import tempfile
import unittest
from pathlib import Path
from unittest import mock

import pandas as pd

import data_manager


class UpdateMarketDataTests(unittest.TestCase):
    def test_update_market_data_accepts_lowercase_fields_and_does_not_fill_volume(self):
        dates = pd.to_datetime(["2024-01-02", "2024-01-03", "2024-01-04"])
        raw = pd.DataFrame(
            {
                ("Close", "AAA"): [10.0, 11.0, 12.0],
                ("Close", "BBB"): [20.0, float("nan"), 22.0],
                ("Open", "AAA"): [9.5, 10.5, 11.5],
                ("Open", "BBB"): [19.5, 20.5, 21.5],
                ("High", "AAA"): [10.5, 11.5, 12.5],
                ("High", "BBB"): [20.5, 21.5, 22.5],
                ("Low", "AAA"): [9.0, 10.0, 11.0],
                ("Low", "BBB"): [19.0, 20.0, 21.0],
                ("Volume", "AAA"): [1000, 1100, 1200],
                ("Volume", "BBB"): [2000, float("nan"), 2200],
            },
            index=dates,
        )
        raw.columns = pd.MultiIndex.from_tuples(raw.columns)

        with tempfile.TemporaryDirectory() as tmpdir:
            with mock.patch.object(data_manager, "DATA_DIR", tmpdir):
                with mock.patch("data_manager.yf.download", return_value=raw) as mocked_download:
                    panels = data_manager.update_market_data(
                        "us",
                        ["AAA", "BBB"],
                        ["close", "open", "high", "low", "volume"],
                    )
                self.assertEqual(set(panels), {"close", "open", "high", "low", "volume"})
                self.assertEqual(panels["close"].loc[dates[1], "BBB"], 20.0)
                self.assertTrue(pd.isna(panels["volume"].loc[dates[1], "BBB"]))
                self.assertTrue((Path(tmpdir) / "us.csv").exists())
                self.assertTrue((Path(tmpdir) / "us_open.csv").exists())
                self.assertTrue((Path(tmpdir) / "us_high.csv").exists())
                self.assertTrue((Path(tmpdir) / "us_low.csv").exists())
                self.assertTrue((Path(tmpdir) / "us_volume.csv").exists())

                saved_high = pd.read_csv(Path(tmpdir) / "us_high.csv", index_col=0, parse_dates=True)
                pd.testing.assert_frame_equal(saved_high, panels["high"], check_freq=False)

                self.assertEqual(mocked_download.call_args.args[0], ["AAA", "BBB"])
                self.assertEqual(mocked_download.call_args.kwargs["auto_adjust"], True)
                self.assertIn("start", mocked_download.call_args.kwargs)

    def test_update_market_data_rejects_unsupported_fields(self):
        with tempfile.TemporaryDirectory() as tmpdir:
            with mock.patch.object(data_manager, "DATA_DIR", tmpdir):
                with self.assertRaisesRegex(ValueError, "Unsupported market data field: adjusted_close"):
                    data_manager.update_market_data("us", ["AAA"], ["adjusted_close"])

    def test_update_market_data_preserves_existing_cache_columns_and_dates(self):
        existing_dates = pd.to_datetime(["2024-01-01", "2024-01-02"])
        new_dates = pd.to_datetime(["2024-01-02", "2024-01-03"])
        existing_close = pd.DataFrame(
            {
                "AAA": [9.0, 10.0],
                "CCC": [30.0, 31.0],
            },
            index=existing_dates,
        )
        downloaded_close = pd.DataFrame({"Close": [10.5, 11.5]}, index=new_dates)

        with tempfile.TemporaryDirectory() as tmpdir:
            existing_close.to_csv(Path(tmpdir) / "us.csv")
            with mock.patch.object(data_manager, "DATA_DIR", tmpdir):
                with mock.patch("data_manager.yf.download", return_value=downloaded_close):
                    panels = data_manager.update_market_data("us", ["AAA"], ["close"])

            expected = pd.DataFrame(
                {
                    "AAA": [9.0, 10.5, 11.5],
                    "CCC": [30.0, 31.0, float("nan")],
                },
                index=pd.to_datetime(["2024-01-01", "2024-01-02", "2024-01-03"]),
            )
            saved_close = pd.read_csv(Path(tmpdir) / "us.csv", index_col=0, parse_dates=True)

        pd.testing.assert_frame_equal(panels["close"], expected, check_freq=False)
        pd.testing.assert_frame_equal(saved_close, expected, check_freq=False)

    def test_update_market_data_volume_merge_can_clear_stale_cached_values(self):
        existing_dates = pd.to_datetime(["2024-01-01", "2024-01-02"])
        new_dates = pd.to_datetime(["2024-01-02", "2024-01-03", "2024-01-04"])
        existing_volume = pd.DataFrame(
            {
                "AAA": [1000.0, 9999.0],
                "CCC": [3000.0, 3100.0],
            },
            index=existing_dates,
        )
        downloaded_volume = pd.DataFrame({"Volume": [float("nan"), 1200.0, 1300.0]}, index=new_dates)

        with tempfile.TemporaryDirectory() as tmpdir:
            existing_volume.to_csv(Path(tmpdir) / "us_volume.csv")
            with mock.patch.object(data_manager, "DATA_DIR", tmpdir):
                with mock.patch("data_manager.yf.download", return_value=downloaded_volume):
                    panels = data_manager.update_market_data("us", ["AAA"], ["volume"])

            expected = pd.DataFrame(
                {
                    "AAA": [1000.0, float("nan"), 1200.0, 1300.0],
                    "CCC": [3000.0, 3100.0, float("nan"), float("nan")],
                },
                index=pd.to_datetime(["2024-01-01", "2024-01-02", "2024-01-03", "2024-01-04"]),
            )
            saved_volume = pd.read_csv(Path(tmpdir) / "us_volume.csv", index_col=0, parse_dates=True)

        pd.testing.assert_frame_equal(panels["volume"], expected, check_freq=False)
        pd.testing.assert_frame_equal(saved_volume, expected, check_freq=False)

    def test_update_market_data_handles_single_ticker_multiindex_download(self):
        dates = pd.to_datetime(["2024-01-02", "2024-01-03"])
        raw = pd.DataFrame(
            {
                ("Close", "AAA"): [10.0, 11.0],
                ("Volume", "AAA"): [1000.0, 1100.0],
            },
            index=dates,
        )
        raw.columns = pd.MultiIndex.from_tuples(raw.columns)

        with tempfile.TemporaryDirectory() as tmpdir:
            with mock.patch.object(data_manager, "DATA_DIR", tmpdir):
                with mock.patch("data_manager.yf.download", return_value=raw):
                    panels = data_manager.update_market_data("us", ["AAA"], ["close", "volume"])

        expected_close = pd.DataFrame({"AAA": [10.0, 11.0]}, index=dates)
        expected_volume = pd.DataFrame({"AAA": [1000.0, 1100.0]}, index=dates)
        pd.testing.assert_frame_equal(panels["close"], expected_close, check_freq=False)
        pd.testing.assert_frame_equal(panels["volume"], expected_volume, check_freq=False)


if __name__ == "__main__":
    unittest.main()