testing

main.py

@@ -1,11 +1,11 @@
 from collections import defaultdict, deque
 from enum import Enum
 from math import ceil
-from typing import Dict, List, Tuple, Optional, Any, Deque
+from typing import Dict, List, Tuple, Optional, Any, Deque, Annotated
 import networkx as nx
-from flask import Flask, render_template, request
+from flask import Flask, render_template, request, jsonify
-from pydantic import BaseModel, Field
+from pydantic import BaseModel, Field, computed_field, BeforeValidator
-from plus import Items, Machines, Recipes, Recipe, RawResources
+from plus import Items, Machines, Recipes, Recipe, RawResources, MachineOrder
 # from vanilla import Items, Machines, Recipes, Recipe, RawResources
 from rich import print
 import matplotlib.pyplot as plt
@@ -29,46 +29,69 @@ def _slugify(name: str) -> str:
             prev_us = False
     return ''.join(out).strip('_')
 
-
-
-class Production(BaseModel):
-    recipe: Recipe
-    production_level: float
-    ingress: Dict[Items, "ProductionLink"] = Field(default_factory=dict)
-    egress: Dict[Items, "ProductionLink"] = Field(default_factory=dict)
-
-    @property
-    def inputs(self):
-        return {
-            item: quantity*self.production_level for item, quantity in self.recipe.inputs.items()
-        }
-
-    @property
-    def outputs(self):
-        return {
-            item: quantity*self.production_level for item, quantity in self.recipe.outputs.items()
-        }
-
-    def demand_satisfied(self):
-        if self.production_level <= 0:
-            return True
-        demand = self.recipe.inputs
-        for item in self.ingress:
-            demand[item] -= self.ingress[item].quantity
-        return all(demand[item] <= 0 for item in demand)
-
-    def remaining_output(self):
-        outputs = self.outputs
-        for item in self.egress:
-            outputs[item] -= self.egress[item].quantity
-        return outputs
-
 class ProductionLink(BaseModel):
     item: Items
     quantity: float
     production: Optional[Production]
     raw: bool = False
 
+def positive_float(number: float) -> float:
+    return max(0.0, number)
+
+class Production(BaseModel):
+    recipe: Recipe
+    ingress: Dict[Items, List[ProductionLink]] = Field(default_factory=lambda : defaultdict(list))
+    egress: Dict[Items, List[ProductionLink]] = Field(
+        default_factory=lambda: defaultdict(list)
+    )
+
+    demand: Dict[Items, Annotated[float, BeforeValidator(positive_float)]] = Field(default_factory=lambda: defaultdict(float))
+
+    @computed_field
+    @property
+    def production_level(self) -> float:
+        levels = []
+        for item, quantity in self.demand.items():
+            levels.append(quantity/(self.recipe.outputs|self.recipe.byproducts)[item])
+        return max(levels) if levels else 0.0
+
+    @computed_field
+    @property
+    def inputs(self) -> Dict[Items, float]:
+        return {
+            item: quantity*self.production_level for item, quantity in self.recipe.inputs.items()
+        }
+
+    @computed_field
+    @property
+    def outputs(self) -> Dict[Items, float]:
+        return {
+            item: quantity*self.production_level for item, quantity in self.recipe.outputs.items() | self.recipe.byproducts.items()
+        }
+
+    def demand_satisfied(self):
+        if self.production_level <= 0:
+            return True
+        current_demand = self.demand.copy()
+        for item in self.ingress:
+            for link in self.ingress[item]:
+                current_demand[item] -= link.quantity
+        return all(current_demand[item] <= 0 for item in current_demand)
+
+    def remaining_output(self):
+        outputs = self.outputs
+        for item in self.egress:
+            for link in self.egress[item]:
+                outputs[item] -= link.quantity
+        return outputs
+
+    def remaining_input(self):
+        inputs = self.inputs
+        for item in self.ingress:
+            for link in self.ingress[item]:
+                inputs[item] -= link.quantity
+        return inputs
+
 
