From 6dc1d5d7983860de92815b85f499386996330afb Mon Sep 17 00:00:00 2001
From: pjht <terppa05@gmail.com>
Date: Sat, 18 Mar 2023 17:40:19 -0500
Subject: [PATCH] Add support for interconnects between cards

---
 src/backplane.rs | 79 +++++++++++++++++++++++++++++++++++++++++++++++-
 src/card.rs      | 19 +++++++++++-
 src/main.rs      | 11 ++++++-
 3 files changed, 106 insertions(+), 3 deletions(-)

diff --git a/src/backplane.rs b/src/backplane.rs
index 1853e0d..e1fac5a 100644
--- a/src/backplane.rs
+++ b/src/backplane.rs
@@ -1,16 +1,67 @@
+use std::any::{self, TypeId};
 use std::cell::{Cell, RefCell, RefMut};
 use std::fmt::{Debug, Display};
+use std::marker::PhantomData;
 use std::rc::Rc;
 
 use anyhow::anyhow;
 use itertools::Itertools;
 use nullable_result::{GeneralIterExt, NullableResult};
 
+use crate::InterconnectConfig;
 use crate::{
     card::{self, Card},
     m68k::BusError,
 };
 
+#[allow(dead_code)]
+pub struct InterconnectSenderBuilder {
+    interconnect_no: usize,
+    card: Rc<RefCell<dyn Card>>,
+    card_no: usize, // used for error message on wrong type passed to build function
+}
+
+impl InterconnectSenderBuilder {
+    #[allow(dead_code)]
+    pub fn build<T>(self) -> InterconnectSender<T> {
+        assert!(
+            self.card
+                .borrow_mut()
+                .get_interconnect_typeid(self.interconnect_no)
+                .unwrap_or_else(|| panic!(
+                    "Card {} interconnect {} does not exist",
+                    self.card_no, self.interconnect_no
+                ))
+                == TypeId::of::<T>(),
+            "Interconnect sender for card {} interconnect {} built with wrong type {}",
+            self.card_no,
+            self.interconnect_no,
+            any::type_name::<T>()
+        );
+        InterconnectSender {
+            interconnect_no: self.interconnect_no,
+            card: self.card,
+            phantom: PhantomData,
+        }
+    }
+}
+
+#[allow(dead_code)]
+pub struct InterconnectSender<T: 'static> {
+    interconnect_no: usize,
+    card: Rc<RefCell<dyn Card>>,
+    phantom: PhantomData<T>,
+}
+
+impl<T> InterconnectSender<T> {
+    #[allow(dead_code)]
+    pub fn send(&mut self, message: T) {
+        self.card
+            .borrow_mut()
+            .handle_interconnect_message(self.interconnect_no, Box::new(message));
+    }
+}
+
 #[derive(Debug)]
 pub struct Backplane {
     cards: Vec<Rc<RefCell<dyn Card>>>,
@@ -33,7 +84,10 @@ impl Display for Backplane {
 }
 
 impl Backplane {
-    pub fn new(card_configs: Vec<card::Config<'_>>) -> anyhow::Result<Self> {
+    pub fn new(
+        card_configs: Vec<card::Config<'_>>,
+        interconnects: Vec<InterconnectConfig>,
+    ) -> anyhow::Result<Self> {
         if card_configs.len() > 255 {
             return Err(anyhow!("A maximum of 255 cards are allowed"));
         }
@@ -49,6 +103,29 @@ impl Backplane {
             .at_most_one()
             .expect("Can't have two MMU cards!");
 
+        for interconnect in interconnects {
+            cards[interconnect.a_index]
+                .borrow_mut()
+                .set_interconnect_sender(
+                    interconnect.a_interconnect_no,
+                    InterconnectSenderBuilder {
+                        interconnect_no: interconnect.b_interconnect_no,
+                        card: Rc::clone(&cards[interconnect.b_index]),
+                        card_no: interconnect.b_index,
+                    },
+                );
+            cards[interconnect.b_index]
+                .borrow_mut()
+                .set_interconnect_sender(
+                    interconnect.b_interconnect_no,
+                    InterconnectSenderBuilder {
+                        interconnect_no: interconnect.a_interconnect_no,
+                        card: Rc::clone(&cards[interconnect.a_index]),
+                        card_no: interconnect.a_index,
+                    },
+                )
+        }
+
         Ok(Self {
             cards,
             mmu,
diff --git a/src/card.rs b/src/card.rs
index e396e67..39a1be7 100644
--- a/src/card.rs
+++ b/src/card.rs
@@ -1,11 +1,15 @@
 #![allow(clippy::transmute_ptr_to_ref)]
 
-use crate::{backplane::Backplane, m68k::BusError};
+use crate::{
+    backplane::{Backplane, InterconnectSenderBuilder},
+    m68k::BusError,
+};
 use anyhow::anyhow;
 use mopa::mopafy;
 use nullable_result::NullableResult;
 use serde::Deserialize;
 use std::{
+    any::{Any, TypeId},
     cell::RefCell,
     fmt::{Debug, Display},
     rc::Rc,
@@ -119,6 +123,19 @@ pub trait Card: Debug + Display + mopa::Any {
     fn try_as_mmu(&mut self) -> Option<&mut dyn MMU> {
         None
     }
+
+    fn set_interconnect_sender(
+        &mut self,
+        _interconnect_no: usize,
+        _sender: InterconnectSenderBuilder,
+    ) {
+    }
+
+    fn get_interconnect_typeid(&mut self, _interconnect_no: usize) -> Option<TypeId> {
+        None
+    }
+
+    fn handle_interconnect_message(&mut self, _interconnect_no: usize, _message: Box<dyn Any>) {}
 }
 
 pub trait MMU: Card {
diff --git a/src/main.rs b/src/main.rs
index 9edc3c3..db199f9 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -34,12 +34,21 @@ use serde::Deserialize;
 use std::{fs, path::Path, process};
 use symbol_tables::SymbolTables;
 
+#[derive(Deserialize, Debug)]
+pub struct InterconnectConfig {
+    a_index: usize,
+    a_interconnect_no: usize,
+    b_index: usize,
+    b_interconnect_no: usize,
+}
+
 #[derive(Deserialize, Debug)]
 struct EmuConfig<'a> {
     #[serde(borrow)]
     cards: Vec<card::Config<'a>>,
     #[serde(borrow)]
     symbol_tables: Option<Vec<&'a str>>,
+    interconnects: Option<Vec<InterconnectConfig>>,
 }
 
 struct EmuState {
@@ -65,7 +74,7 @@ fn main() -> Result<(), anyhow::Error> {
         .map_err(|e| anyhow!("Could not read config file ({})", e))?;
     let config: EmuConfig =
         toml::from_str(&config_str).map_err(|e| anyhow!("Could not parse config file ({})", e))?;
-    let backplane = Backplane::new(config.cards)?;
+    let backplane = Backplane::new(config.cards, config.interconnects.unwrap_or_default())?;
     let mut symbol_tables = SymbolTables::new();
     if let Some(initial_tables) = config.symbol_tables {
         for path in initial_tables {