"""Unit tests for LudwigModel API edge cases."""

import logging
from unittest.mock import MagicMock, patch

import numpy as np
import pandas as pd
import pytest

from ludwig.api import LudwigModel
from ludwig.callbacks import Callback

# ---------------------------------------------------------------------------
# Helpers
# ---------------------------------------------------------------------------


class RecordingCallback(Callback):
    """Records which hooks were called and in what order."""

    def __init__(self):
        self.calls: list[str] = []

    def on_train_start(self, *args, **kwargs):
        self.calls.append("on_train_start")

    def on_train_end(self, *args, **kwargs):
        self.calls.append("on_train_end")

    def on_evaluation_start(self, **kwargs):
        self.calls.append("on_evaluation_start")

    def on_evaluation_end(self, **kwargs):
        self.calls.append("on_evaluation_end")

    def on_preprocess_start(self, *args, **kwargs):
        self.calls.append("on_preprocess_start")

    def on_preprocess_end(self, *args, **kwargs):
        self.calls.append("on_preprocess_end")


# ---------------------------------------------------------------------------
# 1a. Model card / training report exception handling
# ---------------------------------------------------------------------------


def test_model_card_failure_does_not_abort_training(tmpdir, caplog):
    """Training should complete even if model card generation fails.

    The failure should be logged at WARNING with a DEBUG traceback.
    """
    config = {
        "input_features": [{"name": "x", "type": "number"}],
        "output_features": [{"name": "y", "type": "binary"}],
        "trainer": {"train_steps": 1, "batch_size": 8},
    }

    import pandas as pd

    df = pd.DataFrame({"x": range(20), "y": [0, 1] * 10})

    with patch("ludwig.utils.model_card.save_model_card", side_effect=RuntimeError("card boom")):
        with caplog.at_level(logging.WARNING, logger="ludwig"):
            # logging_level=WARNING so LudwigModel.__init__ doesn't override caplog to ERROR
            model = LudwigModel(config, logging_level=logging.WARNING)
            result = model.train(dataset=df, output_directory=str(tmpdir))

    assert result is not None, "training should complete despite model card failure"
    assert any("Failed to generate model card" in m for m in caplog.messages)


def test_training_report_failure_does_not_abort_training(tmpdir, caplog):
    """Training should complete even if training report generation fails."""
    config = {
        "input_features": [{"name": "x", "type": "number"}],
        "output_features": [{"name": "y", "type": "binary"}],
        "trainer": {"train_steps": 1, "batch_size": 8},
    }

    import pandas as pd

    df = pd.DataFrame({"x": range(20), "y": [0, 1] * 10})

    with patch("ludwig.utils.training_report.save_training_report", side_effect=RuntimeError("report boom")):
        with caplog.at_level(logging.WARNING, logger="ludwig"):
            model = LudwigModel(config, logging_level=logging.WARNING)
            result = model.train(dataset=df, output_directory=str(tmpdir))

    assert result is not None
    assert any("Failed to generate training report" in m for m in caplog.messages)


# ---------------------------------------------------------------------------
# 1b. evaluate() batch size fallback
# ---------------------------------------------------------------------------


def _make_evaluate_mock(trainer_dict: dict):
    """Return a MagicMock LudwigModel wired for evaluate() batch size tests."""
    # Don't pass spec= here — config_obj is an instance attribute set in __init__,
    # not a class-level attribute, so spec=LudwigModel would block access to it.
    model = MagicMock()
    model.callbacks = []
    model.config_obj.trainer.to_dict.return_value = trainer_dict

    dataset_mock = MagicMock()
    metadata_mock = MagicMock()
    model._preprocess_for_prediction.return_value = (dataset_mock, metadata_mock)

    predictor = MagicMock()
    predictor.batch_evaluation.return_value = ({}, MagicMock())

    ctx = MagicMock()
    ctx.__enter__ = MagicMock(return_value=predictor)
    ctx.__exit__ = MagicMock(return_value=False)
    model.backend.create_predictor.return_value = ctx

    model.backend.df_engine.df_lib = pd
    model.model.output_features = {}
    return model, predictor


