public static async Task ParseAsync()

in src/dotnet-svcutil/lib/src/Shared/MSBuildProj.cs [167:369]
160 lines of code
33 McCabe index (conditional complexity)

        public static async Task<MSBuildProj> ParseAsync(string projectText, string projectFullPath, ILogger logger, CancellationToken cancellationToken, string tfMoniker = "")
        {
            using (var safeLogger = await SafeLogger.WriteStartOperationAsync(logger, $"Parsing project {Path.GetFileName(projectFullPath)}").ConfigureAwait(false))
            {
                projectFullPath = Path.GetFullPath(projectFullPath);

                MSBuildProj msbuildProj = new MSBuildProj
                {
                    FileName = Path.GetFileName(projectFullPath),
                    DirectoryPath = Path.GetDirectoryName(projectFullPath)
                };

                XDocument projDefinition = XDocument.Parse(projectText);

                var msbuildNS = XNamespace.None;
                if (projDefinition.Root != null && projDefinition.Root.Name != null)
                {
                    msbuildNS = projDefinition.Root.Name.Namespace;
                }

                msbuildProj._msbuildNS = msbuildNS;
                msbuildProj.ProjectNode = projDefinition.Element(msbuildNS + "Project");
                if (msbuildProj.ProjectNode == null)
                {
                    throw new Exception(Shared.Resources.ErrorInvalidProjectFormat);
                }

                // The user project can declare TargetFramework and/or TargetFrameworks property. If both are provided, TargetFramework wins.
                // When TargetFrameworks is provided, the project is built for every entry specified in the TargetFramework property.

                IEnumerable<XElement> targetFrameworkElements = GetSubGroupValues(msbuildProj.ProjectNode, msbuildNS, "PropertyGroup", "TargetFramework");
                if (targetFrameworkElements.Count() > 0)
                {
                    // If property is specified more than once, MSBuild will resolve it by overwriting it with the last value.
                    var targetFramework = targetFrameworkElements.Last().Value.Trim().ToLowerInvariant();
                    if (!string.IsNullOrWhiteSpace(targetFramework))
                    {
                        if(TargetFrameworkHelper.IsSupportedFramework(targetFramework, out FrameworkInfo fxInfo))
                        {
                            msbuildProj._targetFrameworks.Add(targetFramework);
                        }
                    }
                }

                if (msbuildProj._targetFrameworks.Count == 0)
                {
                    // TargetFramework was not provided, check TargetFrameworks property.
                    IEnumerable<XElement> targetFrameworksElements = GetSubGroupValues(msbuildProj.ProjectNode, msbuildNS, "PropertyGroup", "TargetFrameworks");
                    if (targetFrameworksElements.Count() > 0)
                    {
                        var targetFrameworks = targetFrameworksElements.Last().Value;
                        foreach (var targetFx in targetFrameworks.Split(new char[] { ';' }, StringSplitOptions.RemoveEmptyEntries).Select(p => p.Trim()))
                        {
                            if (!string.IsNullOrWhiteSpace(targetFx))
                            {
                                msbuildProj._targetFrameworks.Add(targetFx);
                            }
                        }
                    }
                }

                msbuildProj._targetFrameworks.Sort();
                msbuildProj._targetFramework = TargetFrameworkHelper.GetBestFitTargetFramework(msbuildProj._targetFrameworks);

                if(string.IsNullOrEmpty(msbuildProj._targetFramework))
                {
                    if(!string.IsNullOrEmpty(tfMoniker) && FrameworkInfo.TryParse(tfMoniker, out FrameworkInfo fxInfo))
                    {
                        msbuildProj._targetFramework = fxInfo.FullName;
                    }
                    else
                    {
                        msbuildProj._targetFramework = string.Concat("net", TargetFrameworkHelper.NetCoreVersionReferenceTable.LastOrDefault().Key.ToString());
                    }
                    
                    msbuildProj._targetFrameworks.Add(msbuildProj._targetFramework);
                }

                // Ensure target framework is valid.
                FrameworkInfo frameworkInfo = TargetFrameworkHelper.GetValidFrameworkInfo(msbuildProj.TargetFramework);

                IEnumerable<XElement> runtimeIdentifierElements = GetSubGroupValues(msbuildProj.ProjectNode, msbuildNS, "PropertyGroup", "RuntimeIdentifier");
                if (runtimeIdentifierElements.Count() > 0)
                {
                    msbuildProj.RuntimeIdentifier = runtimeIdentifierElements.Last().Value.Trim();
                }