 
 class ProductionChain:
@@ -188,9 +211,10 @@ class ProductionChain:
         queue: Deque[Items] = deque()
         for target in targets:
             recipe = self.get_recipe(target)
-            p = Production(recipe=recipe, production_level=targets[target]/ recipe.outputs[target])
+            p = Production(recipe=recipe)
-            for inp in p.inputs:
+            p.demand[target] = targets[target]
-                queue.append(inp)
+            p.egress[target].append(ProductionLink(item=target, quantity=targets[target], raw=True, production=None))
+            queue.extend(p.inputs)
             for output in p.outputs:
                 item_to_production[output].append(p)
         while queue:
@@ -198,29 +222,68 @@ class ProductionChain:
             if item in item_to_production or item in RawResources:
                 continue
             recipe = self.get_recipe(item)
-            p = Production(recipe=recipe, production_level=0)
+            p = Production(recipe=recipe)
             for output in p.outputs:
                 item_to_production[output].append(p)
-            for inp in p.inputs:
+            queue.extend(p.inputs)
-                queue.append(inp)
         calc_queue: Deque[Production] = deque()
         for item in item_to_production:
             for production in item_to_production[item]:
                 if not production.demand_satisfied():
                     calc_queue.append(production)
         print(calc_queue)
+
         while calc_queue:
             prod = calc_queue.popleft()
             if prod.demand_satisfied():
                 continue
             for inp in prod.inputs:
                 if inp in RawResources:
-                    prod.ingress.append(ProductionLink(item=inp, quantity=prod.recipe.inputs[inp] - prod..raw_resources[inp], production=None, raw=True))
+                    if prod.remaining_input()[inp] <= 0:
+                        continue
+                    prod.ingress[inp].append(ProductionLink(item=inp, quantity=prod.remaining_input()[inp], production=None, raw=True))
                 else:
-                    for p in item_to_production[inp]:
+                    prod_list = item_to_production[inp]
-                        if p.demand_satisfied():
-                            prod.production_level += p.production_level * p.recipe.outputs[inp] / p.recipe.inputs[inp]
 
+                    prod_source = None
+                    if len(prod_list) == 1:
+                        prod_source = prod_list[0]
+                    else:
+                        for prod_list_item in prod_list:
+                            if self.get_recipe(inp) == prod_list_item.recipe:
+                                prod_source = prod_list_item
+                                break
+                    if not prod_source:
+                        continue
+                    current_quantity = prod_source.remaining_output()[inp]
+                    target_quantity = prod.remaining_input()[inp]
+                    if current_quantity >= target_quantity:
+                        prod.ingress[inp].append(
+                            ProductionLink(
+                                item=inp,
+                                quantity=target_quantity,
+                                production=prod_source,
+                                raw=False,
+                            )
+                        )
+                        prod_source.egress[inp].append(
+                            ProductionLink(
+                                item=inp,
+                                quantity=target_quantity,
+                                production=prod,
+                                raw=False,
+                            )
+                        )
+                    else:
+                        pass
+                    if target_quantity > 0:
+                        prod_source.demand[inp] += target_quantity
+
+                        prod.ingress[inp].append(ProductionLink(item=inp, quantity=target_quantity, production=prod_source, raw=False))
+                        prod_source.egress[inp].append(ProductionLink(item=inp, quantity=target_quantity, production=prod, raw=False))
+                        calc_queue.append(prod_source)
+
+        return item_to_production
         # print("item_to_production:", item_to_production)
 
 
@@ -710,13 +773,290 @@ def index():
     )
 
