feat(script): bind callbacks to runtime varsets

2 files changed, 151 insertions, 16 deletions

diff --git a/crates/fparkan-runtime/src/lib.rs b/crates/fparkan-runtime/src/lib.rs
index 771a1d4..cc58185 100644
--- a/crates/fparkan-runtime/src/lib.rs
+++ b/crates/fparkan-runtime/src/lib.rs
@@ -35,8 +35,8 @@ use fparkan_prototype::{
 };
 use fparkan_resource::{resource_name, CachedResourceRepository, ResourceRepository};
 use fparkan_script::{
-    Handler19DwordWrite, Handler19InitInput, ScriptDispatchSelector, ScriptPackage, VarSet,
-    VarSetDefault,
+    Handler19DwordWrite, Handler19InitInput, ScriptDispatchSelector, ScriptInstruction,
+    ScriptPackage, VarSet, VarSetDefault, VmHostCallbackCommand,
 };
 use fparkan_terrain::SurfaceQuery;
 use fparkan_vfs::{Vfs, VfsError};
@@ -487,6 +487,13 @@ pub enum EngineError {
         /// Proven-contract diagnostic.
         message: String,
     },
+    /// A recovered script handler could not resolve against runtime state.
+    ScriptRuntime {
+        /// Owning TMA clan index.
+        clan_index: usize,
+        /// Handler-specific diagnostic.
+        message: String,
+    },
     /// `NRes` decode error.
     Nres {
         /// Resource path.
@@ -627,6 +634,10 @@ impl std::fmt::Display for EngineError {
                 clan_index,
                 message,
             } => write!(f, "clan {clan_index}: script Init failed: {message}"),
+            Self::ScriptRuntime {
+                clan_index,
+                message,
+            } => write!(f, "clan {clan_index}: script runtime failed: {message}"),
             Self::Nres { path, source } => write!(f, "{path}: {source}"),
             Self::Mission { path, source } => write!(f, "{path}: {source}"),
             Self::TerrainFormat { path, source } => write!(f, "{path}: {source}"),
@@ -670,6 +681,7 @@ impl std::error::Error for EngineError {
             | Self::Script { .. }
             | Self::VarSet { .. }
             | Self::ScriptInit { .. }
+            | Self::ScriptRuntime { .. }
             | Self::Movement(_)
             | Self::PrototypeGraph { .. }
             | Self::SchedulerPhaseOrder { .. }
@@ -1253,6 +1265,61 @@ pub fn loaded_mission_script_varset_states(engine: &Engine) -> Option<&[MissionS
         .map(|state| state.script_varset_states.as_slice())
 }
 
+/// Resolves the proven opaque callback command for one `Handler(30)` record.
+///
+/// Unlike the loader-only resolver, operands are read from the selected
+/// clan's instantiated varset cells. Dispatching the returned host callback
+/// remains outside this function because its game-side consumer is not yet
+/// recovered.
+///
+/// # Errors
+///
+/// Returns an explicit error when no mission, declaration table, or clan state
+/// is available, or if the instruction violates the proven handler contract.
+pub fn resolve_loaded_handler30(
+    engine: &Engine,
+    clan_index: usize,
+    instruction: &ScriptInstruction,
+) -> Result<VmHostCallbackCommand, EngineError> {
+    let state = engine
+        .loaded
+        .as_ref()
+        .ok_or_else(|| EngineError::ScriptRuntime {
+            clan_index,
+            message: "mission script state is unavailable".to_string(),
+        })?;
+    let declarations = state
+        .script_varset
+        .as_ref()
+        .ok_or_else(|| EngineError::ScriptRuntime {
+            clan_index,
+            message: "mission varset declarations are unavailable".to_string(),
+        })?;
+    let values = state
+        .script_varset_states
+        .iter()
+        .find(|varset| varset.clan_index == clan_index)
+        .ok_or_else(|| EngineError::ScriptRuntime {
+            clan_index,
+            message: "instantiated mission varset is unavailable".to_string(),
+        })?;
+    resolve_handler30_from_varset_state(declarations, values, instruction)
+}
+
+fn resolve_handler30_from_varset_state(
+    declarations: &MissionScriptVarSet,
+    values: &MissionScriptVarSetState,
+    instruction: &ScriptInstruction,
+) -> Result<VmHostCallbackCommand, EngineError> {
+    declarations
+        .declarations
+        .resolve_handler30_with_values(instruction, &values.values)
+        .map_err(|source| EngineError::ScriptRuntime {
+            clan_index: values.clan_index,
+            message: source.to_string(),
+        })
+}
+
 /// Returns terrain runtime data for the loaded mission.
 #[must_use]
 pub fn loaded_terrain(engine: &Engine) -> Option<&TerrainWorld> {
@@ -1766,6 +1833,23 @@ mod tests {
                 ],
             }]
         );
+        let callback = resolve_handler30_from_varset_state(
+            &varset,
+            &runtime_varsets[0],
+            &ScriptInstruction {
+                header_words: [30, 0, 0, 0, 0, 2, 0],
+                references: vec![0, 2],
+            },
+        )
+        .expect("runtime Handler(30) callback");
+        assert_eq!(
+            callback,
+            VmHostCallbackCommand {
+                mode: 0,
+                first: 728,
+                second: 1,
+            }
+        );
     }
 
