feat(app): persist rewind branches and enable LAPP

src-tauri/src/lib.rs

@@ -1,18 +1,21 @@
-use std::{fs, path::Path};
+use std::{fs, path::Path, sync::Mutex};
 
 use nana_domain::{
-    ActionSuggestion, AppInfo, BeatKind, DOMAIN_SCHEMA_VERSION, DemoPackSummary, HistoryNodeView,
-    PlayerView, PresentationBeat, PresentationCharacter, PresentationScene, PresentationSnapshot,
-    Promise, PromiseStatus, PromiseWeight, RelationshipAdjustment, RelationshipDimension,
-    ResourceBundle, RuntimeState, StateDelta, StateOp, StoryNode, TurnFailure, TurnFailureCode,
-    TurnIntent, TurnRequest, TurnResult, ValidationIssue, VisualDirective, stable_json_hash,
-    validate_bundle,
+    ActionSuggestion, AppInfo, BeatKind, DOMAIN_SCHEMA_VERSION, DemoPackSummary, ForkBranchRequest,
+    ForkBranchResult, HistoryNodeView, PlayerView, PresentationBeat, PresentationCharacter,
+    PresentationScene, PresentationSnapshot, Promise, PromiseStatus, PromiseWeight,
+    RelationshipAdjustment, RelationshipDimension, ResourceBundle, RuntimeState, StateDelta,
+    StateOp, StoryNode, TurnFailure, TurnFailureCode, TurnIntent, TurnRequest, TurnResult,
+    ValidationIssue, VisualDirective, stable_json_hash, validate_bundle,
 };
 use nana_engine::{
     SceneMetadata, StoryNodePlayerViewProjectionContext, project_story_node_player_view,
 };
-use nana_runtime::{ProviderError, TurnEngine, TurnPlan, TurnPlanProvider, TurnProjector};
-use nana_store::{SqliteStoryStore, StoreError, StoryStore};
+use nana_runtime::{
+    AdjudicatingTurnPlanProvider, AdjudicationCatalog, LappAdjudicationModel, OpenLappChatExecutor,
+    ProviderError, TurnEngine, TurnPlan, TurnPlanProvider, TurnProjector,
+};
+use nana_store::{ForkError, SqliteStoryStore, StoreError, StoryStore};
 use serde::Serialize;
 use tauri::Manager;
 
@@ -60,11 +63,97 @@ impl CommandError {
             issues: Vec::new(),
         }
     }
+
+    fn invalid_input(message: impl Into<String>) -> Self {
+        Self {
+            code: "invalid_input".to_owned(),
+            message: message.into(),
+            retryable: false,
+            issues: Vec::new(),
+        }
+    }
+
+    fn stale_branch() -> Self {
+        Self {
+            code: "stale_node".to_owned(),
+            message: "story branch changed; refresh and retry".to_owned(),
+            retryable: true,
+            issues: Vec::new(),
+        }
+    }
+
+    fn operation_lock() -> Self {
+        Self {
+            code: "storage_unavailable".to_owned(),
+            message: "故事存档暂时不可用。".to_owned(),
+            retryable: true,
+            issues: Vec::new(),
+        }
+    }
+
+    fn fork(error: &ForkError) -> Self {
+        match error {
+            ForkError::BranchAlreadyExists { .. } => Self::stale_branch(),
+            ForkError::Store(StoreError::ParentNotFound(_)) => {
+                Self::invalid_input("selected story node is unavailable")
+            }
+            ForkError::InvalidBranchId(_) => Self {
+                code: "internal".to_owned(),
+                message: "new story branch could not be prepared".to_owned(),
+                retryable: true,
+                issues: Vec::new(),
+            },
+            ForkError::Store(error) => Self::storage(error),
+        }
+    }
 }
 