 
+@app.route("/new", methods=["GET"])
+def new():
+    # Render a page similar to index but powered by ProductionChain.build_chain
+    item_names = sorted([i.value.name for i in Items])
+    name_to_item = {i.value.name: i for i in Items}
+
+    # Parse multiple targets (item_1/rate_1, ...). Fallback to legacy item/rate
+    indexed_pairs: List[Tuple[Optional[str], Optional[str]]] = []
+    max_idx = 0
+    for key in request.args.keys():
+        if key.startswith("item_"):
+            try:
+                idx = int(key.split("_", 1)[1])
+                max_idx = max(max_idx, idx)
+            except ValueError:
+                pass
+    for i in range(1, max_idx + 1):
+        indexed_pairs.append((request.args.get(f"item_{i}"), request.args.get(f"rate_{i}")))
+
+    targets: Dict[Items, float] = defaultdict(float)
+    targets_ui: List[dict] = []
+    errors: List[str] = []
+
+    def _add_row(item_name: Optional[str], rate_str: Optional[str]):
+        nonlocal targets, targets_ui
+        if not item_name and not rate_str:
+            return
+        item_name = (item_name or "").strip()
+        rate_val: Optional[float] = None
+        if rate_str is not None and rate_str != "":
+            try:
+                rate_val = float(rate_str)
+                if rate_val < 0:
+                    raise ValueError
+            except (TypeError, ValueError):
+                errors.append(f"Invalid rate for product '{item_name or '(missing)'}'. Enter a non-negative number.")
+                rate_val = None
+        if item_name:
+            targets_ui.append({"item": item_name, "rate": rate_val if rate_val is not None else 0.0})
+            if rate_val is not None:
+                item_obj = name_to_item.get(item_name)
+                if item_obj is None:
+                    errors.append(f"Unknown item '{item_name}'.")
+                else:
+                    targets[item_obj] += rate_val
+        elif rate_val is not None:
+            # Rate without item name – keep in UI only
+            targets_ui.append({"item": "", "rate": rate_val})
+
+    if indexed_pairs:
+        for item_nm, rate_s in indexed_pairs:
+            _add_row(item_nm, rate_s)
+    else:
+        # Legacy single controls
+        default_item = item_names[0] if item_names else ""
+        single_item = request.args.get("item") or default_item
+        single_rate = request.args.get("rate")
+        _add_row(single_item, single_rate)
+        if not request.args:
+            # Initial load: ensure default row
+            targets_ui = [{"item": default_item, "rate": 60.0}]
+            if default_item:
+                item_obj0 = name_to_item.get(default_item)
+                if item_obj0:
+                    targets[item_obj0] += 60.0
+
+    # Build reset query preserving current targets
+    if indexed_pairs or len(targets_ui) > 1:
+        parts = []
+        for idx, row in enumerate(targets_ui, start=1):
+            parts.append(f"item_{idx}={row['item']}")
+            parts.append(f"rate_{idx}={row['rate']}")
+        reset_query = "?" + "&".join(parts)
+    else:
+        selected_item = targets_ui[0]["item"] if targets_ui else (item_names[0] if item_names else "")
+        selected_rate = targets_ui[0]["rate"] if targets_ui else 60.0
+        reset_query = f"?item={selected_item}&rate={selected_rate}"
+
+    error = " ".join(errors) if errors else None
+
+    # Parse per-item recipe overrides from query params: recipe_for_<slug(item name)>
+    # Build slug -> Items map and recipe name -> Recipe map
+    slug_to_item: Dict[str, Items] = { _slugify(i.value.name): i for i in Items }
+    recipe_name_to_obj: Dict[str, Recipe] = {}
+    for r in Recipes:
+        recipe_name_to_obj[r.value.name] = r.value
+    preferred: Dict[Items, Recipe] = {}
+    for key, value in request.args.items():
+        if not key.startswith("recipe_for_"):
+            continue
+        if not value:
+            # Empty value means no override for this item
+            continue
+        slug = key[len("recipe_for_") :]
+        item_enum = slug_to_item.get(slug)
+        if not item_enum:
+            continue
+        # Validate that the provided recipe name is a candidate for this item
+        candidates = []
+        for r in Recipes:
+            rec = r.value
+            if item_enum in rec.outputs:
+                candidates.append(rec.name)
+        if value in candidates:
+            preferred[item_enum] = recipe_name_to_obj[value]
+
+    # Build chain using the object-oriented builder
+    # Now organize the UI data by production (recipe/building instance) rather than by item
+    chain_ui: List[dict] = []
+    # Additionally, build a separate table for alternate recipes organized by item
+    alternates_by_item_ui: List[dict] = []
+    if not errors and targets:
+        # Pass preferred recipes so alternates can be selected
+        prod_chain = ProductionChain(preferred_recipes=preferred)
+        item_to_production = prod_chain.build_chain(targets)
+
+        def _it_name(i: Items) -> str:
+            return i.value.name
+
+        # Collect unique Production objects (they may appear under multiple output items)
+        seen_ids: set[int] = set()
+        productions: List[Production] = []
+        for plist in item_to_production.values():
+            for p in plist:
+                pid = id(p)
+                if pid in seen_ids:
+                    continue
+                seen_ids.add(pid)
+                productions.append(p)
+
+        # Sort productions by MachineOrder (then by recipe name for stability)
+        order_index_map = {m: i for i, m in enumerate(MachineOrder)}
+        def _prod_sort_key(pr: Production):
+            b = pr.recipe.building
+            # Fallback to the end if a building isn't listed in MachineOrder
+            order_idx = order_index_map.get(b, len(MachineOrder))
+            return (order_idx, pr.recipe.name)
