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

using System;
using System.Globalization;
using System.IO;
using System.IO.Compression;
using System.Linq;
using System.Xml.Linq;

namespace Microsoft.Arcade.Common;

public class NupkgInfoFactory : INupkgInfoFactory
{
    private readonly IPackageArchiveReaderFactory _packageArchiveReaderFactory;

    public NupkgInfoFactory(IPackageArchiveReaderFactory packageArchiveReaderFactory)
    {
        _packageArchiveReaderFactory = packageArchiveReaderFactory;
    }

    public NupkgInfo CreateNupkgInfo(string path)
    {
        if (path == null)
        {
            throw new ArgumentNullException(nameof(path));
        }

        try
        {
            using Stream stream = File.OpenRead(path);
            ZipArchive zipArchive = new(stream, ZipArchiveMode.Read);
            foreach (ZipArchiveEntry entry in zipArchive.Entries)
            {
                if (entry.Name.EndsWith(".nuspec"))
                {
                    using Stream nuspecFileStream = entry.Open();
                    PackageIdentity identity = GetIdentity(nuspecFileStream);
                    return new NupkgInfo(identity);
                }
            }

            throw new InvalidDataException(string.Format(CultureInfo.CurrentCulture, "Did not extract nuspec file from package: {0}", path));
        }
        catch (Exception ex)
        {
            throw new InvalidDataException(string.Format(CultureInfo.CurrentCulture, "Invalid package: {0}", path), ex);
        }
    }

    private static PackageIdentity GetIdentity(Stream nuspecFileStream)
    {
        XDocument doc = XDocument.Load(nuspecFileStream, LoadOptions.PreserveWhitespace);
        XElement metadataElement = GetSingleElement(doc.Root, "metadata");
        return new PackageIdentity(GetSingleElement(metadataElement, "id").Value, GetSingleElement(metadataElement, "version").Value);
    }   

    private static XElement GetSingleElement(XElement el, string name)
    {
        return el.Descendants().First(c => c.Name.LocalName.ToString() == name);
    }
}