"""Tests for configuration loading and validation."""

from pathlib import Path
from typing import Any

import pytest
import yaml
from pydantic import ValidationError

from py_dvt_ate.app.config import (
    APIConfig,
    AppConfig,
    ChamberConfig,
    DashboardConfig,
    DataConfig,
    DUTConfig,
    DUTParameters,
    InstrumentsConfig,
    LoggingConfig,
    PhysicsConfig,
    PyVISAConfig,
    SimulatorConfig,
    ThermalConfig,
    load_config,
)


def test_default_config_values() -> None:
    """Test that default configuration values are correct."""
    config = AppConfig()

    assert config.instruments.backend == "simulator"
    assert config.instruments.simulator.host == "localhost"
    assert config.instruments.simulator.thermal_chamber_port == 5001

    assert config.physics.update_rate_hz == 100.0
    assert config.physics.thermal.chamber_time_constant_s == 30.0
    assert config.physics.thermal.theta_jc == 15.0

    assert config.dut.model == "ldo"
    assert config.dut.parameters.nominal_output_voltage == 3.3
    assert config.dut.parameters.tempco_ppm_per_c == 50.0

    assert config.data.database_path == "./data/py_dvt_ate.db"
    assert config.logging.level == "INFO"
    assert config.dashboard.enabled is True
    assert config.api.enabled is False


def test_load_config_with_defaults_only() -> None:
    """Test loading config without a file uses defaults."""
    config = load_config(None)

    assert config.instruments.backend == "simulator"
    assert config.physics.update_rate_hz == 100.0


def test_load_config_from_file(tmp_path: Path) -> None:
    """Test loading configuration from YAML file."""
    config_file = tmp_path / "test_config.yaml"
    config_data = {
        "instruments": {"backend": "pyvisa"},
        "physics": {"update_rate_hz": 50.0},
        "dut": {"model": "custom_ldo"},
    }

    with config_file.open("w") as f:
        yaml.dump(config_data, f)

    config = load_config(config_file)

    assert config.instruments.backend == "pyvisa"
    assert config.physics.update_rate_hz == 50.0
    assert config.dut.model == "custom_ldo"
    # Defaults still apply
    assert config.instruments.simulator.host == "localhost"


def test_load_config_partial_override(tmp_path: Path) -> None:
    """Test that partial config overrides work correctly."""
    config_file = tmp_path / "partial.yaml"
    config_data = {
        "physics": {
            "thermal": {
                "theta_jc": 20.0,
                # Other thermal params should use defaults
            }
        }
    }

    with config_file.open("w") as f:
        yaml.dump(config_data, f)

    config = load_config(config_file)

    # Overridden value
    assert config.physics.thermal.theta_jc == 20.0
    # Default values
    assert config.physics.thermal.theta_ca == 5.0
    assert config.physics.thermal.chamber_time_constant_s == 30.0


def test_load_config_missing_file() -> None:
    """Test that loading from missing file raises FileNotFoundError."""
    with pytest.raises(FileNotFoundError, match="Configuration file not found"):
        load_config("nonexistent.yaml")


def test_load_config_invalid_yaml(tmp_path: Path) -> None:
    """Test that malformed YAML raises an error."""
    config_file = tmp_path / "invalid.yaml"
    config_file.write_text("invalid: yaml: content: [\n")

    with pytest.raises(yaml.YAMLError):
        load_config(config_file)


def test_load_config_validation_error(tmp_path: Path) -> None:
    """Test that invalid configuration raises ValidationError."""
    config_file = tmp_path / "invalid_config.yaml"
    config_data = {
        "instruments": {"backend": "invalid_backend"},  # Not in Literal["simulator", "pyvisa"]
    }

    with config_file.open("w") as f:
        yaml.dump(config_data, f)

    with pytest.raises(ValidationError):
        load_config(config_file)


def test_env_override_simple(tmp_path: Path, monkeypatch: pytest.MonkeyPatch) -> None:
    """Test environment variable override for simple values."""
    config_file = tmp_path / "config.yaml"
    config_data: dict[str, Any] = {}

    with config_file.open("w") as f:
        yaml.dump(config_data, f)

    monkeypatch.setenv("PYDVTATE__INSTRUMENTS__BACKEND", "pyvisa")
    monkeypatch.setenv("PYDVTATE__PHYSICS__UPDATE_RATE_HZ", "200.0")

    config = load_config(config_file)

    assert config.instruments.backend == "pyvisa"
    assert config.physics.update_rate_hz == 200.0