+        productions.sort(key=_prod_sort_key)
+
+        chain_ui = []
+        used_slugs: set[str] = set()
+        for p in productions:
+            # Choose an anchor output item to bind alternate recipe selection.
+            # Prefer items that actually egress (flow to another production or final output),
+            # falling back to any output if there is no egress.
+            egress_items = list(p.egress.keys())
+            output_items = list(p.outputs.keys())
+            anchor_item: Optional[Items] = None
+            pick_from: List[Items] = egress_items if egress_items else output_items
+            if pick_from:
+                anchor_item = sorted(pick_from, key=lambda i: i.value.name)[0]
+            # Build candidate recipes for the anchor item
+            candidates: List[dict] = []
+            selected_recipe_name = p.recipe.name
+            recipe_slug = _slugify(anchor_item.value.name) if anchor_item else ""
+            if anchor_item is not None:
+                for r in Recipes:
+                    rec = r.value
+                    if anchor_item in rec.outputs:
+                        candidates.append({
+                            "name": rec.name,
+                            "building": rec.building.value.name,
+                        })
+                candidates.sort(key=lambda x: (x["name"]))
+                # Only show the selector once per anchor item to avoid duplicate keys in the form
+                if recipe_slug in used_slugs:
+                    # clear candidates and slug so template renders plain text
+                    candidates = []
+                    recipe_slug = ""
+                else:
+                    used_slugs.add(recipe_slug)
+
+            # Build ingress/egress presentation lists
+            ingress_ui: List[dict] = []
+            for it, links in p.ingress.items():
+                for lk in links:
+                    if lk.raw or lk.production is None:
+                        via = "Raw"
+                    else:
+                        via = f"{lk.production.recipe.name} ({lk.production.recipe.building.value.name})"
+                    ingress_ui.append({
+                        "item": _it_name(it),
+                        "rate": lk.quantity,
+                        "via": via,
+                    })
+
+            egress_ui: List[dict] = []
+            for it, links in p.egress.items():
+                for lk in links:
+                    if lk.production is None:
+                        to = "Final Output"
+                    else:
+                        to = f"{lk.production.recipe.name} ({lk.production.recipe.building.value.name})"
+                    egress_ui.append({
+                        "item": _it_name(it),
+                        "rate": lk.quantity,
+                        "to": to,
+                    })
+
+            chain_ui.append(
+                {
+                    "recipe": p.recipe.name,
+                    "building": p.recipe.building.value.name,
+                    "production_level": p.production_level,
+                    "inputs": [
+                        {"item": _it_name(i), "rate": q} for i, q in p.inputs.items()
+                    ],
+                    "outputs": [
+                        {"item": _it_name(i), "rate": q} for i, q in p.outputs.items()
+                    ],
+                    # Link visualization
+                    "ingress": ingress_ui,
+                    "egress": egress_ui,
+                    # Deprecated in UI: per-production alternate selector (kept for reference)
+                    "recipe_options": candidates,
+                    "recipe_selected": selected_recipe_name,
+                    "recipe_slug": recipe_slug,
+                }
+            )
+
+        # Build the alternate-recipe table data organized by item.
+        # Consider items that appear as outputs in the current chain.
+        items_in_chain: set[Items] = set()
+        for p in productions:
+            for it in p.outputs.keys():
+                items_in_chain.add(it)
+
+        # Helper: map current chain's selected recipe for an item (if any)
+        current_selected_by_item: Dict[Items, str] = {}
+        for p in productions:
+            for it in p.outputs.keys():
+                # if multiple productions output same item, first one wins (they should be consistent)
+                current_selected_by_item.setdefault(it, p.recipe.name)
+
+        # Build candidate lists and choose selected value
+        for item in sorted(items_in_chain, key=lambda i: i.value.name):
+            candidates: List[dict] = []
+            for r in Recipes:
+                rec = r.value
+                if item in rec.outputs:
+                    candidates.append({
+                        "name": rec.name,
+                        "building": rec.building.value.name,
+                    })
+            # Only include items that actually have alternates (2 or more options)
+            if len(candidates) <= 1:
+                continue
+            candidates.sort(key=lambda x: x["name"])
+
+            # Selected recipe prioritizes explicit override if provided; otherwise use what chain used
+            selected_name = None
+            if item in preferred:
+                selected_name = preferred[item].name
+            else:
+                selected_name = current_selected_by_item.get(item)
+
+            alternates_by_item_ui.append({
+                "item": item.value.name,
+                "slug": _slugify(item.value.name),
+                "options": candidates,
+                "selected": selected_name,
+            })
+
+    return render_template(
+        "new.html",
+        items=item_names,
+        targets_ui=targets_ui,
+        error=error,
+        chain=chain_ui,
+        reset_query=reset_query,
+        alternates_by_item=alternates_by_item_ui,
+    )
+
+
 def create_app():
     return app
 
