from __future__ import annotations

from pathlib import Path

import pytest

from app.core.config import ConfigurationError, load_settings


CONFIG_ENV_NAMES = (
    "APP_NAME",
    "APP_ENV",
    "APP_MODE",
    "MODELTF_ROUTE_PREFIX",
    "FRONTEND_PORT",
    "BACKEND_PORT",
    "DATABASE_URL",
    "DATABASE_BASE_URL",
    "DATABASE_USERNAME",
    "DATABASE_PASSWORD",
    "CORS_ALLOW_ORIGINS",
    "COMPUTE_MODE",
    "COMPUTE_STATUS_SYNC_MODE",
    "COMPUTE_POLL_INTERVAL_SECONDS",
    "LOG_LEVEL",
    "LOG_DIR",
    "LOG_FILE_PREFIX",
    "LOG_ERROR_FILE_PREFIX",
    "LOG_MAX_BYTES",
    "LOG_RETENTION_DAYS",
)


def clear_config_env(monkeypatch: pytest.MonkeyPatch) -> None:
    for env_name in CONFIG_ENV_NAMES:
        monkeypatch.delenv(env_name, raising=False)


def write_config(path: Path) -> None:
    path.write_text(
        """
app:
  name: YAML API
  route_prefix: /yaml-api
  cors_allow_origins:
    - http://yaml.example
server:
  frontend_port: 18001
  backend_port: 18002
database:
  url: postgresql+psycopg://db:5432/yaml
  username: yaml-user
  password: yaml-secret
compute:
  mode: simulated
  poll_interval_seconds: 9
logging:
  directory: ./yaml-logs
  max_bytes: 1024
  retention_days: 2
""".strip(),
        encoding="utf-8",
    )


def test_load_settings_from_yaml(tmp_path: Path, monkeypatch: pytest.MonkeyPatch) -> None:
    clear_config_env(monkeypatch)
    config_path = tmp_path / "config.yaml"
    write_config(config_path)

    settings = load_settings(config_path)

    assert settings.app_name == "YAML API"
    assert settings.route_prefix == "/yaml-api"
    assert settings.frontend_port == 18001
    assert settings.backend_port == 18002
    assert settings.database_url == "postgresql+psycopg://yaml-user:yaml-secret@db:5432/yaml"
    assert settings.cors_allow_origins == ["http://yaml.example"]
    assert settings.compute_mode == "simulated"
    assert settings.compute_poll_interval_seconds == 9
    assert settings.log_dir == str(tmp_path / "yaml-logs")
    assert settings.log_max_bytes == 1024
    assert settings.log_retention_days == 2


def test_environment_overrides_yaml(tmp_path: Path, monkeypatch: pytest.MonkeyPatch) -> None:
    clear_config_env(monkeypatch)
    config_path = tmp_path / "config.yaml"
    write_config(config_path)
    monkeypatch.setenv("DATABASE_URL", "postgresql+psycopg://env:secret@db:5432/env")
    monkeypatch.setenv("CORS_ALLOW_ORIGINS", "http://one.example,http://two.example")
    monkeypatch.setenv("COMPUTE_POLL_INTERVAL_SECONDS", "15")
    monkeypatch.setenv("FRONTEND_PORT", "19001")
    monkeypatch.setenv("BACKEND_PORT", "19002")

    settings = load_settings(config_path)

    assert settings.database_url == "postgresql+psycopg://env:secret@db:5432/env"
    assert settings.cors_allow_origins == ["http://one.example", "http://two.example"]
    assert settings.compute_poll_interval_seconds == 15
    assert settings.frontend_port == 19001
    assert settings.backend_port == 19002


def test_separate_database_credentials_are_encoded(
    tmp_path: Path, monkeypatch: pytest.MonkeyPatch
) -> None:
    clear_config_env(monkeypatch)
    config_path = tmp_path / "config.yaml"
    write_config(config_path)
    monkeypatch.setenv("DATABASE_USERNAME", "user@example.com")
    monkeypatch.setenv("DATABASE_PASSWORD", "secret:/?#[]@")

    settings = load_settings(config_path)

    assert settings.database_url == (
        "postgresql+psycopg://user%40example.com:secret%3A%2F%3F%23%5B%5D%40@db:5432/yaml"
    )


def test_explicit_missing_config_is_rejected(tmp_path: Path) -> None:
    with pytest.raises(ConfigurationError, match="does not exist"):
        load_settings(tmp_path / "missing.yaml")


def test_default_cors_follows_frontend_port(
    tmp_path: Path, monkeypatch: pytest.MonkeyPatch
) -> None:
    clear_config_env(monkeypatch)
    config_path = tmp_path / "config.yaml"
    config_path.write_text(
        "server:\n  frontend_port: 28001\n  backend_port: 28002\n",
        encoding="utf-8",
    )

    settings = load_settings(config_path)

    assert settings.cors_allow_origins == [
        "http://localhost:28001",
        "http://127.0.0.1:28001",
    ]


@pytest.mark.parametrize("frontend_port", [0, 65536, "invalid", True])
def test_invalid_server_port_is_rejected(
    tmp_path: Path,
    monkeypatch: pytest.MonkeyPatch,
    frontend_port: object,
) -> None:
    clear_config_env(monkeypatch)
    config_path = tmp_path / "config.yaml"
    config_path.write_text(
        "server:\n"
        f"  frontend_port: {str(frontend_port).lower()}\n"
        "  backend_port: 28002\n",
        encoding="utf-8",
    )

    with pytest.raises(ConfigurationError, match="server.frontend_port"):
        load_settings(config_path)


def test_frontend_and_backend_ports_must_differ(
    tmp_path: Path, monkeypatch: pytest.MonkeyPatch
) -> None:
    clear_config_env(monkeypatch)
    config_path = tmp_path / "config.yaml"
    config_path.write_text(
        "server:\n  frontend_port: 28001\n  backend_port: 28001\n",
        encoding="utf-8",
    )

    with pytest.raises(ConfigurationError, match="must be different"):
        load_settings(config_path)


@pytest.mark.parametrize(
    ("database_base_url", "message"),
    [
        ("mysql://localhost:3306/yg_ft", "must use postgresql"),
        ("postgresql+psycopg://localhost:5432", "must include a database name"),
    ],
)
def test_invalid_database_url_is_rejected(
    tmp_path: Path,
    monkeypatch: pytest.MonkeyPatch,
    database_base_url: str,
    message: str,
) -> None:
    clear_config_env(monkeypatch)
    config_path = tmp_path / "config.yaml"
    write_config(config_path)
    monkeypatch.setenv("DATABASE_BASE_URL", database_base_url)

    with pytest.raises(ConfigurationError, match=message):
        load_settings(config_path)