| """compare_documents tool — compare two (or auto-detected three) documents. |
| |
| Behavior: |
| 1. If the two documents are part of an invoice + delivery_note + purchase_order |
| triplet, automatically locates the third and runs ``three_way_match()``. |
| 2. Otherwise runs ``compare_two_documents()`` on the matching fields. |
| |
| Uses ``validation/compare.py`` for the underlying 4-pass item matching, |
| apples-to-apples amount comparison, and tolerance tiers. |
| """ |
|
|
| from __future__ import annotations |
|
|
| from langchain_core.tools import tool |
|
|
| from tools.context import ChatToolContext |
| from validation.compare import compare_two_documents, three_way_match |
|
|
|
|
| def _format_report(result, header: str, sources: list[str]) -> str: |
| """ComparisonResult → user-friendly text.""" |
| lines = [ |
| f"Total: {result.total_checks} checks, " |
| f"{result.ok_count} OK, {result.warning_count} warnings, " |
| f"{result.critical_count} critical, {result.missing_count} missing", |
| ] |
| for m in result.matches: |
| if m.severity != "ok": |
| lines.append(f" [{m.severity.upper()}] {m.message}") |
| if result.ok_count == result.total_checks: |
| lines.append(" All checks passed.") |
|
|
| body = "\n".join(lines) |
| src = f"[Source: {', '.join(sources)}]" |
| return f"{header}\n{body}\n\n{src}" |
|
|
|
|
| def build_compare_documents_tool(ctx: ChatToolContext): |
| @tool |
| def compare_documents(filename_a: str, filename_b: str) -> str: |
| """Compare the extracted data of two documents. |
| |
| Compares amounts, line items, and dates and reports discrepancies. |
| If the two documents are part of an invoice + delivery_note + |
| purchase_order triplet, automatically locates the third document |
| and runs three-way matching. |
| |
| Args: |
| filename_a: filename of the first document |
| filename_b: filename of the second document |
| """ |
| pd_a = ctx.get_document(filename_a) |
| pd_b = ctx.get_document(filename_b) |
| if pd_a is None or pd_b is None: |
| missing = [] |
| if pd_a is None: |
| missing.append(filename_a) |
| if pd_b is None: |
| missing.append(filename_b) |
| return f"Not found: {', '.join(missing)}. Available: {ctx.list_filenames()}" |
|
|
| a_raw = pd_a.extracted.raw if pd_a.extracted else {} |
| b_raw = pd_b.extracted.raw if pd_b.extracted else {} |
|
|
| type_a = pd_a.classification.doc_type if pd_a.classification else "" |
| type_b = pd_b.classification.doc_type if pd_b.classification else "" |
| types_set = {type_a, type_b} |
|
|
| |
| triplet_types = {"invoice", "delivery_note", "purchase_order"} |
| if types_set <= triplet_types and len(types_set) == 2: |
| needed = triplet_types - types_set |
| needed_type = needed.pop() |
| third_filenames = [ |
| fn for fn in ctx.list_filenames() |
| if (pd := ctx.get_document(fn)) is not None |
| and pd.classification is not None |
| and pd.classification.doc_type == needed_type |
| ] |
| if third_filenames: |
| pd_third = ctx.get_document(third_filenames[0]) |
| if pd_third is not None and pd_third.extracted is not None: |
| docs_by_type = { |
| type_a: a_raw, |
| type_b: b_raw, |
| needed_type: pd_third.extracted.raw, |
| } |
| result = three_way_match( |
| invoice=docs_by_type["invoice"], |
| delivery_note=docs_by_type["delivery_note"], |
| purchase_order=docs_by_type["purchase_order"], |
| ) |
| return _format_report( |
| result, |
| header=( |
| f"Three-way matching: invoice + delivery_note + purchase_order " |
| f"({filename_a}, {filename_b}, {third_filenames[0]})" |
| ), |
| sources=[filename_a, filename_b, third_filenames[0]], |
| ) |
|
|
| |
| all_fields = list(set(a_raw.keys()) | set(b_raw.keys())) |
| all_fields = [f for f in all_fields if not f.startswith("_")] |
| result = compare_two_documents(a_raw, b_raw, all_fields) |
| return _format_report( |
| result, |
| header=f"Compare: {filename_a} vs {filename_b}", |
| sources=[filename_a, filename_b], |
| ) |
|
|
| return compare_documents |
|
|
