// Copyright (c) .NET Foundation. All rights reserved.
// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.

using System;
using System.Diagnostics;
using System.Diagnostics.CodeAnalysis;
using System.Globalization;
using NuGet.Frameworks;
using NuGet.Packaging.Core;
using NuGet.Versioning;

namespace NuGet.Packaging
{
    /// <summary>
    /// Represents a package element in the packages.config file
    /// </summary>
    [DebuggerDisplay("{PackageIdentity} {TargetFramework}")]
    public class PackageReference
    {
        /// <summary>
        /// Creates a new packages config entry
        /// </summary>
        public PackageReference(PackageIdentity identity, NuGetFramework targetFramework)
            : this(identity, targetFramework, true)
        {
        }

        /// <summary>
        /// Creates a new packages config entry
        /// </summary>
        public PackageReference(PackageIdentity identity, NuGetFramework targetFramework, bool userInstalled)
            : this(identity, targetFramework, userInstalled, false, false)
        {
        }

        /// <summary>
        /// Creates a new packages config entry
        /// </summary>
        public PackageReference(PackageIdentity identity,
            NuGetFramework targetFramework,
            bool userInstalled,
            bool developmentDependency,
            bool requireReinstallation)
            : this(identity, targetFramework, userInstalled, developmentDependency, requireReinstallation, null)
        {
        }

        /// <summary>
        /// Creates a new packages config entry
        /// </summary>
        /// <param name="identity">Package id and version</param>
        /// <param name="targetFramework">Package target framework installed to the project</param>
        /// <param name="userInstalled">True if the user installed this package directly</param>
        /// <param name="developmentDependency">True if the package is a development dependency</param>
        /// <param name="requireReinstallation">True if this package needs to be reinstalled</param>
        /// <param name="allowedVersions">Restrict package versions to the allowedVersions range</param>
        public PackageReference(PackageIdentity identity, NuGetFramework targetFramework, bool userInstalled, bool developmentDependency, bool requireReinstallation, VersionRange? allowedVersions)
        {
            PackageIdentity = identity;
            AllowedVersions = allowedVersions;
            TargetFramework = targetFramework;
            IsDevelopmentDependency = developmentDependency;
            IsUserInstalled = userInstalled;
            RequireReinstallation = requireReinstallation;
        }

        /// <summary>
        /// Id and Version of the package
        /// </summary>
        public PackageIdentity PackageIdentity { get; }

        /// <summary>
        /// The allowed range of versions that this package can be upgraded/downgraded to.
        /// </summary>
        /// <remarks>This is null if unbounded</remarks>
        public VersionRange? AllowedVersions { get; }

        /// <summary>
        /// True if allowedVersions exists.
        /// </summary>
        [MemberNotNullWhen(true, nameof(AllowedVersions))]
        public bool HasAllowedVersions
        {
            get { return AllowedVersions != null; }
        }

        /// <summary>
        /// Installed target framework version of the package.
        /// </summary>
        public NuGetFramework TargetFramework { get; }

        /// <summary>
        /// Development dependency
        /// </summary>
        public bool IsDevelopmentDependency { get; }

        /// <summary>
        /// True if the user installed or updated this package directly.
        /// False if this package was installed as a dependency by another package.
        /// </summary>
        public bool IsUserInstalled { get; }

        /// <summary>
        /// Require reinstallation
        /// </summary>
        public bool RequireReinstallation { get; }

        /// <summary>
        /// Displays the identity and target framework of the reference.
        /// </summary>
        /// <returns></returns>
        public override string ToString()
        {
            return String.Format(CultureInfo.InvariantCulture, "{0} {1}", PackageIdentity.ToString(), TargetFramework.ToString());
        }
    }
}