# The House of Icarus - World Building Guide

## Crafting

Crafting information lives on the **output item's YAML file** via the `craft:` block. There is no separate recipe directory. To find out how to make `bronze_dagger`, open `data/items/equipment/bronze_dagger.yaml` and look for the `craft:` block. (The item's **filename is its ID** — `bronze_dagger.yaml` → `bronze_dagger`; there is no `id:` field. `ingredients`/output entries reference items by filename.)

### Craft YAML Reference

| Field          | Type           | Description                                     |
| -------------- | -------------- | ----------------------------------------------- |
| `type`         | string         | Craft type (smithing, cooking, crafting, fletching, pharmacy, construction, combine, or "" for skill-less). Always matches a player skill name. |
| `subtype`      | string         | Production method override (`smelt` for furnace recipes, `clean` for herb cleaning). Defaults empty (no override). |
| `level`        | int            | Required skill level                            |
| `xp`           | int            | XP awarded on success                           |
| `wait`         | float64        | Ticks per craft cycle                           |
| `station`      | []string       | Station object IDs required (optional)          |
| `tool`         | string         | Required tool_type (optional)                   |
| `ingredients`      | []IngredientEntry | Ingredients consumed (see below)                |
| `output_qty`   | int            | Quantity produced (default 1, for stackables)   |
| `fail`         | string         | ItemID produced on failure (optional)           |
| `success_message` | string      | Success message per cycle (optional, see message defaults) |
| `fail_message` | string         | Failure message (optional, empty = silent fail) |
| `start_message`| string         | Message when action begins (optional, see message defaults) |
| `end_message`  | string         | Message when action completes (optional, see message defaults) |
| `steps`        | []CraftStep    | Multi-step messages at tick intervals (optional)|
| `success`      | SuccessFormula | Optional skill check formula (see Behaviors)    |

The output is the item itself — no `output` field needed. The item ID IS the craft ID.

### Message Variables

All message fields (`success_message`, `fail_message`, `start_message`, `end_message`, and `steps[].message`) support variables that expand to colorized item names:

| Variable | Expands to                                      |
| -------- | ----------------------------------------------- |
| `%n`     | Output item name (colored, e.g. "stim potion")  |
| `%i1`    | 1st ingredient entry's matched item (colored)      |
| `%i2`    | 2nd ingredient entry's matched item (colored)      |
| `%b1`    | 1st byproduct item name (colored, success only) |
| `%b2`    | 2nd byproduct item name (colored, success only) |

Numbering follows YAML ingredient/byproduct order. If an ingredient entry has multiple alternative items (`items: [a, b]`), the variable expands to whichever the player actually possesses, colored with that item's `color:` field.

Variables work alongside inline color tags (`{C4}text{/}`) which are expanded after variable substitution.

### Message Defaults

If a message field is omitted from the YAML, the game uses a skill-level default based on the craft `type`:

| Type | Default `success_message` | Default `start_message` |
|------|-------------------|------------------------|
| `cooking` | `"Cooked to perfection. %n looks great!"` | `"You start cooking %i1."` |
| `smelt` | `"You remove a white hot %n!"` | `"You place the %i1 into the furnace."` |
| `smithing` | `"You smith a %n."` | `"You begin smithing %i1."` |
| `crafting` | `"You craft a %n."` | `"You begin crafting %i1."` |
| `fletching` | `"You fletch a %n."` | `"You begin fletching %i1."` |
| `pharmacy` | `"You mix a %n."` | `"You start mixing %i1."` |
| `construction` | `"You construct a %n."` | `"You begin constructing %i1."` |
| `clean` | `"You clean the %i1."` | `"You begin cleaning herbs."` |
| (unset) | `"You produce %n."` | `"You start <verb> %i1."` |

Default messages are keyed by `subtype` when set, otherwise by `type`. For skills that never fail (smithing, crafting, fletching, pharmacy, construction), `fail_message` defaults to empty — no message is shown on failure.

### CraftStep — Multi-Step Messages

Optional interim messages fired at specific tick offsets during the craft cycle. The `tick` is the number of ticks elapsed since the start of the cycle.

```yaml
craft:
  type: ""
  wait: 6
  ingredients:
    - items: [map_piece_1]
      quantity: 1
    - items: [map_piece_2]
      quantity: 1
    - items: [map_piece_3]
      quantity: 1
  steps:
    - tick: 1
      message: "You try to puzzle how the pieces fit together."
    - tick: 3
      message: "Aha, this edge lines up here!"
  success_message: "You assemble the map!"
```

### IngredientEntry — Multi-Item Ingredient Slots

Each ingredient entry defines an ingredient slot with multiple valid items. The first matching item found in the player's inventory is consumed.

```yaml
ingredients:
  - items: [item_id, alternative_id, ...]
    quantity: 1
    byproducts: [byproduct_for_item, byproduct_for_alt, ...]
```

