from __future__ import annotations

from typing import Any, Dict, List, Optional, Tuple

from application.service import InvoiceProcessingService
from application.strategies import InvoiceExtractorStrategy
import application.service as service_module


class DummyExtractor(InvoiceExtractorStrategy):
  """Extractor mínimo para pruebas que devuelve un JSON fijo."""
  def __init__(self, fail_first: bool = False) -> None:
    self.fail_first = fail_first
    self.calls = 0

  def extract(self, images_b64: List[str], instruction: str) -> Dict[str, Any]:
    self.calls += 1
    if self.fail_first and self.calls == 1:
      raise RuntimeError("forced failure")
    return {
      "raw": '{"ok": true}',
      "usage": {},
    }


def test_extract_full_from_pdf_propagates_tiff_page_range(monkeypatch, tmp_path) -> None:
  dummy_pdf = tmp_path / "doc.tif"
  dummy_pdf.write_bytes(b"fake")

  captured: List[Dict[str, Any]] = []

  def fake_document_to_images_bs64(path: str, **kwargs: Any) -> List[str]:
    captured.append({"path": path, **kwargs})
    return ["img"]

  # Parchear el símbolo importado en el módulo de servicio
  monkeypatch.setattr(service_module, "document_to_images_bs64", fake_document_to_images_bs64)

  service = InvoiceProcessingService(DummyExtractor())
  data, usage = service.extract_full_from_pdf(str(dummy_pdf), instruction="x", tiff_page_range=(2, 3))

  assert data == {"ok": True}
  assert isinstance(usage, dict)
  assert captured, "Se esperaba al menos una llamada a document_to_images_bs64"
  # Primera llamada (flujo normal) debe respetar el rango solicitado
  assert captured[0].get("tiff_page_range") == (2, 3)


def test_extract_full_from_pdf_fallback_ignores_tiff_page_range(monkeypatch, tmp_path) -> None:
  dummy_pdf = tmp_path / "doc2.tif"
  dummy_pdf.write_bytes(b"fake")

  captured: List[Dict[str, Any]] = []

  def fake_document_to_images_bs64(path: str, **kwargs: Any) -> List[str]:
    captured.append({"path": path, **kwargs})
    return ["img"]

  monkeypatch.setattr(service_module, "document_to_images_bs64", fake_document_to_images_bs64)

  service = InvoiceProcessingService(DummyExtractor(fail_first=True))
  data, usage = service.extract_full_from_pdf(str(dummy_pdf), instruction="x", tiff_page_range=(2, 3))

  assert data == {"ok": True}
  assert isinstance(usage, dict)
  # Deben existir dos llamadas: una normal (que falla el extractor) y otra fallback
  assert len(captured) == 2
  assert captured[0].get("tiff_page_range") == (2, 3)
  # En fallback NO debe propagarse el rango explícito
  assert captured[1].get("tiff_page_range") is None