"""Unit: the admin settings router's pure helpers (phase 168, task 04)
— the env-native stringification (``_display``), the control-kind
derivation (``_field_type``), the ``_item`` builder's masked and
default branches, and the LOCKED A1 static pins: the module never
opens a file (``.env`` is never written), never shells out and never
``eval``s a value.

The DB-driven behavior (the four routes, the candidate-set validation,
the auth matrix) is pinned in
``tests/integration/test_admin_settings_api.py``.
"""
from __future__ import annotations

import pathlib
import re

import pytest

from app.api.admin_settings import _display, _field_type, _item
from app.config import Settings
from app.core.settings_overlay import LIST_FIELDS


def test_display_bools_are_the_env_spelling() -> None:
    """bool → ``"true"``/``"false"`` — checked BEFORE int (``isinstance(True, int)``
    is ``True`` — a bool field must never stringify through ``str()``'s
    ``"True"``)."""
    assert _display("stream_thinking", True) == "true"
    assert _display("stream_thinking", False) == "false"
    # An int value for an int field is the plain str (no bool confusion).
    assert _display("llm_retries", 3) == "3"


def test_display_list_field_is_json() -> None:
    """The one ``list[str]`` field (``suggestions``) stringifies as the
    JSON array the env spelling would carry (K2: stored in the same
    JSON form, pydantic parses it exactly like the env var)."""
    assert set(LIST_FIELDS) == {"suggestions"}
    assert _display("suggestions", ["a", "b"]) == '["a", "b"]'
    assert _display("suggestions", []) == "[]"


def test_display_scalars_are_plain_strings() -> None:
    """Everything else is ``str()`` — floats, ints, strings, in the
    env-native form (what ``app_settings`` stores, D1)."""
    assert _display("relevance_threshold", 0.55) == "0.55"
    assert _display("llm_timeout", 7.0) == "7.0"
    assert _display("app_name", "Brain of Reese") == "Brain of Reese"
    assert _display("import_extensions", "md,txt") == "md,txt"


def test_field_type_covers_all_kinds() -> None:
    """The panel control kind per annotation: ``bool`` before ``int``
    (a bool annotation is never misread as int), the one list field is
    ``json``, the rest fall through to their annotation."""
    assert _field_type("stream_thinking") == "bool"
    assert _field_type("llm_retries") == "int"
    assert _field_type("relevance_threshold") == "float"
    assert _field_type("app_name") == "str"
    assert _field_type("suggestions") == "json"
    # Every field resolves to one of the five wire kinds.
    kinds = {"int", "float", "bool", "str", "json"}
    for key in Settings.model_fields:
        assert _field_type(key) in kinds


def test_item_masks_secret_fields() -> None:
    """LOCKED A4: a secret field's item is write-only on the wire —
    ``masked=True``, ``value=None``, ``db_value=None``,
    ``default=""`` (the code default is never shown for a secret),
    ``has_value`` = is a non-empty value in effect at all (the test
    env sets a non-empty admin password / session secret)."""
    effective = Settings()
    assert effective.admin_password  # tests/conftest.py pins it non-empty
    item = _item("admin_password", {}, effective)
    assert item.masked is True
    assert item.value is None
    assert item.db_value is None
    assert item.default == ""
    assert item.has_value is True
    assert item.secret is True
    assert item.key == "admin_password"
    assert item.env_var == "BOR_ADMIN_PASSWORD"
    # A stored row for a secret field never exposes the text either.
    # (The effective value is forced via an init kwarg — the operator's
    # local `.env` may legitimately carry a key, so the test does not
    # assume a specific effective value.)
    item = _item("llm_api_key", {"llm_api_key": "sk-x"}, Settings(llm_api_key="sk-x"))
    assert item.masked is True
    assert item.value is None
    assert item.db_value is None
    assert item.has_value is True
    assert item.has_override is True
    item = _item("llm_api_key", {}, Settings(llm_api_key=""))
    assert item.masked is True
    assert item.value is None
    assert item.db_value is None
    assert item.has_value is False  # no value in effect at all


def test_item_reports_env_default_and_db_sources(
    monkeypatch: pytest.MonkeyPatch
) -> None:
    """The ``source`` badge: ``db`` for an in-effect overridable row,
    ``env`` when the ``BOR_*`` var is in the process environment,
    ``default`` otherwise — and a non-overridable row is NEVER an
    override (LOCKED A3: the overlay drops it, so a hand-inserted
    ``database_url`` row is not in effect)."""
    import os

    effective = Settings()
    # "env": tests/conftest.py sets BOR_RELEVANCE_THRESHOLD.
    assert os.environ.get("BOR_RELEVANCE_THRESHOLD") is not None
    item = _item("relevance_threshold", {}, effective)
    assert item.source == "env"
    # The value is the EFFECTIVE float stringified ("0.30" → 0.3 → "0.3").
    assert item.value == str(float(os.environ["BOR_RELEVANCE_THRESHOLD"]))
    assert item.has_override is False
    # "default": no BOR_DOCS_WORK_DIR in the test environment.
    assert os.environ.get("BOR_DOCS_WORK_DIR") is None
    item = _item("docs_work_dir", {}, effective)
    assert item.source == "default"
    assert item.value == effective.docs_work_dir
    # "db": the row is in effect only while the overlay switch is ON
    # (the conftest pin is 0 — flip it for the pin, it restores after).
    monkeypatch.setenv("BOR_SETTINGS_DB", "1")
    item = _item("relevance_threshold", {"relevance_threshold": "0.9"}, effective)
    assert item.source == "db"
    assert item.has_override is True
    # Non-overridable: a stored row is not an override (LOCKED A3) —
    # even with the switch on.
    item = _item("database_url", {"database_url": "postgresql://x"}, effective)
    assert item.has_override is False
    assert item.masked is True
    # The code default stringifies (non-secret fields).
    item = _item("llm_retries", {}, effective)
    assert item.default == "3"
    assert item.value == "3"
    assert item.db_value is None


def test_item_db_value_is_the_stored_string() -> None:
    """A stored non-secret override exposes ``db_value`` (the stored
    string, D1) and ``has_override`` — even while the overlay switch
    is OFF (the row is stored but not in effect: the badge is
    env/default, the panel's ``overlay_enabled`` flag explains the
    rest)."""
    effective = Settings()
    item = _item("llm_retries", {"llm_retries": "7"}, effective)
    assert item.has_override is True
    assert item.db_value == "7"
    assert item.source == "default"  # switch off (the conftest pin): not in effect


def test_module_never_writes_files_or_shells_out() -> None:
    """LOCKED A1 + the module's third invariant (the unit pin): the
    router never opens a file (``.env`` is never written by any code
    path), never shells out and never ``eval``s a value. (The docstring
    legitimately mentions ``.env`` — the pins are on the CALLS, the
    ``test_settings_overlay`` house style.)"""
    source = (
        pathlib.Path(__file__).resolve().parents[2]
        / "app"
        / "api"
        / "admin_settings.py"
    ).read_text()
    assert re.search(r"\bopen\s*\(", source) is None, (
        "app/api/admin_settings.py must never open() a file (LOCKED A1: "
        ".env is never written)"
    )
    assert "subprocess" not in source
    assert "os.system" not in source
    assert re.search(r"\beval\s*\(", source) is None
    assert "import shutil" not in source and "shutil." not in source