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

using System.IO;
using System.Text;

namespace System.Diagnostics
{
    /// <summary>
    /// Provides version information for a physical file on disk.
    /// </summary>
    public sealed partial class FileVersionInfo
    {
        private readonly string _fileName;

        private string? _companyName;
        private string? _fileDescription;
        private string? _fileVersion;
        private string? _internalName;
        private string? _legalCopyright;
        private string? _originalFilename;
        private string? _productName;
        private string? _productVersion;
        private string? _comments;
        private string? _legalTrademarks;
        private string? _privateBuild;
        private string? _specialBuild;
        private string? _language;
        private int _fileMajor;
        private int _fileMinor;
        private int _fileBuild;
        private int _filePrivate;
        private int _productMajor;
        private int _productMinor;
        private int _productBuild;
        private int _productPrivate;
        private bool _isDebug;
        private bool _isPatched;
        private bool _isPrivateBuild;
        private bool _isPreRelease;
        private bool _isSpecialBuild;

        /// <summary>
        /// Gets the comments associated with the file.
        /// </summary>
        /// <value>The comments associated with the file or <see langword="null"/> if the file did not contain version information.</value>
        public string? Comments
        {
            get { return _comments; }
        }

        /// <summary>
        /// Gets the name of the company that produced the file.
        /// </summary>
        /// <value>The name of the company that produced the file or <see langword="null"/> if the file did not contain version information.</value>
        public string? CompanyName
        {
            get { return _companyName; }
        }

        /// <summary>
        /// Gets the build number of the file.
        /// </summary>
        /// <value>A value representing the build number of the file or 0 (zero) if the file did not contain version information.</value>
        public int FileBuildPart
        {
            get { return _fileBuild; }
        }

        /// <summary>
        /// Gets the description of the file.
        /// </summary>
        /// <value>The description of the file or <see langword="null"/> if the file did not contain version information.</value>
        public string? FileDescription
        {
            get { return _fileDescription; }
        }

        /// <summary>
        /// Gets the major part of the version number.
        /// </summary>
        /// <value>A value representing the major part of the version number or 0 (zero) if the file did not contain version information.</value>
        public int FileMajorPart
        {
            get { return _fileMajor; }
        }

        /// <summary>
        /// Gets the minor part of the version number of the file.
        /// </summary>
        /// <value>A value representing the minor part of the version number of the file or 0 (zero) if the file did not contain version information.</value>
        public int FileMinorPart
        {
            get { return _fileMinor; }
        }

        /// <summary>
        /// Gets the name of the file that this instance of <see cref="FileVersionInfo" /> describes.
        /// </summary>
        /// <value>The name of the file described by this instance of <see cref="FileVersionInfo" />.</value>
        public string FileName
        {
            get { return _fileName; }
        }

        /// <summary>
        /// Gets the file private part number.
        /// </summary>
        /// <value>A value representing the file private part number or 0 (zero) if the file did not contain version information.</value>
        public int FilePrivatePart
        {
            get { return _filePrivate; }
        }

        /// <summary>
        /// Gets the file version number.
        /// </summary>
        /// <value>The version number of the file or <see langword="null"/> if the file did not contain version information.</value>
        public string? FileVersion
        {
            get { return _fileVersion; }
        }

        /// <summary>
        /// Gets the internal name of the file, if one exists.
        /// </summary>
        /// <value>The internal name of the file. If none exists, this property will contain the original name of the file without the extension.</value>
        public string? InternalName
        {
            get { return _internalName; }
        }

        /// <summary>
        /// Gets a value that specifies whether the file contains debugging information or is compiled with debugging features enabled.
        /// </summary>
        /// <value><see langword="true"/> if the file contains debugging information or is compiled with debugging features enabled; otherwise, <see langword="false"/>.</value>
        public bool IsDebug
        {
            get { return _isDebug; }
        }