def test_env_override_nested(tmp_path: Path, monkeypatch: pytest.MonkeyPatch) -> None:
    """Test environment variable override for nested values."""
    config_file = tmp_path / "config.yaml"
    config_data: dict[str, Any] = {}

    with config_file.open("w") as f:
        yaml.dump(config_data, f)

    monkeypatch.setenv("PYDVTATE__INSTRUMENTS__SIMULATOR__HOST", "192.168.1.100")
    monkeypatch.setenv("PYDVTATE__INSTRUMENTS__SIMULATOR__THERMAL_CHAMBER_PORT", "6001")
    monkeypatch.setenv("PYDVTATE__PHYSICS__THERMAL__THETA_JC", "25.0")

    config = load_config(config_file)

    assert config.instruments.simulator.host == "192.168.1.100"
    assert config.instruments.simulator.thermal_chamber_port == 6001
    assert config.physics.thermal.theta_jc == 25.0


def test_env_override_types(tmp_path: Path, monkeypatch: pytest.MonkeyPatch) -> None:
    """Test that environment variables are parsed to correct types."""
    config_file = tmp_path / "config.yaml"
    config_data: dict[str, Any] = {}

    with config_file.open("w") as f:
        yaml.dump(config_data, f)

    monkeypatch.setenv("PYDVTATE__DASHBOARD__ENABLED", "false")  # bool
    monkeypatch.setenv("PYDVTATE__DASHBOARD__PORT", "9000")  # int
    monkeypatch.setenv("PYDVTATE__PHYSICS__UPDATE_RATE_HZ", "75.5")  # float

    config = load_config(config_file)

    assert config.dashboard.enabled is False
    assert config.dashboard.port == 9000
    assert config.physics.update_rate_hz == 75.5


def test_env_override_precedence(tmp_path: Path, monkeypatch: pytest.MonkeyPatch) -> None:
    """Test that environment variables override file values."""
    config_file = tmp_path / "config.yaml"
    config_data = {"physics": {"update_rate_hz": 50.0}}

    with config_file.open("w") as f:
        yaml.dump(config_data, f)

    monkeypatch.setenv("PYDVTATE__PHYSICS__UPDATE_RATE_HZ", "150.0")

    config = load_config(config_file)

    # Environment variable should win
    assert config.physics.update_rate_hz == 150.0


def test_env_variables_ignored_without_prefix(
    tmp_path: Path, monkeypatch: pytest.MonkeyPatch
) -> None:
    """Test that environment variables without prefix are ignored."""
    config_file = tmp_path / "config.yaml"
    config_data: dict[str, Any] = {}

    with config_file.open("w") as f:
        yaml.dump(config_data, f)

    # These should be ignored
    monkeypatch.setenv("BACKEND", "pyvisa")
    monkeypatch.setenv("UPDATE_RATE_HZ", "200.0")

    config = load_config(config_file)

    # Should use defaults
    assert config.instruments.backend == "simulator"
    assert config.physics.update_rate_hz == 100.0


def test_simulator_config_defaults() -> None:
    """Test SimulatorConfig default values."""
    config = SimulatorConfig()
    assert config.host == "localhost"
    assert config.thermal_chamber_port == 5001
    assert config.power_supply_port == 5002
    assert config.multimeter_port == 5003


def test_pyvisa_config_defaults() -> None:
    """Test PyVISAConfig default values."""
    config = PyVISAConfig()
    assert config.thermal_chamber is None
    assert config.power_supply is None
    assert config.multimeter is None


def test_complete_config_structure() -> None:
    """Test that all config sections can be instantiated."""
    config = AppConfig(
        instruments=InstrumentsConfig(
            backend="pyvisa",
            simulator=SimulatorConfig(host="192.168.1.1"),
            pyvisa=PyVISAConfig(thermal_chamber="TCPIP::192.168.1.10::INSTR"),
        ),
        physics=PhysicsConfig(
            update_rate_hz=50.0,
            thermal=ThermalConfig(theta_jc=20.0),
            chamber=ChamberConfig(ramp_rate_c_per_min=5.0),
        ),
        dut=DUTConfig(
            model="custom", parameters=DUTParameters(nominal_output_voltage=5.0)
        ),
        data=DataConfig(database_path="/tmp/test.db"),
        logging=LoggingConfig(level="DEBUG"),
        dashboard=DashboardConfig(enabled=False),
        api=APIConfig(enabled=True, port=9000),
    )

    assert config.instruments.backend == "pyvisa"
    assert config.physics.update_rate_hz == 50.0
    assert config.dut.parameters.nominal_output_voltage == 5.0
    assert config.api.port == 9000