"""Unit tests for src/my_deepagent/config.py."""

from __future__ import annotations

from pathlib import Path

import pytest
from pydantic import ValidationError

from my_deepagent.config import Config, load_config

# ---------------------------------------------------------------------------
# Default values (no env, no file)
# ---------------------------------------------------------------------------


def test_default_log_level(monkeypatch: pytest.MonkeyPatch) -> None:
    _clear_env(monkeypatch)
    cfg = Config()
    assert cfg.log_level == "info"


def test_default_lang(monkeypatch: pytest.MonkeyPatch) -> None:
    _clear_env(monkeypatch)
    cfg = Config()
    assert cfg.lang == "ko"


def test_default_budget_daily_usd(monkeypatch: pytest.MonkeyPatch) -> None:
    _clear_env(monkeypatch)
    cfg = Config()
    assert cfg.budget_daily_usd == pytest.approx(5.0)


def test_default_budget_run_usd(monkeypatch: pytest.MonkeyPatch) -> None:
    _clear_env(monkeypatch)
    cfg = Config()
    assert cfg.budget_run_usd == pytest.approx(1.0)


def test_default_budget_on_hit(monkeypatch: pytest.MonkeyPatch) -> None:
    _clear_env(monkeypatch)
    cfg = Config()
    assert cfg.budget_on_hit == "prompt"


def test_default_persona(monkeypatch: pytest.MonkeyPatch) -> None:
    _clear_env(monkeypatch)
    cfg = Config()
    assert cfg.default_persona == "default-interactive"


def test_default_openrouter_api_key_is_none(monkeypatch: pytest.MonkeyPatch) -> None:
    _clear_env(monkeypatch)
    # _env_file=None bypasses any .env that may exist in the cwd (e.g. dev keys).
    cfg = Config(_env_file=None)
    assert cfg.openrouter_api_key is None


# ---------------------------------------------------------------------------
# Env var overrides
# ---------------------------------------------------------------------------


def test_env_budget_daily_usd(monkeypatch: pytest.MonkeyPatch) -> None:
    _clear_env(monkeypatch)
    monkeypatch.setenv("MYDEEPAGENT_BUDGET_DAILY_USD", "10")
    cfg = Config()
    assert cfg.budget_daily_usd == pytest.approx(10.0)


def test_env_lang_en(monkeypatch: pytest.MonkeyPatch) -> None:
    _clear_env(monkeypatch)
    monkeypatch.setenv("MYDEEPAGENT_LANG", "en")
    cfg = Config()
    assert cfg.lang == "en"


def test_env_log_level_debug(monkeypatch: pytest.MonkeyPatch) -> None:
    _clear_env(monkeypatch)
    monkeypatch.setenv("MYDEEPAGENT_LOG_LEVEL", "debug")
    cfg = Config()
    assert cfg.log_level == "debug"


def test_env_openrouter_api_key(monkeypatch: pytest.MonkeyPatch) -> None:
    _clear_env(monkeypatch)
    monkeypatch.setenv("MYDEEPAGENT_OPENROUTER_API_KEY", "sk-test-abc")
    cfg = Config()
    assert cfg.openrouter_api_key == "sk-test-abc"


def test_env_langsmith_tracing(monkeypatch: pytest.MonkeyPatch) -> None:
    _clear_env(monkeypatch)
    monkeypatch.setenv("MYDEEPAGENT_LANGSMITH_TRACING", "true")
    cfg = Config()
    assert cfg.langsmith_tracing is True


# ---------------------------------------------------------------------------
# Validation errors for invalid values
# ---------------------------------------------------------------------------


def test_invalid_lang_raises(monkeypatch: pytest.MonkeyPatch) -> None:
    _clear_env(monkeypatch)
    monkeypatch.setenv("MYDEEPAGENT_LANG", "fr")
    with pytest.raises(ValidationError):
        Config()


def test_invalid_log_level_raises(monkeypatch: pytest.MonkeyPatch) -> None:
    _clear_env(monkeypatch)
    monkeypatch.setenv("MYDEEPAGENT_LOG_LEVEL", "verbose")
    with pytest.raises(ValidationError):
        Config()


def test_invalid_budget_on_hit_raises(monkeypatch: pytest.MonkeyPatch) -> None:
    _clear_env(monkeypatch)
    monkeypatch.setenv("MYDEEPAGENT_BUDGET_ON_HIT", "explode")
    with pytest.raises(ValidationError):
        Config()


def test_negative_budget_raises(monkeypatch: pytest.MonkeyPatch) -> None:
    _clear_env(monkeypatch)
    with pytest.raises(ValidationError):
        Config(budget_daily_usd=-1.0)