 
 if __name__ == "__main__":
     # For local dev: python main.py
-    # app.run(host="0.0.0.0", port=5000, debug=True)
+    app.run(host="0.0.0.0", port=5000, debug=True)
-    prod_chain = ProductionChain()
+    # prod_chain = ProductionChain()
+    # chain = prod_chain.build_chain({Items.BrassBeltDrive: 10.0})
+    # print(chain)
+
+
     # prod_chain.compute_chain({Items.FusedModularFrame: 1.5})
-    prod_chain.build_chain({Items.IronIngot: 1.5})

plus.py

@@ -1,5 +1,5 @@
 from enum import Enum
-from typing import Dict
+from typing import Dict, Tuple
 from shared import Machine, Item
 from pydantic import BaseModel, Field, ConfigDict
 
@@ -17,6 +17,19 @@ class Machines(Enum):
     WetWasher = Machine(name="Wet Washer")
     BoilerMk1 = Machine(name="Boiler Mk1")
 
+MachineOrder: Tuple[Machines, ...] = (
+    Machines.Miner,
+    Machines.BoilerMk1,
+    Machines.Crusher,
+    Machines.WetWasher,
+    Machines.Sorter,
+    Machines.Smelter,
+    Machines.Foundry,
+    Machines.FlexibleBlastFurnace,
+    Machines.Reformer,
+    Machines.Constructor,
+    Machines.Assembler,
+)
 
