2 files changed, 133 insertions, 0 deletions
diff --git a/src/state/mod.rs b/src/state/mod.rs
new file mode 100644
index 0000000..5efd770
--- /dev/null
+++ b/src/state/mod.rs
@@ -0,0 +1,36 @@
+use std::sync::{RwLock, RwLockReadGuard, RwLockWriteGuard};
+
+use mlua::{UserData, UserDataFields};
+
+
+pub mod sheetview;
+
+#[derive(Debug, Default)]
+pub struct GlobalState {
+    pub sheetview: sheetview::SheetViewState,
+}
+
+static GLOBAL_STATE: RwLock<GlobalState> = RwLock::new(GlobalState::new());
+const DUMMY_STATE: GlobalState = GlobalState::new();
+
+impl GlobalState {
+    const fn new() -> Self {
+        Self {
+            sheetview: sheetview::SheetViewState::new()
+        }
+    }
+
+    pub fn instance() -> RwLockReadGuard<'static, Self> {
+        GLOBAL_STATE.read().unwrap()
+    }
+
+    pub fn instance_mut() -> RwLockWriteGuard<'static, Self> {
+        GLOBAL_STATE.write().unwrap()
+    }
+}
+
+impl UserData for GlobalState {
+    fn add_fields<'lua, F: UserDataFields<'lua, Self>>(fields: &mut F) {
+        fields.add_field_function_get("sheetview", |_, _| Ok(DUMMY_STATE.sheetview))
+    }
+}
diff --git a/src/state/sheetview.rs b/src/state/sheetview.rs
new file mode 100644
index 0000000..8108a1d
--- /dev/null
+++ b/src/state/sheetview.rs
@@ -0,0 +1,97 @@
+use std::sync::{Arc, RwLock};
+
+use mlua::{IntoLua, UserData, Value};
+
+use super::GlobalState;
+use crate::{
+    cursor::{Cursor, CursorMove},
+    sheet::{
+        register::{Register, SheetId},
+        Sheet, SheetLuaRef,
+    },
+};
+
+#[derive(Default, Debug)]
+pub struct SheetViewState {
+    pub cursor: Cursor,
+    active_sheet: Option<SheetId>,
+}
+
+impl SheetViewState {
+    pub const fn new() -> Self {
+        Self {
+            cursor: Cursor::new(),
+            active_sheet: None,
+        }
+    }
+
+    pub fn set_active_sheet(&mut self, sheet: Option<SheetId>) {
+        if let Some(id) = sheet {
+            if let Some(lock) = Register::get(id) {
+                let sheet = lock.read().unwrap();
+                self.cursor.set_x_max(sheet.width());
+                self.cursor.set_y_max(sheet.height());
+            }
+        }
+
+        self.active_sheet = sheet
+    }
+
+    pub fn active_sheet(&self) -> Option<Arc<RwLock<Sheet>>> {
+        if let Some(id) = self.active_sheet {
+            Register::get(id)
+        } else {
+            None
+        }
+    }
+}
+
+macro_rules! cfg {
+    () => {
+        GlobalState::instance().sheetview
+    };
+}
+
+macro_rules! cfg_mut {
+    () => {
+        GlobalState::instance_mut().sheetview
+    };
+}
+
+impl UserData for SheetViewState {
+    fn add_fields<'lua, F: mlua::prelude::LuaUserDataFields<'lua, Self>>(fields: &mut F) {
+        fields.add_field_function_get("active", |lua, _| {
+            if let Some(id) = cfg!().active_sheet {
+                SheetLuaRef::new(id).into_lua(lua)
+            } else {
+                Ok(Value::Nil)
+            }
+        });
+
+        fields.add_field_function_set("active", |_, _, sheet: Option<SheetLuaRef>| {
+            if let Some(r) = sheet {
+                cfg_mut!().active_sheet = Some(r.id())
+            } else {
+                cfg_mut!().active_sheet = None
+            }
+
+            Ok(())
+        });
+
+        fields.add_field_function_get("cursor", |lua, _| {
+            let table = lua.create_table()?;
+            table.set("row", cfg!().cursor.y())?;
+            table.set("column", cfg!().cursor.x())?;
+            Ok(table)
+        })
+    }
+
+    fn add_methods<'lua, M: mlua::prelude::LuaUserDataMethods<'lua, Self>>(methods: &mut M) {
+        methods.add_function("move_cursor", |_, (row, column): (usize, usize)| {
+            cfg_mut!()
+                .cursor
+                .move_checked(CursorMove::Jump((row, column)));
+            Ok(())
+        })
+    }
+}