using System;
using System.Collections.Generic;
using System.Linq;
using LibHac.Common;
using LibHac.Tools.FsSystem;
using LibHac.Util;
using Xunit;

namespace LibHac.Tests;

public class PathToolsTests
{
    public static object[][] NormalizedPathTestItems =
    {
        new object[] { "", "/" },
        new object[] { "/", "/" },
        new object[] { "/.", "/" },
        new object[] { "/a/b/c", "/a/b/c" },
        new object[] { "/a/b/../c", "/a/c" },
        new object[] { "/a/b/c/..", "/a/b" },
        new object[] { "/a/b/c/.", "/a/b/c" },
        new object[] { "/a/../../..", "/" },
        new object[] { "/a/../../../a/b/c", "/a/b/c" },
        new object[] { "//a/b//.//c", "/a/b/c" },
        new object[] { "/../a/b/c/.", "/a/b/c" },
        new object[] { "/./aaa/bbb/ccc/.", "/aaa/bbb/ccc" },

        new object[] { "/a/b/c/", "/a/b/c/" },
        new object[] { "a/b/c/", "/a/b/c/" },
        new object[] { "/aa/./bb/../cc/", "/aa/cc/" },
        new object[] { "/./b/../c/", "/c/" },
        new object[] { "/a/../../../", "/" },
        new object[] { "//a/b//.//c/", "/a/b/c/" },
        new object[] { "/tmp/../", "/" },

        new object[] { "a", "/a" },
        new object[] { "a/../../../a/b/c", "/a/b/c" },
        new object[] { "./b/../c/", "/c/" },
        new object[] { ".", "/" },
        new object[] { "..", "/" },
        new object[] { "../a/b/c/.", "/a/b/c" },
        new object[] { "./a/b/c/.", "/a/b/c" },

        new object[] { "a:/a/b/c", "a:/a/b/c" },
        new object[] { "mount:/a/b/../c", "mount:/a/c" },
        new object[] { "mount:", "mount:/" },
        new object[] { "abc:/a/../../../a/b/c", "abc:/a/b/c" },
        new object[] { "abc:/./b/../c/", "abc:/c/" },
        new object[] { "abc:/.", "abc:/" },
        new object[] { "abc:/..", "abc:/" },
        new object[] { "abc:/", "abc:/" },
        new object[] { "abc://a/b//.//c", "abc:/a/b/c" },
        new object[] { "abc:/././/././a/b//.//c", "abc:/a/b/c" },
        new object[] { "mount:/d./aa", "mount:/d./aa" },
    };

    public static object[][] SubPathTestItems =
    {
        new object[] { "/", "/", false },
        new object[] { "/", "/a", true },
        new object[] { "/", "/a/", true },

        new object[] { "/a/b/c", "/a/b/c/d", true },
        new object[] { "/a/b/c/", "/a/b/c/d", true },

        new object[] { "/a/b/c", "/a/b/c", false },
        new object[] { "/a/b/c/", "/a/b/c/", false },
        new object[] { "/a/b/c/", "/a/b/c", false },
        new object[] { "/a/b/c", "/a/b/c/", false },

        new object[] { "/a/b/c/", "/a/b/cdef", false },
        new object[] { "/a/b/c", "/a/b/cdef", false },
        new object[] { "/a/b/c/", "/a/b/cd", false },

        new object[] { "mount:/", "mount:/", false },
        new object[] { "mount:/", "mount:/a", true },
        new object[] { "mount:/", "mount:/a/", true },

        new object[] { "mount:/a/b/c", "mount:/a/b/c/d", true },
        new object[] { "mount:/a/b/c/", "mount:/a/b/c/d", true },

        new object[] { "mount:/a/b/c", "mount:/a/b/c", false },
        new object[] { "mount:/a/b/c/", "mount:/a/b/c/", false },
        new object[] { "mount:/a/b/c/", "mount:/a/b/c", false },
        new object[] { "mount:/a/b/c", "mount:/a/b/c/", false },

        new object[] { "mount:/a/b/c/", "mount:/a/b/cdef", false },
        new object[] { "mount:/a/b/c", "mount:/a/b/cdef", false },
        new object[] { "mount:/a/b/c/", "mount:/a/b/cd", false },
    };

    public static object[][] ParentDirectoryTestItems =
    {
        new object[] { "/", "" },
        new object[] { "/a", "/" },
        new object[] { "/aa/aabc/f", "/aa/aabc" },
        new object[] { "mount:/", "" },
        new object[] { "mount:/a", "mount:/" },
        new object[] { "mount:/aa/aabc/f", "mount:/aa/aabc" }
    };

    public static object[][] IsNormalizedTestItems = GetNormalizedPaths(true);

    public static object[][] IsNotNormalizedTestItems = GetNormalizedPaths(false);