 class Items(Enum):
     IronIngot = Item(name="Iron Ingot")
@@ -169,9 +182,11 @@ class Recipes(Enum):
         building=Machines.Crusher,
         outputs={
             Items.Silica: 60.0,
-            Items.Sand: 40.0,
         },
         inputs={Items.Kyalite: 60.0},
+        byproducts={
+            Items.Sand: 40.0,
+        }
     )
     # - Crushing Powders
     CoarseSand = Recipe(
@@ -206,9 +221,11 @@ class Recipes(Enum):
         outputs={
             Items.CrushedIron: 90.0,
             Items.CrushedTin: 60.0,
-            Items.CrushedGangue: 40.0,
         },
         inputs={Items.CrushedSiterite: 120.0},
+        byproducts={
+            Items.CrushedGangue: 40.0,
+        },
     )
     CrushedCopper = Recipe(
         name="Crushed Copper",
@@ -216,21 +233,23 @@ class Recipes(Enum):
         outputs={
             Items.CrushedCopper: 96.0,
             Items.CrushedMagnesium: 80.0,
-            Items.CrushedGangue: 40.0,
         },
         inputs={Items.CrushedCallanite: 120.0},
+        byproducts={
+            Items.CrushedGangue: 40.0,
+        },
     )
     CrushedZinc = Recipe(
         name="Crushed Zinc",
         building=Machines.Sorter,
         outputs={
             Items.CrushedZinc: 96.0,
-            Items.Sand: 48.0,
         },
         inputs={Items.CrushedLarrussite: 120.0},
         byproducts={
             Items.CrushedGangue: 60.0,
-        }
+            Items.Sand: 48.0,
+        },
     )
     CrushedCaterium = Recipe(
         name="Crushed Caterium",
@@ -744,14 +763,16 @@ class Recipes(Enum):
         name="Molten Steel",
         building=Machines.FlexibleBlastFurnace,
         outputs={
-            Items.MoltenSteel: 40.0,
+            Items.MoltenSteel: 40.0
-            Items.FlueGas: 30.0
         },
         inputs={
             Items.MoltenIron: 40.0,
             Items.CarbonPowder: 40.0,
             Items.Steam: 60.0
         },
+        byproducts={
+            Items.FlueGas: 30.0
+        }
     )
     DirectSteel = Recipe(
         name="Direct Steel",
@@ -890,11 +911,13 @@ class Recipes(Enum):
         building=Machines.WetWasher,
         outputs={
             Items.CrushedTin: 45.0,
-            Items.TailingsSlurry: 60.0
         },
         inputs={
             Items.SiteriteOre: 60.0,
             Items.Water: 30.0,
+        },
+        byproducts={
+            Items.TailingsSlurry: 60.0
         }
     )
     SteamMk1 = Recipe(