def _run_evaluate(model):
    """Call LudwigModel.evaluate() with all saving and collection disabled."""
    return LudwigModel.evaluate(
        model,
        dataset=MagicMock(),
        collect_predictions=False,
        collect_overall_stats=False,
        skip_save_unprocessed_output=True,
        skip_save_predictions=True,
        skip_save_eval_stats=True,
    )


def test_evaluate_uses_eval_batch_size_from_config():
    """Evaluate() should use eval_batch_size from trainer config when batch_size arg is None."""
    model, predictor = _make_evaluate_mock({"eval_batch_size": 64, "batch_size": 32})
    model.backend.is_coordinator.return_value = False
    predictor.batch_evaluation.return_value = ({}, {})

    _run_evaluate(model)

    model.backend.create_predictor.assert_called_once_with(model.model, batch_size=64)


def test_evaluate_falls_back_to_batch_size_when_eval_batch_size_absent():
    """Evaluate() should fall back to batch_size when eval_batch_size is not in trainer config."""
    model, predictor = _make_evaluate_mock({"batch_size": 16})
    model.backend.is_coordinator.return_value = False
    predictor.batch_evaluation.return_value = ({}, {})

    _run_evaluate(model)

    model.backend.create_predictor.assert_called_once_with(model.model, batch_size=16)


def test_evaluate_raises_when_no_batch_size_in_config():
    """Evaluate() must raise ValueError when neither batch_size nor eval_batch_size are set."""
    model, _ = _make_evaluate_mock({})  # empty trainer dict — no batch sizes

    with pytest.raises(ValueError, match="batch_size not specified"):
        _run_evaluate(model)


# ---------------------------------------------------------------------------
# 1c. forecast() boundary conditions
# ---------------------------------------------------------------------------


def _make_forecast_mock(output_features, input_features=None):
    """Return a MagicMock LudwigModel wired for forecast() boundary tests."""
    model = MagicMock(spec=LudwigModel)
    model.callbacks = []
    model.config_obj.output_features = output_features
    model.config_obj.input_features = input_features or []

    dataset_mock = MagicMock()
    model.backend.df_engine.df_lib = pd
    return model, dataset_mock


def test_forecast_raises_when_no_timeseries_input_feature():
    """Forecast() should raise ValueError when no timeseries input feature is present."""
    from unittest.mock import patch as _patch

    # No timeseries input features
    input_features = [MagicMock(type="number", preprocessing=MagicMock(window_size=5))]
    input_features[0].type = "number"  # not TIMESERIES

    model = MagicMock()
    model.callbacks = []
    model.config_obj.input_features = input_features

    df = pd.DataFrame({"x": range(5)})

    with _patch("ludwig.api.load_dataset_uris", return_value=(df, None, None, None)):
        with _patch("ludwig.api.load_dataset", return_value=df):
            with pytest.raises(ValueError, match="timeseries"):
                LudwigModel.forecast(model, dataset=df, horizon=3)


def test_forecast_returns_dataframe_for_valid_config():
    """Forecast() should return a DataFrame with the output feature column for a valid config."""
    from ludwig.constants import TIMESERIES

    window_size = 3
    df = pd.DataFrame({"x": range(window_size + 2), "y": [float(i) for i in range(window_size + 2)]})

    in_feat = MagicMock()
    in_feat.type = TIMESERIES
    in_feat.name = "x"
    in_feat.preprocessing.window_size = window_size
    in_feat.preprocessing.padding_value = 0.0

    out_feat = MagicMock()
    out_feat.type = TIMESERIES
    out_feat.column = "y"
    out_feat.name = "y"

    model = MagicMock()
    model.callbacks = []
    model.config_obj.input_features = [in_feat]
    model.config_obj.output_features = [out_feat]
    model.backend.is_coordinator.return_value = False

    # Set up _check_initialization to be a no-op
    model._check_initialization = MagicMock()

    # Set up preprocessed dataset mock — one row with window_size embedding
    proc_dataset = MagicMock()
    proc_dataset.dataset = {"x__proc": np.array([[1.0, 2.0, 3.0]])}
    model._preprocess_for_prediction.return_value = (proc_dataset, {})

