solitaire_core/src/game_state.rs

@@ -22,11 +22,17 @@ use serde::{Deserialize, Deserializer, Serialize, Serializer};
 ///   indices for enum variants. No longer loadable — v3 files are discarded.
 /// - v4: `saved_moves` uses upstream `KlondikeInstruction` serde with named enum
 ///   variants (e.g. `"Foundation1"` instead of `0`).
-/// - v5 (current): `score`, `undo_count`, and `recycle_count` are no longer
+/// - v5: `score`, `undo_count`, and `recycle_count` are no longer
 ///   persisted. They are derived from the upstream `card_game`/`klondike` session
 ///   stats, which are rebuilt by replaying `saved_moves` on load. Older files that
 ///   still carry those keys load fine — the extra fields are ignored.
-pub const GAME_STATE_SCHEMA_VERSION: u32 = 5;
+/// - v6 (current): `saved_moves` replaced by `recording`, the upstream
+///   `card_game` session serialisation carrying the dealt board explicitly.
+///   Loading no longer re-deals from `seed`, so in-progress saves survive
+///   RNG/upstream upgrades that change the seed→deal mapping (the failure
+///   class that PR #170 fixed for replays). v4/v5 files still load through
+///   the legacy seed path and are rewritten as v6 on next save.
+pub const GAME_STATE_SCHEMA_VERSION: u32 = 6;
 
 /// Default move budget for a solvability check. Matches the winnable-deal retry
 /// loop in the engine.
@@ -95,8 +101,8 @@ pub enum GameMode {
     Difficulty(DifficultyLevel),
 }
 
-/// Output struct for schema v4 serialisation. `saved_moves` uses upstream
-/// `KlondikeInstruction` serde, which produces named enum variants.
+/// Output struct for schema v6 serialisation. `recording` is the upstream
+/// session serialisation (config + dealt board + instruction list).
 #[derive(Debug, Clone, Serialize)]
 struct PersistedGameState {
     pub draw_mode: DrawStockConfig,
@@ -105,15 +111,16 @@ struct PersistedGameState {
     pub seed: u64,
     pub take_from_foundation: bool,
     pub schema_version: u32,
-    pub saved_moves: Vec<KlondikeInstruction>,
+    pub recording: SessionRecording,
 }
 
-/// Input struct that accepts schema v4 and v5 `saved_moves` formats.
+/// Input struct that accepts schema v4, v5, and v6 save formats.
 ///
-/// `saved_moves` is deserialised directly as upstream `KlondikeInstruction`
-/// (named-variant serde). `score`, `undo_count`, and `recycle_count` are
-/// intentionally absent: all three are rebuilt by replaying the instruction
-/// history through the upstream session stats. Older v4 save files still carry
+/// v6 files carry `recording` (the upstream session serialisation, deal
+/// included); v4/v5 files carry `saved_moves` and rebuild the deal from
+/// `seed`. `score`, `undo_count`, and `recycle_count` are intentionally
+/// absent: all three are rebuilt by replaying the instruction history
+/// through the upstream session stats. Older v4 save files still carry
 /// those keys; serde ignores them.
 #[derive(Debug, Clone, Deserialize)]
 struct PersistedGameStateIn {
@@ -126,7 +133,12 @@ struct PersistedGameStateIn {
     pub take_from_foundation: bool,
     #[serde(default = "schema_v1")]
     pub schema_version: u32,
+    /// v4/v5 only. Replayed against a seed-dealt board.
+    #[serde(default)]
     pub saved_moves: Vec<KlondikeInstruction>,
+    /// v6 only. Carries the dealt board explicitly.
+    #[serde(default)]
+    pub recording: Option<SessionRecording>,
 }
 
 #[cfg(feature = "test-support")]
@@ -222,7 +234,7 @@ impl Serialize for GameState {
             seed: self.seed,
             take_from_foundation: self.take_from_foundation,
             schema_version: GAME_STATE_SCHEMA_VERSION,
-            saved_moves: self.saved_moves(),
+            recording: self.recording(),
         }
         .serialize(serializer)
     }
@@ -232,34 +244,51 @@ impl<'de> Deserialize<'de> for GameState {
     fn deserialize<D: Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error> {
         let persisted = PersistedGameStateIn::deserialize(deserializer)?;
 
