implement more item functions

kubi-server/src/main.rs

@@ -1,4 +1,4 @@
-use shipyard::{IntoWorkload, SystemModificator, Workload, WorkloadModificator, World};
+use shipyard::{IntoWorkload, Workload, WorkloadModificator, World};
 use std::{thread, time::Duration};
 use kubi_shared::fixed_timestamp::{FixedTimestamp, init_fixed_timestamp_storage};
 

kubi-shared/src/item.rs

@@ -38,29 +38,194 @@ impl Item {
 pub struct ItemCollection(Option<(Item, NonZeroU8)>);
 
 impl ItemCollection {
-  pub const fn new(item: Item, amount: NonZeroU8) -> Self {
+  /// Create a new item collection with `amount` of `item`
+  ///
+  /// If `amount` is 0, the slot will be empty, and the item will be ignored
+  pub const fn new(item: Item, amount: u8) -> Self {
+    if amount == 0 {
+      return Self::new_empty()
+    }
+    // SAFETY: `amount` guaranteed to be non-zero
+    let amount = unsafe { NonZeroU8::new_unchecked(amount) };
+    Self::new_nonzero(item, amount)
+  }
+
+  /// Create a new item collection with `amount` of `item`
+  pub const fn new_nonzero(item: Item, amount: NonZeroU8) -> Self {
     Self(Some((item, amount)))
   }
 
+  /// Create a new item collection with a single item
   pub const fn new_single(item: Item) -> Self {
     Self(Some((item, nz::u8!(1))))
   }
 
+  /// Create a new empty item collection
   pub const fn new_empty() -> Self {
     Self(None)
   }
 
-  pub const fn with_amount(&self, amount: NonZeroU8) -> Self {
+  /// Set the amount of items in the slot to `amount`\
+  ///
+  /// If `amount` is 0, the slot will be emptied\
+  /// If slot is empty, this will do nothing, even if `amount` is non-zero
+  pub const fn with_amount(&self, amount: u8) -> Self {
+    if amount == 0 {
+      return Self::new_empty()
+    }
+    // SAFETY: `amount` guaranteed to be non-zero
+    let amount = unsafe { NonZeroU8::new_unchecked(amount) };
+    self.with_amount_nonzero(amount)
+  }
+
+  /// Set the amount of items in the slot to `amount`
+  ///
+  /// If slot is empty, this will do nothing
+  pub const fn with_amount_nonzero(&self, amount: NonZeroU8) -> Self {
     Self(match self.0 {
       Some((item, _)) => Some((item, amount)),
       None => None,
     })
   }
 
+  /// Check if the slot is empty (contains no items)
+  pub const fn is_empty(&self) -> bool {
+    self.0.is_none()
+  }
+
+  /// Check if the slot is full (contains the maximum stack size)
+  pub const fn is_full(&self) -> bool {
+    match self.0 {
+      Some((item, amount)) => {
+        amount.get() >= item.descriptor().stack_size.get()
+      },
+      None => false,
+    }
+  }
+
+  /// Get the item in the slot
+  ///
+  /// If the slot is empty, returns None
+  pub const fn item(&self) -> Option<Item> {
+    match self.0 {
+      Some((item, _)) => Some(item),
+      None => None,
+    }
+  }
+
+  /// Get the amount of items in the slot
+  ///
+  /// If the slot is empty, returns 0
+  pub const fn amount(&self) -> u8 {
+    match self.0 {
+      Some((_, amount)) => amount.get(),
+      None => 0,
+    }
+  }
+
+  /// Get the amount of items in the slot
+  ///
+  /// If the slot is empty, returns None
+  pub const fn amount_nonzero(&self) -> Option<NonZeroU8> {
+    match self.0 {
+      Some((_, amount)) => Some(amount),
+      None => None,
+    }
+  }
+
   /// Add items from another slot, copying them\
-  /// Returns the leftover items
+  /// Returns the leftover items (items that could not be added)
   pub fn add(&mut self, from: &Self) -> Self {
-    let Some((item, count)) = from.0 else { return Self::new_empty() };
-    todo!() //TODO finish item slot system
+    // If there are no items to add, return
+    let Some((add_item, add_count)) = from.0 else {
+      return Self::new_empty()
+    };
+    let item_stack_size = add_item.descriptor().stack_size;
+
+    // Add items to the slot
+    let (this_slot, leftovers) = match self.0 {
+      None => (
+        (
+          add_item,
+          add_count.min(item_stack_size)
+        ),
+        match add_count > item_stack_size {
+          true => Self::new_nonzero(
+            add_item,
+            NonZeroU8::new(
+              add_count.get() - item_stack_size.get()
+            ).unwrap(),
+          ),
+          false => Self::new_empty()
+        }
+      ),
+      Some((cur_item, cur_count)) if cur_item == add_item => {
+        let total_count = cur_count.checked_add(add_count.get()).unwrap();
+        (
+          (
+            cur_item,
+            total_count.min(item_stack_size),
+          ),
+          match total_count > item_stack_size {
+            true => Self::new_nonzero(
+              add_item,
+              NonZeroU8::new(
+                total_count.get() - item_stack_size.get()
+              ).unwrap()
+            ),
+            false => Self::new_empty()
+          }
+        )
+      },
+      // If items are different, do not add anything, everything is leftovers
+      _ => return *from,
+    };
+
+    self.0 = Some(this_slot);
+    leftovers
+  }
+
+  /// Move as much as possible items from another slot, removing them
+  ///
+  /// This may not be possible if the slot is full or contains a different item
+  pub fn move_all(&mut self, to: &mut Self) {
+    let leftovers = to.add(self);
+    *self = leftovers;
+  }
+
+  /// Move up to `amount` items from another slot, removing them
+  ///
+  /// If `amount` is 0, nothing will be moved
+  pub fn move_up_to(&mut self, to: &mut Self, limit: u8) {
+
+    if self.is_empty() { return }
+    // SAFETY: slot is guaranteed to be non-empty
+    let amount = unsafe { self.amount_nonzero().unwrap_unchecked() } ;
+
+    if limit == 0 { return }
+    // SAFETY: `limit` guaranteed to be non-zero
+    let limit = unsafe { NonZeroU8::new_unchecked(limit) };
+
+    let amount_with_limit = amount.min(limit);
+    let self_with_limit = self.with_amount_nonzero(amount_with_limit);
+
+    let mut leftovers = to.add(&self_with_limit);
+
+    // Compensate for the amount of items that were not moved
+    let amount_difference = amount.get() - amount_with_limit.get();
+    if amount_difference > 0 {
+      let correct_item = self.item().unwrap();
+      let correct_amount = leftovers.amount() + amount_difference;
+      leftovers = Self::new(correct_item, correct_amount);
+    }
+
+    *self = leftovers;
+  }
+
+  /// Try to move a single item from another slot, removing it
+  ///
+  /// This may not be possible if the slot is full or contains a different item
+  pub fn move_single(&mut self, to: &mut Self) {
+    self.move_up_to(to, 1);
   }
 }