import subprocess
import tempfile
import textwrap
import unittest
from pathlib import Path

import numpy as np

from .. import PySRRegressor
from .params import (
    DEFAULT_NCYCLES,
    DEFAULT_NITERATIONS,
    DEFAULT_PARAMS,
    DEFAULT_POPULATIONS,
)


class TestWarmStart(unittest.TestCase):
    def setUp(self):
        # Using inspect,
        # get default niterations from PySRRegressor, and double them:
        self.default_test_kwargs = dict(
            progress=False,
            model_selection="accuracy",
            niterations=DEFAULT_NITERATIONS * 2,
            populations=DEFAULT_POPULATIONS * 2,
            temp_equation_file=True,
        )
        self.rstate = np.random.RandomState(0)
        self.X = self.rstate.randn(100, 5)

    def test_warm_start_from_file(self):
        """Test that we can warm start in another process."""
        with tempfile.TemporaryDirectory() as tmpdirname:
            model = PySRRegressor(
                **self.default_test_kwargs,
                unary_operators=["cos"],
            )
            model.warm_start = True
            model.temp_equation_file = False
            model.equation_file = Path(tmpdirname) / "equations.csv"
            model.deterministic = True
            model.multithreading = False
            model.random_state = 0
            model.procs = 0
            model.early_stop_condition = 1e-10

            rstate = np.random.RandomState(0)
            X = rstate.randn(100, 2)
            y = np.cos(X[:, 0]) ** 2
            model.fit(X, y)

            best_loss = model.equations_.iloc[-1]["loss"]

            # Save X and y to a file:
            X_file = Path(tmpdirname) / "X.npy"
            y_file = Path(tmpdirname) / "y.npy"
            np.save(X_file, X)
            np.save(y_file, y)
            # Now, create a new process and warm start from the file:
            result = subprocess.run(
                [
                    "python",
                    "-c",
                    textwrap.dedent(
                        f"""
                        from pysr import PySRRegressor
                        import numpy as np

                        X = np.load("{X_file}")
                        y = np.load("{y_file}")

                        print("Loading model from file")
                        model = PySRRegressor.from_file("{model.equation_file}")

                        assert model.julia_state_ is not None

                        model.warm_start = True
                        model.niterations = 0
                        model.max_evals = 0
                        model.ncyclesperiteration = 0

                        model.fit(X, y)

                        best_loss = model.equations_.iloc[-1]["loss"]

                        assert best_loss <= {best_loss}
                    """
                    ),
                ],
                stdout=subprocess.PIPE,
                stderr=subprocess.PIPE,
            )
            self.assertEqual(result.returncode, 0)
            self.assertIn("Loading model from file", result.stdout.decode())
            self.assertIn("Started!", result.stderr.decode())


def runtests():
    suite = unittest.TestSuite()
    loader = unittest.TestLoader()
    suite.addTests(loader.loadTestsFromTestCase(TestWarmStart))
    runner = unittest.TextTestRunner()
    return runner.run(suite)