From ecb90280e81600a5376daeafbeeb9533a88e9237 Mon Sep 17 00:00:00 2001
From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Sun, 1 May 2022 12:19:35 +0100
Subject: [PATCH] delete_piece: Break out into global.rs

fastsplit deletion is going to want this.  This may not be in its
final form, particularly because of ToRecalculate, which fastsplit
doesn't have one of yet.

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---
 daemon/cmdlistener.rs | 54 ++++++++++++-------------------------------
 src/global.rs         | 49 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 64 insertions(+), 39 deletions(-)

diff --git a/daemon/cmdlistener.rs b/daemon/cmdlistener.rs
index 6745b260..a3c1a550 100644
--- a/daemon/cmdlistener.rs
+++ b/daemon/cmdlistener.rs
@@ -1012,45 +1012,21 @@ fn execute_game_insn<'cs, 'igr, 'ig: 'igr>(
     },
 
     MGI::DeletePiece(piece) => {
-      let (ig_g, modperm, _) = cs.check_acl_modify_pieces(ag, ig)?;
-      let ig = &mut **ig_g;
+      let (ig, modperm, _) = cs.check_acl_modify_pieces(ag, ig)?;
       let _ipc = ig.ipieces.as_mut(modperm)
         .get(piece).ok_or(ME::PieceNotFound)?;
-      let gs = &mut ig.gs;
-      let gpc = gs.pieces.as_mut(modperm).get_mut(piece);
-      let mut xupdates = vec![];
-      if let Some(gpc) = gpc {
-        gpc.occult.passive_delete_hook(&mut gs.occults, piece);
-        if gpc.occult.is_active() {
-          xupdates.append(
-            &mut
-              remove_occultation(
-                &mut gs.gen.unique_gen(),
-                &mut gs.players,
-                &mut gs.pieces,
-                &mut gs.occults,
-                &ig.ipieces,
-                &ig.ioccults,
-                to_permute,
-                piece)?
-          );
-        }
-      }
-      let ioccults = &ig.ioccults;
-      let gpc = gs.pieces.as_mut(modperm).remove(piece);
-      let ipc = ig.ipieces.as_mut(modperm).remove(piece).unwrap();
-      let desc_html = if let Some(gpc) = &gpc {
-        let pri = PieceRenderInstructions::new_visible(default());
-        pri.describe(ioccults,&gs.occults, gpc, &ipc)
-      } else {
-        "<piece partially missing from game state>".to_html()
-      };
-      if let Some(gpc) = gpc {
-        ipc.p.into_inner().delete_hook(&gpc, gs);
-      }
-      if let Some(occilk) = ipc.occilk {
-        ig.ioccults.ilks.dispose_iilk(occilk);
-      }
+
+      let (desc_html, xupdates) =
+        ig.delete_piece(modperm, to_permute, piece,
+                        |ioccults, goccults, ipc, gpc| {
+          if let (Some(ipc), Some(gpc)) = (ipc, gpc) {
+            let pri = PieceRenderInstructions::new_visible(default());
+            pri.describe(ioccults,goccults, gpc, &ipc)
+          } else {
+            "<piece partially missing from game state>".to_html()
+          }
+        })?;
+
       (U{ pcs: vec![(piece, PieceUpdateOp::Delete())],
           log: vec![ LogEntry {
             html: hformat!("A piece {} was removed from the game",
@@ -1058,9 +1034,9 @@ fn execute_game_insn<'cs, 'igr, 'ig: 'igr>(
           }],
           raw: None },
        Fine,
-       xupdates.into_unprepared(None),
+       xupdates,
        vec![],
-       ig_g)
+       ig)
     },
 
     MGI::AddPieces(PiecesSpec{ pos,posd,count,face,pinned,angle,info }) => {
diff --git a/src/global.rs b/src/global.rs
index 11da90ed..02ec3169 100644
--- a/src/global.rs
+++ b/src/global.rs
@@ -641,6 +641,55 @@ impl<Id> InstanceAccessDetails<Id>
 }
 
 impl<'ig> InstanceGuard<'ig> {
+  /// Idempotent.
+  #[throws(IE)]
+  pub fn delete_piece<H,T>(&mut self, modperm: ModifyingPieces,
+                             to_permute: &mut ToRecalculate,
+                             piece: PieceId, hook: H)
+                             -> (T, UnpreparedUpdates)
+  where H: FnOnce(&IOccults, &GOccults,
+                  Option<&IPiece>, Option<&GPiece>) -> T
+  {
+    let ig = &mut **self;
+    let gs = &mut ig.gs;
+    let gpc = gs.pieces.as_mut(modperm).get_mut(piece);
+    let mut xupdates = vec![];
+    if let Some(gpc) = gpc {
+      gpc.occult.passive_delete_hook(&mut gs.occults, piece);
+      if gpc.occult.is_active() {
+        xupdates.append(
+          &mut
+            remove_occultation(
+              &mut gs.gen.unique_gen(),
+              &mut gs.players,
+              &mut gs.pieces,
+              &mut gs.occults,
+              &ig.ipieces,
+              &ig.ioccults,
+              to_permute,
+              piece)?
+        );
+      }
+    }
+    let ioccults = &ig.ioccults;
+    let gpc = gs.pieces.as_mut(modperm).remove(piece);
+    let ipc = ig.ipieces.as_mut(modperm).remove(piece);
+
+    let hook_r = hook(ioccults, &gs.occults,
+                      ipc.as_ref(), gpc.as_ref());
+
+    if let Some(ipc) = ipc {
+      if let Some(gpc) = gpc {
+        ipc.p.into_inner().delete_hook(&gpc, gs);
+      }
+      if let Some(occilk) = ipc.occilk {
+        ig.ioccults.ilks.dispose_iilk(occilk);
+      }
+    }
+
+    (hook_r, xupdates.into_unprepared(None))
+  }
+
   /// caller is responsible for logging; threading it through
   /// proves the caller has a log entry.
   #[throws(MgmtError)]
-- 
2.30.2