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

using Microsoft.Build.Framework;
using Microsoft.Build.Utilities;

namespace Microsoft.DotNet.Build.Tasks.Installers;

// MSI versioning
// Encode the CLI version to fit into the MSI versioning scheme - https://msdn.microsoft.com/en-us/library/windows/desktop/aa370859(v=vs.85).aspx
// MSI versions are 3 part
//                           major.minor.build
// Size(bits) of each part     8     8    16
// So we have 32 bits to encode the CLI version

// For a CLI version based on commit count:
//   Starting with most significant bit this how the CLI version is going to be encoded as MSI Version
//   CLI major  -> 6 bits
//   CLI minor  -> 6 bits
//   CLI patch  -> 6 bits
//   CLI commitcount -> 14 bits
//
// For a CLI version based on BuildTools versioning
//   CLI major  -> 5 bits
//   CLI minor  -> 5 bits
//   CLI patch  -> 4 bits
//   BuildNumber major -> 14 bits
//   BuildNumber minor -> 4 bits
[MSBuildMultiThreadableTask]
public class GenerateMsiVersion : Task
{
    [Required]
    public string Major { get; set; }
    [Required]
    public string Minor { get; set; }
    [Required]
    public string Patch { get; set; }
    public string BuildNumber { get; set; }
    public string BuildNumberMajor { get; set; }
    public string BuildNumberMinor { get; set; }
    [Output]
    public string MsiVersion { get; set; }

    public override bool Execute()
    {
        if(BuildNumber == null && BuildNumberMajor == null)
        {
            Log.LogError("Either BuildNumber or BuildNumberMajor and BuildNumberMinor are required parameters.");
            return false;
        }
        if(BuildNumber != null && BuildNumberMajor != null)
        {
            Log.LogError("You must specify either BuildNumber or BuildNumberMajor and BuildNumberMinor, you cannot specify both parameters.");
            return false;
        }
        if (BuildNumberMajor != null && BuildNumberMinor == null)
        {
            Log.LogError("If you specify a BuildNumberMajor, you must also specify the BuildNumberMinor.");
            return false;
        }
        if(BuildNumber != null)
        {
            ParseBuildNumber();
        }
        else
        {
            ParseBuildNumberMajorMinor();
        }
        return true;
    }
    private void ParseBuildNumber()
    {
        var major = int.Parse(Major) << 26;
        var minor = int.Parse(Minor) << 20;
        var patch = int.Parse(Patch) << 14;
        var msiVersionNumber = major | minor | patch | int.Parse(BuildNumber);

        var msiMajor = (msiVersionNumber >> 24) & 0xFF;
        var msiMinor = (msiVersionNumber >> 16) & 0xFF;
        var msiBuild = msiVersionNumber & 0xFFFF;

        MsiVersion = $"{msiMajor}.{msiMinor}.{msiBuild}";
    }
    private void ParseBuildNumberMajorMinor()
    {
        var major = int.Parse(Major) << 27;
        var minor = int.Parse(Minor) << 22;
        var patch = int.Parse(Patch) << 18;

        var buildNumberMajor = (int.Parse(BuildNumberMajor) & 0x3FFF) << 4;
        var buildNumberMinor = int.Parse(BuildNumberMinor) & 0xF;

        var msiVersionNumber = major | minor | patch | buildNumberMajor | buildNumberMinor;

        var msiMajor = (msiVersionNumber >> 24) & 0xFF;
        var msiMinor = (msiVersionNumber >> 16) & 0xFF;
        var msiBuild = msiVersionNumber & 0xFFFF;

        MsiVersion = $"{msiMajor}.{msiMinor}.{msiBuild}";
    }

}