 struct DemoAppState {
     store: SqliteStoryStore,
     bundle: ResourceBundle,
+    operation_lock: Mutex<()>,
+    provider: Mutex<RuntimePlanProvider>,
+}
+
+type LappRuntimeProvider =
+    AdjudicatingTurnPlanProvider<LappAdjudicationModel<OpenLappChatExecutor>>;
+
+enum RuntimePlanProvider {
+    Demo(DemoPlanProvider),
+    Lapp(Box<LappRuntimeProvider>),
+    Unavailable,
+}
+
+impl RuntimePlanProvider {
+    fn configured(bundle: &ResourceBundle) -> Self {
+        if std::env::var("NANA_STORY_PROVIDER")
+            .is_ok_and(|provider| provider.eq_ignore_ascii_case("demo"))
+        {
+            return Self::Demo(DemoPlanProvider);
+        }
+
+        let Ok(catalog) = AdjudicationCatalog::from_bundle(bundle) else {
+            return Self::Unavailable;
+        };
+        let Ok(model) = LappAdjudicationModel::from_default_profile(bundle.clone()) else {
+            return Self::Unavailable;
+        };
+        Self::Lapp(Box::new(AdjudicatingTurnPlanProvider::new(model, catalog)))
+    }
+}
+
+impl TurnPlanProvider for RuntimePlanProvider {
+    fn plan_turn(
+        &mut self,
+        request: &TurnRequest,
+        state: &RuntimeState,
+    ) -> Result<TurnPlan, ProviderError> {
+        match self {
+            Self::Demo(provider) => provider.plan_turn(request, state),
+            Self::Lapp(provider) => provider.plan_turn(request, state),
+            Self::Unavailable => Err(ProviderError::Configuration { code: None }),
+        }
+    }
 }
 
 impl DemoAppState {
@@ -103,7 +192,18 @@ impl DemoAppState {
             Err(error) => return Err(CommandError::storage(&error)),
         }
 
-        Ok(Self { store, bundle })
+        let provider = if cfg!(test) {
+            RuntimePlanProvider::Demo(DemoPlanProvider)
+        } else {
+            RuntimePlanProvider::configured(&bundle)
+        };
+
+        Ok(Self {
+            store,
+            bundle,
+            operation_lock: Mutex::new(()),
+            provider: Mutex::new(provider),
+        })
     }
 
     fn pack_summary(&self) -> DemoPackSummary {
@@ -135,12 +235,70 @@ impl DemoAppState {
     }
 
     fn submit_turn(&self, request: &TurnRequest) -> Result<TurnResult, CommandError> {
-        let provider = DemoPlanProvider;
+        let _operation = self
+            .operation_lock
+            .lock()
+            .map_err(|_| CommandError::operation_lock())?;
+        let mut provider = self
+            .provider
+            .lock()
+            .map_err(|_| CommandError::operation_lock())?;
         let projector = DemoProjector { app: self };
-        let mut engine = TurnEngine::new(&self.store, provider, projector);
+        let mut engine = TurnEngine::new(&self.store, &mut *provider, projector);
         engine.submit_turn(request).map_err(CommandError::turn)
     }
 
+    fn fork_branch(&self, request: &ForkBranchRequest) -> Result<ForkBranchResult, CommandError> {
+        validate_fork_request(request)?;
+        let _operation = self
+            .operation_lock
+            .lock()
+            .map_err(|_| CommandError::operation_lock())?;
+
+        let current = self
+            .store
+            .load_state(&request.story_id, &request.current_branch_id)
+            .map_err(|error| CommandError::storage(&error))?;
+        if current.current_node != request.expected_current_node_id {
+            return Err(CommandError::stale_branch());
+        }
+
+        let current_node = self
+            .store
+            .load_node(&request.story_id, &current.current_node)
+            .map_err(|error| CommandError::storage(&error))?;
+        let current_lineage = self
+            .load_lineage(&current_node)
+            .map_err(|error| CommandError::storage(&error))?;
+        if !current_lineage
+            .iter()
+            .any(|node| node.id == request.source_node_id)
+        {
+            return Err(CommandError::invalid_input(
+                "selected story node is not on the current route",
+            ));
+        }
+
+        let branch_id = branch_id_for_fork(request);
+        let state = self
+            .store
+            .fork_branch(&request.story_id, &request.source_node_id, &branch_id)
+            .map_err(|error| CommandError::fork(&error))?;
+        let source = self
+            .store
+            .load_node(&request.story_id, &request.source_node_id)
+            .map_err(|error| CommandError::storage(&error))?;
+        let lineage = self
+            .load_lineage(&source)
+            .map_err(|error| CommandError::storage(&error))?;
+        let player_view = self.project_view_with_lineage(&state, &source, &lineage);
+
+        Ok(ForkBranchResult {
+            branch_id,
+            player_view,
+        })
+    }
+
     fn project_view(&self, state: &RuntimeState, node: &StoryNode) -> PlayerView {
         let lineage = self
             .load_lineage(node)
@@ -464,6 +622,37 @@ fn node_id_for_action(request: &TurnRequest) -> String {
     )
 }
 
