1 files changed, 75 insertions, 0 deletions
diff --git a/planetwars-rules/src/serializer.rs b/planetwars-rules/src/serializer.rs
new file mode 100644
index 0000000..7eb2e01
--- /dev/null
+++ b/planetwars-rules/src/serializer.rs
@@ -0,0 +1,75 @@
+use super::protocol as proto;
+use super::rules::{Expedition, Planet, PwState};
+
+/// Serialize given gamestate
+pub fn serialize(state: &PwState) -> proto::State {
+    serialize_rotated(state, 0)
+}
+
+/// Serialize given gamestate with player numbers rotated by given offset.
+pub fn serialize_rotated(state: &PwState, offset: usize) -> proto::State {
+    let serializer = Serializer::new(state, offset);
+    serializer.serialize_state()
+}
+
+struct Serializer<'a> {
+    state: &'a PwState,
+    player_num_offset: usize,
+}
+
+impl<'a> Serializer<'a> {
+    fn new(state: &'a PwState, offset: usize) -> Self {
+        Serializer {
+            state: state,
+            player_num_offset: offset,
+        }
+    }
+
+    fn serialize_state(&self) -> proto::State {
+        proto::State {
+            planets: self
+                .state
+                .planets
+                .iter()
+                .map(|planet| self.serialize_planet(planet))
+                .collect(),
+            expeditions: self
+                .state
+                .expeditions
+                .iter()
+                .map(|exp| self.serialize_expedition(exp))
+                .collect(),
+        }
+    }
+
+    /// Gets the player number for given player id.
+    /// Player numbers are 1-based (as opposed to player ids), They will also be
+    /// rotated based on the number offset for this serializer.
+    fn player_num(&self, player_id: usize) -> usize {
+        let num_players = self.state.players.len();
+        let rotated_id = (player_id + num_players - self.player_num_offset) % num_players;
+        // protocol player ids start at 1
+        return rotated_id + 1;
+    }
+
+    fn serialize_planet(&self, planet: &Planet) -> proto::Planet {
+        proto::Planet {
+            name: planet.name.clone(),
+            x: planet.x,
+            y: planet.y,
+            owner: planet.owner().map(|id| self.player_num(id)),
+            ship_count: planet.ship_count(),
+        }
+    }
+
+    fn serialize_expedition(&self, exp: &Expedition) -> proto::Expedition {
+        proto::Expedition {
+            id: exp.id,
+            owner: self.player_num(exp.fleet.owner.unwrap()),
+            ship_count: exp.fleet.ship_count,
+            origin: self.state.planets[exp.origin as usize].name.clone(),
+            destination: self.state.planets[exp.target as usize].name.clone(),
+            turns_remaining: exp.turns_remaining,
+        }
+    }
+}