1 files changed, 40 insertions, 5 deletions

diff --git a/src/client/games/crash.rs b/src/client/games/crash.rs
index affb642..c6dbbd5 100644
--- a/src/client/games/crash.rs
+++ b/src/client/games/crash.rs
@@ -1,7 +1,8 @@
 use super::traits::{Game, GameState};
 use crate::client::view::CrashView;
+use crate::crash::{crash_point_from_seed, seed_from_hex, verify_seed};
 
-pub const CRASH_BOARD_LINES: usize = 6;
+pub const CRASH_BOARD_LINES: usize = 7;
 
 pub struct CrashGame;
 
@@ -29,6 +30,38 @@ impl CrashGame {
         }
     }
 
+    /// Commitment line. The seed is shown only after the round ends, and the
+    /// client recomputes both the hash and the crash point.
+    fn fairness_text(view: &CrashView) -> String {
+        let short = |hash: &str| {
+            hash.char_indices()
+                .nth(12)
+                .map(|(index, _)| &hash[..index])
+                .unwrap_or(hash)
+                .to_string()
+        };
+        let Some(commit) = view.commit.as_deref() else {
+            return "Commit: —".to_string();
+        };
+        let Some(seed) = view.seed.as_deref() else {
+            return format!("Commit {}   Seed hidden until the round ends", short(commit));
+        };
+        let commit_ok = verify_seed(seed, commit);
+        let point_ok = seed_from_hex(seed)
+            .map(|bytes| {
+                let expected = crash_point_from_seed(&bytes);
+                view.crash_point
+                    .map(|point| (expected - point).abs() < 1e-9)
+                    .unwrap_or(false)
+            })
+            .unwrap_or(false);
+        if commit_ok && point_ok {
+            format!("Commit {}   Seed {} verified", short(commit), short(seed))
+        } else {
+            format!("Commit {}   Seed {} VERIFICATION FAILED", short(commit), short(seed))
+        }
+    }
+
     fn controls(view: &CrashView) -> &'static str {
         if view.status == "running" {
             "[C] Cash out   [Q] Forfeit"
@@ -46,19 +79,21 @@ impl CrashGame {
 
         if let Some(error) = &view.error {
             return format!(
-                "=== CRASH ===\r\nBalance: {balance} Kr   Bet: {} Kr\r\n\r\nERROR: {error}\r\n\r\n[SPACE] Play   [+/=/-] Bet   [Q] Quit",
-                view.bet
+                "=== CRASH ===\r\nBalance: {balance} Kr   Bet: {} Kr\r\n\r\nERROR: {error}\r\n\r\n{}\r\n[SPACE] Play   [+/=/-] Bet   [Q] Quit",
+                view.bet,
+                Self::fairness_text(view)
             );
         }
 
         format!(
-            "=== CRASH ===\r\nBalance: {} Kr   Bet: {} Kr\r\nMultiplier: {:.2}x\r\nPotential: {} Kr\r\n{}\r\n{}",
+            "=== CRASH ===\r\nBalance: {} Kr   Bet: {} Kr\r\nMultiplier: {:.2}x\r\nPotential: {} Kr\r\n{}\r\n{}\r\n{}",
             balance,
             view.bet,
             view.multiplier,
             view.potential,
             Self::status_text(view),
-            Self::controls(view)
+            Self::controls(view),
+            Self::fairness_text(view)
         )
     }
 }