1 files changed, 88 insertions, 0 deletions
diff --git a/server/data/src/demands.rs b/server/data/src/demands.rs
new file mode 100644
index 00000000..77e187af
--- /dev/null
+++ b/server/data/src/demands.rs
@@ -0,0 +1,88 @@
+/*
+    Hurry Curry! - a game about cooking
+    Copyright (C) 2025 Hurry Curry! Contributors
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published by
+    the Free Software Foundation, version 3 of the License only.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+*/
+use hurrycurry_protocol::{Demand, ItemIndex, Recipe, TileIndex};
+use std::collections::{HashMap, HashSet};
+
+pub fn generate_demands(
+    tiles: &HashSet<TileIndex>,
+    items: &HashSet<ItemIndex>,
+    raw_demands: &[(ItemIndex, Option<ItemIndex>, f32)],
+    recipes: &[Recipe],
+) -> Vec<Demand> {
+    let recipes = recipes
+        .iter()
+        .filter(|r| r.tile().map(|t| tiles.contains(&t)).unwrap_or(true))
+        .collect::<Vec<_>>();
+
+    let mut producable = HashMap::new();
+
+    for i in items {
+        producable.insert(*i, 0.0);
+    }
+
+    loop {
+        let prod_count = producable.len();
+
+        for r in &recipes {
+            let output_count = r.outputs().iter().filter(|o| !items.contains(o)).count();
+            let Some(ingred_cost) = r
+                .inputs()
+                .iter()
+                .map(|i| producable.get(i).copied())
+                .reduce(|a, b| {
+                    if let (Some(a), Some(b)) = (a, b) {
+                        Some(a + b)
+                    } else {
+                        None
+                    }
+                })
+                .unwrap_or(Some(0.))
+            else {
+                continue;
+            };
+
+            let base_cost = match r {
+                Recipe::Passive { speed, .. } => 2. + (1. / speed) * 0.1,
+                Recipe::Active { speed, .. } => 2. + (1. / speed),
+                Recipe::Instant { .. } => 1.,
+            };
+
+            let output_cost = (ingred_cost + base_cost) / output_count as f32;
+            for o in r.outputs() {
+                let cost = producable.entry(o).or_insert(f32::INFINITY);
+                *cost = cost.min(output_cost);
+            }
+        }
+
+        if prod_count == producable.len() {
+            break;
+        }
+    }
+
+    raw_demands
+        .iter()
+        .filter_map(|(i, o, d)| {
+            producable.get(i).map(|cost| Demand {
+                input: *i,
+                output: *o,
+                duration: *d,
+                points: *cost as i64,
+            })
+        })
+        .collect()
+}