# ---------------------------------------------------------------------------
# Frozen check
# ---------------------------------------------------------------------------


def test_frozen_prevents_mutation(monkeypatch: pytest.MonkeyPatch) -> None:
    _clear_env(monkeypatch)
    cfg = Config()
    with pytest.raises((ValidationError, TypeError)):
        cfg.budget_daily_usd = 99  # type: ignore[misc]


# ---------------------------------------------------------------------------
# Path expansion (~ → absolute path)
# ---------------------------------------------------------------------------


def test_tilde_expansion_workspace_root(monkeypatch: pytest.MonkeyPatch) -> None:
    _clear_env(monkeypatch)
    monkeypatch.setenv("MYDEEPAGENT_WORKSPACE_ROOT", "~/foo/bar")
    cfg = Config()
    assert cfg.workspace_root.is_absolute()
    assert "~" not in str(cfg.workspace_root)


def test_tilde_expansion_data_dir(monkeypatch: pytest.MonkeyPatch) -> None:
    _clear_env(monkeypatch)
    monkeypatch.setenv("MYDEEPAGENT_DATA_DIR", "~/mydata")
    cfg = Config()
    assert cfg.data_dir.is_absolute()


# ---------------------------------------------------------------------------
# TOML priority
# ---------------------------------------------------------------------------


def test_toml_overrides_default(monkeypatch: pytest.MonkeyPatch, tmp_path: Path) -> None:
    _clear_env(monkeypatch)
    toml_file = tmp_path / "config.toml"
    toml_file.write_text('lang = "en"\nbudget_daily_usd = 7.5\n')

    # Patch the toml_file location via init override
    # Config reads toml via SettingsConfigDict; we pass via class-level override trick:
    # Easiest approach: pass budget_daily_usd and lang directly to assert TOML *can* set them.
    # For true TOML path injection, subclass Config temporarily.
    class PatchedConfig(Config):
        model_config = Config.model_config.copy()

    PatchedConfig.model_config["toml_file"] = str(toml_file)

    cfg = PatchedConfig()
    assert cfg.lang == "en"
    assert cfg.budget_daily_usd == pytest.approx(7.5)


# ---------------------------------------------------------------------------
# load_config helper
# ---------------------------------------------------------------------------


def test_load_config_with_overrides(monkeypatch: pytest.MonkeyPatch) -> None:
    _clear_env(monkeypatch)
    cfg = load_config(budget_daily_usd=20.0, lang="en")
    assert cfg.budget_daily_usd == pytest.approx(20.0)
    assert cfg.lang == "en"


def test_load_config_default(monkeypatch: pytest.MonkeyPatch) -> None:
    _clear_env(monkeypatch)
    cfg = load_config()
    assert cfg.log_level == "info"


# ---------------------------------------------------------------------------
# Helpers
# ---------------------------------------------------------------------------


_ENV_KEYS = [
    "MYDEEPAGENT_BUDGET_DAILY_USD",
    "MYDEEPAGENT_BUDGET_DAILY_WARN_USD",
    "MYDEEPAGENT_BUDGET_RUN_USD",
    "MYDEEPAGENT_BUDGET_RUN_WARN_USD",
    "MYDEEPAGENT_BUDGET_ON_HIT",
    "MYDEEPAGENT_LANG",
    "MYDEEPAGENT_LOG_LEVEL",
    "MYDEEPAGENT_OPENROUTER_API_KEY",
    "MYDEEPAGENT_OPENROUTER_BASE_URL",
    "MYDEEPAGENT_LANGSMITH_TRACING",
    "MYDEEPAGENT_LANGSMITH_API_KEY",
    "MYDEEPAGENT_LANGSMITH_PROJECT",
    "MYDEEPAGENT_DATABASE_URL",
    "MYDEEPAGENT_WORKSPACE_ROOT",
    "MYDEEPAGENT_DATA_DIR",
    "MYDEEPAGENT_CONFIG_DIR",
    "MYDEEPAGENT_STATE_DIR",
    "MYDEEPAGENT_DEFAULT_PERSONA",
]


def _clear_env(monkeypatch: pytest.MonkeyPatch) -> None:
    """Remove all MYDEEPAGENT_ env vars to isolate tests from the real environment."""
    for key in _ENV_KEYS:
        monkeypatch.delenv(key, raising=False)
    # Also prevent dotenv file from being loaded
    monkeypatch.setenv("MYDEEPAGENT_ENV_FILE", "")