"""余额表达式引擎测试：运算符、函数、兼容性与安全。"""

import pytest

from app.expr import ExprError, evaluate_balance

DATA = {
    "data": {
        "balance": "1.50",
        "total": 100,
        "used": 40,
        "fee": 2.5,
    },
    "list": [
        {"x": 1, "y": 10},
        {"x": 2, "y": 20},
    ],
    "balances": [1, 2, 3],
    "nested": {"a": {"b": 6}},
}


class TestPlainPath:
    def test_dot_path(self):
        assert evaluate_balance({"data": {"balance": 12.5}}, "data.balance") == 12.5

    def test_array_index(self):
        assert evaluate_balance(DATA, "list[0].x") == 1

    def test_dollar_prefix(self):
        assert evaluate_balance(DATA, "$.data.total") == 100

    def test_string_number(self):
        assert evaluate_balance(DATA, "data.balance") == 1.5

    def test_missing_path(self):
        with pytest.raises(ExprError, match="路径不存在"):
            evaluate_balance(DATA, "data.nope")

    def test_index_out_of_range(self):
        with pytest.raises(ExprError, match="数组索引越界"):
            evaluate_balance(DATA, "list[5].x")


class TestOperators:
    def test_division(self):
        assert evaluate_balance(DATA, "data.total / 100") == 1.0

    def test_addition(self):
        assert evaluate_balance(DATA, "data.total + data.used") == 140

    def test_priority(self):
        assert evaluate_balance(DATA, "data.total + data.used * 2") == 180
        assert evaluate_balance(DATA, "(data.total + data.used) * 2") == 280

    def test_floor_div_and_mod(self):
        assert evaluate_balance(DATA, "data.total // 30") == 3
        assert evaluate_balance(DATA, "data.total % 30") == 10

    def test_power(self):
        assert evaluate_balance(DATA, "2 ** 3 * 5") == 40

    def test_unary_minus(self):
        assert evaluate_balance(DATA, "-data.total") == -100
        assert evaluate_balance(DATA, "data.total - -data.used") == 140

    def test_float_result(self):
        assert evaluate_balance(DATA, "data.total / 8") == 12.5


class TestFunctions:
    def test_float(self):
        assert evaluate_balance(DATA, "float(data.balance)") == 1.5

    def test_int(self):
        assert evaluate_balance(DATA, "int(data.total / 3)") == 33

    def test_abs(self):
        assert evaluate_balance(DATA, "abs(data.used - data.total)") == 60

    def test_round_one_arg(self):
        assert evaluate_balance(DATA, "round(data.fee * 3)") == 8

    def test_round_two_args(self):
        assert evaluate_balance(DATA, "round(data.fee, 1)") == 2.5
        assert evaluate_balance(DATA, "round(3.14159, 2)") == 3.14

    def test_sum_multi_args(self):
        assert evaluate_balance(DATA, "sum(data.total, data.used, data.fee)") == 142.5

    def test_sum_array(self):
        assert evaluate_balance(DATA, "sum(balances)") == 6

    def test_min_max(self):
        assert evaluate_balance(DATA, "min(data.total, data.used)") == 40
        assert evaluate_balance(DATA, "max(data.total, data.used)") == 100
        assert evaluate_balance(DATA, "min(balances)") == 1
        assert evaluate_balance(DATA, "max(balances)") == 3

    def test_len(self):
        assert evaluate_balance(DATA, "len(balances)") == 3

    def test_nested_call(self):
        assert evaluate_balance(DATA, "round(abs(data.used - data.total) / 3, 1)") == 20.0


class TestErrors:
    def test_unknown_function(self):
        with pytest.raises(ExprError, match="不支持的函数"):
            evaluate_balance(DATA, "eval(data.balance)")

    def test_syntax_error(self):
        with pytest.raises(ExprError):
            evaluate_balance(DATA, "data.total +")
        with pytest.raises(ExprError):
            evaluate_balance(DATA, "(data.total")

    def test_bad_arity(self):
        with pytest.raises(ExprError, match="float"):
            evaluate_balance(DATA, "float()")
        with pytest.raises(ExprError, match="round"):
            evaluate_balance(DATA, "round(data.total, 2, 3)")

    def test_division_by_zero(self):
        with pytest.raises((ZeroDivisionError, ExprError)):
            evaluate_balance(DATA, "data.total / 0")

    def test_non_numeric_result(self):
        with pytest.raises(ExprError, match="不是数字"):
            evaluate_balance(DATA, "sum(list)")  # 数组元素是对象，无法转数字

    def test_string_literal_rejected(self):
        with pytest.raises(ExprError):
            evaluate_balance(DATA, "data.total + 'abc'")