+fn branch_id_for_fork(request: &ForkBranchRequest) -> String {
+    let identity = format!(
+        "{}\0{}\0{}\0{}",
+        request.story_id, request.current_branch_id, request.source_node_id, request.action_id
+    );
+    format!(
+        "branch_{}",
+        stable_json_hash(identity.as_bytes()).trim_start_matches("sha256:")
+    )
+}
+
+fn validate_fork_request(request: &ForkBranchRequest) -> Result<(), CommandError> {
+    for (field, value) in [
+        ("story_id", request.story_id.as_str()),
+        ("current_branch_id", request.current_branch_id.as_str()),
+        (
+            "expected_current_node_id",
+            request.expected_current_node_id.as_str(),
+        ),
+        ("source_node_id", request.source_node_id.as_str()),
+        ("action_id", request.action_id.as_str()),
+    ] {
+        if value.trim().is_empty() {
+            return Err(CommandError::invalid_input(format!(
+                "{field} must not be empty"
+            )));
+        }
+    }
+    Ok(())
+}
+
 fn is_return_promise(input: &str) -> bool {
     input.contains("天亮前") && input.contains("回来")
 }
@@ -571,6 +760,15 @@ fn submit_turn(
     state.submit_turn(&request)
 }
 
+#[tauri::command]
+#[allow(clippy::needless_pass_by_value)] // Tauri deserializes command arguments into owned values.
+fn fork_branch(
+    state: tauri::State<'_, DemoAppState>,
+    request: ForkBranchRequest,
+) -> Result<ForkBranchResult, CommandError> {
+    state.fork_branch(&request)
+}
+
 /// Starts the desktop application and opens its local story database.
 ///
 /// # Panics
@@ -591,7 +789,8 @@ pub fn run() {
             get_app_info,
             get_demo_pack_summary,
             get_demo_player_view,
-            submit_turn
+            submit_turn,
+            fork_branch
         ])
         .run(tauri::generate_context!())
         .expect("failed to run nana-story");
@@ -606,9 +805,9 @@ mod tests {
     };
 
     use nana_domain::{
-        PresentationSnapshot, Promise, PromiseStatus, PromiseWeight, RelationshipAdjustment,
-        RelationshipBand, RelationshipDimension, StateDelta, StateOp, StoryNode, TurnIntent,
-        TurnRequest,
+        ForkBranchRequest, PresentationSnapshot, Promise, PromiseStatus, PromiseWeight,
+        RelationshipAdjustment, RelationshipBand, RelationshipDimension, StateDelta, StateOp,
+        StoryNode, TurnIntent, TurnRequest,
     };
     use nana_store::StoryStore;
 
@@ -658,6 +857,16 @@ mod tests {
         }
     }
 
+    fn fork_request(expected_current_node_id: &str, source_node_id: &str) -> ForkBranchRequest {
+        ForkBranchRequest {
+            story_id: DEMO_STORY_ID.to_owned(),
+            current_branch_id: DEMO_BRANCH_ID.to_owned(),
+            expected_current_node_id: expected_current_node_id.to_owned(),
+            source_node_id: source_node_id.to_owned(),
+            action_id: "action_fork_test".to_owned(),
+        }
+    }
+
     fn node(id: &str, parent_id: Option<&str>, ops: Vec<StateOp>) -> StoryNode {
         StoryNode {
             id: id.to_owned(),
@@ -741,6 +950,95 @@ mod tests {
         assert_eq!(restored.character_pose, committed.character_pose);
     }
 
