#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
计算器功能测试
"""

import sys
import os
sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))

from calculator import add, subtract, multiply, divide, calculate

def test_basic_operations():
    """测试基本运算"""
    print("测试基本运算...")

    # 测试加法
    assert add(5, 3) == 8
    assert add(-2, 3) == 1
    assert add(0, 0) == 0

    # 测试减法
    assert subtract(10, 4) == 6
    assert subtract(3, 7) == -4
    assert subtract(0, 5) == -5

    # 测试乘法
    assert multiply(4, 5) == 20
    assert multiply(-3, 2) == -6
    assert multiply(0, 100) == 0

    # 测试除法
    assert divide(10, 2) == 5
    assert divide(7, 2) == 3.5
    assert divide(-12, 3) == -4

    print("基本运算测试通过！")

def test_divide_by_zero():
    """测试除零错误"""
    print("测试除零错误...")
    try:
        divide(5, 0)
        print("错误: 除零异常未触发")
        return False
    except ValueError as e:
        assert str(e) == "除数不能为零"
        print("除零错误测试通过！")
        return True

def test_calculate_function():
    """测试计算函数"""
    print("测试calculate函数...")

    # 测试有效表达式
    assert calculate("5 + 3") == 8
    assert calculate("10 - 4") == 6
    assert calculate("4 * 5") == 20
    assert calculate("10 / 2") == 5
    assert calculate("7.5 + 2.5") == 10.0
    assert calculate("-3 * 4") == -12

    # 测试无效表达式
    test_cases = [
        ("5 +", "表达式格式错误"),
        ("+ 3", "表达式格式错误"),
        ("5 + 3 4", "表达式格式错误"),
        ("5 & 3", "不支持的运算符"),
        ("abc + 3", "操作数必须是数字"),
        ("5 / 0", "除数不能为零"),
    ]

    for expr, expected_error in test_cases:
        try:
            calculate(expr)
            print(f"错误: 表达式 '{expr}' 应触发错误但未触发")
            return False
        except (ValueError, RuntimeError) as e:
            if expected_error not in str(e):
                print(f"错误: 表达式 '{expr}' 返回错误 '{e}'，但期望包含 '{expected_error}'")
                return False

    print("calculate函数测试通过！")
    return True

def main():
    """运行所有测试"""
    print("开始计算器测试...")
    print("=" * 50)

    try:
        test_basic_operations()
        test_divide_by_zero()
        test_calculate_function()

        print("=" * 50)
        print("所有测试通过！")
        return 0
    except AssertionError as e:
        print(f"测试失败: {e}")
        return 1
    except Exception as e:
        print(f"测试过程中出现未知错误: {e}")
        return 1

if __name__ == "__main__":
    sys.exit(main())