"""Label sets shared by the synthetic data generator, the extraction model and JSON assembly."""

FIELD_LABELS = [
    "other",            # decorative / irrelevant text
    "key",              # a label such as "Total:" or "Invoice No." whose value is a separate segment
    "merchant_name", "merchant_address", "merchant_phone", "merchant_tax_id",
    "customer",         # bill-to block on invoices
    "invoice_number", "date", "due_date", "time",
    "item_desc", "item_qty", "item_unit_price", "item_amount",
    "subtotal", "tax", "discount", "total", "amount_paid", "change",
    "heading", "paragraph", "list_item", "table_cell",
    "formula",          # display maths: detected and skipped (not transcribed)
]
LABEL_ID = {n: i for i, n in enumerate(FIELD_LABELS)}

DOC_TYPES = ["receipt", "invoice", "general"]
DOC_ID = {n: i for i, n in enumerate(DOC_TYPES)}

# Pairwise relations between segments.
#   same_row:  both segments belong to the same line item / table row (symmetric)
#   key_value: segment i is the key whose value is segment j (directed)
#   same_block: both segments belong to the same layout block (paragraph, list item, table, caption...)
# New labels and relations are appended so older checkpoints load into the matching rows (train --init).
REL_TYPES = ["same_row", "key_value", "same_block"]

MONEY_FIELDS = {"item_unit_price", "item_amount", "subtotal", "tax", "discount", "total", "amount_paid", "change"}
ITEM_FIELDS = {"item_desc", "item_qty", "item_unit_price", "item_amount"}
STRUCTURE_LABELS = {"heading", "paragraph", "list_item", "table_cell", "formula"}