+    #[test]
+    fn rewind_forks_from_visible_history_without_moving_the_main_branch() {
+        let app = DemoAppState::open_in_memory().expect("valid demo");
+        let main = app
+            .submit_turn(&promise_request("node_001"))
+            .expect("committed main turn");
+
+        let forked = app
+            .fork_branch(&fork_request(&main.committed_node_id, "node_001"))
+            .expect("fork from root");
+
+        assert_ne!(forked.branch_id, DEMO_BRANCH_ID);
+        assert_eq!(forked.player_view.branch_id, forked.branch_id);
+        assert_eq!(forked.player_view.node_id, "node_001");
+        assert_eq!(forked.player_view.history.len(), 1);
+        assert!(forked.player_view.promises.is_empty());
+
+        let main_state = app
+            .store
+            .load_state(DEMO_STORY_ID, DEMO_BRANCH_ID)
+            .expect("main branch remains readable");
+        assert_eq!(main_state.current_node, main.committed_node_id);
+        assert_eq!(main_state.promises.len(), 1);
+
+        let fork_turn = app
+            .submit_turn(&TurnRequest {
+                story_id: DEMO_STORY_ID.to_owned(),
+                branch_id: forked.branch_id.clone(),
+                expected_node_id: "node_001".to_owned(),
+                action_id: "action_fork_continues".to_owned(),
+                intent: TurnIntent::SpeakOrAct,
+                input: "我先看看站台另一侧。".to_owned(),
+            })
+            .expect("fork advances independently");
+        assert_eq!(fork_turn.player_view.branch_id, forked.branch_id);
+        assert_eq!(
+            app.store
+                .load_state(DEMO_STORY_ID, DEMO_BRANCH_ID)
+                .expect("main head")
+                .current_node,
+            main.committed_node_id
+        );
+    }
+
+    #[test]
+    fn reopen_then_rewind_and_advance_preserves_both_branches() {
+        let database = TemporaryDatabase::new();
+        let main_node = {
+            let app = DemoAppState::open(database.path()).expect("new file demo");
+            app.submit_turn(&promise_request("node_001"))
+                .expect("committed main turn")
+                .committed_node_id
+        };
+
+        let (fork_branch, fork_node) = {
+            let app = DemoAppState::open(database.path()).expect("reopened before rewind");
+            let forked = app
+                .fork_branch(&fork_request(&main_node, "node_001"))
+                .expect("durable fork");
+            let turn = app
+                .submit_turn(&TurnRequest {
+                    story_id: DEMO_STORY_ID.to_owned(),
+                    branch_id: forked.branch_id.clone(),
+                    expected_node_id: "node_001".to_owned(),
+                    action_id: "action_after_reopen_fork".to_owned(),
+                    intent: TurnIntent::Continue,
+                    input: String::new(),
+                })
+                .expect("advance fork");
+            (forked.branch_id, turn.committed_node_id)
+        };
+
+        let reopened = DemoAppState::open(database.path()).expect("reopened after fork");
+        let main = reopened
+            .store
+            .load_state(DEMO_STORY_ID, DEMO_BRANCH_ID)
+            .expect("main branch");
+        let fork = reopened
+            .store
+            .load_state(DEMO_STORY_ID, &fork_branch)
+            .expect("fork branch");
+
+        assert_eq!(main.current_node, main_node);
+        assert_eq!(main.promises.len(), 1);
+        assert_eq!(fork.current_node, fork_node);
+        assert_eq!(fork.current_branch, fork_branch);
+        assert!(fork.promises.is_empty());
+    }
+
     #[test]
     fn player_view_does_not_serialize_hidden_item_facts_or_checks() {
         let app = DemoAppState::open_in_memory().expect("valid demo");