templates/new.html

@@ -0,0 +1,228 @@
+<!doctype html>
+<html lang="en">
+<head>
+  <meta charset="utf-8">
+  <meta name="viewport" content="width=device-width, initial-scale=1">
+  <title>Satisfactory Production Calculator — New</title>
+  <style>
+    :root { --bg: #0f172a; --card: #111827; --text: #e5e7eb; --muted:#94a3b8; --accent:#22d3ee; --ok:#4ade80; }
+    * { box-sizing: border-box; }
+    body { margin:0; font-family: system-ui, -apple-system, Segoe UI, Roboto, sans-serif; background: var(--bg); color: var(--text); }
+    .container {  margin: 0 auto; padding: 24px; }
+    h1 { font-size: 1.75rem; margin: 0 0 8px; }
+    p { color: var(--muted); margin-top: 0; }
+    .card { background: var(--card); border: 1px solid #1f2937; border-radius: 10px; padding: 16px; }
+    .row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
+    @media (max-width: 800px) { .row { grid-template-columns: 1fr; } }
+    label { display:block; margin-bottom:8px; font-weight:600; }
+    select, input[type=number] { width: 100%; padding: 10px 12px; border-radius: 8px; border: 1px solid #334155; background: #0b1220; color: var(--text); }
+    button { padding: 10px 14px; border: 0; border-radius: 8px; background: var(--accent); color: #012b30; font-weight: 700; cursor: pointer; }
+    button:hover { filter: brightness(1.08); }
+    .mt { margin-top: 16px; }
+    .error { color: #fda4af; background: #451a1a; border: 1px solid #7f1d1d; padding: 10px; border-radius: 8px; }
+    table { width: 100%; border-collapse: collapse; }
+    th, td { text-align: left; padding: 8px; border-bottom: 1px solid #1f2937; vertical-align: top; }
+    th { color: var(--muted); font-weight: 600; }
+    code { color: var(--accent); }
+    .mono { font-variant-numeric: tabular-nums; font-family: ui-monospace, SFMono-Regular, Menlo, monospace; }
+    .pill { display:inline-block; padding:2px 8px; border-radius: 999px; background:#0b1220; border:1px solid #334155; color: var(--muted); font-size: 12px; }
+  </style>
+  <link rel="preconnect" href="/">
+  <meta name="robots" content="noindex">
+  <meta name="color-scheme" content="dark">
+  <meta name="viewport" content="width=device-width, initial-scale=1">
+  <meta name="description" content="Satisfactory Production Calculator (new build-chain view)">
+  <link rel="icon" href="data:,">
+  <base href="/new">
+  <style>
+    details summary { cursor: pointer; }
+  </style>
+</head>
+<body>
+  <div class="container">
+    <h1>Satisfactory Production Calculator — New</h1>
+    <p>Compute production using the new build-chain logic. This page mirrors the index UI.</p>
+
+    <form class="card" method="get" id="targets-form">
+      <div>
+        <label>Products</label>
+        <table style="width:100%; border-collapse: collapse;">
+          <thead>
+            <tr>
+              <th style="width:60%">Item</th>
+              <th style="width:30%" class="mono">Rate (items/min)</th>
+              <th style="width:10%"></th>
+            </tr>
+          </thead>
+          <tbody id="targets-rows">
+            {% for row in targets_ui %}
+              <tr class="target-row">
+                <td>
+                  <select name="item_{{ loop.index }}" required>
+                    {% for it in items %}
+                      <option value="{{ it }}" {% if row.item == it %}selected{% endif %}>{{ it }}</option>
+                    {% endfor %}
+                  </select>
+                </td>
+                <td>
+                  <input name="rate_{{ loop.index }}" type="number" step="0.01" min="0" value="{{ row.rate }}" required>
+                </td>
+                <td>
+                  <button type="button" class="pill" onclick="removeRow(this)" title="Remove">✕</button>
+                </td>
+              </tr>
+            {% endfor %}
+          </tbody>
+        </table>
+        <div class="mt">
+          <button type="button" onclick="addRow()">Add product</button>
+        </div>
+      </div>
+
+      <div class="mt">
+        <button type="submit">Calculate</button>
+        <a href="{{ reset_query }}" class="pill" style="margin-left:8px; display:inline-block; text-decoration:none;">Reset</a>
+      </div>
+      {% if error %}
+        <div class="mt error">{{ error }}</div>
+      {% endif %}
+    </form>
+
+    {% if chain and chain|length > 0 %}
+      <div class="mt card">
+        <h2 style="margin-top:0">Results</h2>
+        <form method="get" style="background: transparent; border:0; padding:0;">
+          {# Preserve all target rows in the recalculation #}
+          {% for row in targets_ui %}
+            <input type="hidden" name="item_{{ loop.index }}" value="{{ row.item }}">
+            <input type="hidden" name="rate_{{ loop.index }}" value="{{ row.rate }}">
+          {% endfor %}
+
+          {# Separate table: Alternate recipe choices organized by item #}
