
+));
+
+named!(empty_message<&[u8], EngineMessage>,
+    do_parse!(tag!("\0") >> (EngineMessage::Empty))
+);
+
+named!(non_empty_message<&[u8], EngineMessage>, length_value!(length_specifier,
+    alt!(
+          map!(synced_message, |m| EngineMessage::Synced(m, 0))
+        | map!(unsynced_message, |m| EngineMessage::Unsynced(m))
+        | map!(config_message, |m| EngineMessage::Config(m))
+        | unrecognized_message
+    )
+));
+
+named!(message<&[u8], EngineMessage>, alt!(
+      empty_message
+    | non_empty_message
+    )
+);
+
+named!(pub extract_messages<&[u8], Vec<EngineMessage> >, many0!(complete!(message)));
+
+#[test]
+fn parse_length() {
+    assert_eq!(length_specifier(b"\x01"), Ok((&b""[..], 1)));
+    assert_eq!(length_specifier(b"\x00"), Ok((&b""[..], 0)));
+    assert_eq!(length_specifier(b"\x3f"), Ok((&b""[..], 63)));
+    assert_eq!(length_specifier(b"\x40\x00"), Ok((&b""[..], 64)));
+    assert_eq!(length_specifier(b"\xff\xff"), Ok((&b""[..], 49215)));
 }
+
+#[test]
+fn parse_synced_messages() {
+    assert_eq!(message(b"\x02+l"), Ok((&b""[..], EngineMessage::Synced(SyncedEngineMessage::Left(KeystrokeAction::Press), 0))));
+}
+
+#[test]
+fn parse_unsynced_messages() {
+    assert_eq!(message(b"\x0aesay hello"), Ok((&b""[..], EngineMessage::Unsynced(UnsyncedEngineMessage::Say(String::from("hello"))))));
+}
+
+#[test]
+fn parse_incorrect_messages() {
+    assert_eq!(message(b"\x00"), Ok((&b""[..], EngineMessage::Empty)));
+    assert_eq!(message(b"\x01\x00"), Ok((&b""[..], EngineMessage::Unknown)));
+}
+
+#[test]
+fn parse_config_messages() {
+    assert_eq!(
+        message(b"\x01C"),
+        Ok((
+            &b""[..],
+            EngineMessage::Config(ConfigEngineMessage::ConfigRequest)
+        ))
+    );
+}
+#[test]
+fn parse_test_general() {
+    assert_eq!(string_tail(b"abc"), Ok((&b""[..], String::from("abc"))));
+}