# Source file format (`traderx_build.py`)

The source is a single YAML (or JSON – identical keys) file with four top-level sections.
Everything is optional except `categories`.

```yaml
defaults:    # global defaults
groups:      # named, reusable lists of class names
items:       # products that are NOT shown in any category (attachments, variants…)
categories:  # what the traders sell
```

Class names are matched case-insensitively. Product and category ids are derived from
names automatically (`AKM` → `prod_akm_001`, `Assault Rifles` → `cat_assault_rifles_001`)
and are stable across builds as long as the name doesn't change. Set `id:` explicitly
to keep an id from an existing config (the reverse-importer does this for you).

---

## `defaults`

| Key | Default | Meaning |
|---|---|---|
| `stock` | `unlimited` | `unlimited` or an integer max stock |
| `coefficient` | `1.0` | Dynamic price factor; only has an effect with a finite `stock` |
| `sell_percent` | `25` | Sell price as % of buy price when `sell` isn't given |
| `buy` | `full` | Item quantity on purchase – see *Quantity words* |
| `sell` | `full` | Required quantity on sale |
| `restart` | `keep` | Stock behaviour at server restart: `keep` / `reset` / `random` |
| `destock` | `0` | Fraction (0–1) of stock removed at every restart |
| `attachment_price` | `50` | Buy price for attachments/variants that are not defined anywhere else (auto-created hidden products) |
| `attachment_sell_percent` | `25` | Sell % for those auto-created products |

Every key except the two `attachment_*` ones can be overridden per category and per item.
Resolution order is **item → category → defaults**.

---

## `groups`

```yaml
groups:
  ak_optics:   [PSO1Optic, KobraOptic, SNAFU_AKKahles]
  ak_muzzle:   [AK_Suppressor, SNAFU_AK19Muzzel]
  ak_full_kit: [ak_optics, ak_muzzle, Mag_AKM_30Rnd]   # groups can contain groups
```

A group name can be used anywhere a list of class names is expected: `attachments`,
`variants`, preset contents. Duplicates are removed; recursion is detected.

---

## `items`

Products that exist but are not listed in any category. Typical use: attachments and
variants that you price explicitly rather than relying on `attachment_price`.

```yaml
items:
  - SNAFU_AKKahles: {price: 800}
  - PSO1Optic:      {price: 300, sell: 60}
  - AKM_Tan                          # all defaults, price -1 (unbuyable) – only useful as variant
```

---

## `categories`

```yaml
categories:
  - name: Assault Rifles            # required, shown in the trader UI
    id: cat_assault_rifles_001      # optional, otherwise derived from name
    traders: [Boris, 3]             # givenName or npcId from TraderXGeneralSettings.json
    licenses: [Weapons License]     # license *names*; created if missing
    visible: true                   # false hides the category (products still work as attachments)
    icon: ""                        # image path for the category card
    price: 1200                     # default buy price for items below
    stock / coefficient / sell_percent / buy / sell / restart / destock   # category defaults
    items: [...]
```

`traders` controls `categoriesId` in `TraderXGeneralSettings.json`. Every trader that is
named by at least one category gets its list rebuilt in source order; traders not named
anywhere are left untouched (with a warning).

---

## Items

Three spellings are accepted:

```yaml
items:
  - AKM                                  # bare class, all defaults
  - AKM: {price: 1000, stock: 5}         # class as key
  - {class: AKM, price: 1000}            # explicit key
```

Item options:

| Key | Meaning |
|---|---|
| `id` | Keep a specific product id (`prod_…_NNN`). |
| `price` | Buy price. `-1` = cannot be bought. Required somewhere (item, category or `price` in defaults is *not* a thing – an item without a resolvable price is an error). |
| `sell` | Sell price (integer). `-1` = cannot be sold. If omitted, derived from `sell_percent`. |
| `sell_percent` | Override the percentage for this item. |
| `stock` | `unlimited` or integer. |
| `coefficient` | Dynamic price factor (see the configuration guide, §4.2). |
| `buy` | Purchase quantity word. |
| `sell_mode` | Sale quantity word (named `sell_mode` because `sell` is the price). At category/defaults level the key is `sell`. |
| `restart`, `destock` | Stock behaviour at restart. |
| `attachments` | List of class names / group names / `@compat` refs. |
| `variants` | List of class names / groups. Variants that don't define their own `attachments` inherit the base item's. |
| `presets` | Map of preset name → attachment list (see below). |

An item may appear in several categories; the first occurrence with options defines it,
later occurrences just add it to that category (a warning is printed if they carry
conflicting options).

---

## Quantity words

Used for `buy` (item state when purchased) and `sell` / `sell_mode` (state required when sold):

| Word | Buy | Sell |
|---|---|---|
| `full` | item spawns full | must be full |
| `empty` | spawns empty | must be empty |
| `any` | – | any amount accepted, paid pro-rata |
| `static N` | exactly N units | exactly N units |
| `coef 50%` (or `coef 0.5`) | 50 % of max | 50 % of max |

The build packs these into the mod's `tradeQuantity` bitfield using the layout the mod's
runtime actually reads (`TraderXTradeQuantity`), not the one in its CSV packer, which is
inconsistent.

---

## Presets

```yaml
- AKM:
    attachments: [ak_optics, ak_muzzle, Mag_AKM_30Rnd]
    presets:
      "CQB*":  [KobraOptic, AK_Suppressor, Mag_AKM_30Rnd]   # * marks the default preset
      "DMR":   [PSO1Optic, Mag_AKM_30Rnd]
```

Each item with `presets` produces `TraderXPresets/presets_<productId>.json`. Rules enforced
at build time:

- every preset attachment must be in the item's own `attachments` list (the mod won't
  let players select it otherwise) – error;
- exactly one preset can carry `*`; if none does, the first one becomes the default;
- preset ids are derived (`preset_akm_cqb_001`) and stable.

Player-saved presets live in the same folder and are not touched.

---

## `@compat` references

Require `build --compat FILE`. See [compat.md](compat.md).

| Ref | Expands to |
|---|---|
| `@compat` | every attachment the compat file lists for this weapon **that is defined as a product somewhere in the source** |
| `@compat_mags` | same, for magazines |
| `@compat_all` | everything compatible, auto-creating products that don't exist (rarely what you want) |

---

## What the build checks

Errors (nothing is written):

- item without a resolvable price
- unknown quantity/restart word, out-of-range values
- preset using a class not in the weapon's attachments, or not defined at all
- `@compat` used without `--compat`
- trader or category reference that doesn't exist
- trader `className` with the wrong `SurvivorM_`/`SurvivorF_` prefix for a known survivor name
- duplicate explicit ids
- with `--strict`: attachment/variant class not defined anywhere

Warnings:

- `coefficient` set while stock is unlimited (the mod ignores it)
- sell price higher than buy price
- attachment not attachable according to the compat file
- item listed twice in a category; item defined twice with options
- category with no items; trader not referenced by any category
- auto-created hidden products (as notes)

---

## Minimal complete example

```yaml
defaults:
  sell_percent: 30

categories:
  - name: Food
    traders: [Eve]
    price: 50
    items: [Apple, Pear, BakedBeansCan]
```

builds three product files, one category file and sets Eve's `categoriesId`.