+          {% if alternates_by_item and alternates_by_item|length > 0 %}
+            <h3>Alternate recipes by item</h3>
+            <table class="mt">
+              <thead>
+                <tr>
+                  <th style="width:40%">Item</th>
+                  <th style="width:60%">Preferred recipe</th>
+                </tr>
+              </thead>
+              <tbody>
+                {% for row in alternates_by_item %}
+                  <tr>
+                    <td>{{ row.item }}</td>
+                    <td>
+                      <select name="recipe_for_{{ row.slug }}">
+                        {% for opt in row.options %}
+                          <option value="{{ opt.name }}" {% if opt.name == row.selected %}selected{% endif %}>{{ opt.name }} ({{ opt.building }})</option>
+                        {% endfor %}
+                      </select>
+                    </td>
+                  </tr>
+                {% endfor %}
+              </tbody>
+            </table>
+          {% endif %}
+          <table>
+            <thead>
+              <tr>
+                <th>Recipe</th>
+                <th>Building</th>
+                <th class="mono">Production level</th>
+                <th>Ingress</th>
+                <th>Outputs</th>
+                <th>Egress</th>
+              </tr>
+            </thead>
+            <tbody>
+            {% for p in chain %}
+              <tr>
+                <td>{{ p.recipe }}</td>
+                <td>{{ p.building }}</td>
+                <td class="mono">{{ '%.2f'|format(p.production_level) }}</td>
+                <td>
+                  {% if p.ingress and p.ingress|length > 0 %}
+                    <div>
+                      {% for ing in p.ingress %}
+                        <div>{{ ing.item }} ← {{ ing.via }} — <span class="mono">{{ '%.2f'|format(ing.rate) }}</span></div>
+                      {% endfor %}
+                    </div>
+                  {% else %}
+                    <span class="pill">None</span>
+                  {% endif %}
+                </td>
+                <td>
+                  {% if p.outputs and p.outputs|length > 0 %}
+                    <div>
+                      {% for out in p.outputs %}
+                        <div>{{ out.item }} — <span class="mono">{{ '%.2f'|format(out.rate) }}</span></div>
+                      {% endfor %}
+                    </div>
+                  {% else %}
+                    <span class="pill">None</span>
+                  {% endif %}
+                </td>
+
+                <td>
+                  {% if p.egress and p.egress|length > 0 %}
+                    <div>
+                      {% for eg in p.egress %}
+                        <div>{{ eg.item }} → {{ eg.to }} — <span class="mono">{{ '%.2f'|format(eg.rate) }}</span></div>
+                      {% endfor %}
+                    </div>
+                  {% else %}
+                    <span class="pill">None</span>
+                  {% endif %}
+                </td>
+              </tr>
+            {% endfor %}
+            </tbody>
+          </table>
+          <div class="mt">
+            <button type="submit">Recalculate</button>
+            <a href="{{ reset_query }}" class="pill" style="margin-left:8px; display:inline-block; text-decoration:none;">Reset overrides</a>
+          </div>
+        </form>
+      </div>
+    {% endif %}
+  </div>
+
+  <script>
+    // Dynamic add/remove for multiple product targets
+    const itemsList = {{ items | tojson }};
+    function addRow() {
+      const tbody = document.getElementById('targets-rows');
+      const idx = tbody.querySelectorAll('tr').length + 1;
+      const tr = document.createElement('tr');
+      tr.className = 'target-row';
+      const options = itemsList.map(it => `<option value="${it}">${it}</option>`).join('');
+      tr.innerHTML = `
+        <td>
+          <select name="item_${idx}" required>${options}</select>
+        </td>
+        <td>
+          <input name="rate_${idx}" type="number" step="0.01" min="0" value="60.0" required>
+        </td>
+        <td>
+          <button type="button" class="pill" onclick="removeRow(this)" title="Remove">✕</button>
+        </td>`;
+      tbody.appendChild(tr);
+    }
+    function removeRow(btn) {
+      const tr = btn.closest('tr');
+      const tbody = tr && tr.parentElement;
+      if (!tbody) return;
+      tbody.removeChild(tr);
+      // Renumber names to keep indices compact
+      Array.from(tbody.querySelectorAll('tr')).forEach((row, i) => {
+        const idx = i + 1;
+        const sel = row.querySelector('select[name^="item_"]');
+        const rate = row.querySelector('input[name^="rate_"]');
+        if (sel) sel.name = `item_${idx}`;
+        if (rate) rate.name = `rate_${idx}`;
+      });
+    }
+  </script>
+</body>
+</html>