        /// <summary>
        /// Gets a value that specifies whether the file has been modified and is not identical to the original shipping file of the same version number.
        /// </summary>
        /// <value><see langword="true"/> if the file is patched; otherwise, <see langword="false"/>.</value>
        public bool IsPatched
        {
            get { return _isPatched; }
        }

        /// <summary>
        /// Gets a value that specifies whether the file was built using standard release procedures.
        /// </summary>
        /// <value><see langword="true"/> if the file is a private build; <see langword="false"/> if the file was built using standard release procedures or if the file did not contain version information.</value>
        public bool IsPrivateBuild
        {
            get { return _isPrivateBuild; }
        }

        /// <summary>
        /// Gets a value that specifies whether the file is a development version, rather than a commercially released product.
        /// </summary>
        /// <value><see langword="true"/> if the file is prerelease; otherwise, <see langword="false"/>.</value>
        public bool IsPreRelease
        {
            get { return _isPreRelease; }
        }

        /// <summary>
        /// Gets a value that specifies whether the file is a special build.
        /// </summary>
        /// <value><see langword="true"/> if the file is a special build; otherwise, <see langword="false"/>.</value>
        public bool IsSpecialBuild
        {
            get { return _isSpecialBuild; }
        }

        /// <summary>
        /// Gets the default language string for the version info block.
        /// </summary>
        /// <value>The description string for the Microsoft Language Identifier in the version resource or <see langword="null"/> if the file did not contain version information.</value>
        public string? Language
        {
            get { return _language; }
        }

        /// <summary>
        /// Gets all copyright notices that apply to the specified file.
        /// </summary>
        /// <value>The copyright notices that apply to the specified file or <see langword="null"/> if the file did not contain version information.</value>
        public string? LegalCopyright
        {
            get { return _legalCopyright; }
        }

        /// <summary>
        /// Gets the trademarks and registered trademarks that apply to the file.
        /// </summary>
        /// <value>The trademarks and registered trademarks that apply to the file or <see langword="null"/> if the file did not contain version information.</value>
        public string? LegalTrademarks
        {
            get { return _legalTrademarks; }
        }

        /// <summary>
        /// Gets the name the file was created with.
        /// </summary>
        /// <value>The name the file was created with or <see langword="null"/> if the file did not contain version information.</value>
        public string? OriginalFilename
        {
            get { return _originalFilename; }
        }

        /// <summary>
        /// Gets information about a private version of the file.
        /// </summary>
        /// <value>Information about a private version of the file or <see langword="null"/> if the file did not contain version information.</value>
        public string? PrivateBuild
        {
            get { return _privateBuild; }
        }

        /// <summary>
        /// Gets the build number of the product this file is associated with.
        /// </summary>
        /// <value>A value representing the build number of the product this file is associated with or 0 (zero) if the file did not contain version information.</value>
        public int ProductBuildPart
        {
            get { return _productBuild; }
        }

        /// <summary>
        /// Gets the major part of the version number for the product this file is associated with.
        /// </summary>
        /// <value>A value representing the major part of the product version number or 0 (zero) if the file did not contain version information.</value>
        public int ProductMajorPart
        {
            get { return _productMajor; }
        }

        /// <summary>
        /// Gets the minor part of the version number for the product the file is associated with.
        /// </summary>
        /// <value>A value representing the minor part of the product version number or 0 (zero) if the file did not contain version information.</value>
        public int ProductMinorPart
        {
            get { return _productMinor; }
        }

        /// <summary>
        /// Gets the name of the product this file is distributed with.
        /// </summary>
        /// <value>The name of the product this file is distributed with or <see langword="null"/> if the file did not contain version information.</value>
        public string? ProductName
        {
            get { return _productName; }
        }

        /// <summary>
        /// Gets the private part number of the product this file is associated with.
        /// </summary>
        /// <value>A value representing the private part number of the product this file is associated with or 0 (zero) if the file did not contain version information.</value>
        public int ProductPrivatePart
        {
            get { return _productPrivate; }
        }