`byproducts` is optional. When present, it matches the `items` list by index — consuming `items[0]` returns `byproducts[0]` to inventory. Use `""` for items with no byproduct:

```yaml
ingredients:
  - items: [bucket_of_water, vial_of_water]
    quantity: 1
    byproducts: [empty_bucket, ""]   # bucket returns empty, vial is consumed entirely
  - items: [herb]
    quantity: 1                       # no byproducts — herb is consumed entirely
```

### Skill-Based Production

```yaml
# data/items/consumables/stim_potion.yaml
craft:
  type: pharmacy
  level: 3
  xp: 25
  wait: 4
  ingredients:
    - items: [guam_potion_unf]
      quantity: 1
    - items: [eye_of_newt]
      quantity: 1
  success_message: "You mix a %n."       # %n expands to "stim potion" colored
```

### Station-Based Production

```yaml
# data/items/materials/bronze_bar.yaml
craft:
  type: smithing
  subtype: smelt
  level: 1
  xp: 6
  wait: 4
  station: [furnace]
  ingredients:
    - items: [copper_ore]
      quantity: 1
    - items: [tin_ore]
      quantity: 1
  success_message: "You smelt a %n."  # default is "You remove a white hot %n!"
                                       # overridden here for simpler flavor
```

```yaml
# data/items/equipment/bronze_dagger.yaml
craft:
  type: smithing
  level: 1
  xp: 12
  wait: 4
  station: [anvil]
  ingredients:
    - items: [bronze_bar]
      quantity: 1
  # success_message omitted — uses default "You smith a %n."
```

For stackable outputs, use `output_qty`:

```yaml
# data/items/ammo/bronze_nails.yaml
craft:
  type: smithing
  level: 4
  xp: 12
  wait: 4
  station: [anvil]
  ingredients:
    - items: [bronze_bar]
      quantity: 1
  output_qty: 15
  # success_message omitted — uses default "You smith a %n."
```

### Tool-Based Production

```yaml
# data/items/ammo/arrow_shafts.yaml
craft:
  type: fletching
  level: 1
  xp: 5
  wait: 3
  tool: knife
  ingredients:
    - items: [logs, oak_logs, willow_logs]
      quantity: 1
  output_qty: 15
```

The `tool` field requires the player to have an item with that `tool_type` equipped or in inventory. The tool is NOT consumed.

### Skill-Less Combinations (Item-on-Item)

Omit `type` (or leave it empty) for combinations with no skill check, no XP, and 100% success:

```yaml
# data/items/consumables/bucket_of_water.yaml
craft:
  wait: 0
  ingredients:
    - items: [vial_of_water, jug_of_water]
      quantity: 1
      byproducts: [empty_vial, empty_jug]
    - items: [empty_bucket]
      quantity: 1
  success_message: "You pour the %i1 into the %i2."  # %i1 = water source, %i2 = bucket
```

### Multi-Piece Assembly (3+ items → 1)

```yaml
# data/items/quest/ancient_map.yaml
craft:
  wait: 0
  ingredients:
    - items: [torn_page_1]
      quantity: 1
    - items: [torn_page_2]
      quantity: 1
    - items: [torn_page_3]
      quantity: 1
  steps:
    - tick: 1
      message: "You try to puzzle how the pieces fit together."
    - tick: 3
      message: "Aha, this edge lines up here!"
  success_message: "You assemble the %n."
```

### Clean Recipes

Clean herb recipes use `type: pharmacy` with `subtype: clean` and are handled as background actions (one herb per cycle, directly mutating inventory):

```yaml
# data/items/materials/guam.yaml  (clean guam)
craft:
  type: pharmacy
  subtype: clean
  level: 3
  xp: 3
  wait: 2
  ingredients:
    - items: [grimy_guam]
      quantity: 1
  # success_message omitted — uses default "You clean the %i1."
  # %i1 expands to the grimy herb name with its color
```

### Food/Healing Items

Items with `heal_value` and `eat_message` can be consumed via the `eat` command.

```yaml
name: bread
color: "DE"
description: "A fresh loaf of bread, still warm from the oven."
value: 5
heal_value: 5
eat_message: "You eat the bread. Warm and satisfying."
```

### Architecture

The `CraftIndex` (`internal/game/production_index.go`) is built once at startup from all item YAMLs that have a `craft:` block. It provides `O(1)` lookups by type, subtype, input item, and station. All crafting commands query the CraftIndex — no runtime file scanning.

**Indexes:**
- `byType["pharmacy"]` → all pharmacy-craftable items (used by `mix`)
- `bySubtype["clean"]` → all items with subtype `clean` (grimy herb cleaning)
- `bySubtype["smelt"]` → all items with subtype `smelt` (furnace smelting)
- `byInput["guam"]` → all items that use guam (used by `use` to find combinations)
- `byStation["anvil"]` → all items craftable at an anvil (used by `use bar on anvil`)
- `FindByTwoInputs(a, b)` → items consuming both inputs in different ingredient entries