-        // Accept v4 (upstream named-variant serde) and v5 (current, derived
-        // stats). v3 (legacy u8-index format) and all others are rejected.
-        match persisted.schema_version {
-            4 | 5 => {}
+        // Accept v6 (current, recording-based), plus v4/v5 (legacy seed-dealt
+        // saves — loadable while the seed→deal mapping they were written
+        // under still holds; rewritten as v6 on the next save). v3 (legacy
+        // u8-index format) and all others are rejected.
+        let (mut game, instructions) = match persisted.schema_version {
+            6 => {
+                let Some(recording) = persisted.recording else {
+                    return Err(serde::de::Error::custom(
+                        "v6 save file is missing the session recording",
+                    ));
+                };
+                // The dealt board and session config come from the recording
+                // itself; `seed` is presentation metadata only.
+                Self::from_recording(&recording, persisted.seed, persisted.mode)
+            }
+            4 | 5 => (
+                Self {
+                    mode: persisted.mode,
+                    elapsed_seconds: 0,
+                    seed: persisted.seed,
+                    take_from_foundation: true,
+                    session: Self::new_session(persisted.seed, persisted.draw_mode),
+                    #[cfg(feature = "test-support")]
+                    test_pile_state: None,
+                },
+                persisted.saved_moves,
+            ),
             v => {
                 return Err(serde::de::Error::custom(format!(
                     "unsupported GameState schema version {v}"
                 )));
             }
-        }
-
-        let mut game = Self {
-            mode: persisted.mode,
-            elapsed_seconds: persisted.elapsed_seconds,
-            seed: persisted.seed,
-            take_from_foundation: persisted.take_from_foundation,
-            session: Self::new_session(persisted.seed, persisted.draw_mode),
-            #[cfg(feature = "test-support")]
-            test_pile_state: None,
         };
+        game.mode = persisted.mode;
+        game.elapsed_seconds = persisted.elapsed_seconds;
+        game.take_from_foundation = persisted.take_from_foundation;
 
-        // Replay the saved instruction history. The upstream session tracks
-        // score components and recycle_count as it processes each move, so the
-        // derived stats are correct once replay completes. `undo_count()` resets
-        // to 0 across save/load because undone moves are not part of the saved
-        // forward history.
+        // Replay the saved instruction history with validation — a tampered
+        // or corrupt file must surface an error, not a silently wrong board.
+        // The upstream session tracks score components and recycle_count as
+        // it processes each move, so the derived stats are correct once
+        // replay completes. `undo_count()` resets to 0 across save/load
+        // because undone moves are not part of the saved forward history.
         let replay_config = Self::replay_config(persisted.draw_mode);
-        for instruction in persisted.saved_moves {
+        for instruction in instructions {
             if !game
                 .session
                 .state()
@@ -524,16 +553,6 @@ impl GameState {
         KlondikeAdapter::config_for(self.draw_mode(), self.take_from_foundation)
     }
 
-    /// Collects the session instruction history as upstream types for schema v4
-    /// serialisation.
-    fn saved_moves(&self) -> Vec<KlondikeInstruction> {
-        self.session
-            .history()
-            .iter()
-            .map(|snapshot| *snapshot.instruction())
-            .collect()
-    }
-
     /// Returns the deterministic instruction history for the current deal as
     /// upstream [`KlondikeInstruction`] values.
     ///
@@ -1697,6 +1716,91 @@ mod tests {
         assert_eq!(replayed.move_count(), game.move_count());
     }
 