                IEnumerable<XElement> packageReferenceElements = GetSubGroupValues(msbuildProj.ProjectNode, msbuildNS, "ItemGroup", "PackageReference");
                foreach (XElement reference in packageReferenceElements)
                {
                    if(!TryGetItemIdentity(reference, out var packageName))
                        continue;

                    string version = GetItemValue(reference, "Version");
                    if (!ProjectDependency.IsValidVersion(version))
                    {
                        version = "";
                    }

                    ProjectDependency packageDep = ProjectDependency.FromPackage(packageName, version);

                    msbuildProj._dependencies.Add(packageDep);
                }

                IEnumerable<XElement> toolReferenceElements = GetSubGroupValues(msbuildProj.ProjectNode, msbuildNS, "ItemGroup", "DotNetCliToolReference");
                foreach (XElement reference in toolReferenceElements)
                {
                    if (!TryGetItemIdentity(reference, out var packageName))
                        continue;

                    string version = GetItemValue(reference, "Version");

                    ProjectDependency packageDep = ProjectDependency.FromCliTool(packageName, version);

                    msbuildProj._dependencies.Add(packageDep);
                }

                IEnumerable<XElement> projectReferenceElements = GetSubGroupValues(msbuildProj.ProjectNode, msbuildNS, "ItemGroup", "ProjectReference");
                foreach (XElement reference in projectReferenceElements)
                {
                    string projectPath = GetItemValue(reference, "Include", throwIfMissing: true);

                    ProjectDependency projectDep = ProjectDependency.FromProject(projectPath);

                    msbuildProj._dependencies.Add(projectDep);
                }

                IEnumerable<XElement> binReferenceElements = GetSubGroupValues(msbuildProj.ProjectNode, msbuildNS, "ItemGroup", "Reference");
                foreach (XElement reference in binReferenceElements)
                {
                    //Find hint path or path
                    string binReference = GetItemIdentity(reference);

                    if (!Path.IsPathRooted(binReference))
                    {
                        string fullPath = null;
                        bool fullPathFound = true;

                        XElement hintPath = reference.Element("HintPath");
                        XElement path = reference.Element("Path");
                        if (path != null)
                        {
                            fullPath = path.Value;
                        }
                        else if (hintPath != null)
                        {
                            fullPath = hintPath.Value;
                        }
                        else
                        {
                            try
                            {
                                fullPath = new FileInfo(Path.Combine(msbuildProj.DirectoryPath, binReference)).FullName;
                            }
                            catch
                            {
                            }

                            if (fullPath == null || !File.Exists(fullPath))
                            {
                                fullPathFound = false;

                                // If we're only targeting .NET Core or .NET Standard projects we throw if we can't find the full path to the assembly.
                                if (!TargetFrameworkHelper.ContainsFullFrameworkTarget(msbuildProj._targetFrameworks))
                                {
                                    throw new Exception(string.Format(CultureInfo.CurrentCulture, Shared.Resources.ErrorProjectReferenceMissingFilePathFormat, binReference));
                                }
                            }
                        }

                        if (fullPathFound)
                        {
                            if (System.IO.Directory.Exists(fullPath)) // IsDir?
                            {
                                fullPath = Path.Combine(fullPath, binReference);
                            }
                            else if (Directory.Exists(Path.Combine(msbuildProj.DirectoryPath, fullPath)))
                            {
                                fullPath = Path.Combine(msbuildProj.DirectoryPath, fullPath, binReference);
                            }

                            binReference = fullPath;
                        }
                    }

                    ProjectDependency projectDep = ProjectDependency.FromAssembly(binReference);

                    msbuildProj._dependencies.Add(projectDep);
                }

                // ensure we have a working directory for the ProcessRunner (ProjectPropertyResolver)..
                if (!Directory.Exists(msbuildProj.DirectoryPath))
                {
                    Directory.CreateDirectory(msbuildProj.DirectoryPath);
                    msbuildProj._ownsDirectory = true;
                }

                var sdkVersion = await ProjectPropertyResolver.GetSdkVersionAsync(msbuildProj.DirectoryPath, logger, cancellationToken).ConfigureAwait(false);
                msbuildProj.SdkVersion = sdkVersion ?? string.Empty;

                return msbuildProj;
            }
        }