    [Theory]
    [MemberData(nameof(NormalizedPathTestItems))]
    public static void NormalizePath(string path, string expected)
    {
        string actual = PathTools.Normalize(path);

        Assert.Equal(expected, actual);
    }

    [Theory]
    [MemberData(nameof(IsNormalizedTestItems))]
    public static void IsNormalized(string path)
    {
        Assert.True(PathTools.IsNormalized(path.AsSpan()));
    }

    [Theory]
    [MemberData(nameof(IsNotNormalizedTestItems))]
    public static void IsNotNormalized(string path)
    {
        Assert.False(PathTools.IsNormalized(path.AsSpan()));
    }

    [Theory]
    [MemberData(nameof(SubPathTestItems))]
    public static void TestSubPath(string rootPath, string path, bool expected)
    {
        bool actual = PathTools.IsSubPath(rootPath.AsSpan(), path.AsSpan());

        Assert.Equal(expected, actual);
    }

    [Theory]
    [MemberData(nameof(SubPathTestItems))]
    public static void TestSubPathReverse(string rootPath, string path, bool expected)
    {
        bool actual = PathTools.IsSubPath(path.AsSpan(), rootPath.AsSpan());

        Assert.Equal(expected, actual);
    }

    [Theory]
    [MemberData(nameof(ParentDirectoryTestItems))]
    public static void TestParentDirectory(string path, string expected)
    {
        string actual = PathTools.GetParentDirectory(path);

        Assert.Equal(expected, actual);
    }

    private static object[][] GetNormalizedPaths(bool getNormalized)
    {
        var normalizedPaths = new HashSet<string>();
        var notNormalizedPaths = new HashSet<string>();

        foreach (object[] pair in NormalizedPathTestItems)
        {
            string pathNotNorm = (string)pair[0];
            string pathNorm = (string)pair[1];

            if (pathNorm != pathNotNorm) notNormalizedPaths.Add(pathNotNorm);
            normalizedPaths.Add(pathNorm);
        }

        HashSet<string> paths = getNormalized ? normalizedPaths : notNormalizedPaths;

        return paths.Select(x => new object[] { x }).ToArray();
    }

    public static object[][] GetFileNameTestItems =
    {
        new object[] { "/a/bb/ccc", "ccc" },
        new object[] { "/a/bb/ccc/", "" },
        new object[] { "/a/bb", "bb" },
        new object[] { "/a/bb/", "" },
        new object[] { "/a", "a" },
        new object[] { "/a/", "" },
        new object[] { "/", "" },
    };

    [Theory]
    [MemberData(nameof(GetFileNameTestItems))]
    public static void GetFileNameTest(string path, string expected)
    {
        var u8Path = path.ToU8Span();

        ReadOnlySpan<byte> fileName = PathTools.GetFileName(u8Path);

        string actual = StringUtils.Utf8ZToString(fileName);

        Assert.Equal(expected, actual);
    }

    public static object[][] GetLastSegmentTestItems =
    {
        new object[] { "/a/bb/ccc", "ccc" },
        new object[] { "/a/bb/ccc/", "ccc" },
        new object[] { "/a/bb", "bb" },
        new object[] { "/a/bb/", "bb" },
        new object[] { "/a", "a" },
        new object[] { "/a/", "a" },
        new object[] { "/", "" },
    };

    [Theory]
    [MemberData(nameof(GetLastSegmentTestItems))]
    public static void GetLastSegmentTest(string path, string expected)
    {
        var u8Path = path.ToU8Span();

        ReadOnlySpan<byte> fileName = PathTools.GetLastSegment(u8Path);

        string actual = StringUtils.Utf8ZToString(fileName);

        Assert.Equal(expected, actual);
    }
}