+    /// v6 save files carry the deal in the recording; the `seed` field is
+    /// presentation metadata. Corrupting it must not change the loaded board.
+    #[test]
+    fn v6_save_load_ignores_seed_for_dealing() {
+        let game = game_with_some_moves(51);
+        let mut value = serde_json::to_value(&game).expect("serialise");
+        assert_eq!(value["schema_version"], 6);
+        value["seed"] = serde_json::Value::from(0xDEAD_BEEF_u64);
+        let loaded: GameState =
+            serde_json::from_value(value).expect("v6 save with wrong seed must still load");
+        assert_eq!(loaded.stock_cards(), game.stock_cards());
+        assert_eq!(loaded.waste_cards(), game.waste_cards());
+        for index in 0..7 {
+            let t = GameState::tableau_from_index(index).expect("tableau index");
+            assert_eq!(
+                loaded.pile(KlondikePile::Tableau(t)),
+                game.pile(KlondikePile::Tableau(t)),
+                "tableau {index} differs"
+            );
+        }
+        assert_eq!(loaded.move_count(), game.move_count());
+        assert_eq!(loaded.score(), game.score());
+    }
+
+    /// Legacy v5 files (seed + saved_moves, no recording) must still load
+    /// through the seed-dealt path until players resave as v6.
+    #[test]
+    fn v5_legacy_save_still_loads() {
+        let game = game_with_some_moves(145);
+        let v5 = serde_json::json!({
+            "draw_mode": game.draw_mode(),
+            "mode": game.mode,
+            "elapsed_seconds": 12,
+            "seed": game.seed,
+            "take_from_foundation": true,
+            "schema_version": 5,
+            "saved_moves": game.instruction_history(),
+        });
+        let loaded: GameState =
+            serde_json::from_value(v5).expect("v5 save must load via the legacy seed path");
+        assert_eq!(loaded.move_count(), game.move_count());
+        assert_eq!(loaded.stock_cards(), game.stock_cards());
+        assert_eq!(loaded.elapsed_seconds, 12);
+    }
+
+    /// A v6 file without the recording payload is malformed and must be
+    /// rejected with an error rather than silently re-dealt from the seed.
+    #[test]
+    fn v6_save_without_recording_is_rejected() {
+        let game = GameState::new(7, DrawStockConfig::DrawOne);
+        let mut value = serde_json::to_value(&game).expect("serialise");
+        value.as_object_mut().expect("object").remove("recording");
+        let err = serde_json::from_value::<GameState>(value)
+            .expect_err("v6 save without recording must fail");
+        assert!(err.to_string().contains("recording"), "got: {err}");
+    }
+
+    /// A recording whose instruction list is invalid for its own deal must
+    /// be rejected on load — tampered or corrupt files surface an error,
+    /// never a silently wrong board.
+    #[test]
+    fn v6_save_with_invalid_history_is_rejected() {
+        use klondike::{DstFoundation, Foundation, KlondikePile};
+        // A foundation move from an empty tableau is never legal on a fresh
+        // deal's first instruction slot for this source shape.
+        let bogus = KlondikeInstruction::DstFoundation(DstFoundation {
+            src: KlondikePile::Foundation(Foundation::Foundation1),
+            foundation: Foundation::Foundation2,
+        });
+        let recording =
+            SessionRecording::from_instructions_unchecked(7, DrawStockConfig::DrawOne, [bogus]);
+        let v6 = serde_json::json!({
+            "draw_mode": DrawStockConfig::DrawOne,
+            "mode": GameMode::Classic,
+            "elapsed_seconds": 0,
+            "seed": 7,
+            "take_from_foundation": true,
+            "schema_version": 6,
+            "recording": recording,
+        });
+        let err =
+            serde_json::from_value::<GameState>(v6).expect_err("invalid history must be rejected");
+        assert!(err.to_string().contains("invalid"), "got: {err}");
+    }
+
     #[test]
     fn from_recording_of_fresh_deal_returns_empty_instructions() {
         let game = GameState::new(7, DrawStockConfig::DrawThree);

solitaire_data/src/storage.rs

@@ -477,7 +477,7 @@ mod tests {
     /// again must reproduce byte-identical JSON. `undo_count` deliberately resets
     /// to 0 on load because only the forward instruction history is persisted.
     #[test]
-    fn game_state_v5_mid_game_round_trip() {
+    fn game_state_v6_mid_game_round_trip() {
         use solitaire_core::KlondikeInstruction;
         use solitaire_core::game_state::GameState;
 
@@ -518,11 +518,16 @@ mod tests {
 
         save_game_state_to(&path, &gs).expect("save");
 
-        // Verify the file carries the v5 schema marker.
+        // Verify the file carries the v6 schema marker and the recording.
         let json = fs::read_to_string(&path).expect("read json");
+        let parsed: serde_json::Value = serde_json::from_str(&json).expect("parse saved json");
+        assert_eq!(
+            parsed["schema_version"], 6,
+            "saved file must use schema version 6",
+        );
         assert!(
-            json.contains("\"schema_version\"") && json.contains('5'),
-            "saved file must use schema version 5",
+            parsed["recording"].is_object(),
+            "saved file must embed the session recording",
         );
 
         let loaded =
@@ -530,7 +535,7 @@ mod tests {
 
         // The forward instruction history round-trips, so the reconstructed board
         // re-serialises to byte-identical JSON.
-        let path_reload = gs_path("v5_mid_game_reload");
+        let path_reload = gs_path("v6_mid_game_reload");
         let _ = fs::remove_file(&path_reload);
         save_game_state_to(&path_reload, &loaded).expect("re-save loaded");
         assert_eq!(