"""The sysconfig registry: its order is the admin page's tab order, and a closed-set knob is a CHOICE.

The admin Configuration page used to keep its own hand-written group order, which had already drifted
(`explore` was missing, so its tab sorted last). The page now follows SPECS, so SPECS has to read in
tab order: one run of keys per group.

A closed-set admin knob is a CHOICE, not free text (E22 S2 follow-up).

`log_level`, `search_source`, `download_layout` and the transcode `hw`/`preset` used to be free-text
fields: the admin could type anything and every consumer carried its own `or "auto").lower()` guess
at what a typo meant. Now the value set is a `Literal` in config.py, pydantic holds the env to it at
boot, sysconfig holds a stored override to it, and the admin page renders a picker from the same list.
The DB lane (`db` fixture) covers the store; the rest is pure logic.
"""

import pytest
from pydantic import ValidationError

from app import sysconfig
from app.config import Settings, choices_of

CHOICE_KEYS = {s.key for s in sysconfig.SPECS if s.type == "choice"}


def test_each_group_is_one_run_of_keys_so_the_registry_reads_in_tab_order():
    runs = [
        s.group
        for i, s in enumerate(sysconfig.SPECS)
        if i == 0 or sysconfig.SPECS[i - 1].group != s.group
    ]
    assert len(runs) == len(set(runs)), runs
    assert runs[:2] == ["access", "email"]


def test_every_closed_set_knob_is_a_choice_whose_options_come_from_config():
    assert CHOICE_KEYS == {
        "search_source",
        "download_layout",
        "log_level",
        "plex_transcode_hw",
        "plex_transcode_preset",
    }
    for s in sysconfig.SPECS:
        field = Settings.model_fields[s.default_attr]
        if s.type == "choice":
            assert s.choices, s.key
            assert field.default in s.choices, s.key
        else:
            # A Literal-typed setting exposed as "str" would be a free-text field again.
            assert s.choices == () and choices_of(field.annotation) == (), s.key


def test_the_env_accepts_any_letter_case_and_rejects_an_unknown_value():
    assert Settings(log_level="debug").log_level == "DEBUG"
    assert Settings(search_source=" API ").search_source == "api"
    with pytest.raises(ValidationError):
        Settings(log_level="verbose")


class _Row:
    def __init__(self, value):
        self.value, self.encrypted = value, False


class _FakeDb:
    """Just enough of a Session for sysconfig's reads: one stored override row per key."""

    def __init__(self, **rows):
        self.rows = {k: _Row(v) for k, v in rows.items()}

    def get(self, _model, key):
        return self.rows.get(key)


def test_a_stored_value_reads_back_canonical_and_a_stale_one_falls_back_to_the_default():
    assert sysconfig.get_str(_FakeDb(plex_transcode_hw="OFF"), "plex_transcode_hw") == "off"
    # A value that is no longer (or never was) a choice is not passed through to the consumer.
    assert sysconfig.get_str(_FakeDb(plex_transcode_hw="maybe"), "plex_transcode_hw") == "auto"


def test_describe_hands_the_picker_its_options():
    items = {i["key"]: i for g in sysconfig.describe(_FakeDb())["groups"].values() for i in g}
    assert items["log_level"]["choices"] == ["TRACE", "DEBUG", "INFO", "WARNING", "ERROR"]
    assert items["log_level"]["value"] == "INFO"
    assert items["quota_daily_budget"]["choices"] == []


def test_set_value_stores_the_canonical_spelling_and_refuses_anything_else(db):
    sysconfig.set_value(db, "search_source", "API")
    assert sysconfig.get_str(db, "search_source") == "api"
    with pytest.raises(ValueError, match="scrape, api"):
        sysconfig.set_value(db, "search_source", "bing")
    db.rollback()