        /// <summary>
        /// Gets the version of the product this file is distributed with.
        /// </summary>
        /// <value>The version of the product this file is distributed with or <see langword="null"/> if the file did not contain version information.</value>
        public string? ProductVersion
        {
            get { return _productVersion; }
        }

        /// <summary>
        /// Gets the special build information for the file.
        /// </summary>
        /// <value>The special build information for the file or <see langword="null"/> if the file did not contain version information.</value>
        public string? SpecialBuild
        {
            get { return _specialBuild; }
        }

        /// <summary>
        /// Returns a <see cref="FileVersionInfo" /> representing the version information associated with the specified file.
        /// </summary>
        /// <param name="fileName">The path and name of the file to retrieve version information for.</param>
        /// <returns>A <see cref="FileVersionInfo" /> containing information about the file. If the file did not contain version information, the <see cref="FileVersionInfo" /> contains only the name of the file requested.</returns>
        /// <remarks>
        ///     <note type="caution">
        ///         Use this only with trusted files. Malformed or malicious files can cause unexpected behavior.
        ///     </note>
        /// </remarks>
        /// <exception cref="FileNotFoundException"><paramref name="fileName"/> does not exist or cannot be accessed.</exception>
        public static FileVersionInfo GetVersionInfo(string fileName)
        {
            // Check if fileName is a full path. Relative paths can cause confusion if the local file has the .dll extension,
            // as .dll search paths can take over & look for system .dll's in that case.
            if (!Path.IsPathFullyQualified(fileName))
            {
                fileName = Path.GetFullPath(fileName);
            }
            // Check for the existence of the file. File.Exists returns false if Read permission is denied.
            if (!File.Exists(fileName))
            {
                throw new FileNotFoundException(fileName);
            }

            return new FileVersionInfo(fileName);
        }

        /// <summary>
        /// Returns a partial list of properties in the <see cref="FileVersionInfo" /> and their values.
        /// </summary>
        /// <returns>A list of the following properties in this class and their values: <see cref="FileName" />, <see cref="InternalName" />, <see cref="OriginalFilename" />, <see cref="FileVersion" />, <see cref="FileDescription" />, <see cref="ProductName" />, <see cref="ProductVersion" />, <see cref="IsDebug" />, <see cref="IsPatched" />, <see cref="IsPreRelease" />, <see cref="IsPrivateBuild" />, <see cref="IsSpecialBuild" />, <see cref="Language" />. If the file did not contain version information, <see cref="FileName" /> will still contain the name of the file requested, Boolean values will be <see langword="false" />, and the other version-related values will be empty.</returns>
        public override string ToString()
        {
            // An initial capacity of 512 was chosen because it is large enough to cover
            // the size of the static strings with enough capacity left over to cover
            // average length property values.
            var sb = new StringBuilder(512);
            sb.Append("File:             ").AppendLine(FileName);
            sb.Append("InternalName:     ").AppendLine(InternalName);
            sb.Append("OriginalFilename: ").AppendLine(OriginalFilename);
            sb.Append("FileVersion:      ").AppendLine(FileVersion);
            sb.Append("FileDescription:  ").AppendLine(FileDescription);
            sb.Append("Product:          ").AppendLine(ProductName);
            sb.Append("ProductVersion:   ").AppendLine(ProductVersion);
            sb.Append("Debug:            ").AppendLine(IsDebug.ToString());
            sb.Append("Patched:          ").AppendLine(IsPatched.ToString());
            sb.Append("PreRelease:       ").AppendLine(IsPreRelease.ToString());
            sb.Append("PrivateBuild:     ").AppendLine(IsPrivateBuild.ToString());
            sb.Append("SpecialBuild:     ").AppendLine(IsSpecialBuild.ToString());
            sb.Append("Language:         ").AppendLine(Language);
            return sb.ToString();
        }
    }
}