feat(web client): take & replay game snapshot

clients/web/src/game/session.rs

@@ -50,6 +50,44 @@ pub async fn run_local_bot_game(
         suppress_dice_anim: false,
     }));
 
+    run_local_bot_game_loop(screen, cmd_rx, pending, player_name, backend, vs).await
+}
+
+/// Runs a bot game from a pre-built backend and initial ViewState (used for snapshot replay).
+/// Returns `true` if the player wants to play again.
+pub async fn run_local_bot_game_with_backend(
+    screen: RwSignal<Screen>,
+    cmd_rx: &mut mpsc::UnboundedReceiver<NetCommand>,
+    pending: RwSignal<VecDeque<GameUiState>>,
+    player_name: String,
+    backend: TrictracBackend,
+) -> bool {
+    let mut vs = backend.get_view_state().clone();
+    patch_bot_names(&mut vs, &player_name);
+    screen.set(Screen::Playing(GameUiState {
+        view_state: vs.clone(),
+        player_id: 0,
+        room_id: String::new(),
+        is_bot_game: true,
+        waiting_for_confirm: false,
+        pause_reason: None,
+        my_scored_event: None,
+        opp_scored_event: None,
+        last_moves: None,
+        suppress_dice_anim: false,
+    }));
+
+    run_local_bot_game_loop(screen, cmd_rx, pending, player_name, backend, vs).await
+}
+
+async fn run_local_bot_game_loop(
+    screen: RwSignal<Screen>,
+    cmd_rx: &mut mpsc::UnboundedReceiver<NetCommand>,
+    pending: RwSignal<VecDeque<GameUiState>>,
+    player_name: String,
+    mut backend: TrictracBackend,
+    mut vs: ViewState,
+) -> bool {
     use futures::StreamExt;
     loop {
         match cmd_rx.next().await {

clients/web/src/game/trictrac/backend.rs

@@ -1,5 +1,5 @@
 use backbone_lib::traits::{BackEndArchitecture, BackendCommand};
-use trictrac_store::{Dice, DiceRoller, GameEvent, GameState, TurnStage};
+use trictrac_store::{Color, Dice, DiceRoller, GameEvent, GameState, Player, Stage, TurnStage};
 
 use super::types::{GameDelta, PlayerAction, PreGameRollState, SerStage, SerTurnStage, ViewState};
 
@@ -130,6 +130,65 @@ impl TrictracBackend {
     pub fn get_game(&self) -> &GameState {
         &self.game
     }
+
+    /// Build a backend pre-loaded with the given `ViewState` snapshot so a bot
+    /// game can resume from an arbitrary position (debug feature).
+    pub fn from_view_state(vs: ViewState, player_name: &str) -> Self {
+        let mut game = GameState::new(false);
+
+        game.board.set_positions(&Color::White, vs.board);
+
+        game.stage = match vs.stage {
+            SerStage::InGame => Stage::InGame,
+            SerStage::Ended => Stage::Ended,
+            _ => Stage::InGame,
+        };
+
+        game.turn_stage = match vs.turn_stage {
+            SerTurnStage::RollDice => TurnStage::RollDice,
+            SerTurnStage::RollWaiting => TurnStage::RollWaiting,
+            SerTurnStage::MarkPoints => TurnStage::MarkPoints,
+            SerTurnStage::HoldOrGoChoice => TurnStage::HoldOrGoChoice,
+            SerTurnStage::Move => TurnStage::Move,
+            SerTurnStage::MarkAdvPoints => TurnStage::MarkAdvPoints,
+        };
+
+        game.dice = Dice { values: vs.dice };
+
+        game.active_player_id = match vs.active_mp_player {
+            Some(0) => HOST_PLAYER_ID,
+            Some(1) => GUEST_PLAYER_ID,
+            _ => HOST_PLAYER_ID,
+        };
+
+        let build_player = |score: &crate::game::trictrac::types::PlayerScore,
+                             color: Color|
+         -> Player {
+            let mut p = Player::new(score.name.clone(), color);
+            p.points = score.points;
+            p.holes = score.holes;
+            p.can_bredouille = score.can_bredouille;
+            p
+        };
+
+        game.players.insert(HOST_PLAYER_ID, build_player(&vs.scores[0], Color::White));
+        game.players.insert(GUEST_PLAYER_ID, build_player(&vs.scores[1], Color::Black));
+
+        let mut view_state = ViewState::from_game_state(&game, HOST_PLAYER_ID, GUEST_PLAYER_ID);
+        view_state.scores[0].name = player_name.to_string();
+        view_state.scores[1].name = "Bot".to_string();
+
+        TrictracBackend {
+            game,
+            dice_roller: DiceRoller::default(),
+            commands: Vec::new(),
+            view_state,
+            arrived: [true, true],
+            pre_game_dice: [None; 2],
+            tie_count: 0,
+            ceremony_started: false,
+        }
+    }
 }
 
 impl BackEndArchitecture<PlayerAction, GameDelta, ViewState> for TrictracBackend {