package com.ruoyi.common.utils;

import org.junit.jupiter.api.Test;

import java.util.Collection;
import java.util.Arrays;

import static org.junit.jupiter.api.Assertions.*;

class StringUtilsTest {

    @Test
    void testIsEmpty() {
        assertTrue(StringUtils.isEmpty((String) null));
        assertTrue(StringUtils.isEmpty(""));
        assertTrue(StringUtils.isEmpty(" ")); // isEmpty 会 trim 空格
        assertFalse(StringUtils.isEmpty("test"));
    }

    @Test
    void testIsNotEmpty() {
        assertFalse(StringUtils.isNotEmpty((String) null));
        assertFalse(StringUtils.isNotEmpty(""));
        assertFalse(StringUtils.isNotEmpty(" ")); // isNotEmpty 会 trim 空格
        assertTrue(StringUtils.isNotEmpty("test"));
    }

    @Test
    void testIsNull() {
        assertTrue(StringUtils.isNull(null));
        assertFalse(StringUtils.isNull(""));
        assertFalse(StringUtils.isNull("test"));
    }

    @Test
    void testIsNotEmpty_Collection() {
        Collection<String> emptyList = Arrays.asList();
        Collection<String> nonEmptyList = Arrays.asList("item1", "item2");
        
        assertFalse(StringUtils.isNotEmpty(emptyList));
        assertTrue(StringUtils.isNotEmpty(nonEmptyList));
    }

    @Test
    void testNvl() {
        assertEquals("default", StringUtils.nvl(null, "default"));
        assertEquals("value", StringUtils.nvl("value", "default"));
        assertEquals("", StringUtils.nvl("", "default"));
    }

    @Test
    void testEquals() {
        assertTrue(StringUtils.equals("test", "test"));
        assertFalse(StringUtils.equals("test1", "test2"));
        assertFalse(StringUtils.equals(null, "test"));
        assertFalse(StringUtils.equals("test", null));
        assertTrue(StringUtils.equals(null, null));
    }

    @Test
    void testContains() {
        assertTrue(StringUtils.contains("hello world", "world"));
        assertFalse(StringUtils.contains("hello world", "test"));
        assertFalse(StringUtils.contains(null, "test"));
        assertFalse(StringUtils.contains("test", null));
    }

    @Test
    void testStartsWith() {
        assertTrue(StringUtils.startsWith("hello", "hel"));
        assertFalse(StringUtils.startsWith("hello", "world"));
        assertFalse(StringUtils.startsWith(null, "test"));
    }

    @Test
    void testSubstring() {
        assertEquals("ell", StringUtils.substring("hello", 1, 4));
        assertEquals("hello", StringUtils.substring("hello", 0));
        assertEquals("", StringUtils.substring(null, 0));
    }

    @Test
    void testTrim() {
        assertEquals("test", StringUtils.trim("  test  "));
        assertEquals("", StringUtils.trim("   "));
        assertEquals("", StringUtils.trim(null));
    }
}