"""Tests for Sunday-week / ISO dual-read week keys and GET helpers."""

from datetime import datetime
from unittest.mock import MagicMock, patch

from shared import db
from shared.week_keys import (
    WEEK_ID_RE,
    candidate_week_ids,
    candidate_week_pks,
    week_id_iso,
    week_id_ustrftime,
)

MISMATCH_DT = datetime(2026, 1, 1)
MATCH_DT = datetime(2026, 1, 4)


def test_ustrftime_and_iso_differ_on_new_year():
    assert week_id_ustrftime(MISMATCH_DT) == "2026-W00"
    assert week_id_iso(MISMATCH_DT) == "2026-W01"
    assert WEEK_ID_RE.match("2026-W00")
    assert WEEK_ID_RE.match("2026-W01")


def test_candidate_week_ids_u_week_first_then_iso():
    # 2026-01-01: same instant encoded two ways, not a next-week lookup.
    assert candidate_week_ids(MISMATCH_DT) == ("2026-W00", "2026-W01")


def test_candidate_week_ids_unique_when_formats_match():
    ids = candidate_week_ids(MATCH_DT)
    assert week_id_ustrftime(MATCH_DT) == week_id_iso(MATCH_DT) == "2026-W01"
    assert ids == ("2026-W01",)
    assert len(ids) == 1


def test_candidate_week_pks_prefixed():
    assert candidate_week_pks(MISMATCH_DT) == ("WEEK#2026-W00", "WEEK#2026-W01")
    assert candidate_week_pks(MATCH_DT) == ("WEEK#2026-W01",)


def _table_with_get_items(items_by_pk: dict[str, dict]):
    table = MagicMock()

    def get_item(Key):
        item = items_by_pk.get(Key["PK"])
        if item is None:
            return {}
        if item.get("SK") != Key["SK"]:
            return {}
        return {"Item": item}

    table.get_item.side_effect = get_item
    return table


def test_get_menu_when_falls_back_to_iso():
    iso_item = {"PK": "WEEK#2026-W01", "SK": "MENU", "source": "iso"}
    table = _table_with_get_items({"WEEK#2026-W01": iso_item})

    with patch.object(db, "_get_table", return_value=table):
        result = db.get_menu("2026-W00", when=MISMATCH_DT)

    assert result == iso_item
    pks = [call.kwargs["Key"]["PK"] for call in table.get_item.call_args_list]
    assert pks == ["WEEK#2026-W00", "WEEK#2026-W01"]


def test_get_menu_when_prefers_u_week_if_both_exist():
    u_item = {"PK": "WEEK#2026-W00", "SK": "MENU", "source": "u"}
    iso_item = {"PK": "WEEK#2026-W01", "SK": "MENU", "source": "iso"}
    table = _table_with_get_items({"WEEK#2026-W00": u_item, "WEEK#2026-W01": iso_item})

    with patch.object(db, "_get_table", return_value=table):
        result = db.get_menu("2026-W00", when=MISMATCH_DT)

    assert result == u_item
    assert table.get_item.call_count == 1
    assert table.get_item.call_args.kwargs["Key"]["PK"] == "WEEK#2026-W00"


def test_get_menu_without_when_uses_week_argument_as_single_key():
    table = _table_with_get_items({})

    with patch.object(db, "_get_table", return_value=table):
        result = db.get_menu("2026-W34")

    assert result is None
    table.get_item.assert_called_once_with(Key={"PK": "WEEK#2026-W34", "SK": "MENU"})


def test_get_orders_when_falls_back_to_iso():
    iso_orders = [{"PK": "WEEK#2026-W01", "SK": "ORDER#pat"}]
    table = MagicMock()
    table.query.side_effect = [{"Items": []}, {"Items": iso_orders}]

    with patch.object(db, "_get_table", return_value=table):
        result = db.get_orders("2026-W00", when=MISMATCH_DT)

    assert result == iso_orders
    assert table.query.call_count == 2