# Data Rules

## Component Categories (lot_category)

### Source

Categories are **always** taken from `lot.lot_category` (table `lot`).

**NOT** from `qt_lot_metadata`.
**NOT** derived from the LOT name or article name.

### When creating pricelists

1. **Estimate**: include only components with `current_price > 0` and `is_hidden = 0` (`pricelist_type='estimate'`), then load `lot.lot_category`.
2. **Warehouse**: load `lot.lot_category` for all positions (`pricelist_type='warehouse'`).
3. **Competitor**: load `lot.lot_category` for all positions (`pricelist_type='competitor'`).
4. **World**: load `lot.lot_category` for all positions (`pricelist_type='world'`).
5. Persist into `lot_category` column of `qt_pricelist_items`.

### Model

```go
type PricelistItem struct {
    LotCategory *string `gorm:"column:lot_category;size:50" json:"category,omitempty"`
    // JSON field is "category" for the frontend
}
```

### Rules

- Category is **not** a virtual field — it is persisted to DB when the pricelist is created.
- JOIN with `lot` is only needed for `lot_description`; category is already in `qt_pricelist_items`.
- Default value when category is absent in source or LOT row is missing: `PART_`.

---

## Price Method

- **Estimate**: method determined by per-component settings in `qt_lot_metadata` (`pricelist_type='estimate'`). Default: `median`.
- **Warehouse**: `weighted_avg` (quantity-weighted average). Default `period_days=7`.
- **Competitor**: `weighted_median`. `qty NULL` → weight = 1.
- **World**: `weighted_median` across all supplier types. `qty NULL` → weight = 1.

---

## supplier_type

The `supplier` table `supplier_type` column determines which pricelist(s) a supplier's quotes feed:

| supplier_type | Feeds into |
|---------------|-----------|
| `trader` | estimate, world |
| `self` | warehouse, world |
| `competitor` | competitor, world |

**price_uplift**: divisor applied at import. `effective_price = raw_price / price_uplift`. All prices in `parts_log` are always in USD.

**Defaults by type**:
| supplier_type | price_uplift | default_lead_time_weeks |
|---------------|-------------|------------------------|
| trader | 1.0 | NULL |
| self | 1.0 | 0 |
| competitor | 1.3 | 2 |

---

## offer_type

`parts_log.offer_type` ENUM: `'private'` or `'public'` (default `'public'`).

Selected at import time. Both types are currently included in all pricelist calculations.

---

## qt_ignore_rules

Replaces the `is_ignored` mechanism in `qt_vendor_partnumber_seen`. Checked at import before mapping.

| field | match_type | behavior |
|-------|-----------|---------|
| partnumber / vendor / description | exact / glob / contains | DROP row if matched |

Order of checks at import: **ignore rules → partnumber book → write to parts_log**.

---

## Filtering by qt_partnumber_book_items

**Rule (CRITICAL)**: only `parts_log` rows with a non-NULL `lot_name` are included in any pricelist. `lot_name` is populated by the daily backfill job (`PartsLogBackfillService`) which resolves partnumbers via `qt_partnumber_book_items`. Rows that cannot be resolved remain with `lot_name=NULL` and are excluded from all pricelists.

---

## Component Data Source

- Source: MariaDB (not SQLite).
- `handlers/component.go` uses `componentService.List()` (MariaDB).