feat: add prisoners dilemma code

Author: Jovian-Dsouza

prisoners_dilemma/encrypted-ixs/src/lib.rs

@@ -4,15 +4,74 @@ use arcis_imports::*;
 mod circuits {
     use arcis_imports::*;
 
-    pub struct InputValues {
-        v1: u8,
-        v2: u8,
+    // Consider 0 - split, 1 - steal
+    pub struct GameMoves {
+        player_a_move: u8,
+        player_b_move: u8,
     }
 
     #[instruction]
-    pub fn add_together(input_ctxt: Enc<Shared, InputValues>) -> Enc<Shared, u16> {
-        let input = input_ctxt.to_arcis();
-        let sum = input.v1 as u16 + input.v2 as u16;
-        input_ctxt.owner.from_arcis(sum)
+    pub fn init_game(mxe: Mxe) -> Enc<Mxe, GameMoves> {
+        let game_moves = GameMoves {
+            player_a_move: 2, // invalid move
+            player_b_move: 2,
+        };
+
+        mxe.from_arcis(game_moves)
+    }
+
+    pub struct PlayerMove {
+        player: u8,
+        player_move: u8,
+    }
+
+    #[instruction]
+    pub fn player_move(
+        player_move_ctxt: Enc<Shared, PlayerMove>,
+        game_ctxt: Enc<Mxe, GameMoves>,
+    ) -> Enc<Mxe, GameMoves> {
+        let player_move = player_move_ctxt.to_arcis();
+        let mut game_moves = game_ctxt.to_arcis();
+
+        // Check which player is moving, if the player hasn't played their move yet, and the move is valid
+        if player_move.player == 0 && game_moves.player_a_move == 2 && player_move.player_move < 2 {
+            game_moves.player_a_move = player_move.player_move;
+        } else if player_move.player == 1
+            && game_moves.player_b_move == 2
+            && player_move.player_move < 2
+        {
+            game_moves.player_b_move = player_move.player_move;
+        }
+
+        game_ctxt.owner.from_arcis(game_moves)
+    }
+
+    #[instruction]
+    pub fn compare_moves(game_ctxt: Enc<Mxe, GameMoves>) -> u8 {
+        let game_moves = game_ctxt.to_arcis();
+
+        // 0 - both players splits
+        // 1 - player A steals
+        // 2 - player B steals
+        // 3 - both players steal
+        // 4 - invalid move
+
+        let mut result = 4;
+
+        if game_moves.player_a_move == game_moves.player_b_move {
+            if game_moves.player_a_move == 0 {
+                //both split
+                result = 0;
+            } else if game_moves.player_a_move == 1 {
+                // both steal
+                result = 3;
+            }
+        } else if (game_moves.player_a_move == 1 && game_moves.player_b_move == 0) {
+            result = 1; // Player A steals
+        } else if (game_moves.player_a_move == 0 && game_moves.player_b_move == 1) {
+            result = 2; // Player B steals
+        }
+
+        result.reveal()
     }
 }