"""Tests for data preprocessors."""

import numpy as np
import pandas as pd
import pytest

from src.data.preprocessors import filter_session, handle_missing_data, remove_duplicates


@pytest.fixture
def sample_data_with_missing():
    """Create sample DataFrame with missing values."""
    dates = pd.date_range("2024-01-01 03:00", periods=10, freq="1min")
    df = pd.DataFrame(
        {
            "timestamp": dates,
            "open": [100.0] * 10,
            "high": [100.5] * 10,
            "low": [99.5] * 10,
            "close": [100.2] * 10,
        }
    )
    # Add some missing values
    df.loc[2, "close"] = np.nan
    df.loc[5, "open"] = np.nan
    return df


@pytest.fixture
def sample_data_with_duplicates():
    """Create sample DataFrame with duplicates."""
    dates = pd.date_range("2024-01-01 03:00", periods=10, freq="1min")
    df = pd.DataFrame(
        {
            "timestamp": dates,
            "open": [100.0] * 10,
            "high": [100.5] * 10,
            "low": [99.5] * 10,
            "close": [100.2] * 10,
        }
    )
    # Add duplicate
    df = pd.concat([df, df.iloc[[0]]], ignore_index=True)
    return df


def test_handle_missing_data_forward_fill(sample_data_with_missing):
    """Test forward fill missing data."""
    df = handle_missing_data(sample_data_with_missing, method="forward_fill")
    assert df["close"].isna().sum() == 0
    assert df["open"].isna().sum() == 0


def test_handle_missing_data_drop(sample_data_with_missing):
    """Test drop missing data."""
    df = handle_missing_data(sample_data_with_missing, method="drop")
    assert df["close"].isna().sum() == 0
    assert df["open"].isna().sum() == 0
    assert len(df) < len(sample_data_with_missing)


def test_remove_duplicates(sample_data_with_duplicates):
    """Test duplicate removal."""
    df = remove_duplicates(sample_data_with_duplicates)
    assert len(df) == 10  # Should remove duplicate


def test_filter_session():
    """Test session filtering."""
    # Create data spanning multiple hours
    dates = pd.date_range("2024-01-01 02:00", periods=120, freq="1min")
    df = pd.DataFrame(
        {
            "timestamp": dates,
            "open": [100.0] * 120,
            "high": [100.5] * 120,
            "low": [99.5] * 120,
            "close": [100.2] * 120,
        }
    )

    # Filter to 3-4 AM EST
    df_filtered = filter_session(df, session_start="03:00", session_end="04:00")

    # Should have approximately 60 rows (1 hour of 1-minute data)
    assert len(df_filtered) > 0
    assert len(df_filtered) <= 60