    # Set up model.input_features for the embedding extraction loop
    i_feat_mock = MagicMock()
    i_feat_mock.proc_column = "x__proc"
    model.model.input_features.values.return_value = [i_feat_mock]
    model.model.output_features = {out_feat.name: MagicMock()}

    # Set up predictor as context manager returning predict_single results
    raw_pred = pd.DataFrame({"y_predictions": [np.array([42.0])]})
    predictor = MagicMock()
    predictor.predict_single.return_value = raw_pred
    ctx = MagicMock()
    ctx.__enter__ = MagicMock(return_value=predictor)
    ctx.__exit__ = MagicMock(return_value=False)
    model.backend.create_predictor.return_value = ctx

    postproc_pred = pd.DataFrame({"y_predictions": [np.array([42.0])]})

    horizon = 3
    with patch("ludwig.api.load_dataset_uris", return_value=(df, None, None, None)):
        with patch("ludwig.api.load_dataset", return_value=df):
            with patch("ludwig.api.postprocess", return_value=postproc_pred):
                result = LudwigModel.forecast(model, dataset=df, horizon=horizon)

    assert isinstance(result, pd.DataFrame)
    assert "y" in result.columns
    assert len(result) <= horizon


# ---------------------------------------------------------------------------
# _check_initialization
# ---------------------------------------------------------------------------


def test_check_initialization_missing_model():
    """_check_initialization should name missing components."""
    model = MagicMock(spec=LudwigModel)
    model.model = None
    model._user_config = {"input_features": [], "output_features": []}
    model.training_set_metadata = {"x": {}}

    # Call the real method on the mock instance
    with pytest.raises(ValueError, match="model"):
        LudwigModel._check_initialization(model)


def test_check_initialization_missing_metadata():
    model = MagicMock(spec=LudwigModel)
    model.model = MagicMock()
    model._user_config = {"input_features": [], "output_features": []}
    model.training_set_metadata = None

    with pytest.raises(ValueError, match="training_set_metadata"):
        LudwigModel._check_initialization(model)


def test_check_initialization_all_present():
    model = MagicMock(spec=LudwigModel)
    model.model = MagicMock()
    model._user_config = {"input_features": [], "output_features": []}
    model.training_set_metadata = {"x": {}}

    # Should not raise
    LudwigModel._check_initialization(model)


# ---------------------------------------------------------------------------
# 1d. Callback lifecycle ordering
# ---------------------------------------------------------------------------


def test_preprocess_callbacks_fire_in_order(tmpdir):
    """on_preprocess_start fires before on_preprocess_end."""
    config = {
        "input_features": [{"name": "x", "type": "number"}],
        "output_features": [{"name": "y", "type": "binary"}],
        "trainer": {"train_steps": 1, "batch_size": 8},
    }

    import pandas as pd

    df = pd.DataFrame({"x": range(20), "y": [0, 1] * 10})
    cb = RecordingCallback()
    model = LudwigModel(config, callbacks=[cb])
    model.preprocess(dataset=df, output_directory=str(tmpdir))

    assert "on_preprocess_start" in cb.calls
    assert "on_preprocess_end" in cb.calls
    assert cb.calls.index("on_preprocess_start") < cb.calls.index("on_preprocess_end")


def test_evaluate_callbacks_fire_in_order(tmpdir):
    """on_evaluation_start fires before on_evaluation_end."""
    config = {
        "input_features": [{"name": "x", "type": "number"}],
        "output_features": [{"name": "y", "type": "binary"}],
        "trainer": {"train_steps": 1, "batch_size": 8},
    }

    import pandas as pd

    df = pd.DataFrame({"x": range(20), "y": [0, 1] * 10})
    cb = RecordingCallback()
    model = LudwigModel(config, callbacks=[cb])
    model.train(dataset=df, output_directory=str(tmpdir))

    cb.calls.clear()
    model.evaluate(dataset=df)

    assert "on_evaluation_start" in cb.calls
    assert "on_evaluation_end" in cb.calls
    assert cb.calls.index("on_evaluation_start") < cb.calls.index("on_evaluation_end")