import pytest

from core.utils import SelectConf, select
from core.Expando import Expando


def test_i_can_select_basic_attributes():
  """Test basic selection of existing attributes."""
  items = [
      Expando({"name": "alice", "age": 25, "city": "paris"}),
      Expando({"name": "bob", "age": 30, "city": "london"})
  ]
  settings = [
      SelectConf(attr="name"),
      SelectConf(attr="age")
  ]
  
  result = select(items, settings)
  
  assert len(result) == 2
  assert result[0].name == "alice"
  assert result[0].age == 25
  assert not hasattr(result[0], "city")  # city not selected
  assert result[1].name == "bob"
  assert result[1].age == 30


def test_i_can_select_with_renamed_attributes():
  """Test renaming attributes using SelectConf.to."""
  items = [
      Expando({"name": "alice", "age": 25}),
      Expando({"name": "bob", "age": 30})
  ]
  settings = [
      SelectConf(attr="name", to="full_name"),
      SelectConf(attr="age", to="years")
  ]
  
  result = select(items, settings)
  
  assert len(result) == 2
  assert result[0].full_name == "alice"
  assert result[0].years == 25
  assert not hasattr(result[0], "name")  # original name not present
  assert not hasattr(result[0], "age")  # original name not present
  assert result[1].full_name == "bob"
  assert result[1].years == 30


def test_i_can_select_with_formatter():
  """Test applying formatters to selected attributes."""
  items = [
      Expando({"name": "alice", "age": 25}),
      Expando({"name": "bob", "age": 30})
  ]
  settings = [
      SelectConf(attr="name", formatter=lambda item: item.name.upper()),
      SelectConf(attr="age", formatter=lambda item: item.age * 2)
  ]
  
  result = select(items, settings)
  
  assert len(result) == 2
  assert result[0].name == "ALICE"
  assert result[0].age == 50
  assert result[1].name == "BOB"
  assert result[1].age == 60


def test_i_can_select_with_formatter_and_rename():
  """Test combining formatter and renaming."""
  items = [
      Expando({"name": "alice", "age": 25}),
      Expando({"name": "bob", "age": 30})
  ]
  settings = [
      SelectConf(attr="name", to="upper_name", formatter=lambda item: item.name.upper()),
      SelectConf(attr="age", to="double_age", formatter=lambda item: item.age * 2)
  ]
  
  result = select(items, settings)
  
  assert len(result) == 2
  assert result[0].upper_name == "ALICE"
  assert result[0].double_age == 50
  assert not hasattr(result[0], "name")
  assert not hasattr(result[0], "age")
  assert result[1].upper_name == "BOB"
  assert result[1].double_age == 60


def test_i_can_handle_empty_items_list():
  """Test that empty items list returns empty list."""
  items = []
  settings = [SelectConf(attr="name")]
  
  result = select(items, settings)
  
  assert result == []


def test_i_can_handle_empty_settings_list():
  """Test that empty settings list returns items with empty properties."""
  items = [
      Expando({"name": "alice", "age": 25}),
      Expando({"name": "bob", "age": 30})
  ]
  settings = []
  
  result = select(items, settings)
  
  assert len(result) == 2
  # Each result should be an Expando with empty properties
  assert result[0]._props == {}
  assert result[1]._props == {}


def test_i_can_handle_missing_attributes():
  """Test that missing attributes return None (normal behavior)."""
  items = [
      Expando({"name": "alice"}),  # no age attribute
      Expando({"name": "bob", "age": 30})
  ]
  settings = [
      SelectConf(attr="name"),
      SelectConf(attr="age")  # missing in first item
  ]
  
  result = select(items, settings)
  
  assert len(result) == 2
  assert result[0].name == "alice"
  assert result[0].age is None  # missing attribute returns None
  assert result[1].name == "bob"
  assert result[1].age == 30


def test_i_can_handle_whitespace_in_attr_names():
  """Test that whitespace in attribute names is stripped."""
  items = [
      Expando({"name": "alice", "age": 25})
  ]
  settings = [
      SelectConf(attr="  name  "),  # whitespace around attr
      SelectConf(attr="\tage\n")  # tabs and newlines
  ]
  
  result = select(items, settings)
  
  assert len(result) == 1
  assert result[0].name == "alice"
  assert result[0].age == 25


def test_i_can_select_multiple_attributes():
  """Test selecting multiple attributes from multiple items."""
  items = [
      Expando({"name": "alice", "age": 25, "city": "paris", "country": "france"}),
      Expando({"name": "bob", "age": 30, "city": "london", "country": "uk"}),
      Expando({"name": "charlie", "age": 35, "city": "madrid", "country": "spain"})
  ]
  settings = [
      SelectConf(attr="name"),
      SelectConf(attr="city", to="location"),
      SelectConf(attr="country", formatter=lambda item: item.country.upper())
  ]
  
  result = select(items, settings)
  
  assert len(result) == 3
  assert result[0].name == "alice"
  assert result[0].location == "paris"
  assert result[0].country == "FRANCE"
  assert result[1].name == "bob"
  assert result[1].location == "london"
  assert result[1].country == "UK"
  assert result[2].name == "charlie"
  assert result[2].location == "madrid"
  assert result[2].country == "SPAIN"


def test_i_can_handle_formatter_with_whole_item():
  """Test that formatter receives the whole item, not just the attribute value."""
  items = [
      Expando({"first_name": "alice", "last_name": "smith"}),
      Expando({"first_name": "bob", "last_name": "jones"})
  ]
  settings = [
      SelectConf(
        attr="first_name",
        to="full_name",
        formatter=lambda item: f"{item.get('first_name')} {item.get('last_name')}"
      )
  ]
  
  result = select(items, settings)
  
  assert len(result) == 2
  assert result[0].full_name == "alice smith"
  assert result[1].full_name == "bob jones"


def test_i_cannot_select_when_formatter_raises_exception():
  """Test that formatter exceptions are propagated."""
  items = [
      Expando({"name": "alice", "value": None})
  ]
  settings = [
      SelectConf(
        attr="value",
        formatter=lambda item: item.get("value").upper()  # will fail on None
      )
  ]
  
  with pytest.raises(AttributeError):
    select(items, settings)


def test_i_can_handle_none_values_in_formatter():
  """Test formatter handling None values gracefully when designed to do so."""
  items = [
      Expando({"name": "alice", "value": None}),
      Expando({"name": "bob", "value": "test"})
  ]
  settings = [
      SelectConf(
        attr="value",
        formatter=lambda item: item.get("value").upper() if item.get("value") else "NO_VALUE"
      )
  ]
  
  result = select(items, settings)
  
  assert len(result) == 2
  assert result[0].value == "NO_VALUE"
  assert result[1].value == "TEST"


def test_i_can_select_nested_attributes():
  """Test selecting nested attributes using Expando.get() path notation."""
  items = [
      Expando({"user": {"profile": {"name": "alice"}}, "age": 25}),
      Expando({"user": {"profile": {"name": "bob"}}, "age": 30})
  ]
  settings = [
      SelectConf(attr="user.profile.name", to="name"),
      SelectConf(attr="age")
  ]
  
  result = select(items, settings)
  
  assert len(result) == 2
  assert result[0].name == "alice"
  assert result[0].age == 25
  assert result[1].name == "bob"
  assert result[1].age == 30