     #[test]
diff --git a/crates/fparkan-script/src/lib.rs b/crates/fparkan-script/src/lib.rs
index 9acbcb7..6887a03 100644
--- a/crates/fparkan-script/src/lib.rs
+++ b/crates/fparkan-script/src/lib.rs
@@ -378,8 +378,32 @@ impl VarSet {
         &self,
         instruction: &ScriptInstruction,
     ) -> Result<VmHostCallbackCommand, Handler30ResolveError> {
-        let first = self.resolve_handler30_operand(instruction, 0)?;
-        let second = self.resolve_handler30_operand(instruction, 1)?;
+        let values: Vec<_> = self
+            .declarations
+            .iter()
+            .map(|declaration| declaration.default_value)
+            .collect();
+        self.resolve_handler30_with_values(instruction, &values)
+    }
+
+    /// Resolves `Handler(30)` against instantiated runtime varset values.
+    ///
+    /// The declaration table still establishes the original numeric kind; the
+    /// supplied cells carry state after prior recovered handlers have written
+    /// it. This is the execution-time counterpart of [`Self::resolve_handler30`].
+    ///
+    /// # Errors
+    ///
+    /// Returns the same bounded errors as [`Self::resolve_handler30`] when an
+    /// instruction, declaration, or runtime cell cannot satisfy the proven
+    /// DWORD operand contract.
+    pub fn resolve_handler30_with_values(
+        &self,
+        instruction: &ScriptInstruction,
+        values: &[VarSetDefault],
+    ) -> Result<VmHostCallbackCommand, Handler30ResolveError> {
+        let first = self.resolve_handler30_operand_with_values(instruction, values, 0)?;
+        let second = self.resolve_handler30_operand_with_values(instruction, values, 1)?;
         Ok(VmHostCallbackCommand {
             mode: 0,
             first,
@@ -387,28 +411,34 @@ impl VarSet {
         })
     }
 
-    fn resolve_handler30_operand(
+    fn resolve_handler30_operand_with_values(
         &self,
         instruction: &ScriptInstruction,
+        values: &[VarSetDefault],
         position: usize,
     ) -> Result<u32, Handler30ResolveError> {
         let index = *instruction
             .references
             .get(position)
             .ok_or(Handler30ResolveError::MissingReference { position })?;
-        match self.declarations.get(index as usize) {
-            Some(VarSetDeclaration {
-                default_value: VarSetDefault::Dword(value),
-                ..
-            }) => Ok(*value),
-            Some(VarSetDeclaration {
-                default_value: VarSetDefault::FloatBits(_),
-                ..
-            }) => Err(Handler30ResolveError::FloatRequiresX87 { index }),
-            None => Err(Handler30ResolveError::VarSetIndexOutOfBounds {
+        let declaration = self.declarations.get(index as usize).ok_or(
+            Handler30ResolveError::VarSetIndexOutOfBounds {
                 index,
                 declarations: self.declarations.len(),
-            }),
+            },
+        )?;
+        let value =
+            values
+                .get(index as usize)
+                .ok_or(Handler30ResolveError::VarSetIndexOutOfBounds {
+                    index,
+                    declarations: values.len(),
+                })?;
+        match (declaration.type_name, value) {
+            (VarSetType::Dword, VarSetDefault::Dword(value)) => Ok(*value),
+            (VarSetType::Float, _) | (_, VarSetDefault::FloatBits(_)) => {
+                Err(Handler30ResolveError::FloatRequiresX87 { index })
+            }
         }
     }
 
@@ -1324,6 +1354,27 @@ STRING( 8, ignored, ignored, ignored)\r\n";
     }
 
     #[test]
+    fn handler_thirty_reads_instantiated_dword_cells_instead_of_defaults() {
+        let varset =
+            parse_varset(b"VAR( DWORD, first, 0x12)\nVAR( DWORD, second, 9)\n").expect("varset");
+        let instruction = ScriptInstruction {
+            header_words: [30, 0, 0, 0, 0, 2, 0],
+            references: vec![0, 1],
+        };
+        assert_eq!(
+            varset.resolve_handler30_with_values(
+                &instruction,
+                &[VarSetDefault::Dword(728), VarSetDefault::Dword(449)],
+            ),
+            Ok(VmHostCallbackCommand {
+                mode: 0,
+                first: 728,
+                second: 449,
+            })
+        );
+    }
+
+    #[test]
     fn handler_thirty_keeps_float_and_malformed_references_explicit() {
         let varset = parse_varset(b"VAR( float, f0, 0.5)\n").expect("varset");
         let float_operand = ScriptInstruction {