// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.

using System.Text.RegularExpressions;
using System.Xml.Linq;

namespace Microsoft.DotNet.SourceBuild.Tasks.UsageReport;

public class UsagePattern
{
    public string IdentityRegex { get; set; }

    public string IdentityGlob { get; set; }

    public XElement ToXml() => new XElement(
        nameof(UsagePattern),
        IdentityRegex.ToXAttributeIfNotNull(nameof(IdentityRegex)),
        IdentityGlob.ToXAttributeIfNotNull(nameof(IdentityGlob)));

    public static UsagePattern Parse(XElement xml) => new UsagePattern
    {
        IdentityRegex = xml.Attribute(nameof(IdentityRegex))?.Value,
        IdentityGlob = xml.Attribute(nameof(IdentityGlob))?.Value
    };

    public Regex CreateRegex()
    {
        if (!string.IsNullOrEmpty(IdentityRegex))
        {
            return new Regex(IdentityRegex, RegexOptions.IgnoreCase | RegexOptions.Compiled);
        }

        if (!string.IsNullOrEmpty(IdentityGlob))
        {
            // Escape regex characters like '.', but handle '*' as regex '.*'.
            string regex = Regex.Escape(IdentityGlob).Replace("\\*", ".*");

            return new Regex(
                $"^{regex}$",
                RegexOptions.IgnoreCase | RegexOptions.Compiled);
        }

        return new Regex("");
    }
}